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Hach Digital Titrator Manual

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1. Digits Digit Required Multiplier mg L Volatile Acids as acetic acid CH COOH 5 Add the contents of 6 Place the delivery 7 Calculate one Phenolphthalein tube tip into the solution Indicator Powder Pillow and swirl while titrating Digits Required x and swirl to mix with sodium hydroxide until a light pink color Digits Multiplier mg L Volatile Acids as acetic acid appears Record the CH3COOH number of digits required Note Approximately 70 of the volatile acids in the sample will be found in the distillate This has been accounted for in the calculation Summary of Method A sample acidified with sulfuric acid is distilled and the distillate titrated to the phenolphthalein end point with sodium hydroxide standard REQUIRED REAGENTS Volatile Acids Reagent Set about 100 tests Includes 1 942 99 1 14842 01 Description Phenolphthalein Indicator Powder Pillows Sodium Hydroxide Titration Cartridge 0 9274 N Water deionized eee REQUIRED APPARATUS Cylinder graduated 250 mL Digital Titrator ooonccnnccnnnccnnonanonncnnnnccnnnnonnnccnnncnnns Flask Erlenmeyer 250 mL 174 M NEE 24602 00 Unit Cat No ENEE 100 pkg 942 99 c eee es each 14842 01 EM TRETEN BEN 4 L 272 56 MU MO each 508
2. 987 99 Potassium Iodide Powder Pillows eee 100 pkg 1077 99 Sodium Thiosulfate Titration Cartridge 0 113 N sss each 22673 01 Starch Indicator Solupon eese 100 mL MDB 349 32 Water deionized iubeas tiber re ENS qz 272 56 REQUIRED REAGENTS For Using the 2 00 N Titration Cartridge Chlorine Reagent Set 2 000 70 000 mg L about 100 tests esses 24448 00 Includes 1 349 32 1 987 99 2 14401 01 2 20599 96 Dissolved Oxygen 3 Powder Dos 100 pkg 987 99 Potassium Iodide Powder Pillows eee S0 pkg 20599 96 Sodium Thiosulfate Titration Cartridge 2 00 N eee each 14401 01 Starch Indicator Solupon iaip 100 mL MDB 349 32 EE Le ME E DN E 272 56 REQUIRED APPARATUS Clippers for opening pillows esee ene each 968 00 Digital Date deed ees Mire Sete p Beret each 16900 01 Flask Erlenmeyer 1 25m Lis eere nr eerte een anal each 505 43 Pipet Filler te lada e teinte c Le d PEE ope each 12189 00 Select one or more based on sample concentration Pipet serological 1 Miri tette teet eee each 532 35 Pipet volumetric Class A Im each 14515 35 Pipet volumetric Class A 2 ml each 14515 36 Pipet volumetric Class A Amt each 14515 04 Pipet volumetric Class A icono eine nel each 14515 37 Pipet volumetric Class
3. The Procedure details how to perform the method step by step To select the appropriate sample volume and titration cartridge based on expected sample concentration use the tables provided in each procedure If the expected sample concentration is not known start with one of the smaller sample volumes and determine its approximate concentration Retest with the appropriate sample size The ranges in the table overlap to offer more flexibility In most procedures the number of digits used for each concentration range will be 100 to 400 digits To determine the actual concentration of the sample use the correct digit multiplier for the sample volume and titration cartridge used Throughout the procedure the notes will provide additional information The Accuracy Check provides a way to verify the results and determine if interferences are present It also provides a method for checking the performance of reagents the Digital Titrator and the operator s technique Further information is provided in Appendix A Accuracy Check and Standard Additions 12 GENERAL DESCRIPTION continued 1 2 Step By Step The Interferences section identifies common interferences causing inaccurate results and describes how to eliminate their effects The interference levels are based on the sample volume that has 1 0 as the digit multiplier Higher interference levels may be tolerated if a smaller sample is used The Summary of Method secti
4. 49 Select sample volume 4 Select a sample volume for the expected concentration range from Table I Table 4 on page 51 Note See Sampling and Storage following these steps AMMONIA HIGH RANGE Ammonium Hydroxide continued I A 5 Attach a clean pp to 6 Dispense the sample 7 Add 1 mL one full 8 Swirl to mix The the pipettor and collect below the liquid level in dropper of Wide Range solution will turn purple 100 uL 0 100 mL of the flask Dispense pH Indicator Solution to the aqua ammonia another 100 uL of the flask sample sample into the flask Note Alternatively use a 200 uL sample size TenSette Pipet Cat No For other sample sizes 19700 01 with a clean tip repeat until the required sample volume from Note Review the Step 4 has been added instructions supplied with the 100 uL pipettor before Note Review the using Depress the instructions supplied with plunger to the first stop the 100 uL pipettor before and release to fill with using Depress the sample plunger to the first stop to fill depress the plunger completely to dispense Find Digit Multiplier 9 Place the delivery 10 Find the digit 11 Calculate tube tip into the solution multiplier from Table 1 Digits Used x Swirl the flask while Table 4 on page 51 Digits Multiplier titrating with the sulfuric concentration acid titrant until the solution color changes Note See example on from purple
5. Note See Sampling and Step 3 in Step by Step Storage following these steps Table 1 Range Sample le Catalog Digit mg L Clo Volume mL 9 Number Multiplier N Na252053 1 4 100 0 02256 24091 01 0 01 2 8 50 0 02256 24091 01 0 02 5 20 20 0 02256 24091 01 0 05 10 40 10 0 02256 24091 01 0 10 20 80 5 0 02256 24091 01 0 20 50 200 2 0 02256 24091 01 0 50 100 400 1 0 02256 24091 01 1 00 79 CHLORINE TOTAL continued 5 Add 2 Droppers 2 mL Acetate Buffer Solution pH 4 and swirl to mix 9 Continue the titration until the solution changes from dark blue to colorless Record the number of digits required 6 Clip open the end of one Potassium Iodide Powder Pillow Add the contents to the flask Swirl to mix Digits Digit Required Multiplier mg L Total Chlorine Cl 10 Calculate Digits Required x Digit Multiplier mg L Total Chlorine CI2 Note These procedures can be used to check iodine and bromine concentrations if chlorine is not present Multiply the test result in mg L chlorine by 3 58 or 2 25 respectively to accurately express the iodine or bromine content of your sample 80 o gt 7 Place the delivery 8 Add one dropper of tube tip into the solution starch indicator solution and swirl the flask while and swirl to mix A dark titrating with sodium blue color will develop thiosulfate until the solution is a pale yellow CHLORINE
6. 4 Each 0 1 mL addition of standard should require 25 additional digits of 1 600 N titrant or 250 digits of 0 1600 N titrant If these uniform increases do not occur refer to Appendix A Accuracy Check and Standard Additions Highly colored or turbid samples may mask the color change at the end point Use a pH meter for these samples Chlorine may interfere with the indicators Add one drop of 0 1 N Sodium Thiosulfate to eliminate this interference The sample is titrated with sulfuric acid to a colorimetric end point corresponding to a specific pH Phenolphthalein alkalinity is determined by titration to a pH of 8 3 as evidenced by the color change of phenolphthalein indicator and indicates the total hydroxide and one half the carbonate present M methyl orange or T total alkalinity is determined by titration to a pH between 3 7 and 5 1 and includes all carbonate bicarbonate and hydroxide 46 ALKALINITY continued REQUIRED REAGENTS varies with sample characteristics Description Unit Alkalinity Reagent Set about 100 tests eese Includes 1 942 99 1 943 99 1 14388 01 1 14389 01 Bromcresol Green Methyl Red Powder Pillows sees 100 pkg Phenolphthalein Powder Pillows eene 100 pkg Sulfuric Acid Titration Cartridge 1 600 N sse each Sulfuric Acid Titration Cartridge 0 1600 N eee each Water delo is AL REQUIRED APPARATUS Digital Ru e
7. 11 Add the contents of one ManVer 2 Hardness Indicator Powder Pillow Cat No 928 99 or 4 drops of Hardness 2 Test Solution Cat No 425 32 Swirl to mix 136 Digits Required Digit Multiplier mg L Calcium Hardness as CaCO 8 Calculate the sample concentration of calcium hardness by using one of the formulas below Digits Required x Digit Multiplier Table 1 mg L Calcium Hardness as CaCO3 Digits Required x Digit Multiplier Table 2 G d h Note Do not reset the counter to zero 12 Place the delivery tube tip into the solution and swirl the flask while titrating with EDTA from red to pure blue Record the number of digits required Note Titrate slowly near the end point because the reaction is slow especially in colder samples HARDNESS TOTAL SEQUENTIAL continued Digits Digit Required Multiplier mg L Total Hardness as CaCO Total Hardness mg L CaCO Ca Hardness mg L CaCO Mg Hardness mg L CaCO 13 Use the appropriate 14 The first titration formula below to calculate the final concentration based on sample size and cartridge used Digits Required x Digit Multiplier Table 1 mg L Total Hardness as CaCO Digits Required x Digit Multiplier Table 2 G d h gives the mg L calcium hardness and the second gives the mg L total hardness The difference between the values is the mg L magnesium hardness as CaCO Total Hardness
8. Accuracy Check Standard Additions Method This accuracy check should be performed when interferences are suspected or to verify analytical technique 1 Use a TenSette Pipet to add 0 4 mL of 0 035 N EDTA Standard Solution to the solution titrated in step 6 Resume titration back to the same end point Record the number of digits required 2 Each 0 4 mL addition of standard should require 70 additional digits of 0 0800 M titrant If this increase does not occur refer to Appendix A Accuracy Check and Standard Additions 60 CHELANT FREE continued Interferences Summary of Method Chelant residual is determined by titration with a standard solution of magnesium chloride at pH 10 The end point is determined by a color change from blue to red violet If chelant residual in boiler water is being analyzed adjust the pH before adding the Hardness 1 Buffer Solution as follows a To another 100 mL sample add 2 drops of Phenolphthalein Indicator Solution b Counting the drops add 5 25 N Sulfuric Acid Standard Solution one drop at atime until the solution changes from pink to colorless Discard this sample c Tothe actual 100 mL sample add the same number of drops of 5 25 N Sulfuric Acid Standard Solution before adding the buffer in step 4 Orthophosphate causes a slow end point Polyphosphate must be absent for accurate results All apparatus must be scrupulously clean and rinsed frequently with acid and deionized
9. 100 ml each 508 42 Marked Dropper Bottle MDB Contact Hach for larger sizes 125 HARDNESS CALCIUM continued OPTIONAL REAGENTS Calcium and Magnesium Total Hardness Reagent Set about 100 tests 22721 00 Includes 2 282 32 1 424 32 1 851 99 1 947 99 1 14364 01 1 14399 01 Description Unit Cat No Calcium Chloride Standard Solution 1000 mg L as CaCO 1000 ml 121 53 CalVer 2 Calcium Indicator Powder eese ertet HS 281 14 Calcium Standard Solution Voluette Ampules 10 000 mg L as CaCO Im 16 pkg 2187 10 Magnesium Standard Solution 10 g L CaCO 29 mL SCDB 1022 33 EH e EE 500 mL 152 49 Nitric Acid Solution II 500 mL 2540 49 Potassium Cyanide ACS 1 ue meinen epe coru t eb t geo o boots 125 8 5 nis 767 14 OPTIONAL APPARATUS Bottle wash poly SO0 ml esee eene each 620 11 Clamp 2 prong extension 38 mm esee each 21145 00 Clamp Hold i ante REOR EP each 326 00 Demineralizer Assembly 473 ml each 21846 00 Delivery Tubes with 180 book sese S pkg 17205 00 Delivery Tubes 90 with hook eee 5 pkg 41578 00 pH Paper 1 0 to 11 pH iiem mee men E E ert 5 rolls pkg 391 33 Pipet TenSette 0 1 to LO ME else each 19700 01 Pipet T
10. Add Step by Step for and wipe the tip deionized water to about assembly instructions if Note For added the 75 mL mark if necessary convenience use the Necessary TitraStir Stir Plate See Note A pipet is General Description recommended for sample Step 3 in Step by Step volumes less than 10 mL Digits Digit Required Multiplier mg L Sodium Nitrite NaNO 5 Add five drops of 6 Add one drop of 7 Place the delivery tip 8 Calculate 5 25 N Sulfuric Acid Ferroin Indicator into the solution While Dietz Required x Digit Standard Solution to the Solution to the flask titrating with Ceric J s Sequen a g flask Swirl Swirl Standard Soluti d Multiplier mg L Sodium ask Swirl to mix wirl to mix tandard Solution swirl Nitrite NaNO the flask until the solution color changes Note See from orange to pale Standardization of Ceric blue Record the number Solution dali SA f normality of digits required 151 NITRITE continued Table 1 Expected Sample Concentration Sample Volume mL Digit Multiplier as NaNO 100 400 25 0 86 400 800 10 2 15 800 1500 5 4 31 1500 2500 2 10 78 Standardization of Ceric Solution The normality of the Ceric Solution will sometimes decrease over time Before use verify the normality with the following procedure This standardization should be done monthly 1 Use a graduated cylinder or pipet to measure 50 mL of deionized water into a 125 mL
11. If a pink color forms no carbon dioxide is present Sampling and Storage Accuracy Check Collect samples in clean plastic or glass bottles Fill completely and cap tightly Avoid excessive agitation or prolonged exposure to air Analyze samples as soon as possible after collection If immediate analysis is not possible the samples may be stored for at least 24 hours by cooling to 4 C 39 F or below Before analysis warm the samples to room temperature Standard Additions Method This accuracy check should be performed when interferences are suspected or to verify analytical technique 1 Snap the neck off a Carbon Dioxide Standard Solution Voluette Ampule 10 000 mg L CO 56 CARBON DIOXIDE continued Interferences Summary of Method Acidity due to carbon dioxide in a sample is titrated with sodium hydroxide to a phenolphthalein end point Strong acids are assumed to be absent or of insignificant concentration Request Hach s Water Analysis Handbook Publication 8376 to obtain additional information on carbon dioxide determinations 2 Use a TenSette Pipet to add 0 1 mL of standard to the sample titrated in step 6 If using 0 3636 N titrant use 1 0 mL of standard Resume titration back to the same end point Record the number of digits required Repeat using additions of 0 2 mL and 0 3 mL 2 0 and 3 0 Titrate to the same end point after each addition Each addition of standard should require 50 additi
12. Material Safety Data Sheets and become familiar with all safety procedures before handling any chemicals DANGER La manipulation des echantillons chimiques talons et reactifs peut tre dangereuse Lire les Fiches de Donnees de Securite des Produits FDSP et se familiariser avec toutes les procedures de securite avant de manipuler tous les produits chimiques PELIGRO La manipulacion de muestras quimicas est ndares y reactivos puede ser peligrosa Revise las fichas de seguridad de materiales y familiaricese con los procedimientos de seguridad antes de manipular productos quimicos GEFAHR Das Arbeiten mit chemischen Proben Standards und Reagenzien ist mit Gefahren verbunden Es wird dem Benutzer dieser Produkte empfohlen sich vor der Arbeit mit sicheren Verfahrensweisen und dem richtigen Gebrauch der Chemikalien vertraut zu machen und alle entsprechenden Materialsicherheitsdatenbl tter aufmerksam zu lesen PERIGO A manipulac o de amostras padr es e reagentes quimicos pode ser perigosa Reveja a folha dos dados de seguranca do material e familiarize se com todos os procedimentos de seguranga antes de manipular quaisquer produtos qu micos 10 GENERAL DESCRIPTION 1 1 Introduction Figure 1 Hach s Digital Titrator is a new concept in titrimetric analysis It is a precision dispensing device fitted with compact cartridges that contain concentrated titrants Accurate titrations are made without the bulk and fragility of
13. The results can be used to check the performance of the reagents the apparatus and the procedure First Step The Accuracy Check Perform the procedure and accuracy check as described in this manual In each accuracy check the number of digits expected for each increment is given If the actual number of digits required is within 1 of the expected number of digits the analyst can conclude the answer for the sample is accurate and the reagents apparatus and method used are working properly Second Step The Decision Tree If the actual number of digits varies noticeably then it must be concluded the problem was caused by either the reagents the apparatus the procedure or an interfering substance By following a logical troubleshooting approach the source of the problem can be systematically determined Using the step by step decision tree in Figure 1 will greatly ease identifying the problem An explanation of each step in the decision tree follows Third Step The Branches Branch A Suppose the first or all three standard additions to the sample did not give the correct incremental digit increase A possible cause for this could be the presence of interferences Other causes could be defective reagents an incorrect procedure defective apparatus or a defective standard used for standard addition If interferences are either absent or assumed to be absent proceed to Branch B If interferences are present proceed to Branch C
14. of course nor do they apply only to the procedures provided in this handbook They are general in nature but emphasize practices that are often key factors in personal injury incidents e Read labels carefully Never remove the label from a reagent container When preparing a reagent or standard solution be sure to label the container clearly and date it e A Material Safety Data Sheet MSDS comes with each reagent This sheet contains helpful information on first aid 24 GENERAL DESCRIPTION continued spill and disposal procedures and precautionary measures and should be read before using the product Warning labels also appear on some of the apparatus used with the test procedures Wear protective clothing when handling chemicals that cause irritation or burns Eye protection in particular is important to guard against spattering and splashes from accidental spills when caustic materials are being used Use tongs or finger cots when transferring apparatus that is hot e Use mechanical pipetters Mouth pipetting could result in accidentally ingesting dangerous chemicals Make a habit of using mechanical pipet fillers for all pipetting This will avoid mistakes that could cause serious injury e Use special care with dangerous chemicals and apparatus Follow the test procedure steps carefully and observe all precautionary measures It is good practice to read the entire procedure carefully before beginning the pr
15. 0 2068 N 22676 01 0 5 100 400 10 0 2068 N 22676 01 1 0 gt 400 5 0 2068 N 22676 01 2 0 113 CHROMATE continued 5 Add the contents of one Potassium Iodide Powder Pillow and swirl to mix 9 Continue titrating until the solution turns from blue to colorless Record the number of digits required 6 Add the contents of 7 Place the delivery one Dissolved Oxygen 3 tube tip into the solution Reagent Powder Pillow and swirl the flask while and swirl to mix Wait at titrating with sodium least three minutes but thiosulfate to a straw not more than 10 minutes yellow color before completing steps 7 to 9 Note A yellow or brown color indicates the presence of chromate Digits Digit Required Multiplier mg L Chromate CrO 10 Calculate Total Digits Required x Digit Multiplier mg L chromate CrO4 Note Results may be expressed as mg L sodium chromate NazCrO4 or chromium Cr by multiplying the mg L chromate by 1 4 or 0 448 respectively 114 8 Add one dropper of Starch Indicator Solution and swirl to mix Note A blue color will form CHROMATE continued Sampling and Storage Accuracy Check Collect 200 to 300 mL of sample in an acid washed glass or polyethylene container If sample cannot be analyzed immediately add 1 mL concentrated sulfuric acid and swirl to mix Standard Additions Method This accuracy check should be performe
16. 50 ml each 14515 41 Pipet volumetric Class A 100 ml each 14515 42 Pipet Filler safety bulb nenne each 14651 00 sension 1 Basic Portable pH Meter with electrode 555111111155010110 each 51700 10 Spoon measuring 0 1 eram eene nennen nenne each 511 00 Spoon measuring 0 5 geram en each 907 00 Support Ring Stand dee each uie 563 00 TitraStir Stir Plate 115 Vac ssseseeeeeereeneen eene rennen each 19400 00 TitraStir Stir Plate 230 Nac each 19400 10 Voluette Ampule Breaker Kit essent tette tete nntnen each 21968 00 141 142 Method 10100 HYPOCHLORITE Bleach 50 to 150 g L 5 to 15 as CH Iodometric Method Scope and Application For testing concentrated liquid bleach sodium hypochlorite soda bleach used as a disinfectant in drinking water or wastewater treatment 1 Insert a clean 2 Flush the delivery A Fill a 125 mL 4 Add the contents of delivery tube into the tube by turning the Erlenmeyer flask to one Potassium Iodide 2 26 N Thiosulfate deliver knob to ejecta about the 75 mL mark Powder Pillow to the Titrant Solution few drops of titrant with deionized or flask and swirl to mix cartridge Attach the Reset the counter to zero tap water cartridge to the and wipe off the tip Note The level of residual chlorine found in tap water will not interfere in the
17. A 10 ML eese each 14515 38 Pipet volumetric Class A 25 ml each 14515 40 Contact Hach for larger sizes 85 CHLORINE TOTAL continued OPTIONAL REAGENTS Description Unit Cat No Chlorine Standard Solution PourRite Ampules 30 75 mg E as EE 20 pkg 14268 20 OPTIONAL APPARATUS Clamp 2 prong extension 38 mm each 21145 00 Clamp Holder etu aede each 326 00 Cylinder graduated mb 2er tas Ces each 508 37 Cylinder srad ted Trek eendeitege pee tette each 508 38 Cylinder sr duated 25 mL trt etre te Ege peo peris each 508 40 Delivery Tubes with 180 hook ooooooonoccnnnccnonccnoncconananonnanonncnnncccnnoconnnccnnnnos S pkg 17205 00 Delivery Tubes 90 with hook for TitraStir Stir Plate S pkg 41578 00 AA nanan each 19700 01 Pipet Tips for 19700 01 TenSette Pipet esses 50 pkg 21856 96 pH Paper EL PH ita made 5 rolls pkg 391 33 PourRite Ampule Breaker eene ene each 24846 00 sension 1 Basic Portable pH Meter with electrode neee each 51700 10 Support Ring Stand en le ie each 563 00 TitraStir Stir Plate 115 Vac eene enne each 19400 00 TitraStir Stir Plate 230 Vac sa nina each 19400 10 86 CHLORINE FREE 0 to 1000 ug L as CL Amperometric Forward Titration USEPA Accepted for Repor
18. A continued Branch J If the standard addition gave the correct result the analyst must then determine if interfering substances are present If interfering substances are not present the result of the analysis prior to the standard addition is correct If interfering substances are present proceed to Branch C One of the greatest aids to the analyst is knowledge of the water sample s composition An analyst need not know the exact composition of each sample but should be aware of potential interferences in the method of analysis to be used When performing a particular method the analyst should know if those interferences are present or not in order to have confidence in the accuracy of the results Once the interferences are known the Interference section of each procedure describes how to correct for many common interferences If the correct result is obtained with one standard addition when no interfering species are present the chance of an error in sample results is very small Possible sources of error not revealed include sample quality sample quantity unless the sample and standard volume used is equal and inconsistent end point determinations Call Hach Technical and Customer Support 1 800 227 4224 for additional help 187 188 D GENERAL INFORMATION At Hach Company customer service is an important part of every product we make With that in mind we have compiled the following information for your c
19. Class A volumetric flask and diluted to volume with 0 05 NTU water will give a 0 5 NTU formazin standard The size of the volumetric flask should be chosen so that the number of digits calculated is approximately 100 or more Example 2 50 mL of a50 NTU formazin standard is required It is found that the dilution water is 0 1 NTU Because the dilution water is only 0 2 of the desired standard the dilution water correction can be ignored The number of digits necessary to dispense the formazin is DIGITS 0 2 50 0 50 500 500 digits of formazin diluted with 50 0 mL of dilution water will give a50 NTU formazin standard Because dirty or scratched glassware air bubbles and color in a sample will interfere with turbidity measurements sample cells must be scratch free and samples should be colorless without air bubbles The measurement of turbidity is based on the scattering of light by the suspended particles clay sand bacteria in solution The amount of light scattered at 90 to the incident light is directly proportional to the turbidity Turbidity is measured in nephelometric turbidity units NTUs These units of measurement are based on the amount of light scattered by particles of a polymer reference standard called 170 TURBIDITY STANDARDS continued formazin Formazin a mixture of hydrazine sulfate and hexamethylenetetramine produces particles which scatter light in a reproducible manner The Hach 4000
20. Cobalt 200 mg L Copper 100 mg L lron 100 mg L Manganese 200 mg L Nickel 400 mg L Zinc 300 mg L 130 HARDNESS TOTAL continued e If more than one metal is present at or above the concentrations shown above an additional CDTA Magnesium Salt Powder Pillow may be required Results obtained by this procedure include the hardness contributed by the metals If the concentration of each metal is known a correction can be applied to obtain the calcium and magnesium hardness concentration The hardness in mg L as CaCO contributed by each mg L of metal is listed below and can be subtracted from the total hardness value obtained above to determine the calcium and magnesium hardness See Table 4 Table 4 Metal Hardness as CaCO Contributed by Each mg L of Metal Aluminum 3 710 Barium 0 729 Cobalt 1 698 Copper 1 575 wo a S Manganese 1 822 Nickel 1 705 Strontium 1 142 Zinc 1 531 Barium strontium and zinc titrate directly Highly buffered samples or extreme sample pH may exceed the buffering capacity of the reagents and require sample pretreatment Summary of Method After the sample is buffered to pH 10 1 ManVer 2 Hardness Indicator is added and forms a red complex with a portion of the calcium and magnesium in the sample EDTA titrant reacts first with the free calcium and magnesium ions then with those bound to the indicator causing it to change to a blue color at t
21. NTU Formazin Cartridge when used with the Hach Digital Titrator offers a quick yet accurate method for the preparation of formazin standards used in turbidimeter calibration REQUIRED REAGENTS Description Unit Cat No Formazin Titration Cartridge 4000 NTU esee el CA 2461 01 Water dei nized un are sr en en EE ees 272 56 REQUIRED APPARATUS Clippers for opening pillows eene each xus 968 00 Digital Titr tor eii A eee eere each 16900 01 Filter Holder 47 mm magnetic base sse each 13529 00 Aspirator vacuum pump poly sees each 2131 00 Filters membrane 0 45 mierons 100 pkg 13530 00 Flask filtering 1000 MUn riin en aana anea as iia each 546 53 Flask volumetric Class A 50 ml each 14574 41 Flask volumetric Class A 100 mt each 14574 42 Flask volumetric Class A 500 mt each 14574 49 Stopper rubber No 7 one hole sss 6 pkg 2119 07 Tubing rubber 2 4 mm ID I2 ft 560 19 Tweezers plastic eerte ie Ree eee ae edits each 14282 00 OPTIONAL APPARATUS Bottle wash poly 500 ml esee each soo 620 11 Clamp 2 prong extension 38 mm each 21145 00 Clamp Holder 2 Rp adi each 326 00 Demineralizer Assembly 473 ml each 21846 00 Delivery Tubes with 180 book 5 pkg 17205 00 TitraStir Stir Plate 115 Vac sses
22. Pacific Rim Telephone 970 669 3050 FAX 970 669 2932 In Europe the Middle East or Mediterranean Africa HACH Company c o Dr Bruno Lange GmbH Willst tterstr 11 D 40549 D sseldorf Germany Telephone 49 0 211 52 88 0 Fax 49 0 211 52 88 231 193 REPAIR SERVICE Authorization must be obtained from Hach Company before sending any items for repair Please contact the HACH Service Center serving your location In the United States Hach Company 100 Dayton Avenue Ames Iowa 50010 800 227 4224 U S A only Telephone 515 232 2533 FAX 515 232 1276 In Canada Hach Sales amp Service Canada Ltd 1313 Border Street Unit 34 Winnipeg Manitoba R3H 0X4 800 665 7635 Canada only Telephone 204 632 5598 FAX 204 694 5134 E mail canada hach com In Latin America the Caribbean the Far East the Indian Subcontinent Africa Europe or the Middle East Hach Company World Headquarters P O Box 389 Loveland Colorado 80539 0389 U S A Telephone 970 669 3050 FAX 970 669 2932 E mail intl hach com 194 WARRANTY Hach warrants most products against defective materials or workmanship for at least one year from the date of shipment longer warranties may apply to some items HACH WARRANTS TO THE ORIGINAL BUYER THAT HACH PRODUCTS WILL CONFORM TO ANY EXPRESS WRITTEN WARRANTY GIVEN BY HACH TO THE BUYER EXCEPT AS EXPRESSLY SET FORTH IN THE PRECEDING SENTENCE HACH MAKES NO WAR
23. Reset the counter to zero and wipe the tip Note For added convenience use the TitraStir Stir Plate See General Description Step 3 in Step by Step 121 4 Use a graduated cylinder or pipet to measure the sample volume from Table 1 or Table 2 Transfer the sample into a clean 250 mL Erlenmeyer flask Dilute to about the 100 mL mark with deionized water if necessary HARDNESS CALCIUM continued 5 Add2 mL of 8N Potassium Hydroxide Standard Solution and swirl to mix Note For samples of 50 mL or less 1 mL may be added Note Magnesium is not included in the results but must be present for a 6 Add the contents of one CalVer 2 Calcium Indicator Powder Pillow Cat No 852 99 and swirl to mix Note A 0 1 gram scoop of CalVer 2 Calcium Indicator Powder Cat No 281 14 may be substituted here 7 Place the delivery tube tip into the solution and swirl the flask while titrating with EDTA from pink to blue Record the number of digits required Note Titrate slowly near the end point because the reaction is slow especially sharp end point If it is known to be absent add one to two drops of Mag nesium Standard Solution in cold samples Total Digits Required Digit Multiplier mg L Calcium Hardness as CaCO 8 Calculate the sample concentration using one of the formulas below Total Digits Required x Digit Multiplier Table 1 mg L Calcium Hardne
24. Standard Solution If the solution is blue add 5 25 N Sulfuric Acid Standard Solution dropwise until the solution changes to yellow Add one additional drop 7 Place the delivery tube tip into the solution While swirling the flask titrate with the Bismuth Nitrate until the color changes from yellow to blue green Record the number of digits required Note Titrate slowly as the end point is approached Note For best results determine a reagent blank Use 50 mL of deionized water in step 3 Subtract the number of digits required for the reagent blank from the number of digits required for titrating the sample 8 Calculate the final concentration Digits Required x 0 188 Total Chelant as mg L Na EDTA Interference from ferric iron Fe3 is minimized by adding ascorbic acid The end point should by approached slowly in samples containing ferric iron because the iron decreases the sharpness of the color change Summary of Method Total chelant is determined by titrating an acid sample with bismuth nitrate the presence of methylthymol blue indicator The end point is signaled by a color change from yellow to blue green 64 CHELANT TOTAL continued REQUIRED REAGENTS Description Unit Ascorbic Acid Powder Dos 100 pkg Bismuth Nitrate Titration Cartridge 0 0200 M sese each Methylthymol Blue Indicator Powder Pillows eese 50 pkg Sulfuric Acid Stand
25. THE soo a each 19700 01 Pipet Tips for 19700 01 TenSette Pipet sssssssssssss 50 pkg 21856 96 PourRite Ampule Breaker AAA each 24846 00 103 104 Method 10026 CHLORINE TOTAL 0 to 1000 ug L as Cl For drinking water or wastewater Amperometric Forward Titration USEPA Accepted for Reporting 1 Assemble the 2 Install the 3 With minimum 4 Add the contents of Amperometric Digital Phenylarsine Oxide agitation measure one Potassium Iodide Titrator System PAO 0 00564 N 200 mL sample witha Powder Pillow and swirl according to the Cartridge Flush the clean graduated cylinder to dissolve instructions in the Digital Titrator delivery Transfer the sample to a Amperometric Titrator tube by turning the clean 250 mL beaker Instruction Manual delivery knob to ejecta containing the 50 mm few drops of titrant stirring bar supplied Reset the counter to zero with the system and wipe the tip Note An improper size of Note When a new probe X Stirring bar can result in is used or when the probe volatilization of chlorine has not been used instability of readings and recently prepare it loss of sensitivity according to the Probe Stabilization instructions in the Amperometric Titrator Instruction Manual Procedure is equivalent to USEPA method 330 1 and 330 3 Standard Methods for the Examination of Water and Wastewater 18th ed 4500 Cl D for drinking water an
26. alkaline sodium hypochlorite solution bleach with stirring Use good ventilation Allow to stand for 24 hours before disposal usable up to 30 mg L iron Substitute a 0 0800 M CDTA or 0 800 M CDTA titration cartridge for the 0 0800 M EDTA or 0 800 M EDTA titration cartridges respectively if iron interference is probable Manganese titrates directly up to 20 mg L but masks the end point above this level Adding a 0 1 gram scoop of hydroxylamine hydrochloride monohydrate raises this level to 200 mg L manganese Copper and aluminum interfere at levels above 0 10 and 0 20 mg L respectively Cobalt and nickel interfere at all levels and must be absent or masked A 0 5 gram scoop of potassium cyanide removes interference from up to 100 mg L copper 100 mg L zinc 100 mg L cobalt and 100 mg L nickel It raises the permissible aluminum level to 1 mg L Metals masked with cyanide will not be included in the hardness result Orthophosphate causes a slow end point and polyphosphate must be absent for accurate results Acidity and alkalinity at 10 000 mg L as CaCO3 do not interfere Saturated sodium chloride solutions do not give a distinct end point but the titration can be run directly on sea water Adding the contents of one CDTA Magnesium Salt Powder Pillow removes metal interferences at or below the levels shown in Table 3 Table 3 Metal CDTA Removes Interference Below This Level Aluminum 50 mg L
27. conventional burets A main drive screw in the Digital Titrator controls a plunger which forces the concentrated titrant from a titration cartridge in a carefully regulated flow The titrator body is constructed of precision molded heavy duty chemical and impact resistant acetal plastic Accuracy is rated at 1 or better for a titration of more than 100 digits For titrations less than 100 accuracy is 1 digit Titration solutions titrants are packaged in disposable polypropylene or Kynar containers with Teflon covered neoprene seals and polyethylene resealable closures to cover the cartridge tips Each cartridge contains approximately 13 mL of titrating solution enough for 50 100 average titrations Titrant solutions are typically controlled to 0 5 concentration with normality and tolerances listed on the label Titrant concentrations are designed for titrations of 10 to 40 turns 100 to 400 digits of the delivery knob For the most commonly used concentration ranges the digits appearing in the counter window correspond to the sample concentration Hach Digital Titrator Titration Cartridge Contains high strength prestandardized Delivery Knob Controls titrant flow Most titrations will require between 10 and 40 turns titrating solution Teflon seal at base Digital Counter end and reseal cap covering tip protect Displays number of digits used against evaporation loss during storage Delivery Tube Ejects titran
28. estimating free and combined chlorine fractions present together The magenta species resulting from the oxidation of DPD by chlorine is destroyed quantitatively by titration with ferrous ethylenediammonium sulfate and the volume of titrant required to reach a colorless end point is proportional to the chlorine concentration Total residual chlorine may also be determined by this test 77 CHLORINE FREE AND TOTAL continued REQUIRED REAGENTS Description Unit Free and Total Chlorine Reagent Set about 100 tests uennsnennen Includes 1 14064 99 1 14070 99 1 22923 01 DPD Free Chlorine Powder Pillows 25 mL eese 100 pkg DPD Total Chlorine Powder Pillows 25 mL ee 100 pkg Ferrous Ethylenediammonium Sulfate Titration Cartridge 0 00564 N each REQUIRED APPARATUS Digital Vitra tor ii Deere gh nebenher each Flask Erlenmeyer SO mii each Pipet volumetric Class A 25 ML eese each Pipet Filler Safety bulbo tii e o tede tene ete ER each OPTIONAL REAGENTS Chlorine Standard Solution PourRite Ampules 20 7 mg E Cl 2 mL tuc A RO o tet 20 pkg Potassium Iodide Solution een 100 mL MDB Sulfuric Acid Standard Solution 1 000 N sess 100 mL MDB Sodium Hydroxide Standard Solution 1 000 N 100 mL MDB Sodium Arsenite Solution eene 100 mL MDB OPTIONAL APPARATUS Cl
29. exact concentration To determine the exact number of digits required for each 1 0 mL addition multiply the exact concentration times the volume of the addition in mL Divide this by five For example 50 mg L x 1 0 mL 5 10 digits If these uniform increases do not occur refer to Appendix A Accuracy Check and Standard Additions Total chlorine concentration equals the concentration of the free and the combined forms of chlorine Free chlorine reacts readily with ammonia to form combined chlorine such as monochloramines When potassium iodide is added to a sample containing chlorine at a pH less than 8 free iodine is liberated in direct proportion to the amount of total chlorine present The iodine is then titrated with sodium thiosulfate 84 CHLORINE TOTAL continued REQUIRED REAGENTS For Using the 0 02256 N Titration Cartridge Description Unit Cat No Acetate Buffer Solution pH A 100 mL MDB 14909 32 Potassium Iodide Powder Pillows eene 100 pkg 1077 99 Starch Indicator Solution eene 100 mL MDB 349 32 Sodium Thiosulfate Titration Cartridge 0 02256 N see each 24091 01 REQUIRED REAGENTS For Using the 0 113 N Titration Cartridge Chlorine Reagent Set 20 2 000 mg L about 100 teste 22725 00 Includes 1 349 32 1 987 99 1 1077 99 1 22673 01 Dissolved Oxygen 3 Powder Pillows eee 100 pkg
30. following formula Digits Required x Digit Multiplier Sample Concentration Where 10 Digits Required the number that appeared in the digital counter window in Step 8 Digit Multiplier the number from the table given in the procedure It takes into account the sample dilution and titrant strength After completing testing for the day press the plunger release button and manually retract the plunger into the body of the titrator Remove the cartridge Remove the delivery tube and reseal the cartridge with the polyethylene cap See Figure 7 Figure 7 Retracting the Plunger HACH TAL TITRATION CARTRIDGE 11 Discard or clean the delivery tube immediately after use To clean force water then air into the tube opening with a syringe or wash bottle 17 GENERAL DESCRIPTION continued 1 3 Helpful Hints 1 3 1 To Reuse a Partially Emptied Cartridge 1 With the plunger fully retracted attach cartridge to the titrator 2 Press the plunger release then manually push the plunger against the cartridge seal 3 Attach a delivery tube Hold the tip of the cartridge up Eject air and a few drops of titrant zero the counter and wipe the tip 4 Titrate as usual 1 3 3 To Calculate Titrant Volume Used Normalities of many Hach titration cartridge solutions have been designed so that the number of digits used in a titration corresponds to the sample concentration in mg L To determine the volume used in
31. free chlorine or chloramines are present in the sample CHLORINE TOTAL continued 9 As the end point of the titration is approached record the LED readings along with the corresponding digits displayed on the Digital Titrator counter Near the titration end point add 2 to 5 digits of titrant wait a few seconds for a stable reading and record 10 Continue the titration recording at least three points on the downward sloping curve and at least three points after the end point has been reached The latter points will have little change in the LED readings Figure 1 Sample Plot Meter Reading 11 Using linear graph paper plot the recorded readings from the Amperometric Titrator on the vertical axis and the corresponding Digital Titrator digits on the on the horizontal axis Draw the two best intersecting lines through the points see Figure 1 Determine the number of digits at the intersection of the lines this is the end point Digits 107 Digits at End Point x 1 25 ug L Total Chlorine as Cl 12 Calculate the pg L total chlorine Digits at End Point X 1 25 ug L total chlorine as Clo CHLORINE TOTAL continued Accuracy Check Standard Additions Method 1 Snap the top off a Chlorine Standard Solution PourRite Ampule Note the certificate value of the standard in mg L 2 Split a fresh sample into two 200 mL portions 3 Using a TenSette Pipet a
32. hydroxide from yellow Methyl Orange Acidity Bromphenol Blue Indicator 1 blue violet pH 3 7 Solution may be Record the number of substituted in this step digits required Note A solution ofone pH 3 7 Buffer Powder Pillow and one Bromphenol Blue Indicator Powder Pillow in 50 mL of deionized water is recommended as a comparison for determining the proper end point color 36 ACIDITY continued Phenolphthalein Total Method Method 8202 Digits x Digit Required Multiplier mg L as CaCO Phenolphthalein Acidity 1 Measure a second 2 Addthe contents of 3 Titrate with sodium 4 Calculate portion of the sample one Phenolphthalein hydroxide from a i Digits Required x selected from step 1 on Indicator Powder Pillow colorless to a light pink Digit Multiplier page 35 into a clean and swirl to mix color that persists for 30 mg L as CaCO 250 mL Erlenmeyer Note Four drops of seconds Record the Phenolphthalein Acidity flask Dilute to about the Phenolphthalein Indicator number of digits 100 mL mark with Solution may be required on we ee fOr Dan Note A solution ofone pH necessary Phenolphthalein Indicator g 3 Buffer Powder Pillow POWER and one Phenolphthalein Powder Pillow in 50 mL of deionized water is recommended as a comparison for determining the proper end point color Sampling and Storage Collect samples in clean plastic or glass bottles Fill completely and cap tightly Minimize agitation or pr
33. iron manganese or aluminum use the following procedure a Adjust the sample in step for phenolphthalein acidity to pH 4 0 or less if necessary by using the Digital Titrator with an acid titration cartridge of identical normality to the Sodium Hydroxide Titration Cartridge used Record the number of digits of acid added to lower the pH b Add five drops of 30 Hydrogen Peroxide Solution and boil the solution for 2 5 minutes c Cool to room temperature Titrate following the Phenolphthalein Procedure steps 2 and 3 Subtract the number of digits of acid added to lower the pH from the number of digits required in step 3 of the Phenolphthalein Procedure Continue with step 4 38 ACIDITY continued colorimetric end point Bromphenol blue gives a better end point than methyl orange indicator Titration to pH 3 7 determines strong mineral acidity also referred to as methyl orange acidity whereas the pH 8 3 phenolphthalein end point includes weaker acid species as well and represents the total acidity The results are expressed in mg L as calcium carbonate CaCO3 at a specified pH REQUIRED REAGENTS varies with sample characteristics Description Unit Acidity Reagent Set about 100 tests sese Includes 1 942 99 1 14377 01 1 14379 01 1 14550 99 Bromphenol Blue Powder Pillows eene 100 pkg Phenolphthalein Powder Pillows eene 100 pkg Sodium Hydroxide Titration Cartridge 0 160
34. knob until titrant begins flowing from the end of the tube Wipe the tip and reset the counter to Zero Note For added convenience use the TitraStir Stir Plate See General Description Step 3 in Step by Step 6 Titrate the sample with mercuric nitrate until the color changes from yellow to light pink Record the number of digits ppt parts per thousand 3 Using the 3 mL 3 cc syringe collect a 2 0 mL water sample Add to the vial provided Digits 0 1 Required ppt Salinity 7 Determine the salin ity of the water sample in parts per thousand ppt by multiplying the reading by 0 1 Note Results may be ex pressed as mg L CF by multiplying the ppt salinity by 569 Hesults may be expressed as mg L NaC by multiplying the ppt sa linity by 940 161 Method 10073 4 Fill the vial to the 10 mL mark with deionized water SALINITY continued Summary of Method The mercuric nitrate method of chloride analysis has become popular due to the sharp yellow to pinkish purple end point of diphenylcarbazone A single stable powder has been developed combining the color indicator with an appropriate buffer to establish the correct pH REQUIRED REAGENTS Description Unit Cat No Diphenylcarbazone Reagent Powder Pillows nenne 100 pkg 967 99 Mercuric Nitrate Titration Cartridge 2 570 N sse each 23937 01 REQUIRED APPARATU
35. masked e Orthophosphate causes a slow end point and polyphosphate must be absent for accurate results e Acidity and alkalinity at 10 000 mg L as CaCO3 do not interfere e Saturated sodium chloride solutions do not give a distinct end point but the titration can be run directly on sea water Adding the contents of one CDTA Magnesium Salt Powder Pillow removes metal interferences at or below the levels shown in Table 3 e If more than one metal is present at or above the concentrations shown in Table 3 an additional CDTA Magnesium Salt Powder Pillow may be required 138 HARDNESS TOTAL SEQUENTIAL continued e Results obtained by this procedure include the hardness contributed by polyvalent metal ions If the concentration of each metal is known a correction can be applied to obtain the calcium and magnesium hardness concentration The hardness in mg L as CaCO3 contributed by each mg L of metal is listed in Table 4 Hardness contributed by metals can be subtracted from the total hardness value obtained in step 13 to determine the calcium and magnesium hardness concentration e Barium strontium and zinc titrate directly Table 3 Metal CDTA Removes Interference Below this Level Aluminum 50 mg L Cobalt 200 mg L Copper 100 mg L lron 100 mg L Manganese 200 mg L Nickel 400 mg L Zinc 300 mg L Table 4 Metal Hardness as CaCO Contributed by Each mg L of Metal Alumin
36. of excess iodide with chlorine and combined chlorine at pH 4 During the titration with phenylarsine oxide PAO the free iodine is reduced to iodide at the cathode and PAO is oxidized from the 3 oxidation state to the 5 oxidation state at the anode Prior to the end point of the titration both iodine and iodide are present in solution therefore current can flow even with a very small applied potential At the end point no free iodine remains and the solution cannot conduct even if excess PAO titrant is added The end point is defined when no change in current occurs signaling all total chlorine has been reacted 110 CHLORINE TOTAL continued REQUIRED REAGENTS Description Unit Phenylarsine Oxide Solution 0 00564 N Digital Titrator cartridge each Acetate Buffer Solution pH A 100 mL MBD Potassium Iodide Powder Pillows eee 100 pkg REQUIRED APPARATUS Amperometric Titrator Assembly A each Digital Titr tor un ERBE ie each Beaker low form 2Z 0 ml enne enne each Cylinder graduated 250 ME sse each Delivery Tubes 90 with book 5 pkg Probe Assembly Amperometric Titrator eee each Stir Bar octagonal Teflon coated 50 8 x 7 9 mm each TitraStir Stir Plate E KEE each TitraStir Stir AA ns each OPTIONAL REAGENTS Chlorine Standard Solution PourRite Ampules 30 75 mg L EE 20 pkg Water deionized a Een NENNEN 4L OPTIONAL APPARATUS Pipet TenSette 0 1 to T
37. test titrator body 5 Add the contents of 6 Attach a clean tip to 7 Use the pipet to 8 Swirl to mix one Acid Reagent the TenSette Pipet dispense 0 2 mL of The solution will turn Powder Pillow to the bleach sample below the dark brown flask and swirl to mix solution level in Note Proceed the flask immediately with Step 9 Adapted from ASTM method D2022 143 HYPOCHLORITE Bleach continued g L Chlorine as Cl Digits at End Point x 0 5 9 Place the delivery 10 Addonedropperof 11 Continue the 12 Calculate the g L tube tip into the solution Starch Indicator titration until the chlorine and swirl the flask while Solution to the flask and solution becomes g L chlorine Digits titrating with the swirl to mix A dark blue colorless Record the i a Required x 0 5 thiosulfate titrant until or green color will number of digits the solution is pale develop required Note Divide the g L yellow chlorine by 10 to obtain the by volume chlorine trade percent Sample Collection Preservation and Storage Soda bleach solutions are relatively unstable Avoid exposing the sample to heat or light Collect samples in glass bottles and store in acool dark place until analyzed Analyze as soon as practical Accuracy Check Standard Solution Method Hach strongly recommends that for optimum test results reagent accuracy be checked with each new lot of reagents The st
38. the horizontal axis The point of intersect of the line with the horizontal axis gives a more accurate estimate of the concentration of the substance in question for the sample In the example the first analysis of the sample gave 50 mg L The result located graphically 100 mg L using the accuracy check should be much closer to the correct result Other interference effects may also be present or interferences may not be consistent in all samples Use of another method not subject to the interference or elimination of the interference is preferred over extrapolation or use of the percent recovery calculation Apparent interferences also may be caused by errors in the method a defect in the apparatus or standards Before assuming the interference is chemical in nature perform Branch B Table 8 Plot D Total Total Standard Total Number Total Standard Parameter Added mL of Digits Used Added mg L Found mg L 0 0 0 E 0 1 25 25 25 0 2 50 50 50 0 3 75 75 iS Plot D illustrates correct results but may hide a problem for the analyst The increments found are uniform and the recovery of the standard was complete The result of the first analysis was 0 mg L and the plot graphs back through 0 mg L If interfering species are present the interference may be sufficient to change the sample result but not sufficient to prevent the analyst from finding uniform increments and complete recovery of the additions This w
39. to orange page 51 red Record the number of digits used 50 AMMONIA HIGH RANGE Ammonium Hydroxide continued Example A bulk solution of aqua ammonia was delivered to a facility and was expected to have a concentration of 19 percent 19 NH3 A portion of the sample was titrated to confirm the concentration The sample volume from Table 1 was found to be 0 2 mL 200 uL The acid titration procedure was followed and 218 digits were used to reach the endpoint The digit multiplier from Table 1 was found to be 0 085 The concentration of ammonia was found to be 18 5 percent NH 218 digits x 0 085 NH 18 5 Tables for Sample Volume and Digit Multiplier Find the expected sample concentration from one of the tables for ammonia or g L or ammonium hydroxide or g L and then find the corresponding sample volume and Digit Multiplier Table 1 Ammonia Percent Expected NH3 Sample Volume mL Digit Multiplier 5 15 0 5 0 034 10 35 0 2 0 085 Table 2 Ammonia g L Expected g L NH3 Sample Volume mL Digit Multiplier 50 150 0 5 0 34 100 350 0 2 0 85 Table 3 Ammonium Hydroxide Percent Expected NH OH Sample Volume mL Digit Multiplier 5 15 1 0 035 10 30 0 5 0 070 25 60 0 2 0 175 Table 4 Ammonium Hydroxide g L Expected g L NH OH Sample Volume mL Digit Multiplier 50 150 1 0 35 100 300 0 5 0 70 250 600 0 2 1 75 51 AMMONIA HIGH RANGE
40. will give low results Store the solutions in tightly capped bottles Precision In a single laboratory using an ammonium hydroxide solution of 9 71 a single operator obtained a standard deviation of 0 1 as NH4OH 52 AMMONIA HIGH RANGE Ammonium Hydroxide continued Summary of Method Ammonia exists in water as ammonium hydroxide The hydroxide ions are titrated with sulfuric acid to a colorimetric end point corresponding to a pH value between 4 4 and 6 2 The hydroxide concentration is directly proportional to the volume of acid titrant used REQUIRED REAGENTS Description Cat No HR Aqua Ammonia Reagent Set about 100 Tests 29305 00 Includes 1 14391 01 1 23293 32 Sulfuric Acid Titration Cartridge NON each 14391 01 Wide Range pH Indicator Solution eee 100 mL 23293 32 Water CelONIZE i xus O REN e AI n 272 56 REQUIRED APPARATUS Digital Titrator Assembly eese eene each 16900 01 Delivery Tubes J hook iie dite eh S pkg 17205 00 Flask Erlenmeyer LIM as each 505 43 Pipettor 100 Ws acs erraten gs each 22753 00 Pipettor Tips for 22753 00 arnesa inina ii 10 pkg 22754 10 OPTIONAL REAGENTS AND APPARATUS Ammonium Hydroxide Solution 1066 esee 500 mL 14736 49 Bottle sampling square glass 118 ml 3 pkg 21631 03 Bottle wash poly 2O0 ml sese eene nennen each 620 11 Demineralizer Bott
41. with deionized water rather than wiped if desired 14 GENERAL DESCRIPTION continued Figure 4 Using the TitraStir Stir Plate Figure 5 Using a Laboratory Stand 15 GENERAL DESCRIPTION continued Figure 6 Titrating the Sample 6 Use the smallest appropriate graduated cylinder or pipet to measure the sample volume from the given table Transfer the sample into a 125 mL or 250 mL Erlenmeyer flask Dilute to the appropriate total volume with deionized water if necessary Note Sample volume measurements and dilutions if required must be made accurately However final total volume of titrated solution is not critical Add the necessary reagents to the sample and swirl to mix Immerse the delivery tube tip in the solution and swirl the flask while titrating Titrate by turning the delivery knob Keep turning the knob and swirling the sample until the end point is reached Record the number of digits that appear in the digital counter window See Figure 6 16 GENERAL DESCRIPTION continued Note The number of digits required will usually range from 100 to 400 In nearly all of the procedures if the digits required is less than 100 or more than 400 an alternate sample volume or titrant cartridge should be used Note Inaccurate results will occur if the delivery tube tip is held out of the solution rather than under the solution surface Calculate the concentration of your sample by using the
42. with step 5 The results will be expressed as mg L total chlorine 6 Calculate Digits Required x 0 01 mg L Free Chlorine mg L Total Chlorine mg L Free Chlorine mg L Combined Chlorine 75 4 Add the contents of a DPD Free Chlorine Powder Pillow to the sample and swirl to mix Note Accuracy is unaffected if a small portion is undissolved Note See Sampling and Storage following these steps CHLORINE FREE AND TOTAL continued Sampling and Storage Chlorine in water is easily lost Therefore start chlorine determinations immediately after sampling avoiding excessive light and agitation Do not store samples Accuracy Check Standard Additions Method This accuracy check should be performed when the analyst suspects interferences or to verify analytical technique 1 Snap the neck off a Chlorine Standard Solution PourRite Ampule 2 Use a TenSette Pipet to add 0 10 mL 0 20 and 0 30 mL of standard respectively to three 25 mL samples Mix each well 3 Analyze each sample as described in the procedure 4 Each 0 1 mL addition of standard should require approximately 20 digits Check the certificate enclosed with the PourRite Ampules to obtain the exact concentration To determine the exact number of digits required for each 0 2 mL addition multiply the exact concentration times the volume of the addition in mL times four Example 50 mg L x 0 1 mL x 4 20 digits If these uniform increases d
43. 0 5 mL of the standard to one portion and swirl to mix This is the spiked sample 3 Analyze each sample as described above and record the chlorine concentrations 4 Calculate the theoretical concentration of the spiked sample Cu x V Cs x Vg Theoretical concentration 48 S V V u S Where C measured concentration of sample in mg L ug L divided by 1000 V volume of sample in mL C concentration of chlorine standard mg L certificate value V volume of standard added in mL 5 Calculate the percent spiked recovery o E Spiked sample result in mg L pSpiketecevely Theoretical concentration calculated in mg L N Standard additions is not applicable for samples containing excess reducing agents such as sulfur dioxide sulfite or bisulfite 100 CHLORINE TOTAL continued Precision Detection Limit Interferences Example Sample result C 120 ug L or 0 120 mg L Spiked sample result 185 ug L or 0 185 mg L Volume Sample V 200 mL Volume Standard V 0 2 mL Chlorine Standard C4 68 1 mg L ion _ 0 120 x 200 68 1 x 0 2 _ Theoretical concentration 200 40 2 0 188 mg L Ideally the percent recovery should be 100 Generally results from 80 120 recovery are considered acceptable In a single laboratory using a standard solution of 120 ug L chlorine a single operator obtained a standard deviation of 19 ug L chlorine The estimated detectable con
44. 0 N ess each Sodium Hydroxide Titration Cartridge 1 600 sss each Water deionized EE AL REQUIRED APPARATUS Digital Titratol iia de ERR izle each Flask Erlenmeyer 250 mL eerie eene eene eene tient tn ternos en nete each Select one or more based on sample concentration Cylinder graduated 10 mL sss each Cylinder graduated 23 mt sse eee nere each Cylinder graduated 50 mL sess each Cylinder graduated 100ML eese each OPTIONAL REAGENTS Acidity Standard Solution Voluette Ampules 0 300 N H55 EE EE 16 pkg Bromphenol Blue Indicator Solution sess 100 mL MDB Buffer Powder Pillows pH 3 7 eee 25 pkg Buffer Powder Pillows pH 8 3 eee 25 pkg Hydrogen Peroxide Solution 3066 eese 200 mL MDB Phenolphthalein Indicator Solution 5 g L 100 mL MDB Sodium Thiosulfate Standard Solution 0 1 N 100 mL MDB Contact Hach for larger sizes 39 Cat No ACIDITY continued OPTIONAL APPARATUS Description Unit Cat No Bottle wash poly 2O0 ml sees eene each 620 11 Clamp 2 prong extension 38 mm esee enne each 21145 00 Clamp Holder 22 eaten eei sei neat enter each 326 00 Demineralizer Assembly 473 mL esee ene e
45. 00 pkg CDTA Titration Cartridge 0 0800 M A each CDTA Titration Cartridge 0 800 M A each Calcium Standard Solution Voluette Ampules 10 000 mg L as CaCO3 LO Men sinne 16 pkg Hydroxylamine Hydrochloride Monohydrate ACS 113 g ManVer 2 Hardness Indicator Powder 113 g ManVer Hardness Indicator Solution 100 mL MDB Ne Acid Solution Hl rn Rss 500 mL Nitric Acid EE 500 mL Potassium Cyanide AC 125g Contact Hach for larger sizes 132 Cat No det 24478 00 EE 24479 00 eet 24480 00 ER 24481 00 pens 14364 01 kamin 14960 01 en 14959 01 snp 14399 01 P 14402 01 teh 14403 01 HARDNESS TOTAL continued OPTIONAL APPARATUS Description Unit Cat No Bottle wash poly 2O0 ml esses each 620 11 Clamp 2 prong extension 28 mm seen each 21145 00 Clamp Holder edu enne euet eue each 326 00 Demineralizer Assembly 473 mL eese each 21846 00 Delivery Tubes with 180 book 5 pkg 17205 00 Delivery Tubes 90 with book S pkg 41578 00 pH Paper 1 046 1H eiii eerte t eese drei 5 rolls pkg 391 33 Pipet TenSette 0 1 La each 19700 01 Pipet Tips for 19700 01 TenSette Pipet ENEE 50 pkg 21856 96 Pipet volumetric Class A 10 mL eese each 14515 38 Pipet volumetric Class A 20 mL essere each 14515 20 Pipe
46. 001 53 OPTIONAL APPARATUS pH Paper l 11 neuen ee en Rn 5 pkg 391 33 Pipet volumetric Class A 50 00 ml each 14515 41 Marked Dropping Bottle 146 IRON 10 to 1000 mg L as Fe Using the TitraVer Titration Cartridge Table 1 y 1 Select a sample volume and a TitraVer Titration Cartridge corresponding to the expected iron Fe concentration from y 2 Insert a clean delivery tube into the titration cartridge Attach the cartridge to the titrator body See General Description Step by Step for assembly instructions Method 8214 3 Turn the delivery knob to eject a few drops of titrant Reset the the tip counter to zero and wipe Note For added convenience use the TitraStir Stir Plate See 4 Use a graduated cylinder to measure the sample volume from Table 1 Transfer the sample into a clean 125 mL Erlenmeyer flask Dilute to about the 50 mL mark with if necessary General Description deionized water if Step 3 in Step by Step necessary Table 1 Range Sample Titration Catalog Digit mg L as Fe Volume mL Cartridge Number Multiplier M TitraVer 10 40 50 0 0716 20817 01 0 1 25 100 20 0 0716 20817 01 0 25 100 400 50 0 716 20818 01 1 0 250 1000 20 0 716 20818 01 2 5 147 IRON continued 5 Add the contents of 6 Add the contents of 7 Add the contents of 8 Place the delivery one Citrate Buffer one Sodium Pe
47. 0011111001 each 51700 10 Support Ring Stand niani reete e cete eee Po ge rer dece dan each 563 00 TitraStir Stir Plate 115 Vac rennen sennern nn each 19400 00 TitraStir Stir Plate 230 VAC uisus see SMS each 19400 10 Voluette Ampule Breaker Kit esses eese tenente tn ononono secos each 21968 00 73 74 Method 8210 CHLORINE FREE AND TOTAL 00 to 3 00 mg L as CL DPD FEAS Method G 1 Insert a clean delivery tube into a 0 00564 N Ferrous Ethylenediammonium Sulfate FEAS Titration Cartridge Attach the cartridge to the titrator body See General Description Step by Step for assembly instructions if necessary 5 Place the delivery tube tip into the solution and swirl the flask while immediately titrating with FEAS to a colorless end point Record the number of digits required Note Complete the titration rapidly 2 Turn the delivery 3 Pipet 25 0 mL of knob to eject a few drops sample into a 50 mL of titrant Reset the Erlenmeyer flask counter to zero and wipe the tip Note For added convenience use the TitraStir Stir Plate See General Description Step 3 in Step by Step mg L Total Chlorine mg L Free Chlorine mg L Combined Chlorine 7 Tf total residual chlo rine is desired return to step 3 and substitute a DPD Total Chlorine Powder Pillow in step 4 Wait three minutes be fore titrating Continue
48. 1 Starch Indicator Solution eere 100 mL MDB 349 32 Sulfamic Acid Powder Pillows eese 25 pkg 20762 68 REQUIRED APPARATUS FOR 300 ML BOD BOTTLE Bottle with stopper BOD 300 mL esee each 621 00 Clippers for opening pillows eee each 968 00 Cylinder graduated 2a0 ml seen each us 508 46 Digital Eitrator uc tune e De en desire each 16900 01 Flask Erlenmeyer 250 mL sess enne each 505 46 Contact Hach for larger sizes 159 OXYGEN DISSOLVED continued REQUIRED REAGENTS FOR 60 ML BOD BOTTLE Description Unit Cat No Dissolved Oxygen 1 Reagent Powder Pillows es 100 pkg 981 99 Dissolved Oxygen 2 Reagent Powder Pillows ess 100 pkg 982 99 Dissolved Oxygen 3 Reagent Powder Pllows eese 25 pkg8 987 68 Sodium Thiosulfate Titration Cartridge 0 2000 N esses each 22675 01 REQUIRED APPARATUS FOR 60 ML BOD BOTTLE Bottle with stopper BOD 60 mL eese each 1909 02 Clippers for opening pillows eese each i 968 00 Cylinder graduated 20 ml nono nonnccnnncna nennen each 1081 41 Digital Titratot ias Sei R mendo oet each 16900 01 Flask Erlenmeyer LIME haters denen ine each 505 43 O
49. 1 0 200 800 10 0 3998 14961 01 2 0 gt 400 5 0 3998 14961 01 4 0 163 SULFITE continued 5 Add the contents of one Dissolved Oxygen 3 Reagent Powder Pillow and swirl gently to mix Note 0 5 mL of 19 2 N Sulfuric Acid Standard Solution may be substituted for the powder pillow 6 Add one dropperful of Starch Indicator Solution and swirl to mix 7 Place the delivery tube tip into the solution and swirl the flask while titrating with the iodate iodide to a permanent blue end point Record the number of digits required Table 2 Digits Required Digit Multiplier mg L Sulfite SO 8 Calculate Digits Required x Digit Multiplier mg L Sulfite SOz Note To obtain the concentration of other sulfite forms multiply the mg L SO determined in step 8 by the appropriate multiplier from Table 2 Bisulfite Hydrogen Sulfite HSO37 Form Multiplier Sodium Bisulfite Sodium Hydrogen Sulfite NaHSO Sodium Metabisulfite Sodium Pyrosulfite Na2S205 Sodium Sulfite NazSO3 Sampling and Storage Samples must be analyzed immediately Cool hot samples to Accuracy Check 50 C or lower Standard Additions Method This accuracy check should be performed when interferences are suspected or to verify analytical technique 1 Snap the neck off a Sulfite Standard Solution Voluette Ampule 5 000 mg L SO32 164 SULFITE continued 2 Use a TenSe
50. 14378 01 2 0 3 636 N NaOH 14380 01 Chloride 12 500 mg L CI 14250 10 0 1 0 2256 N Hg NO3 2 125 14393 01 0 1 0 2256 N AgNO 125 14396 01 1 0 1 128 N AgNO 250 14397 01 1 0 2 256 N Hg NO3 125 921 01 20 GENERAL DESCRIPTION continued Table 1 Titration Standards Continued Procedure Standard Description a Titration Cartridge Expected Parameter Cat No mL Cat No Digits Chlorine 50 mg L Cl 2 0 0 02256 N NapS203 varies 14268 20 24091 01 see certificate 25 mg L Cl 0 5 0 00564 N FEAS varies 26300 20 22923 01 Chromate 1000 mg L Cr 1 0 0 2068 N Na5S gt 03 223 2231 mg L CrO 22676 01 14664 42 Hardness 0 1 0 0800 M EDTA 100 mg L CaCO 10 000 mg L CaCO 2187 10 14364 01 0 1 0 0800 M CDTA 100 14402 01 1 0 0 800 M EDTA 100 14399 01 1 0 0 800 M CDTA 100 14403 01 G d h 10 000 mg L CaCO 2187 10 0 2 0 1428 M EDTA 112 14960 01 1 0 0 714 M EDTA 112 14959 01 lron 50 mg L Fe 10 0 0 0716 M TitraVer 200 14254 10 20817 01 1000 mg L Fe 10 0 0 716 M TitraVer 100 2271 42 20818 01 Oxygen 10 mg L as DO 100 0 2000 N NazS 03 500 Dissolved 401 11 22675 01 200 2 00 N NasS203 100 14401 01 Sulfite 5000 mg L SO 22674 10 1 0 0 3998 N KIO Kl 250 14961 01 One to two drops of Magnesium Standard Solution 10 g L as CaCO3 must be added to get a sharp end point These added drops will not change the results The expe
51. 2418 99 Sulfuric Acid Standard Solution 5 25 N see 100 mL MDB 2449 32 72 CHLORIDE continued OPTIONAL APPARATUS Description Unit Cat No Bottle wash poly 2O0 ml essere each 620 11 Clamp 2 prong extension 38 mm eese each 21145 00 Clamp Holder 5 eii tte iet entered des P dE each 326 00 Demineralizer Assembly 473 mL eene each 21846 00 Delivery Tubes with 180 book S pkg 17205 00 Delivery Tubes 90 with hook for TitraStir Stir Plate 5 pkg 41578 00 Filter Paper folded K CMe 2 iere t Re st 100 pkg 1894 57 Funnel poly DEER EE EEN each 1083 67 Pipet enseres ista each 19700 01 Pipet Tips for 19700 01 TenSette Pipet esses 50 pkg 21856 96 Pipet volumetric Class A 2 ml eere nnne each 14515 36 Pipet volumetric Class A SML nenn each 14515 37 Pipet volumetric Class A IO mt enne each 14515 38 Pipet volumetric Class A 20 mt essere each 14515 20 Pipet volumetric Class A 23 mt enne each 14515 40 Pipet volumetric Class A 50 mL essere each 14515 41 Pipet volumetric Class A 100 mL eese each 14515 42 Pipet Filler safety b lb ore 24a ran each 14651 00 sension 1 Basic Portable pH Meter with electrode ss1111111155
52. 250 ml each Funnel analytical poly 65 mm each Pipet TenSette 0 1 to 1 0 mos anes esau eco es Dro eR each Pipet Tips for 19700 01 TenSette Pipet eee 50 pkg Spoon measuring 0 5 gram eee ecceeecceesecessecesceceeeeecseeeeseeeeaeceeaeeeeeeeeeees each Support Ring Stand ue une en er ee each TitraStir Stir A Eat bbb Ren each TitraStir Stir Plate 230 Vic En each Contact Hach for larger sizes 62 Method 8350 CHELANT TOTAL 0 to 40 0 mg L as NaEDTA Using Bismuth Nitrate y 1 Insert a clean 2 Hold the Digital 3 Use a graduated 4 Add the contents of delivery tube into the Titrator with the cylinder to measure the one Ascorbic Acid Bismuth Nitrate Titration cartridge tip pointing up 50 mL of clear sample Powder Pillow to the Cartridge Attach the Turn the delivery knob into a 125 mL flask and swirl to mix cartridge to the titrator until a few drops of Erlenmeyer flask body See General titrant are expelled Note Filtration is required Description Step By Reset the counter to Zero for turbid samples Step for assembly and wipe the tip instructions Note For added convenience use the TitraStir Stir Plate See General Description Step 3 in Step by Step 63 CHELANT TOTAL continued 5 Add the contents of one Methylthymol Blue Powder Pillow to the flask and swirl to mix Interferences 6 If the solution in the flask is yellow add one drop of 5 25 N Sulfuric Ac d
53. 38 mm sess each 21145 00 Clamp Holder nettement esee ete ederet each 326 00 Demineralizer Assembly 473 mL eese each 21846 00 Delivery Tubes with 180 hook eene S pkg 17205 00 Delivery Tubes 90 with hook for TitraStir Stir Plate S pkg 41578 00 Pipet TenSette 0 1 to 1 0 ML tt ibid este each 19700 01 Pipet Tips for 19700 01 TenSette Pipet ssccssessssssssssesessecsseeeeerss 50 pkg 21856 96 Pipet volumetric Class A IO mt sess each 14515 38 Pipet volumetric Class A 20 mt sess each 14515 20 Pipet volumetric Class A 23 mt essere each 14515 40 Pipet volumetric Class A S0O ml sese each 14515 41 Pipet volumetric Class A LO eese each 14515 42 Pipet Fuller safety bulb eme ete eie enge each 14651 00 sension 1 Basic Portable pH Meter with electrode ee each 51700 10 Support Ring Stand anne anregen each 563 00 TitraStir Stir MM AO each 19400 00 TitraStir Stir Plate 230 Vac esee treten treten each 19400 10 Voluette Ampule Break nette oe Etonterstio eee see ioet each 21968 00 48 Method 10222 AMMONIA HIGH RANGE Ammonium Hydroxide 5 to 35 50 to 350 g L as NH or 5 to 60 50 to 600 g L as NH OH Acid Titration Method For use with Digital Titrator Test Kit Model NI HRDT Cat No 29304 00 Scope and Applicatio
54. 4 5 color as required by Note Carbonate the sample composition bicarbonate and hydroxide concentrations may be see Table 2 Record the ay nressed individually number of digits using the relationships required shown in Table 3 Note A solution of one Note meq L Alkalinity Bromcresol Green Methyl mg L as CaCOs 50 Red Powder Pillow and one pillow of the appropriate pH buffer in 50 mL of deionized water is recommended as a comparison for judging the proper end point color If the pH 3 7 end point is used use a Bromphenol Blue Powder Pillow instead of a Bromcresol Green Methyl Red and titrate to a green end point Table 2 T End Sample Composition Point Alkalinity about 30 mg L pH 4 9 Alkalinity about 150 mg L pH 4 6 Alkalinity about 500 mg L pH 4 3 Silicates or Phosphates present pH 4 5 Industrial waste or complex system pH 4 5 43 ALKALINITY continued Sampling and Storage Collect samples in clean plastic or glass bottles Fill completely and cap tightly Avoid excessive agitation or prolonged exposure to air Samples should be analyzed as soon as possible after collection but can be stored at least 24 hours by cooling to 4 C 39 F or below Warm to room temperature before analyzing Alkalinity Relationship Table Total alkalinity primarily includes hydroxide carbonate and bicarbonate alkalinities The concentration of these alkalinities in a sample may be determined when the pheno
55. 46 PET each 16900 01 ORO HE CERES each 505 46 VOLATILE ACIDS continued OPTIONAL APPARATUS Clamp 2 prong extension 38 mm each 21145 00 Clamp Holder tives ten o te ete titor ette tita each 326 00 Delivery Tubes with 180 book S pkg 17205 00 Delivery Tubes 90 with book S pkg 41578 00 Distillation Heater and Support Apparatus 115 Vac sss each 22744 00 Distillation Heater and Support Apparatus 230 Vac sess each 22744 02 Distillation Apparatus Set each 22653 00 Standard Methods for the Examination of Water and Wastewater 19th ed each 22708 00 Support Ring Stand ze cao rS eee te derer eine each 563 00 Titrastir Stir Plate KEE each 19400 00 TitraStir Stir Plate 230 Vac eese entente tne tree tnenen each 19400 10 175 176 APPENDIX A ACCURACY CHECK AND STANDARD ADDITIONS Most of the procedures in this manual have an accuracy check based on the standard additions method Standard additions is a widely accepted technique for checking the validity of test results Also known as spiking and known additions the technique adds a small amount of the component parameter being measured to an analyzed sample and the analysis is repeated The increase in the test results should equal the amount of the standard added
56. 7 1 Select the sample 2 Insert a clean 3 Turn the delivery 4 Use a graduated volume and Silver delivery tube into the knob to ejecta few drops cylinder or pipet to Nitrate Titration titration cartridge of titrant Reset the measure the sample Cartridge corresponding Attach the cartridge to counter to zero and wipe volume from Table 2 to the expected chloride the titrator body See the tip Transfer the sample into concentration from General Description Note For added a clean 250 mL l Table 2 Section Step by Step convenience use the Erlenmeyer flask Dilute for assembly TitraStir Stir Plate See to about the 100 mL instructions if necessary General Description mark with deionized Step 3 in Step by Step water if necessary Note See following these steps 68 CHLORIDE continued Table 2 Sample Titration e Range e Catalog Digit mg L as CH pos AG Number Multiplier 3 10 40 100 0 2256 14396 01 0 1 25 100 40 0 2256 14396 01 0 25 100 400 50 1 128 14397 01 1 0 250 1000 20 1 128 14397 01 2 5 1000 4000 5 1 128 14397 01 10 0 2500 10000 2 1 128 14397 01 25 0 5 Add the contents of one Chloride 2 Indicator Powder Pillow and swirl to mix Note Results will still be accurate if a small amount of the powder does not dissolve 6 Place the delivery tube tip into the solution and swirl the flask while titrating with silver nitrate from a yellow to red brown color Record the numb
57. 7 Using the Digital Titrator delivery knob dispense the Standard Iodine Titrant Solution in 5 10 digit increments while noting the LED reading Record at least 3 points null current values and Digital Titrator reading before end point is reached 98 8 After the end point of the titration is reached record the increasing LED readings along with the corresponding digits displayed on the Digital Titrator counter Add 5 10 digits of titrant wait a few seconds for a stable reading and record Stop the titrant addition when the LED readings exceed 0 60 Note LED readings above 0 60 will be excessively noisy With samples containing excess de chlorinating agents such as sulfur dioxide sulfite or bisulfite the titration end point number of digits will be greater than the number of digits obtained during the standardization It is not necessary to continue the titrant addition if the number of digits used in the sample titration exceeds that calculated for the standardization end point This indicates that no free or combined chlorine is present in the sample CHLORINE TOTAL continued 9 Using linear graph paper plot the recorded readings from the Amperometric Titrator on the vertical axis and the corresponding Digital Titrator digits on the horizontal axis Draw the two best intersecting lines through the points plotted See Figure 1 on page 96 Determine the number of digits at the intersect
58. 8 N NaOH 14381 01 10 0 8 N H2SO4 14391 01 8 N HCI 14390 01 30 ACID BASE continued Base Determination 1 Select the sample volume corresponding to the expected base concentration in milliequivalents L or normality from Table 1 5 Add the contents of one Phenolphthalein Indicator Powder Pillow and swirl to mix The solution should be a pink color Note Four drops of Phenolphthalein Indicator Solution may be substituted for the Phenolphthalein Indicator Powder Pillow G 2 Insert aclean delivery tube into the appropriate Hydrochloric Acid or Sulfuric Acid Titration Cartridge Attach the cartridge to the titrator body See General Description Section Step by Step for assembly instructions if necessary 6 Titrate with 8 00 N hydrochloric acid or sulfuric acid until the solution is colorless Record the number of digits required 3 Flush the delivery tube by turning the delivery knob to eject a few drops of titrant Reset the counter to zero and wipe the tip Note For added convenience use the TitraStir Stir Plate See General Description Step 3 in Step by Step Digits Required Digit Multiplier Milliequivalents L of Base 7 Calculate Digits Required x Digit Multiplier Milliequivalents per Liter of Base Note To determine the normality of the sample divide the milliequivalents per liter obtained by 1000 31 4 Use a graduated
59. Ammonium Hydroxide continued Sampling and Storage Collect samples in clean glass bottles and cap tightly Store in a cool place Analyze as soon as possible Interferences Other strong bases such as sodium hydroxide and potassium hydroxide will cause a positive interference in the test Other alkaline substances such as carbonates will also react with the strong acid titrant The amounts of these compounds should be insignificant in aqua ammonia solutions however and will not affect test results High levels of alkalinity in the dilution water will cause high results Be sure to use deionized water in step 3 Accuracy Check 1 Fill an Erlenmeyer flask with approximately 75 mL of deionized water 2 Use a Class A 1 0 mL pipet to transfer 1 0 mL of a 10 ammonium hydroxide solution to the flask 3 Add 1 mL one full dropper of Wide Range pH Indicator Solution to the flask The solution will turn a purple color 4 Titrate the sample using the Digital Titrator to the red orange endpoint with 8 00 N sulfuric acid The titration should use 270 300 digits of 8 00 N sulfuric acid to reach the endpoint Note If the number of digits used to reach the endpoint does not fall within the 270 300 digit range make sure that the dilution water does not contain excess alkalinity and that the 1 0 mL of ammonium hydroxide is measured accurately Ammonium hydroxide solutions that are left open to the atmosphere will lose ammonia over time and
60. Cartridge corresponding to the expected alkalinity concentration as mg L calcium carbonate CaCO3 from Table 1 Note See Sampling and 2 Insert a clean delivery tube into the titration cartridge Attach the cartridge to the titrator body See General Description Step by Step for assembly instructions if necessary 3 Turn the delivery knob to eject a few drops of titrant Reset the the tip Note For added counter to zero and wipe convenience use the TitraStir Stir Plate See General Description Step 3 in Step by Step Method 8203 4 Use a graduated cylinder or pipet to measure the sample volume from Table 1 Transfer the sample into a clean 250 mL Erlenmeyer flask Dilute to about the 100 mL mark with deionized water if Storage following necessary these steps Table 1 Range Sample ae Catalog Digit mg L as CaCO 3 Volume mL 9 Number Multiplier H2504 10 40 100 0 1600 14388 01 0 1 40 160 25 0 1600 14388 01 0 4 100 400 100 1 600 14389 01 1 0 200 800 50 1 600 14389 01 2 0 500 2000 20 1 600 14389 01 5 0 1000 4000 10 1 600 14389 01 10 0 41 ALKALINITY continued 5 Add the contents of one Phenolphthalein Indicator Powder Pillow and swirl to mix Note A solution ofone pH 8 3 Buffer Powder Pillow and one Phenolphthalein Powder Pillow in 50 mL of deionized water is recommended as a comparison for determining the proper end point c
61. D 16900 08 Digital Titrator Model 16900 Hach Company 1980 2006 Digital Titrator manufactured under U S patent 4 086 062 jk dk June 2006 24 ed All rights reserved TABLE OF CONTENTS SPECIFIEATIONS ctio ae licita 7 OPERATION DE 9 GENERAL DESCRIPTION erit t tet eth tte Do eno ce hee Ee get HE E sd 11 I 1 dntroduction ctn ete eae nete ted ee eei cese dee ee 11 1 1 1 Following a Procedure for the First Time 12 LD Step BY Pi tere eret ete etd oe dette te i ge caet 13 1 3 Helpful Hints idi EE dE EE see 18 1 3 1 To Reuse a Partially Emptied Cartridge AAA 18 1 3 2 To Calculate Titrant Volume Used eese eene 18 1 3 3 To Fill Your Own Titration Cartridges eee 18 1 3 4 Verifying Technique eic 2 er Ibn 19 1 4 Adapting a Buret Titration to the Digital Titrator 0 eee ceeeeeeeeeeecnseceseeeeeeeeeeneesnaees 22 1 5 Using PermaChem Powder Pillows ette ee aes 23 IL JL 24 TITRATION PROCEDURES 1 netten tette een 27 ACID BASE Acid Determination ita Gta iem tae tene me Pede Leo 29 Base Determination edid e aie a oH e eter 31 ACIDITY Methyl Orange Method u reset Eger eite en ae 35 Phenolphthalein Total Method 37 ALKALINITY Phenolphthalein and Total Method A 41 AMMONIA HIGH RANGE Ammonium Hydroxide Ammonia Titration Procedure esses eene eee nre neetne trennen entente nnne 49 CARBON DIOXIDE Using Sodium Hydroxide pd eie a e enata eto ordo 55 CHELANT FREE Using Magn
62. Erlenmeyer flask Add 5 mL of 19 2 N Sulfuric Acid Standard Solution Swirl to mix Insert a clean delivery tube into a Ceric Standard Titration Cartridge Hold the Digital Titrator with the cartridge tip pointing up Turn the delivery knob until a few drops of titrant are expelled Reset the counter to zero and wipe the tip Place the delivery tube tip into the solution While swirling the flask add 200 digits of Ceric Standard Insert a clean delivery tube into a 0 200 N Sodium Thiosulfate Titration Cartridge Hold the Digital Titrator with the cartridge tip pointing up Turn the delivery knob until a few drops of titrant are expelled Reset the counter to zero and wipe the tip Place the delivery tube tip into the solution While swirling the flask titrate with the sodium thiosulfate from an intense yellow color to a faint yellow color Record the number of 152 NITRITE continued digits required This step should require about 400 450 digits of titrant 9 Add one drop of Ferroin Indicator Solution Swirl to mix The solution will turn a faint blue 10 Continue titrating the Ceric Standard Solution using the 0 20 Sodium Thiosulfate Titration Cartridge from a faint blue to orange color Record the number of digits required 11 Calculate the correction factor Digits Required Correction Factor QS Required 500 12 Multiply the mg L sodium nitrite from step 6 of the nitrite titration procedure by the correcti
63. H titration cartridge of titrant Reset the measure the sample Titration Cartridge Attach the cartridge to counter to zero and wipe volume from Table 1 corresponding to the the titrator body See the tip Transfer the sample expected acidity General Description Note For added into a clean 250 mL concentration as mg L Step by Step for convenience use the Erlenmeyer flask Dilute calcium carbonate assembly instructions TitraStir Stir Plate See to about the CaCO3 from Table 1 if necessary General Description 100 mL mark with Notez Eoo Sampling ana Step 3 in Step by Step deionized water if Storage following necessary these steps Note Minimize agitation because dissolved gases in the sample such as carbon dioxide hydrogen sulfide and ammonia may be lost and cause inaccurate results Table 1 Sample Titration A ings Caco j Volume Cartridge ae em 3 mL N NaOH 10 40 100 0 1600 14377 01 0 1 40 160 25 0 1600 14377 01 0 4 100 400 100 1 600 14379 01 1 0 200 800 50 1 600 14379 01 2 0 500 2000 20 1 600 14379 01 5 0 1000 4000 10 1 600 14379 01 10 0 35 ACIDITY continued Bt Digits Digit Required Multiplier mg L as CaCO Methyl Orange Acidity 5 Add the contents of 6 Place the delivery 7 Calculate one Bromphenol Blue tube tip into the solution Indicator Powder Pillow and swirl the flask while Digits Required x and swirl to mix titrating with sodium a Note Six drops of
64. L REAGENTS CDTA Magnesium Salt Powder Dllows eee 100 pkg CDTA Titration Cartridge 0 08 M A each CDTA Titration Cartridge 0 8 M A each Hardness 2 Test Solution oooccnooccncnonncnonononononcnnncnnnnncnnncnnnnnnoss 100 mL MDB Hardness Standard Solution Voluette Ampules 10 000 mg L as CaCO3 MOM ae 16 pkg Hydroxylamine Hydrochloride AAA 113g Nitric Acid 7090655 inire da d o ev v ih eda 500 mL Other reagents and apparatus are listed with the specific procedure Marked Dropper Bottle MDB Contact Hach for larger sizes 140 E 14364 01 eus 14960 01 TM 14959 01 ne 14399 01 EE 14080 99 idibus 14402 01 HARDNESS TOTAL SEQUENTIAL continued OPTIONAL APPARATUS Description Unit Cat No Bottle wash poly 500 ml sese each 620 11 Clamp 2 prong extension 38 mm each 21145 00 Clamp Holder enema e each isisisi 326 00 Demineralizer Assembly 473 ml each 21846 00 Delivery Tubes with 180 book 5 pkg 17205 00 Delivery Tubes 90 with book S pkg 41578 00 pH Paper 1 0to T pH ung treten deserere 5 rolls pkg 391 33 Pipet TenSette 0 1 tod Oman each 19700 01 Pipet Tips for 19700 01 TenSette Pipet EE 50 pkg 21856 96 Pipet volumetric Class A IOmt eene each 14515 38 Pipet volumetric Class A 20 mt each 14515 20 Pipet volumetric Class A 25 mt each 14515 40 Pipet volumetric Class A
65. O gtE u ann Dan each Pipet Tips for 19700 01 TenSette Dpet 50 pkg PourRite Ampule Breaker AAA each Standard Methods for the Examination of Water and Wastewater 19th edition eese ene eene nnne each 111 Cat No 1999 01 14909 32 1077 99 19400 00 19400 10 19700 01 21856 96 24846 00 22708 00 112 CHROMATE 20 to gt 400 mg L as CrO429 Using Sodium Thiosulfate Y 1 Insert a clean delivery tube into the Sodium Thiosulfate titration cartridge Attach the cartridge to the titrator body See General Description Step by Step for assembly instructions if necessary Method 8211 2 Turn the delivery knob to eject a few drops of titrant Reset the counter to zero and wipe the tip Note For added convenience use the TitraStir Stir Plate See General Description Step 3 in Step by Step 3 Select a sample volume corresponding to the expected chromate CrO42 concentration from Table 1 Note Collect 200 to 300 mL of sample in an acid washed glass or polyethylene container Note See Sampling and Storage following these steps 4 Use a graduated cylinder or pipet to measure the sample volume from Table 1 Transfer the sample to a clean 125 mL Erlenmeyer flask Dilute to about the 50 mL mark with deionized water Table 1 Sample Titration S DL Se 2 Yal ma Cartridge SE are 4 mL N Na S203 20 80 50 0 2068 N 22676 01 0 2 50 200 20
66. PTIONAL REAGENTS Iodate Iodide Standard Solution 10 mg L as DO 500 mL 401 49 OPTIONAL APPARATUS Cap BOD Bottle plastic 2 iet dete itio ent 6 pkg 2419 06 Clamp Holder uiii ee e eee aee eee each 326 00 Clamp 2 prong extension 38 mm each 21145 00 Delivery Tubes with 180 hook eene 5 pkg 17205 00 Delivery Tubes 90 with hook eere 5 pkg 41578 00 Sewage Sampler Lab Line eese each 427 00 Support Ring Stand ducite einen each 563 00 TitraSur Stir Plate 115 Vacs aa ii isch tere Se ee ne eects each 19400 00 TitraStir Stir Plate 230 Vac retener ener each 19400 10 Procedures and kits for portable dissolved oxygen measurements using this method are available from Hach Contact Hach for larger sizes 160 SALINITY 0 to 100 ppt as Salinity Using Mercuric Nitrate UA 1 Insert a clean straight stem delivery tube to a Mercuric Nitrate Titration Cartridge Attach the cartridge to the titrator body See General Description Step by Step for assembly instructions if necessary 5 Add the contents of one Diphenylcarbazone Reagent Powder Pillow to the vial and mix Note Results will not be affected if a small portion of the diphenylcarbazone reagent powder does not dissolve 2 Flush out the delivery tube by turning the
67. Plate and immerse the tips of the probe and delivery tube in the solution The probe s platinum wires must be submerged Turn on the stirring motor 6 Note the LED reading on the Amperometric Titrator It should read 0 00 0 05 DO NOT adjust the BIAS control 7 Using the Digital Titrator delivery knob dispense 100 digits of Standard Iodine Titrant Solution and note the LED reading 95 8 Continue dispensing titrant in 5 10 digit increments while noting the LED reading Record at least 3 points null current values and Digital Titrator reading before the end point is reached After the end point of the titration nominal 160 digits record the increasing LED readings along with the corresponding digits displayed on the Digital Titrator counter Add 5 10 digits of titrant wait a few seconds for a stable reading and record it Stop adding titrant when the LED readings exceed 0 60 Note LED readings above 0 60 will be excessively noisy CHLORINE TOTAL continued 9 Using linear graph paper plot the recorded readings from the Amperometric Titrator on the vertical axis and the corresponding Digital Titrator digits on the horizontal axis Draw the two best intersecting lines through the points plotted See Figure 1 Determine the number of digits at the intersection of the lines This is the standard end point Figure 1 Back Amperometric Titration Graph 10 Record the standard
68. RANTY OF ANY KIND WHATSOEVER WITH RESPECT TO ANY PRODUCTS HACH EXPRESSLY DISCLAIMS ANY WARRANTIES IMPLIED BY LAW INCLUDING BUT NOT BINDING TO ANY WARRANTY OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE LIMITATION OF REMEDIES Hach shall at its option replace or repair nonconforming products or refund all amounts paid by the buyer THIS IS THE EXCLUSIVE REMEDY FOR ANY BREACH OF WARRANTY LIMITATION OF DAMAGES IN NO EVENT SHALL HACH BE LIABLE FOR ANY INCIDENTAL OR CONSEQUENTIAL DAMAGES OF ANY KIND FOR BREACH OF ANY WARRANTY NEGLIGENCE ON THE BASIS OF STRICT LIABILITY OR OTHERWISE This warranty applies only to Hach products purchased and delivered in the United States Catalog descriptions pictures and specification although accurate to the best of our knowledge are not a guarantee or warranty For a complete description of Hach Company s warranty policy request acopy of our Terms and Conditions of Sale for U S Sales from our Customer Service Department 195 HACH COMPANY WORLD HEADQUARTERS P O Box 389 Loveland Colorado 80539 0389 Telephone 970 669 3050 FAX 970 669 2932 FOR TECHNICAL ASSISTANCE PRICE INFORMATION AND ORDERING Inthe U S A Call toll free 800 227 4224 Outside the U S A Contact the HACH office or distributor serving you On the Worldwide Web www hach com E mail techhelp hach com
69. Resume titration back to the same end point Record the number of digits required Repeat using two more additions of 0 1 mL Titrate to the end point after each addition Each 0 1 mL addition of standard should require 10 additional digits of 0 800 N titrant or 100 digits of 0 0800 N titrant 11 digits of 0 714 M or 56 digits of 0 1428 M titrant If these uniform increases do not occur refer to Appendix A Accuracy Check and Standard Additions Some transition and heavy metals complex the indicators and prevent the color change at the end point Adding a 0 5 g scoop of potassium cyanide KCN after the addition of potassium hydroxide removes interference from the following metals at the levels listed in an undiluted 100 mL sample see Table 3 123 HARDNESS CALCIUM continued Table 3 Max Tolerance Max Toerana Metal Level with KCN Level without KCN present Cobalt 20 mg L none Copper 100 mg L 0 10 mg L Nickel 200 mg L 0 5 mg L Zinc 100 mg L 5 mg L Proportionally higher levels of these elements are tolerable in smaller sample sizes since their effect is diluted when bringing the volume to 100 mL Because Tables 1 and 2 have sample volumes of 10 100 mL the interference concentrations may be greater in your sample and have no effect because of sample dilution Iron interferes above 8 mg L in undiluted samples Above this level it causes a red orange to green end point which is sharp and usab
70. S Vial 2 5 10 15 20 25 mL make each 2193 00 Syringe 3 cc Luer lock tip hee ae each 43213 00 Demineralizer Assembly 473 ml each 21846 00 OPTIONAL APPARATUS TitraStir Stir Plate 115 Vac rennen ennt each 19400 00 TitraStir Stir Plate 230 Vac esee nre trennt each 19400 10 162 SULFITE 4 to greater than 400 mg L as SO32 Using Iodate Iodide KR 1 Select a sample volume corresponding to the expected sulfite SO32 concentration from Table 1 2 Insert a clean delivery tube into the Iodate Iodide Titration Cartridge KIO3 KD Attach the cartridge to the titrator body See General Description Step by Step for assembly instructions if 3 Turn the delivery knob to eject a few drops of titrant Reset the counter to zero and wipe the tip Note For added convenience use the TitraStir Stir Plate See General Description Method 8216 4 Use a graduated cylinder or pipet to measure the sample volume from Table 1 Transfer the sample into a clean 125 mL Erlenmeyer flask Dilute to about the 50 mL mark with deionized water en Step 3 in Step by SteP sad unnecessary agitation throughout the procedure Note See Sampling and Storage on page 164 Table 1 Range Sample E Catalog Digit 2 mg L as SO32 Volume mL N KIO Ki Number Multiplier Up to 160 50 0 3998 14961 01 0 4 100 400 20 0 3998 14961 01
71. Stir Stir Plate or a clamp holder and clamp to attach the titrator to a laboratory stand See Figure 4 and Figure 5 The TitraStir Stir Plate holds the Digital Titrator during the titration and also stirs the sample at a constant speed leaving the analyst free to detect the end point When a TitraStir Stir Plate is used substitute or add the following Optional Apparatus APPARATUS Quantity Required Description Per Test Unit Cat No Delivery Tubes 90 with hook for TitraStir Stir Plate Vest S pkg 41578 00 Flask Erlenmeyer 125 ml IRRE NER each 505 43 Flask Erlenmeyer 250 ml rm each 505 46 Stir Bar 28 6 x 7 9 mm rc each 20953 52 TitraStir Stir Plate isaac Lm each 19400 00 TitraStir Stir Plate 230 Vac seen 1 each 19400 10 5 To start titrant flowing and flush the delivery tube hold the tip of the cartridge up Advance the plunger release button to engage the piston with the cartridge push the button in and toward the cartridge Do not expel solution when pushing the piston toward the cartridge Turn the delivery knob until air is expelled and several drops of solution flow from the tip As you turn the knob a drive screw pushes a piston against the cartridge seal and forces liquid out through the delivery tube Then use the counter reset knob to turn the digital counter back to zero and wipe the tip The tip can be rinsed
72. Summary of the Mercuric Nitrate Method When using Mercuric Nitrate Standard Solution the sample is titrated under acid conditions in the presence of diphenylcarbazone indicator Upon addition of a slight excess of mercuric ion a pink purple complex is formed with the indicator signaling the end point Summary of the Silver Nitrate Method The sample is titrated with Silver Nitrate Standard Solution in the presence of potassium chromate from the Chloride 2 Indicator Powder The silver nitrate reacts with the chloride present to produce insoluble white silver chloride After all the chloride has been precipitated the silver ions react with the excess chromate present to form a red brown silver chromate precipitate marking the end point of the titration Request Hach s Water Analysis Handbook Publication 8376 to obtain additional information on chloride determinations 71 CHLORIDE continued REQUIRED REAGENTS FOR THE MERCURIC NITRATE METHOD Description Unit Cat No Mercuric Nitrate Chloride Reagent Set about 100 tests sess 22726 00 Includes 2 836 46 1 921 01 1 14393 01 Diphenylcarbazone Reagent Powder Pillows sess 100 pkg 836 99 Mercuric Nitrate Titration Cartridge 0 2256 N sess each 14393 01 Mercuric Nitrate Titration Cartridge 2 256 N each 921 01 Water Oe besi ou ter et Dai E a ER Herb HUP eI Tae eed 4L uus 272 56 REQUIRED REAGENTS FOR THE SILVER NITRA
73. TE METHOD Silver Nitrate Chloride Reagent Set about 50 tests 22880 00 Includes 2 1057 66 1 14396 01 1 14397 01 Chloride 2 Indicator Powder Pillows eere 50 pkg 1057 66 Silver Nitrate Titration Cartridge 0 2256 N AA each 14396 01 Silver Nitrate Titration Cartridge 1 128 N occ ee serere each 14397 01 Mater CE1OMIZE AAA E taste a ses 272 56 REQUIRED APPARATUS FOR THE MERCURIC NITRATE METHOD AND SILVER NITRATE METHOD Clippers for opening pillows esee each 968 00 Digital Titrator 2 28222 2 ai Be ae each 16900 01 Flask Erlenmeyer Z mmere Ree hte ere ne bett each 505 46 Select one or more based on sample concentration Cylinder graduated 10 mL eene each 508 38 Cylinder graduated 25 mL vivian cat nee aaah Seesen each 508 40 Cylinder graduated 20 ml essent each 508 41 Cylinder graduated 100 mL eene each 508 42 OPTIONAL REAGENTS Chloride Standard Solution 1000 mg L CT esses 500 mL 183 49 Chloride Standard Solution Voluette Ampules 12 500 mg L I 10 mbDE ee sea Re 16 pkg 14250 10 Hydrogen Peroxide 30 AC sse 200 mL 144 45 Sodium Hydroxide Standard Solution 5 0 N 100 mL MDB 2450 32 Sulfide Inhibitor Powder Pillows eee 100 pkg
74. TOTAL continued Sampling and Storage Collect at least 200 mL of sample in a clean glass or polyethylene container Analyze on site or as soon as possible after collection Accuracy Check Standard Additions Method Perform this accuracy check when you suspect interferences or to verify analytical technique 1 Snap the neck off a Chlorine Standard Solution PourRite Ampule Use a TenSette Pipet to add 0 2 mL 0 4 mL and 0 6 mL of standard to three aliquots of sample of the same volume as used in the procedure Analyze each sample as described in the procedure Each 0 2 mL addition of standard should require approximately 10 digits of the titration cartridge solution Check the certificate enclosed with the PourRite Ampules to obtain the exact concentration To determine the exact number of digits required for each 0 2 mL addition multiply the exact concentration times the volume of the addition in mL Example 50 mg L x 0 2 mL 10 digits If these uniform increases do not occur refer to Appendix A Accuracy Check and Standard Additions 81 CHLORINE TOTAL continued Iodometric Method 20 to 70 000 mg L as Cl Using Sodium Thiosulfate y 1 Select the sample 2 Insert a clean 3 Flush the delivery 4 Use a pipet or volume and Sodium delivery tube into the tube by turning the graduated cylinder to Thiosulfate Titration titration cartridge delivery knob to ejecta measure the sample Cartridge corresponding Atta
75. The Chloride Procedure Silver Nitrate Method is used as an example throughout these steps 177 APPENDIX A continued Figure 1 Decision Tree Did a Single Standard Addition Give the Correct Recovery Are Interferences Present Do Multiple Analysis Standard Additions Is Correct On DI Water Give Correct Recovery Interferences Present Is the Procedure in Do Multiple Standard Use Correct Additions On Sample Give Uniform Increments Use Correct Procedure and Repeat B Analysis May be Correct Analysis Is Incorrect Are the Reagents Working Properly Repeat B with New Reagents Repair Replace Standards Defective Instrument Apparatus Repeat B with New and Repeat B Standards 178 APPENDIX A continued Branch B Repeat the Accuracy Check given in the procedure substituting the same volume of deionized water for the sample For example using the Chloride Procedure Silver Nitrate Method 1 Take a 50 0 mL sample of deionized water and follow the Chloride Procedure Silver Nitrate Method Record the number of digits required for the titration 2 Add 0 10 mL of Chloride Standard Solution 12 500 mg L and titrate to the end point Record the number of digits required for the titration 3 Repeat using two more additions of 0 1 mL of 12 500 chloride standard titrating to the end point after each addition Record the number of digits required 4 Tabulat
76. Total Standard Added mL 0 3 mL in the above formula gives 75 mg L total standard added The data shown above reveals several points e The chemicals apparatus procedures and standards are in good working condition This conclusion is made because chloride added to the deionized water sample was recovered entirely in the same uniform steps of addition e Because chloride added to deionized water was recovered but was not recovered during the Accuracy Check one may 180 APPENDIX A continued conclude the sample contains interferences which prevent the test reagents from operating properly e The first analysis of the water sample gave an incorrect result If the above results gave the expected increments between additions proceed to Branch C If the results did not give the expected increments proceed to Branch D Branch C If interfering ions are present it may be concluded the analysis is incorrect However with the completed accuracy check it may be possible to arrive at an approximation of the correct result Tabulate the results as follows Table 3 Total Standard Added mL 0 Total Number of Digits Used Total Standard Added mg L 0 Total Parameter Found mg L II The Total Standard Added mL will vary depending on the procedure used The Total Number of Digits Used are the total digits recorded after each addition of standard as specified in the accurac
77. a colorimetric indicator In this case titrate to pH 7 or to the pH required REQUIRED REAGENTS varies with sample characteristics Description Cat No Acid Determination Reagent Set about 100 tests 1 10 meq L includes 1 942 99 1 14379 01 sese 24459 00 10 4 000 meq L includes 1 942 99 1 14381 01 nennen 24460 00 32 ACID BASE continued REQUIRED REAGENTS continued Description Unit Hydrochloric Acid Titration Cartridge 8 00 N sese each Phenolphthalein Indicator Powder Pillows sees 100 pkg Sodium Hydroxide Titration Cartridge 1 600 N sess each Sodium Hydroxide Titration Cartridge 8 00 N ss each Sulfuric Acid Titration Cartridge 1 600 NA each Sulfuric Acid Titration Cartridge 8 00 N esee each Water delo dius tr ey tare pie eerie eas te e aa AL REQUIRED APPARATUS Digital Tirar io epe E e e dd each Flask Erlenmeyer 250 mL eese eene eren tn ntt noie tnn etur each Select one or more based on sample concentration Cylinder eraduated 5 mL eege eer bete een each Cylinder graduated IO ml essere each Cylinder graduated 23 ml sse ener each Cylinder graduated a0 ml sss each Cylinder graduated 100 ME essere each OPTIONAL REAGENTS Phenolphthalein Indicator Solution 5 ail 100 mL Sodium Hydroxide Standard Solution 0 100 NA 1000 mL Sulfuric Acid Standard S
78. ach 21846 00 Delivery Tubes with 180 hook eene S pkg 17205 00 Delivery Tubes 90 with hook for TitraStir Stir Plate S pkg 41578 00 Hot Plate 3Y inch circular II85N nos each 12067 01 Hot Plate variable control 4 inch circular 230 V esses each 12067 02 Pipet TenSette 0 1 EE EE each 19700 01 Pipet Tips for 19700 01 TenSette Pipet esses 50 pkg 21856 96 Pipet volumetric Class A IO mt eese each 14515 38 Pipet volumetric Class A 20 mt sess each 14515 20 Pipet volumetric Class A 25 mL sese each 14515 40 Pipet volumetric Class A S0O ml essere each 14515 41 Pipet volumetric Class A 100 mL cococcnnoccnonoconocaconnncnonaconnccnnnnonnnnccnnccnnncnnns each 14515 42 Ber Filler safety bulb iie erect erret tees each 14651 00 sension 1 Basic Portable pH Meter with electrode eeee each 51700 10 SUPport Ring Stande rete een ne beten ie as each 563 00 Titrastir Stir Plate 115 TEE each 19400 00 TitraStir Stir Plate 230 Vac esses treten ener each 19400 10 Voluette Ampule Breaker Kit c ccsscsssssssesscsssesssesecscscssseseesssssssesnesssesees each 21968 0 40 ALKALINITY 10 to 4000 mg L as CaCO3 Phenolphthalein and Total Method SI 1 Select the sample volume and Sulfuric Acid H SO Titration
79. amp 2 prong Extension enne eene nnne nennen nen each Clamp Holder att RR each Delivery Tubes with 180 hook eene 5 pkg Delivery Tubes 90 with hook for TitraStir Stir Plate S pkg Pipet TenSette 0 1 to 1 0 mL trennen each Pipet Tips for 19700 01 TenSette Dipet 50 pkg PourRite Ampule Breaker each Support Ring Stan eri egent ertet cent ire ce bes erige each TitraStir Stir Plate 115 Vac rennen each TitraStir Stir Plate 230 Vicio dea each 78 Cat No E 24453 00 Ban 14070 99 E 14064 99 ET 22923 01 ieee 1045 32 Pte hte 1047 32 CHLORINE TOTAL Iodometric Method 1 to 400 mg L as Cl Using Sodium Thiosulfate Method 8209 1 Select the sample volume and Sodium Thiosulfate Titration Cartridge corresponding to the expected chlorine concentration from Table 1 2 Insert a clean delivery tube into the titration cartridge Attach the cartridge to the titrator body See General Description Step by Step for assembly instructions if 3 Flush the delivery tube by turning the delivery knob to eject a few drops of titrant Reset the counter to zero and wipe the tip Note For added convenience use the 4 Use aclean graduated cylinder to take a water sample Pour sample into a clean 125 or 250 mL Erlenmeyer flask Dilute to about the 100 mL mark with deionized necessary TitraStir Stir Plate See Water General Description
80. ampling and Storage on page 158 5 Remove the stopper and add the contents of one Sulfamic Acid Pow der Pillow Replace the stopper without trap ping air in the bottle and invert several times Note The floc will dis solve and leave a yellow color if oxygen is present 2 Add the contents of one Manganous Sulfate Powder Pillow and one Alkaline Iodide Azide Reagent Powder Pillow 3 Immediately insert the stopper so air is not trapped in the bottle In vert several times to mix Note A flocculent precipi tate will form It will be or ange brown if oxygen is present or white if oxygen is absent The floc settles slowly in salt water and normally requires 5 addi tional minutes before pro ceeding to step 5 4 Wait until the floc in the solution has settled Again invert the bottle several times and wait until the floc has settled Note Waiting until floc has settled twice assures complete reaction of the sample and reagents 6 Select a sample volume and Sodium Thiosulfate Titration Cartridge corresponding to the expected dissolved oxygen D O concentration from Table 1 7 Insert a clean delivery tube into the titration cartridge Attach the cartridge to the titrator body See General Description Step by Step for assembly instructions if necessary 155 8 Turn the delivery knob to eject a few drops of titrant Reset the counter to zero and wipe the tip Note For added co
81. and Wastewater 19th edion nnne each 22708 00 Method 10025 For wastewater CHLORINE TOTAL 6 to 1000 ug L as CL Amperometric Back Titration USEPA Accepted for Reporting Phase 1 Adjusting the Electrode Response Slope 1 Assemble the Amperometric Digital Titrator System according to the instructions in the Amperometric Titrator Instruction Manual 2 Install the Standard Iodine Titrant Cartridge 0 028 N Flush the Digital Titrator delivery tube by turning the delivery knob to eject a few drops of titrant Reset the counter to zero and wipe the tip Note When a new probe is used or the probe has not been used recently prepare it according to the Probe Stabilization instructions in the Amperometric Titrator Instruction Manual 3 Using a graduated cylinder measure 200 mL of deionized water into a clean 250 mL beaker Place the 50 mm stirring bar supplied with the system into the beaker Note An improper size stirring bar can result in volatilization of iodine instability of readings and loss of sensitivity 4 Add 1 mL of pH 4 Acetate Buffer and the contents of one Potassium Iodide Pillow Procedure is equivalent to USEPA method 330 2 and Standard Methods for the Examination of Water and Wastewater 17th ed 4500 Cl C for wastewater 93 CHLORINE TOTAL continued 5 Place the beakeron 6 Using the Digital 7 Note the LED 8 Remove the probe the TitraStir Stir Plate Ti
82. ard Solution 5 25 N 100 mL MDB REQUIRED APPARATUS Cylinder graduated poly 100 mt each Delivery Tubes 90 with hook for TitraStir Stir Plate S pkg Digital TitratO usina plo t eat tn Ee Ee pato ien each Flask Erlenmeyer 125 mL eee eee trt eerte each Stir Bar analytical Teflon coated 50 mm each TitraStir Stir Plate 115 Vac voc cececccceccsscecssccsessseceecsesssessecesceaceaeeesesenees each TitraStir Stir Plate 230 Vac rte po Pe E Oe e each OPTIONAL REAGENTS Ee e EE 4L OPTIONAL APPARATUS Clamp 2 prong extension 38 mm eene each Clamp Holdert petere deno a crn e iie re ea co each Clippers shears 7 25 inch ee ea each Delivery Tubes with 180 book 5 pkg Filter paper folded 12 5 CM sse 100 pkg Flask Erlenmeyer 250 mL recette titer roe n eere te eee each Funnel analytical poly 65 mm each 65 Tees 1 Cat No 4577 99 We 24345 01 Ahh 22847 99 2449 32 66 Methods 8206 and 8207 CHLORIDE Mercuric Nitrate and Silver Nitrate Methods Mercuric Nitrate Method 10 to 8000 mg L as CH Method 8206 1 Select the sample 2 Insert aclean 3 Turn the delivery 4 Use a graduated volume and Mercuric delivery tube into the knob to ejectafew drops cylinder or pipet to Nitrate Titration titration cartridge of titrant Reset the measure the sample Cartridge corresponding Attach the cartridge to counter to zero and wipe volume from Table 1 to the expected ch
83. ast three points on the downward sloping curve and at least three points after the end point has been reached The latter points will have little change in the LED readings Digits at x 1 25 End Point ug L Free Clorine as Cl 10 Using linear graph 11 Calculate the ug L paper plot the recorded free chlorine P Digits at End Point x 1 25 Amperometric Titrator ug L free chlorine as on the vertical axis and Cl the corresponding Digital Titrator digits on the horizontal axis Draw the two best intersecting lines through the points see Figure 1 Determine the number of digits at the intersection of the lines this is the end point Figure 1 Sample Plot Meter Reading Digits 89 CHLORINE FREE continued Accuracy Check Standard Additions Method 1 Snap the top off a Chlorine Standard Solution PourRite Ampule Note the certificate value of the standard in mg L Split a fresh sample into two 200 mL portions Using a TenSette Pipet add from 0 1 to 0 5 mL of the standard to one portion and swirl to mix This is the spiked sample 4 Analyze both the sample and spiked sample and record the chlorine concentration of each 5 Calculate the theoretical concentration of the spiked sample Cy x Vy Cs x Vg Theoretical concentration L 4 8 8 V V u s Where Cu measured concentration of sample in mg L ug L divided by 1000 Vy volume of sample in mL C conce
84. centration is equivalent to one digit of 0 0282 N Standard Iodine Titrant Solution or approximately 6 ug L chlorine e Silver ions poison the electrode Copper ions interfere Interferences are sometimes found in highly turbid water and those containing surface active agents Oxidized manganese and other oxidizing reagents give positive interferences e Some uncertainty in the end point may be observed with samples containing high organic content e Iron and nitrite interference are minimized by buffering to pH 4 before adding potassium iodide 101 CHLORINE TOTAL continued e In samples containing excess reducing agents such as sulfur dioxide sulfite and bisulfite the titration end point will be shifted indicating the sample contains no free or combined chlorine Highly buffered samples or extreme sample pH may exceed the buffering capacity of the buffer reagent If necessary add additional buffer and check the pH of the sample prior to titration Summary of Method The back titration procedure minimizes errors caused by liberating the full concentration of iodine in the sample and is the preferred method for amperometric measurement for total chlorine in wastewaters In the back titration procedure the end point signal is reversed because the remaining thiosulfate or phenylarsine oxide added to the sample is titrated with standard iodine The end point of the back titration is reached just when free iodine e
85. cess PAO titrant is added The end point is defined when no change in current occurs signaling all free chlorine has been reacted REQUIRED REAGENTS Description Unit Cat No Phenylarsine Oxide Solution 0 00564 N Digital Titrator Cartridge each 1999 01 Phosphate Buffer Solution pH 7 eere 100 mL MDB 21553 32 REQUIRED APPARATUS Amperometric Titrator Assembly sese each 19299 00 Digital Fitrator ipe teer tt b doe etae tenere each 16900 01 Beaker lowsform 250 mE ee san each 500 46 Cylinder graduated 250 ml each 508 46 Delivery Tubes 90 with hook esee 5 pkg 41578 00 Probe Assembly Amperometric Titrator eee each 19390 00 Stir Bar octagonal Teflon coated 50 8 x 7 9 MM sss each 20953 55 TitraStir Stir Plate 115 Vac remet each 19400 00 TitraStir Stir Plate 230 AAA E ve oda ee each 19400 10 OPTIONAL REAGENTS Chlorine Standard Solution PourRite Ampules ITA A retenir detta is 20 pkg 14268 20 Water deionized 2 nott Deet AE Dita reb etre Ferr b e rebas osi d Seege AE ZE stater 272 56 OPTIONAL APPARATUS Pipet TenSette 0 1 to 1 0 ML AAA ies a ete each 19700 01 Pipet Tips for 19700 01 TenSette Dipet ENEE 50 pkg 21856 96 PourRite Ampule Breaker eene ene each 24846 00 Standard Methods for the Examination of Water
86. ch the cartridge to few drops of titrant volume from Table 2 to the expected chlorine the titrator body See Reset the counter to zero Transfer the sample into concentration from General Description and wipe the tip a 125 mL Erlenmeyer Table 2 Step by Step for l Note For added flask and dilute to about assembly instructions convenience use the the 50 mL mark with if necessary TirtaStir stirring deionized water apparatus See General Description Step 3 of Step by Step Table 2 Range Sample se Catalog Digit mg L Cl Volume mL N Na5S 04 Number Multiplier 20 80 25 0 113 22673 01 0 2 50 200 10 0 113 22673 01 0 5 100 400 5 0 113 22673 01 1 250 1000 2 0 113 22673 01 2 5 500 2000 1 0 113 22673 01 5 2000 9000 4 2 00 14401 01 22 2 0 2 0 9 5000 18 000 2 2 00 14401 01 44 3 0 5 1 8 10 000 35 000 1 2 00 14401 01 88 7 1 0 3 5 20 000 70 000 0 5 2 00 14401 01 177 2 0 7 0 82 CHLORINE TOTAL continued 5 Add the contents of one Dissolved Oxygen 3 Powder Pillow 7 Place the delivery tube tip into the solution and swirl the flask while titrating with sodium thiosulfate until the solution is a pale yellow 6 If you are using the 2 00 N titration cartridge add the contents of one Potassium Iodide Powder Pillow Cat No 20599 96 to the flask and swirl to mix Note Normally the addition of the powder pillow will lower the pH to 4 or less If the sample size is large and high
87. complete the table the following calculations were made based on the above formula First Addition 21 x 12 500 Total Standard Added mg L 25 mg L Second Addition 0 1 0 1 0 2 mL Total Standard Added mL 0 2 mL in the above formula gives 50 mg L Total Standard Added Third Addition 0 1 0 1 0 1 0 3 mL Total Standard Added mL 0 3 mL in the above formula gives 75 mg L Total Standard Added 182 APPENDIX A continued Branch D Carefully check the instructions or directions for use of the procedure making sure the proper techniques reagents titrant sample volume and digit multiplier were used Verify there is no air or liquid other than the titrant being used in the delivery tube by ejecting several drops of solution If the procedure in use is found to be in error repeat Branch B using the correct procedure If the procedure is found to be correct proceed to Branch E Branch E Check the performance of the reagents This may be done easily by using a known standard solution to run the test or by obtaining a new fresh lot of the reagent A list of known standard solutions is given in Table 1 on page 20 If it is determined reagents are defective repeat Branch B with new reagents If the reagents are proven in good condition proceed with Branch H Branch F Examples of non uniform increments between standard additions on a sample are shown below in Table 5 Table 6 and Figure 2 on page 186 These plots illu
88. cted digits equal the volume of standard times the concentration on the certificate e g 2 mL x 50 mg L 100 digits The expected digits equals the volume of standard times the concentration on the certificate times the constant 4 Example 0 5 mL x 50 mg L x 4 100 digits Add one Sulfamic Acid Powder Pillow to the volume of standard and follow Steps 10 to 12 in the Dissolved Oxygen Procedure It is not necessary to add the first two reagents 21 GENERAL DESCRIPTION continued 1 4 Adapting a Buret Titration to the Digital Titrator Adapt any standard titration procedure using a buret to the Digital Titrator by using the following procedure 1 Determine the approximate number of digits required The Digital Titrator dispenses 1 mL per 800 digits on the counter Using the following equation determine the digits required for your buret method N x mL x 800 Nc Digits Required Where N Normality of buret titrant mL milliliters of buret titrant required for an average titration N Normality of Digital Titrator cartridge 2 Ifthe number of digits required is within the range of 70 to 350 you can use the procedure as written substituting the Digital Titrator directly for the buret Or if the number of digits is outside of this range make the following modifications a Ifthe number of digits required is more than 350 reduce the sample size to save titrant b Ifthe number of digits required is l
89. cylinder or pipet to measure the sample volume from Table 1 Transfer the sample into a clean 250 mL Erlenmeyer flask Dilute to about the 100 mL mark with deionized water if necessary ACID BASE continued Sampling and Storage Accuracy Check Interferences Summary of Method Collect samples in clean plastic or glass bottles Fill completely and cap tightly Minimize agitation or prolonged exposure to air Sample may be stored at least 24 hours by cooling to 4 C 39 F or below if they cannot be analyzed immediately Warm to room temperature before analyzing Using a clean Class A 20 00 mL pipet transfer 20 00 mL 0 100 N NaOH Standard Solution for base determination or 20 00 mL 0 100 N Sulfuric Acid Standard Solution for acid determination to a clean 250 mL Erlenmeyer flask Dilute to about 100 mL with deionized water Follow the procedure for base determination using 8 00 N HCl or H SO Titration Cartridge or for acid determination using 8 00 N NaOH Titration Cartridge About 200 digits of titrant should be required Highly colored or turbid samples may mask the color change at the end point Use a pH meter for these samples A measured amount of sample is treated with a colorimetric indicator and then titrated with a strong acid or base The amount of titrant used is directly proportional to the milliequivalents of acid or base in the sample These titrations also can be performed using a pH meter instead of
90. d 155 Using a 300 ME BOD Bottle rere nen ni 155 Using 4 60 mL BOD B ottle teet ette rene eerie enean 157 SALINITY Using Mercurie Nitrate so ee aee rt e et pe Rn 161 SULFITE Using Tod te lodide cir ai 208 208 dd EE RR 163 TURBIDITY STANDARDS Preparing Turbidity Free Water AA 167 VOLATILE ACIDS Using Sodium Hydroxide etii eet ia Ree P een 173 APPENDIX A ACCURACY CHECK AND STANDARD ADDITIONS eee 177 GENERAL INFORMATION 189 REPLACEMENT PARTS AND ACCESSORIES eese nee 191 HOW TO ORDER ics 5 20 a 193 REPAIR SERVICE inter tia ote et e iens 194 KE EK EE 195 SPECIFICATIONS Digital Titrator Delivery 800 digits mL or 0 00125 mL digit Accuracy 1 for readings over 100 digits Uncertainty of readings is 1 digit Most samples require more than 100 digits Weight 132 g 4 7 oz Cartridges for the Digital Titrator Volume 13 mL Number of tests Most reagents are formulated to provide 100 typical titrations the number may vary depending on sample concentration Weight full 56 75 g 2 oz Overall method accuracy includes in addition to the Digital Titrator other sources of error controlled by the analyst The other sources of error include sampling sample volume dilution if required end point detection reagent quality and interferences OPERATION DANGER Handling chemical samples standards and reagents can be dangerous Review the necessary
91. d Standard Methods 17th ed 4500 Cl D for wastewater 105 CHLORINE TOTAL continued 5 Add 1 mL of pH 4 Acetate Buffer Solution 6 Place the beaker on the TitraStir Stir Plate and immerse the tips of the probe and delivery tube in the solution The probe s platinum wires must be submerged Turn on the stirring motor 7 Note the LED reading on the Amperometric Titrator Unlock the BIAS control and adjust the BIAS control knob until a reading between 0 50 0 60 is obtained Lock the BIAS control Note The bias adjustment controls the slope of the titration curve The actual instrument reading is not important but rather the change in the readings as the titration proceeds The adjustment need not be precise 106 8 Using the Digital Titrator delivery knob dispense the PAO titrant Solution in 5 10 digit increments while noting the downward reading Note If the chlorine content of the sample is high add titrant at a faster rate only the end point of the titration and the volume of titrant used at the end point are of concern For example if the chlorine content is approximately 500 ug L up to 300 digits of 0 00564 N PAO could be added at once As the end point is approached dispense in small increments Note If excess reductant such as sulfite bisulfite or sulfur dioxide is present in the sample the LED readings will not decrease and may even increase This indicates that no
92. d when interferences are suspected or to verify analytical technique 1 Use a TenSette Pipet to add 0 1 mL 0 2 mL and 0 3 mL of Hexavalent Chromium Standard Solution 1000 mg L to three samples of the same volume as that titrated in the procedure 2 Analyze each as described in the procedure 3 Each 0 1 mL addition of standard should require 22 additional digits of titrant If these uniform increases do not occur refer to Appendix A Accuracy Check and Standard Additions Standard Preparation Interferences Summary of Method A standard solution equivalent to 67 mg L chromate 30 mg L Cr can be prepared by diluting 3 0 mL of Hexavalent Chromium Standard Solution 1000 mg L Cr to 100 mL in a volumetric flask Titrate a 20 mL or 50 mL sample as described in the procedure Substances capable of oxidizing iodide to iodine under acidic conditions such as ferric iron and copper will interfere to give high results The effects of iron and copper may be masked by dissolving a Magnesium CDTA Powder Pillow followed by two 1 0 gram measuring spoons of Sodium Acetate in the sample between steps 6 and 7 Chromate in the sample reacts with iodide under acidic conditions to form iodine as triiodide Addition of starch 115 CHROMATE continued indicator produces a blue color complex with the iodine This complex is titrated with sodium thiosulfate to a colorless end point The volume of titrant used is proportional to the chro
93. dd Magnesium Chloride cartridge tip pointing up 100 mL of sample intoa 2 mL of Hardness 1 Titration Cartridge Turn the delivery knob 125 mL Erlenmeyer Buffer Solution to the Attach the cartridge to until a few drops of flask flask and swirl to mix the titrator body See titrant are expelled T s Note Filter sample if General Description Reset the counter to zero necessary If sample is Step By Step for and wipe the tip boiler water or highly assembly instructions Note For added dat refer p convenience use the eege TitraSti Stir Plate See 1ese steps General Description Step 3 in Step by Step 59 CHELANT FREE continued Digits Digit Required Multiplier mg L as CaCO Free Chelant 5 Add the contents of 6 Place the delivery 7 Calculate one ManVer 2 tube tip into the solution _ M Digits Required x 0 10 Hardness Indicator While swirling the flask mg L Free Chelant Powder Pillow to the titrate until a red violet as CaCOs flask and swirl to mix If color appears Record S the solution turns blue the number of digits Note The results may be free chelant is present required expressed as mg L tetra sodium EDTA digits required x 0 38 mg L as Nag EDTA Proceed to step 6 If the solution turns red a deficiency of chelant exists Note Four drops of ManVer Hardness Indicator Solution or a 0 1 g scoop of ManVer 2 Hardness Indicator Powder may be substituted in this step
94. dd from 0 1 to 0 5 mL of the standard to one portion and swirl to mix This is the spiked sample 4 Analyze both the sample and spiked sample and record the concentration of each 5 Calculate the theoretical concentration of the spiked sample C EV C X WO Theoretical concentration 1 2 V V u s Where Cu measured concentration of sample in mg L ug L divided by 1000 Vy volume of sample in mL C concentration of chlorine standard mg L certificate value Vs volume of standard added in mL 6 Calculate the percent spiked recovery PET 8 Spiked sample result in mg L Bene Recovery E Theoretical concentration calculated in mg L SES Example Sample result C 120 ug L or 0 120 mg L Spiked sample result 185 ug L or 0 185 mg L Volume Sample V 200 mL Volume Standard V 0 2 mL Chlorine Standard C 68 1 mg L The standard additions technique is not applicable for samples containing excess reducing agents such as sulfur dioxide sulfite or bisulfite 108 CHLORINE TOTAL continued Precision Detection Limit ion _ 0 120 x 200 68 1 x 0 2 _ Theoretical concentration 200 402 0 188 mg L Ideally the percent recovery should be 10046 Generally results from 80 120 recovery are considered acceptable In a single laboratory using a standard solution of 347 ug L chlorine a single operator obtained a standard deviation of x 32 ug L chlorine With good operator techni
95. delivery tube to the 4000 one minute to mix the formazin suspension 3 Flush the delivery tube by turning the NTU Formazin delivery knob until a few Cartridge Cut the drops of formazin are hooked end off the ejected from the tube delivery tube with clippers Attach the cartridge to the titrator body See General Description Step by Step for assembly instructions if Zero the counter and wipe the tip Note For added convenience use the TitraStir Stir Plate See General Description Step 3 in Step by Step See Table 1 4 Select the standard concentration from the list below Dispense the formazin into a clean Class A volumetric flask Dilute with turbidity free water to the mark and mix well Refer to the table below for the standard s you require necessary Table 1 Formazin Standard Number of Digits Flask Size Concentration NTU Required 100 1000 50 mL 40 400 50 mL 10 100 50 mL 4 80 100 mL 168 TURBIDITY STANDARDS continued Prepararation of a 1 NTU Formazin Standard There will be a residual amount of turbidity in even the purest water used to make formazin dilutions At the 1 NTU level this can affect the value of the formazin standard significantly causing a positive error The following procedure corrects for the turbidity of the dilution water when making a 1 NTU formazin standard in a 500 mL Class A volumetric flask 1 Standardize the turbidimeter w
96. e EDTA then removes the calcium complexed with the indicator causing a color change to blue REQUIRED REAGENTS Description Unit Cat No Calcium Hardness Reagent Sets about 100 tests 1 16 G d h includes 1 282 32 1 852 99 1 14960 01 sss 24473 00 10 100 G d h includes 1 282 32 1 852 99 1 14959 01 sess 24474 00 10 160 mg L includes 1 282 32 1 852 99 1 14364 01 sss 24472 00 100 4 000 mg L includes 1 282 32 1 852 99 1 14399 01 24475 00 CalVer 2 Indicator Powder Pillows neneneennnnne 100 pkg 852 99 Potassium Hydroxide Standard Solution 8 00 N 100 mL MDB 282 32 Water delo iuris niente A4 A 272 56 Select one or more based on sample concentration EDTA Titration Cartridge 0 0800 M A each 14364 01 EDTA Titration Cartridge 0 1428 M A each 14960 01 EDTA Titration Cartridge 0 714 NM each 14959 01 EDTA Titration Cartridge 0 800 M sese each 14399 01 REQUIRED APPARATUS Digital Titratot 2 2 0 2 ee eet ated each 16900 01 Flask Erlenmeyer 250 ml each 505 46 Select one or more based on sample concentration Cylinder graduated 10 ml each 508 38 Cylinder graduated 25 ml each 508 40 Cylinder graduated 50 ml each 508 41 Cylinder graduated
97. e based on sample volume Cylinder graduated 100 mL poly eee each 1081 42 Pipet serological Jm Een edd ee 25 pkg 2093 1 28 REQUIRED APPARATUS Using Titrastir Stir Plate Modification Delivery Tubes 90 with hook essere 5 pkg 41578 00 Digital Titrator isidro eit eot each 16900 01 Flask Erlenmeyer 125 Mii litiasis each 505 43 Stir Bar octagonal Teflon coated 50 8 x 7 9 MM sssssssssssssesssssesssersssessses each 20953 55 TitraStir Stir Plate 115 Vegas ale each 19400 00 TitraStir Stir EA each 19400 10 OPTIONAL REAGENTS Sodium Thiosulfate Titration Cartridge 0 200 NN each 22675 01 SodiumiNitrite ACS ases etes teer eis 454 g 2452 01 Sulfuric Acid Standard Solution 19 2 N sese 100 mL 2038 32 Mater tere EE dI oss 272 56 OPTIONAL APPARATUS Balance electronic analytical essen each 22310 00 Flask volumetric Class A 50 mt each 14547 41 154 Methods 8215 and 8332 OXYGEN DISSOLVED 1 to greater than 10 mg L as DO Azide Modification of Winkler Method Using a 300 mL BOD Bottle Method 8215 URB I 1 Collect a water sample in a clean 300 mL BOD Bottle Note Allow the sample to overflow the bottle for 2 8 minutes to ensure air bubbles are not trapped Note If samples cannot be analyzed immediately see S
98. e the date as shown below Table 1 Total Parameter Found mg L Total Standard Total Number Total Standard Added mL of Digits Used Added mg L 0 0 1 0 2 0 3 0 Wi The Total Standard Added mL will vary depending on the procedure used The Total Number of Digits Used are the total digits recorded after each titration The Total Standard Added mg L is determined for each addition by the following equation Total Standard Added mL Sample Volume mL x Standard Concentration mg L Total Standard Added mg L The Total Parameter Found mg L is determined by following the calculation step of the procedure used Use the same volume of 179 APPENDIX A continued deionized water as used for the sample The addition of standard will not change the digit multiplier Performing the above procedure the completed table would look like this Table 2 Total Total Standard Total Number Total Standard Parameter Added mL of Digits Used Added mg L Found mg L 0 0 0 0 0 1 25 25 23 0 2 50 50 50 0 3 75 75 75 To complete the table the following calculations were made based on the above formula First Addition 24 x 12 500 Total Standard Added mg L 25 mg L Second Addition 0 14 0 1 0 2 mL Total Standard Added mL 0 2 mL in the above formula gives 50 mg L total standard added Third Addition 0 1 4 0 1 4 0 1 0 3 mL
99. each Flask Erlenmeyer 2230 ml esses eese eere nnne terere enne each Select one or more based on sample concentration Cylinder graduated 10 ML ieiipnntiinieneste ii EEE s each Cylinder graduated 25 Moi een A each Cylinder graduated 50 mL essent each Cylinder graduated 100 mL eese each OPTIONAL REAGENTS Alkalinity Standard Solution Voluette Ampules 0 500 N Na5C O3 TO Maca o aUe ia 16 pkg Bromcresol Green Methyl Red Indicator Solution 100 mL MDB Bromphenol Blue Indicator Solution esses 100 mL MDB Bromphenol Blue Powder Pillows eee 100 pkg Buffer Powder Pillows pH 3 7 eene 25 pkg Buffer Powder Pillows pH 4 5 eese 25 pkg Buffer Powder Pillows pH AN 25 pkg Buffer Powder Pillows pH 5 1 eere 25 pkg Buffer Powder Pillows pH 8 3 eene 25 pkg Methyl Purple Indicator Solution eese 100 mL MDB Phenolphthalein Indicator Solution 5 g L 100 mL MDB Sodium Thiosulfate Standard Solution 0 1 N 100 mL MDB Contact Hach for larger sizes 47 Cat No i 14278 10 Aus 23292 32 diced 14552 32 ERES 14550 99 ALKALINITY continued OPTIONAL APPARATUS Description Unit Cat No Bottle wash poly 500 ME soniri n a a each 620 11 Clamp 2 prong extension
100. ected total Attach the cartridge to counter to zero and wipe volume from Table 1 or hardness as calcium the titrator body See the tip Table 2 Transfer the carbonate CaCO3 General Description Note For added sample into a clean concentration Step by Step for conveniente use the 250 mL Erlenmeyer Use Table 1 for assembly instructions TitraStir Stir Plate See flask Dilute to about the concentrations in if necessary General Description 100 mL mark with mg L or Table 2 for Step 3 in Step by Step deionized water concentrations in if necessary German degrees of hardness G d h Note One German degree hardness equals 17 9 mg L hardness as CaCOs Note Collect at least 100 mL of sample in a glass or polyethylene container Samples may be held up to seven days before analysis if stored at 4 C and acidified to pH 2 with concentrated nitric acid Neutralize acidified sample to pH 7 with ammonium hydroxide before testing 127 HARDNESS TOTAL continued 5 Add2 mL of Hardness 1 Buffer Solution and swirl to mix 6 Add the contents of one ManVer 2 Hardness Indicator Powder Pillow Cat No 851 99 and swirl to mix Note Four drops of 7 Place the delivery tube tip into the solution and swirl the flask while titrating with EDTA from red to pure blue Record the number of digits required TotalDigits Digit Required Multiplier mg L Total Hardness as CaCO 8 Use one of the fol lo
101. eeeeeeeree nemen enne each 19400 00 TitraSur Stir Plate AAA A kein each 19400 10 171 172 VOLATILE ACIDS Using Sodium Hydroxide 1 Distill the sample and collect 150 mL of distillate Note Use the Volatile Acids Procedure Sample Distillation accompanying the General Purpose Distillation Apparatus Set or the distillation procedure described in Standard Methods for the Y 2 Attach a clean delivery tube to a 0 9274 N Sodium Hydroxide titration cartridge Attach the cartridge to the titrator body See General Description Step by Step for assembly instructions if 3 Flush the delivery tube by turning the delivery knob to eject a few drops of titrant Reset the counter to zero and wipe the tip Note For added convenience use the TitraStir Stir Plate See General Description Step Method 8218 4 Select the distillate volume corresponding to the expected volatile acids concentration as acetic acid from Table 1 Using a graduated cylinder transfer the distillate volume into a clean 250 mL Erlenmeyer flask and Examination of Water and Cessaty 3 in Step by Step dilute to about the Wastewater 150 mL mark with deionized water Table 1 Range Volume eae Catalog Digit mg L as CH COOH mL N NaOH Number Multiplier 100 400 150 0 9274 14842 01 1 200 800 75 0 9274 14842 01 2 600 2400 25 0 9274 14842 01 6 173 VOLATILE ACIDS continued
102. eject a few drops of titrant Reset the counter to zero and wipe the tip Note For added convenience use the TitraStir Stir Plate See General Description Step 3 in Step by Step Digit Multiplier Digits Required Milliequivalents L of Acid 7 Calculate Digits Required x Digits Multiplier Milliequivalents per Liter of Acid Note To determine the normality of the sample divide the milliequivalents per liter obtained by 1000 29 Method 8200 4 Use a graduated cylinder or pipet to measure the sample volume from Table 1 Transfer the sample into a clean 250 mL Erlenmeyer flask Dilute to about the 100 mL mark with deionized water if necessary ACID BASE continued Table 1 Sample Titration Catalog Digit Range meg E Range N Volume mL Cartridge Number Multiplier 1 4 0 001 0 004 100 1 6 N NaOH 14379 01 0 02 1 6 N H2SO4 14389 01 4 10 0 004 0 01 50 1 6 N NaOH 14379 01 0 04 1 6 N H2SO4 14389 01 10 40 0 01 0 04 100 8 N NaOH 14381 01 0 1 8 N H2SO4 14391 01 8 N HCI 14390 01 20 80 0 02 0 08 50 8 N NaOH 14381 01 0 2 8 N H2SO4 14391 01 8 N HCI 14390 01 50 200 0 05 0 2 20 8 N NaOH 14381 01 0 5 8 N H2SO4 14391 01 8 N HCI 14390 01 100 400 0 1 0 4 10 8 N NaOH 14381 01 1 0 8 N H2SO 14391 01 8 N HCI 14390 01 200 800 0 2 0 8 5 8 N NaOH 14381 01 2 0 8 N H2SO 14391 01 8 N HCI 14390 01 500 2000 0 5 2 2 8 N NaOH 14381 01 5 0 8 N H2SO4 14391 01 8 N HCI 14390 01 1000 4000 1 4 1
103. end point digits value This value will be used in calculation of the sample chlorine concentration Note The iodine titrant concentration is approximately 0 0282 N which relates to 160 digits needed to titrate 1 00 mL of 0 00564 N Thiosulfate If the calculated end point is greater than 160 digits this indicates the Standard lodine Titrant is weaker than when packaged Discard the Standard lodine Titrant cartridge if the calculated standardization end point is greater than 200 digits 40 35 w gt NO a Meter Reading o oa 8 o 140 Table 1 11 Locate the appropriate multiplier based on the standard end point in Table 1 on page 99 The multiplier is used in Phase 3 Titration of Sample for Total Residual Chlorine Interpolation between values in the table is not necessary End Point 150 160 170 180 190 200 Digits 96 CHLORINE TOTAL continued Phase 3 Titration of Sample for Total Residual Chlorine 1 Set up the Amperometric Digital Titrator System as in Phase 1 Adjusting the Electrode Response Slope if it has not already been done Reset the Digital Titrator counter to zero and wipe the tip 2 Place aclean 50 mm stirring bar supplied with the system into a clean 250 mL beaker Using a Class A pipet transfer 1 00 mL of 0 00564 N Sodium Thiosulfate Solution to the a beaker Add 1 mL of pH 4 Acetate Buffer Solution to the bea
104. er of digits required Sampling and Storage Collect at least 100 to 200 mL of sample in a clean glass or polyethylene container Samples may be stored up to 7 days before analysis Digit Multiplier Digits Required x mg L Chloride 7 Calculate Digits Required x Digit Multiplier mg L Chloride Note Results may be expressed as mg L sodium chloride by multiplying the mg L chloride by 1 65 Note meq L Chloride mg L CF 35 45 69 CHLORIDE continued Accuracy Check Standard Additions Method This accuracy check should be performed when interferences are suspected or to verify analytical technique 1 Snap the neck off a Chloride Standard Solution Voluette Ampule 12 500 mg L CH Use a TenSette Pipet to add 0 1 mL of standard to the sample after titration in step 6 Resume titration back to the same end point Record the number of digits required Repeat using additions of 0 2 and 0 3 mL Titrate to the end point after each addition Each 0 1 mL addition of standard should require 12 5 additional digits of 2 256 N titrant 25 digits of 1 128 N titrant or 125 digits of 0 2256 N titrant If these uniform increases do not occur refer to Appendix A Accuracy Check and Standard Additions Interferences Using the Mercuric Nitrate Method Chromate ferric iron and sulfite in excess of 10 mg L interfere with this method Eliminate sulfite interference by adding three drops of hydro
105. esium Chlotride 1t ee eere enlarge 59 CHELANT TOTAL Using Bism th Nitr te notando a a ete 63 TABLE OF CONTENTS continued CHLORIDE Mercurie Nitrate Method SES ideada 67 silver Nitrate Method eee een aa 68 CHLORINE FREE AND TOTAL DPD FEAS Method sauce A ER E E E E T a 75 CHLORINE TOTAL Iodometric Method 1 to 400 mg L as Cl Using Sodium Thiosulfate s 79 Iodometric Method 20 to 70 000 mg L as Cl Using Sodium Thiosulfate 82 CHLORINE FREE Amperometric Forward Titration eene nennen nennen enne 87 CHLORINE TOTAL Amperometric Back Titration eis ge alee esent ee eee 93 CHLORINE TOTAL Amperometric Forward Titration eseeseeeseeeeeeeeeeee eene nennen nenne eren eren 105 CHROMATE Using Sodium Thiosulfate i ii mee Ra Ei obe cies 113 HARDNESS DECISION TREE 3 aha HP AER 119 HARDNESS CALCIUM Using EDTA ett tete Ada teet ticks to e E IER di s EOD elit 121 HARDNESS TOTAL Using EDTA ui ada tna 127 HARDNESS TOTAL SEQUENTIAL Sequential Titration Procedure Limited Sample eee 135 HYPOCHLORITE Bleach Iodometric Method imita a atlas 143 IRON Using the Titra Ver Titration Cartridge nu ae aa 147 NITRITE Using Ceric Standard Solution a e eene eene nennen i tenis 151 TABLE OF CONTENTS continued OXYGEN DISSOLVED Azide Modification of Winkler Metho
106. ess than 70 increase the sample size to increase precision c Ifthe sample size is altered adjust the amount of buffering or indicating reagents by the same proportion 3 Whenusing the Digital Titrator for your buret method note the number of digits required for a sample titration To convert the digits required to the equivalent number of milliliters if the buret method was used calculate Nc Equivalent Buret Milliliters Digits Required x 800 x N If the sample size was changed adjust the equivalent buret milliliters accordingly If the sample size was increased reduce the equivalent buret milliliters if the sample size was reduced increase the equivalent buret milliliters Multiply the equivalent 22 GENERAL DESCRIPTION continued buret milliliters by any normally used factors to calculate concentration in oz gal g L etc Example Adapt a buret procedure which normally requires about 20 mL of a 0 4 N titrant to the Digital Titrator Try an 8 0 N titration cartridge The first equation above gives Digits Required gt 800 digits Because this would use excessive titrant reduce the sample size to one fourth its normal size to reduce the digits required to 200 well within the recommended range Upon completion of the titration using the smaller sample size calculate the equivalent buret milliliters by the second equation above If 205 were the digits required 205 x 8 0 ET e Multiply the 5 13 mL by 4 t
107. f an error made in the standard addition and the analysis should be repeated with a fresh portion of sample The two examples illustrate chemical interferences which most certainly mean the result of the first analysis of the water sample was incorrect When this type of interference is encountered review the Interference section for the procedure for corrective steps If this fails the analyst should attempt to analyze the sample with an alternate method which if possible uses a different type of chemistry Branch G Examples of uniform increments between standard additions on a sample are shown below in Table 7 and Table 8 on page 185 These plots illustrate the effect of interferences upon the standard addition and upon substances in the sample The plots were made by graphing the Total Standard Added mg L on the X axis and the Total Parameter Found mg L on the Y axis as shown in Figure 2 on page 186 Table 7 Plot C Total Total Standard Total Number Total Standard Parameter Added mL of Digits Used Added mg L Found mg L 0 50 0 50 0 1 63 25 BS 0 2 75 50 iS 0 3 88 75 3e 184 APPENDIX A continued Plot C illustrates a common interference with a uniform effect upon the standard and the substances in the sample The four data points form a straight line but the titration increments between the additions is not correct The straight line between the additions may be extrapolated back through
108. f titrant Reset the the tip Note For added counter to zero and wipe convenience use the TitraStir Stir Plate See Method 8205 mn 4 Collect a water sample directly into the titration flask by filling to the appropriate mark Note Minimize agitation because carbon dioxide may be lost Note For most accurate p necessary General Description Note See Sampling and Step 3 in Step by Step results check the calibration of the Erlenmeyer flask by measuring the proper volume in a graduated cylinder Mark the proper volume on the flask with a permanent marker Table 1 Range Sample es Catalog Digit mg L as CO Volume mL N NaOH Number Multiplier 10 50 200 0 3636 14378 01 0 1 20 100 100 0 3636 14378 01 0 2 100 400 200 3 636 14380 01 1 0 200 1000 100 3 636 14380 01 2 0 55 CARBON DIOXIDE continued 5 Add the contents of one Phenolphthalein Indicator Powder Pillow and mix Note Four drops of Phenolphthalein Indicator Solution may be Digits Required Digit Multiplier x mg L as CO 6 Place the delivery 7 Calculate tube tip into the soluti UAS ME TIA or Digits Required x and swirl the flask Digit Multiplier mg L as gently while titrating co2 with sodium hydroxide from colorless to a light pink color that persists substituted for the for 30 seconds Record Phenolphthalein Indicator the number of digits Powder Pillow required Note
109. gen peroxide 30 in step 4 Remove sulfide interference by adding the contents of one Sulfide Inhibitor Reagent Powder Pillow to about 125 mL of sample mixing for one minute and filtering through a folded filter paper Iodide and bromide interfere directly and titrate as chloride Neutralize strongly alkaline or acid samples to a pH of 2 to 7 with 5 25 N Sulfuric Acid Standard Solution or 5 0 N Sodium Hydroxide Standard Solution Determine the amount of acid or base necessary in a separate sample because pH electrodes will introduce chloride into the sample 70 CHLORIDE continued Interferences Using the Silver Nitrate Method Iron in excess of 10 mg L masks the end point e Orthophosphate in excess of 25 mg L will precipitate the silver e Sulfite in excess of 10 mg L interferes Eliminate sulfite interference by adding three drops of 3096 hydrogen peroxide in step 4 Remove sulfide interference by adding the contents of one Sulfide Inhibitor Reagent Powder Pillow to about 125 mL of sample mixing for one minute and filtering through a folded filter paper Cyanide iodide and bromide interfere directly and titrate as chloride e Neutralize strongly alkaline or acid samples to a pH of 2 to 7 with 5 25 N Sulfuric Acid Standard Solution or 5 0 N Sodium Hydroxide Standard Solution Determine the amount of acid or base necessary in a separate sample because pH electrodes will introduce chloride into the sample
110. he end point 131 HARDNESS TOTAL continued REQUIRED REAGENTS Description Unit Total Hardness Reagent Sets about 100 tests 1 16 G d h includes 1 424 32 1 851 99 1 14960 01 10 100 G d h includes 1 424 32 1 851 99 1 14959 01 10 160 mg L includes 1 424 32 1 851 99 1 14364 01 100 4 000 mg L includes 1 424 32 1 851 99 1 14399 01 Hardness 1 Buffer Solunon irenetsiistirercrssenors sinite siiiis senese 100 mL MDB ManVer 2 Hardness Indicator Powder Pillow sess 100 pkg KENE ee DE 4L Select one or more based on sample concentration EDTA Titration Cartridge 0 0800 M A each EDTA Titration Cartridge 0 1428 M A each EDTA Titration Cartridge 0 714 NM each EDTA Titration Cartridge 0 800 M A each REQUIRED APPARATUS Digital Titrator en an en Rn each Flask Erlenmeyer 250 mL elei esee eee eene entente ernannt each Select one or more based on sample concentration Cylinder graduated 10 mL sirisser n ae e n each Cylinder graduated 23 mt esee each Cylinder graduated 20 ml essen each Cylinder graduated 100 mL esee each OPTIONAL REAGENTS Ammonium Hydroxide 1046 seen 100 mL MDB Calcium Chloride Standard Solution 1000 mg L as CaCO 1000 mL CDTA Magnesium Salt Powder Pillows eene 1
111. he Calcium Standard Solution 1000 mg L as CaCO Perform the procedure as described above This solution will read 1000 mg L or 55 9 G d h Perform this accuracy check when interferences are suspected 1 Snap the neck off a Hardness Standard Solution Voluette Ampule 10 000 mg L as CaCO 2 Use a TenSette Pipet to add 0 1 mL of standard to the sample titrated in step 7 Resume titration back to the same end point Record the number of digits required 3 Repeat using two more additions of 0 1 mL Titrate to the end point after each addition 4 Each 0 1 mL addition of standard should require 10 additional digits of 0 800 M titrant 100 digits of 0 0800 M titrant 11 digits of 0 714 M or 56 digits of 0 1428 M titrant If these uniform increases do not occur refer to Appendix A Accuracy Check and Standard Additions e Although less common than calcium and magnesium other polyvalent metal ions cause the same hardness effects and will be included in the results e Some transition and heavy metals complex the indicator and prevent the color change at the end point Iron does not interfere up to 15 mg L Above this level it causes a red orange to green end point which is sharp and 129 HARDNESS TOTAL continued WARNING Potassium cyanide is toxic Always add it after the potassium hydroxide Excess potassium cyanide does not affect results All cyanide wastes should be disposed of by adding an excess of strongly
112. igit Range G d h ini M EDTA Number Multiplier 1 4 100 0 1428 14960 01 0 01 4 16 25 0 1428 14960 01 0 04 10 40 50 0 714 14959 01 0 1 25 100 20 0 714 14959 01 0 25 gt 100 10 0 714 14959 01 0 5 135 HARDNESS TOTAL SEQUENTIAL continued LULA 5 Add2 mL of 8N Potassium Hydroxide Standard Solution and swirl to mix Note For samples of 50 mL or less 1 mL may be added Note Magnesium is not included in the results but must be present for a sharp end point If it is known to be absent add 1 2 drops of Hardness Standard Solution 9 After completing the calcium titration add 1 mL of 5 25 N Sulfuric Acid Standard Solution Add additional acid dropwise and swirl the solution until the color changes from pure blue to purple then to blue and finally to red Swirl the flask to ensure that all precipitated magne sium hydroxide has re dissolved 6 Add the contents of one CalVer 2 Calcium Indicator Powder Pillow Cat No 947 99 and swirl to mix Note Do not use potassium cyanide to eliminate interferences or toxic gas will form in subsequent steps 10 Add 2 mL of Hardness 1 Buffer Solution and swirl to mix 7 Place the delivery tube tip into the solution and swirl the flask while titrating with EDTA from pink to blue Record the number of digits required Note Titrate slowly near the end point because the reaction is slow especially in colder samples
113. ion and to stabilize the ferric ion in solution 149 IRON continued REQUIRED REAGENTS varies with sample characteristics Iron Reagent Sets about 100 tests 10 100 mg L includes 1 984 99 1 20815 99 1 20816 69 1 20817 01 24492 00 100 1000 mg L includes 1 984 99 1 20815 99 1 20816 69 1 20818 01 24493 00 Description Unit Cat No Citrate Buffer Powder Pillows sse 100 pkg 20815 99 Sodium Periodate Powder Pillows eene 100 pkg 984 09 Sulfosalicylic Acid Powder Pillows eene 100 pkg 20816 69 TitraVer Standard Solution Titration Cartridge 0 0716 M each 20817 01 TitraVer Standard Solution Titration Cartridge 0 716 M each 20818 01 Water deionized nette te cen bors aea user oet tier Ir URS d Tous 272 56 REQUIRED APPARATUS Clippers for opening pillows eene each 968 00 Dreital NR e each 16900 01 Flask Erlenmeyer 125 mm e ee rasen ann TA sos 505 43 Select one or more based on sample concentration Cylinder graduated 25 ml each 508 40 Cylinder graduated 50 ml each 508 41 OPTIONAL REAGENTS Iron Standard Solution 1000 mg L as Fe eee 100 mL 2271 42 OPTIONAL APPARATUS Bottle wash poly 500 ml each 620 11 Clamp 2 prong extensio
114. ion of the lines This is the sample end point 10 Calculate the ug L total chlorine Digits Standard End Point Digits Sample End Point x Multiplier ug L Cl Multiplier is from Phase 2 Example Standard EP 160 digits Multiplier 6 25 Sample EP 150 digits ug L total chlorine 160 150 x 6 25 10 x 6 25 63 round up Note To preserve the strength of the iodine titrant solution always remove the delivery tube from the Digital Titrator cartridge and replace the cap when not in use Protect the iodine titrant solution from direct sunlight 99 Table 1 andad a point Multiplier 160 6 25 165 6 06 170 5 88 175 5 71 180 5 56 185 5 40 190 5 26 195 5 13 200 5 00 CHLORINE TOTAL continued Sampling and Storage Accuracy Check Chlorine is rapidly lost from water Avoid exposure to sunlight or other strong light Avoid excessive agitation Analyze samples immediately or fix the sample by pre addition of standard thiosulfate and buffer as indicated in Phase 3 Titration of Sample for Total Residual Chlorine The fixing procedure should be used for brief transportation delays not for storage of samples Standard Additions Method Snap the top off a Chlorine Standard Solution PourRite Ampule Note the certificate value of the standard in mg L 1 Split a fresh sample into two 200 mL portions 2 Using a TenSette Pipet add from 0 1 to
115. ips for 19700 01 TenSette Pipet sss 50 pkg 21856 96 Pipet volumetric Class A 10 mML esee each 14515 38 Pipet volumetric Class A 20 mt eese each 14515 20 Pipet volumetric Class A 25 mL sese each 14515 40 Pipet volumetric Class A S0O ml eese each 14515 41 Pipet volumetric Class A IO eee each 14515 42 Pipet Filler safety bulb 2 2 ie erp eite ee ict He eoe each 14651 00 sension 1 Basic Portable pH Meter with electrode sss each 51700 10 Spoon measuring 0 l gram e sssseesesesressssresrrrrestesrressersesressesrrsreeseeesee each zie 511 00 Spoon measuring 0 5 graM inciri iiie E a a each aiios 907 00 Support Ring Stand ine et ge eere et breton each 563 00 TitraStir Stir Plate 115 Val a ra rtr verge pe ONERE Reps each 19400 00 TitraStir Stir Plate 230 Vac retenti each 19400 10 Voluette Ampule Breaker Kit s sssccssccscssscsssessenesenesssecssesssenssereenees each 21968 00 126 Method 8213 HARDNESS TOTAL 10 to 4000 mg L as CaCO3 Using EDTA Ce 1 Select a sample size 2 Insert a clean 3 Turn the delivery 4 Use a graduated and an EDTA Titration delivery tube into the knob to eject a few drops cylinder or pipet to Cartridge corresponding titration cartridge of titrant Reset the measure the sample to the exp
116. ith a secondary standard on a range appropriate for the measurement of the dilution water usually the 0 1 NTU range 2 Measure and record the turbidity of the dilution water to be used in making the 1 NTU formazin standard 3 Calculate the number of digits necessary to dispense the proper amount of formazin into a 500 mL Class A volumetric flask for a 1 NTU formazin standard DIGITS 100 1 T Where Ty is the turbidity of the dilution water 4 Carefully dispense the calculated number of digits into a 500 mL volumetric flask Dilute with dilution water to the 500 mL mark and mix well Preparation of any Formazin Standard The following formula may be used to determine the correct number of digits necessary to dispense formazin for a standard of any value DIGITS 0 2 V Tp Ty Where Tp desired turbidity of the formazin standard Ty turbidity of the dilution water this term may be dropped if it is 1 or less of the TD value V volume of the flask in mL 169 TURBIDITY STANDARDS continued Interferences Summary of Method Example 1 One liter of a 0 5 NTU formazin standard is required It is found that the dilution water has a turbidity of 0 05 NTU Because the dilution water turbidity is 10 of the desired standard the dilution water correction must be made The number of digits of formazin is equal to DIGITS 0 2 1000 0 0 5 0 05 90 Thus 90 digits of formazin dispensed in a 1000 mL
117. ity and 250 mg L as CaCO total alkalinity What is the concentration of hydroxide carbonate and bicarbonate alkalinities The phenolphthalein alkalinity does not equal 0 it is 170 mg L see step a The phenolphthalein alkalinity does not equal total alkalinity 170 mg L vs 250 mg L see step b The phenolphthalein alkalinity multiplied by 2 340 mg L see step c Because 340 mg L is greater than 250 mg L select Row 5 see step d The hydroxide alkalinity is equal to see step e 340 250 90 mg L hydroxide alkalinity The carbonate alkalinity is equal to 250 170 80 80 x 2 160 mg L carbonate alkalinity The bicarbonate alkalinity equals 0 mg L Check see step f 90 mg L hydroxide alkalinity 160 mg L carbonate alkalinity 0 mg L bicarbonate alkalinity 250 mg L The above answer is correct the sum of each type equals the total alkalinity 45 ALKALINITY continued Accuracy Check Interferences Summary of Method Standard Additions Method This accuracy check should be performed when interferences are suspected or to verify analytical technique 1 Snap the neck off an Alkalinity Standard Solution Voluette Ampule 0 500N 2 Use a TenSette Pipet to add 0 1 mL of standard to the sample titrated in Steps 6 or 9 Resume titration back to the same end point Record the number of digits needed 3 Repeat using two more additions of 0 1 mL Titrate to the end point after each addition
118. ker Note An improper size stirring bar can result in volatilization of chlorine instability of readings and loss of sensitivity Alternatively use 0 00564 N Phenylarsine Oxide PAO Cat No 1999 instead of thiosulfate 3 With minimum agitation measure 200 mL sample with a clean graduated cylinder and transfer the sample to the beaker Swirl to mix the reagents with sample Note Steps 2 3 can be performed at the sampling site thereby fixing the sample for later analysis Pipet 1 00 mL of 0 00564 N Sodium Thiosulfate and add 1 0 mL of Acetate Buffer into a clean dry glass sampling bottle e g BOD bottle At the sample site measure 200 mL of sample with a graduated cylinder and transfer to the sampling bottle Swirl to mix Before analysis quantitatively transfer the entire contents of the sampling bottle to the 250 mL beaker Minimize delay between sampling and analysis 1 hour maximum to prevent decomposition of thiosulfate in the sample 4 Place the beaker on the TitraStir Stir Plate and immerse the tips of the probe and delivery tube in the solution The probe s platinum wires must be submerged Turn on the stirring motor CHLORINE TOTAL continued 5 Add the contents of one pillow of Potassium Iodide Reagent to the beaker and allow the powder to dissolve 6 Note the LED reading on the Amperometric Titrator It should read 0 00 0 05 DO NOT adjust the BIAS control
119. kg 987 99 Iodate Iodide Titration Cartridge 0 3998 NA each 14961 01 Starch Indicator Solution eee 100 mL MDB 349 32 Water dei nized 8u Besen nn euren cada ves A E ES 272 56 Contact Hach for larger sizes 165 SULFITE continued REQUIRED APPARATUS Description Unit Clippers for opening pillows eese each Digital Tita I each Flask Erlenmeyer 125 mt each Select one or more based on sample concentration Cylinder graduated 10 ml each Cylinder graduated 25 ml each Cylinder graduated O MR ae inte asien sii each OPTIONAL REAGENTS Sodium Thiosulfate Standard Solution 0 025 N eese 1000 mL Sulfite Standard Solution Voluette Ampules 3 000 mg L SO RE 16 pkg Sulfuric Acid Standard Solution 19 2 N 100 mL MDB OPTIONAL APPARATUS Bottle wash poly 500 ml each Clamp 2 prong extension 38 mm each Clamp Holdet nier Ee Ene eret de ede each Demineralizer Assembly 473 ml each Delivery Tubes with 180 hook eene 5 pkg Delivery Tubes 90 with hook eee 5 pkg Flask volumetric Class B 250 mL eee each Pipet TenSette 0 1 to 1 0 nl ossa et pe hr each Pipet Tips for 19700 01 TenSette Dipet 50 pkg Pipet volumetric Class A 5 ml each Pipet volumetric Class A IOmt each Pipet volumetric Class A 20 mt each Pipet volumetric Class A 50 ml each Pipet Filler safety bulb er
120. le 473 mL sees eene each 21846 00 Delivery Tubes 90 with hook for TitraStir Stir Plate S pkg 41578 00 Gloves chemical resistant size 9 9V2 esses eene enne pair 24101 04 Go sgles safety n near dee nun each 25507 00 Hypochlorite HR Bleach Digital Titrator Ku each 26871 00 Notebook ET EE each 20918 00 Pipet Tensette 0 1 1 0 ME reete E I Bel each 19700 01 Pipet volumetric Class A 1 0 ML nen each 14515 35 Pipet B lb 3 2 tania nen each 14651 00 Pipet Tips for TenSette Pipet 19700 01 esee S0 pkg 21856 96 Tech Board with built in calculator eene each 27473 00 TitraStir Sar Plate 115 VAC ae seen each 19400 00 TitraStir Stir Plate 230 VAC ias each 19400 10 Pipettor Tips for 22753 00 vecinal de 1000 pkg 22754 00 Other sizes available 53 54 CARBON DIOXIDE 10 to 1000 mg L as CO Using Sodium Hydroxide 2 Insert aclean delivery tube into the titration cartridge Attach the cartridge to the titrator body See General Description Step by Step for assembly instructions if 1 Select a sample size and a Sodium Hydroxide NaOH Titration Cartridge corresponding to the expected carbon dioxide CO3 concentration see Table 1 Storage following these steps 3 Turn the delivery knob to eject a few drops o
121. le up to 20 mg L iron Manganese interferes above 5 mg L Aluminum causes a slow end point but up to 200 mg L can be tolerated by allowing enough time for color change Magnesium interference up to 200 mg L is prevented by formation of magnesium hydroxide at the high test pH but higher levels prevent a distinct end point Orthophosphate causes a slow end point but does not interfere if the calcium phosphate that forms is allowed enough time to redissolve during the titration Polyphosphate must be absent for accurate results Barium and strontium are titrated with calcium but seldom present in natural waters in significant amounts Acidity and alkalinity at 10 000 mg L as CaCO do not interfere Saturated sodium chloride solutions do not give a distinct end point but the titration can be run directly on sea water 124 HARDNESS CALCIUM continued e Samples at about 20 C 68 F or colder should be titrated slowly near the end point to allow enough time for the color change Highly buffered samples or extreme sample pH may exceed the buffering capacity of the reagents and require sample pretreatment Summary of Method The sample is made alkaline pH 12 13 with potassium hydroxide to precipitate magnesium as magnesium hydroxide CalVer 2 Indicator is added and combines with any calcium to form a pink red color As EDTA is added it reacts with the free calcium ions present When no free calcium ions remain th
122. loride the titrator body See the tip Transfer the sample into concentration from General Description Note For added a clean 250 mL l Table 1 Section Step by Step convenience use the Erlenmeyer flask Dilute for assembly TitraStir Stir Plate See to about the 100 mL instructions if necessary General Description mark with deionized step 3 in Step by Step water if necessary Note See following these steps Table 1 Sample Titration er Range A Catalog Digit Volume Cartridge ert mg L as Cl Number Multiplier mg mL NHg NO3 P 10 40 100 0 2256 14393 01 0 1 40 160 25 0 2256 14393 01 0 4 100 400 100 2 256 921 01 1 0 200 800 50 2 256 921 01 2 0 500 2000 20 2 256 921 01 5 0 1000 4000 10 2 256 921 01 10 0 2000 8000 5 2 256 921 01 20 00 67 CHLORIDE continued Digits Digit Required Multiplier mg L Chloride 5 Add the contents of 6 Place the delivery 7 Calculate one Diphenylcarbazone tube tip into the solution Powder Pillow and swirl and swirl the flask while Digits Required x to mix titrating with mercuric LOT i Note Results will still pe Tate from a yellow to accurate if a small light pink color Note Results may be amount of the powder Record the number of expressed as mg L does not dissolve digits required BRAIN GRIGIO OM multiplying the mg L chloride by 1 65 Note meq L Chloride mg L CF 35 45 Silver Nitrate Method 10 to 10000 mg L as CT Method 820
123. lphthalein and total alkalinities are known see Table 3 Table 3 Alkalinity Relationship Hydroxide m Bicarbonate Row Result of Titration Alkalinity Carbonate Alkalinity Alkalinity i is equal to is equal to is equal to 1 Phenolphthalein 0 0 Total Alkalinity 0 Alkalinity Phenolphthalein Total Alkalinity 0 0 2 Alkalinity equal to Total Alkalinity Phenolphthalein 0 2 times the Total Alkalinity minus 3 Alkalinity less than one Phenolphthalein two times half of Total Alkalinity Phenolphthalein Alkalinity Alkalinity Phenolphthalein 0 Total Alkalinity 0 4 Alkalinity equal to one half of Total Alkalinity Phenolphthalein 2 times the 2 times the 0 Alkalinity greater than Phenolphthalein difference between 5 one half of Total minus Total Total and Alkalinity Alkalinity Phenolphthalein Alkalinity To use the table follow these steps a Does the phenolphthalein alkalinity equal zero If yes use Row 1 b Does the phenolphthalein alkalinity equal total alkalinity If yes use Row 2 44 ALKALINITY continued c Multiply the phenolphthalein alkalinity by 2 d Select Row 3 4 or 5 based on comparing the result of step c with the total alkalinity e Perform the required calculations in the appropriate row if any f Check your results The sum of the three alkalinity types will equal the total alkalinity For example A sample has 170 mg L as CaCO phenolphthalein alkalin
124. ly alkaline verify the solution pH is 4 or less with a pH meter or pH paper before proceeding If you are using the 0 113 N titration cartridge add the contents of one Potassium Iodide Powder Pillow Cat No 1077 99 to the flask and swirl to mix Digits Required Digit Multiplier mg L Total Chlorine CL 9 Continue the 10 Calculate titration until the solution changes from dark blue to colorless Record the number of digits required Digits Required x Digits Multiplier mg L Total Chlorine CI2 To convert the above results to the equivalent percent chlorine Cl5 divide by 10 000 83 8 Add one dropperful of starch indicator solution and swirl to mix A dark blue color will develop CHLORINE TOTAL continued Standard Additions Method This accuracy check is applicable only for the 0 113 N titration cartridge Perform it when interferences are suspected or to verify analytical technique Accuracy Check 1 2 3 4 Summary of Method Snap the neck off a Chlorine Standard Solution PourRite Ampule Use a TenSette Pipet or glass pipet to add 1 0 mL 2 0 mL and 3 0 mL of standard to three samples of the same volume as used in the procedure Analyze each sample as described in the procedure Each 1 0 mL addition of standard should require approximately 10 digits of the 0 113 N titration cartridge Check the certificate enclosed with the PourRite Ampules to obtain the
125. m and or magnesium hardness No Use the Total Hardness Procedure Are you determining calcium hardness only Are you determining both calcium and magnesium Yes Use the Calcium Hardness Procedure Is plenty of sample available Use both the Calcium and Use the Sequential Total Hardness Procedures Titration Procedure calculate magnesium by for Total and Calcium difference Hardness Calculate magnesium hardness by difference 119 120 HARDNESS CALCIUM 10 to 4000 mg L as CaCO3 Using EDTA es 2 Insert a clean delivery tube into the titration cartridge Attach the cartridge to the titrator body See General Description Step by Step for assembly instructions if necessary 1 Select a sample size and an EDTA Titration Cartridge corresponding to the expected calcium as calcium carbonate CaCO concentration Use Table 1 for concentrations in mg L or Table 2 for concentrations in German degrees of hardness G d h Note One German degree hardness equals 17 9 mg L hardness as CaCOs Note If sample cannot be analyzed immediately add 1 5 mL Nitric Acid per liter of sample to preserve the sample and to prevent adsorption of the calcium to the container walls Store in a refrigerator Samples preserved in this manner are stable for one week Neutralize to pH 7 before running the test Method 8204 3 Turn the delivery knob to eject a few drops of titrant
126. mL divide the Digital Titrator reading by 800 1 3 3 To Fill Your Own Titration Cartridges Cartridges may be cleaned and refilled or new empty cartridges Cat No 14495 01 can be purchased from Hach Company See Figure 8 When preparing to refill old cartridges push the cartridge seal out of the cartridge with air pressure applied through the tip Cap the tip fill with solution and reinsert the cartridge seal using care to avoid wrinkling the Teflon sheath Filling also can be accomplished at the tip with a syringe Figure 8 Digital Titrator Cartridges T r E if i 4 e 18 GENERAL DESCRIPTION continued 1 3 4 Verifying Technique Whenever procedures are changed or new equipment is used it is helpful to run a sample of known concentration This technique will confirm the operator is following the procedure correctly and the new equipment is working properly One objective important to Hach Company is making our tests self verifying This means Hach makes the tools available so the operator can check their own work for accurate results without relying on an outside lab or chemist For most of the tests in this manual Table 1 on page 20 lists each procedure the suggested standard the volume of standard needed the titration cartridge used and the number of expected digits when the test is performed correctly The suggested standards are Voluette or PourRite Ampules whenever possible because of their su
127. mate concentration REQUIRED REAGENTS Description Unit Cat No Chromate Reagent Set about 100 reste 22724 00 Includes 1 349 32 1 987 99 1 20599 96 1 22676 01 Dissolved Oxygen 3 Reagent Powder Pillows se 100 pkg 987 99 Potassium Iodide Powder Pillows seen 50 pkg 20599 96 Sodium Thiosulfate Titration Cartridge 0 2068 N sess each 22676 01 Starch Indicator Solution esee 100 mL MDB 349 32 Water deionized Gb teuren nite ee M ee AC ZI unes 272 56 REQUIRED APPARATUS Clippers for opening pillows eee each 968 00 Digital TifatoE a een us son Degen each 16900 01 Flask Erlenmeyer 125 mL cccssssessscesnsecscecescesnecssnsessnsessnsecnsesenses each 505 43 Select one or more based on sample concentration Cylinder graduated IO ml eee each ue 508 38 Cylinder graduated Z 5i eae es eed each 508 40 Cylinder eraduated JO ia each ios 508 41 OPTIONAL REAGENTS Chromium Hexavalent Standard Solution 1000 mg L 100 mL 14664 42 Magnesium CDTA Powder Pillows eee 100 pkg 14080 99 Sodium Acetate trihydrate AC 100 g 178 26 OPTIONAL APPARATUS Clamp 2 prong Extension nenne nennen nennen each 21145 00 Clamp Holder uper nk Edhen 326 00 Demineralize
128. metric Titrator Unlock the BIAS control and adjust the BIAS control knob until a reading between 0 50 0 60 is obtained Lock the BIAS control Note The bias adjustment controls the slope of the titration curve The actual instrument reading is not important but rather the change in the readings as the titration proceeds The adjustment need not be precise 7 Using the Digital Titrator delivery knob dispense the PAO titrant Solution in 5 10 digit increments while noting the LED reading Note If the chlorine content of the sample is high add titrant at a faster rate only the end point of the titration and the volume of titrant used at the end point are of concern For example if the chlorine content is approximately 500 ug L up to 300 digits of 0 00564 N PAO could be added at once As the end point is approached dispense in small increments Note If excess reductant such as sulfite bisulfite or sulfur dioxide is present in the sample the LED readings will not decrease and may even increase This indicates that no free chlorine is present in the sample 88 8 As the end point of the titration is approached record the LED readings along with the corresponding digits displayed on the Digital Titrator counter Near the titration end point add 2 to 5 digits of titrant wait a few seconds for a stable reading and record CHLORINE FREE continued 9 Continue the titration recording at le
129. mg L CaCO Ca Hardness mg L CaCO Mg Hardness mg L CaCOs Note See below for conversion factors Hardness Relationships Interferences mg L Mg Hardness as CaCO mg L Total Hardness as CaCO mg L Ca Hardness as CaCO mg L MgCO mg L Mg Hardness as CaCO x 0 842 mg L Mg mg L MgCOz x 0 29 WARNING Do not use potassium cyanide to eliminate interferences because it will generate deadly hydrogen cyanide gas when the sulfuric acid solution is added in step 9 e Although less common than calcium and magnesium other polyvalent metal ions cause the same hardness effects and will be included in the results 137 HARDNESS TOTAL SEQUENTIAL continued e Some transition and heavy metals complex the indicator and prevent the color change at the end point Iron does not interfere up to 15 mg L Above this level it causes a red orange to green end point which is sharp and usable up to 30 mg L iron Substitute a 0 0800 M CDTA or 0 800 M CDTA titration cartridge for the 0 0800 M EDTA or 0 800 M EDTA titration cartridges respectively if iron interference is probable For results in G d h divide the mg L result by 17 9 Manganese titrates directly up to 20 mg L but masks the end point above this level Adding a 0 1 gram scoop of hydroxylamine hydrochloride raises this level to 200 mg L manganese Copper interferes at levels of 0 10 and 0 20 mg L Cobalt and nickel interfere at all levels and must be absent or
130. n 38 mm each 21145 00 Clamp Holder rhe AN n eR each 326 00 Demineralizer Assembly 473 ml each 21846 00 Delivery Tubes with 180 hook seen 5 pkg 17205 00 Delivery Tubes 90 with hook sese S pkg 41578 00 Pipet Tono efte 930 1 402 Win bsg u each 19700 01 Pipet Tips for 19700 01 TenSette Pipet essen 50 pkg 21856 96 Pipet volumetric Class A 25 0 ml each 14515 40 Pipet volumetric Class A 50 0 ml each 14515 41 Pipet Filler safety bulb ihi eoe een each 14651 00 Support Ring Stand cuina dd each 563 00 TitraStir Stir Plate 115 Vac rennen each 19400 00 TitraStir Stir Plate 230 Vac retener each 19400 10 150 Method 8351 NITRITE 100 to 2500 mg L as NaNO Using Ceric Standard Solution SI 1 Select the sample 2 Insert aclean 3 Hold the Digital 4 Use a graduated volume from Table 1 delivery tube into the Titrator with the cylinder or pipet to which corresponds tothe Ceric Standard Solution cartridge tip pointing up measure the sample expected sample sodium Titration Cartridge Turn the delivery knob volume from Table 1 nitrite concentration as Attach the cartridge to until a few drops of Transfer the sample to a NaNO the titrator body See titrant are expelled clean 125 mL General Description Reset the counter to zero Erlenmeyer flask
131. n For determining high levels of aqua ammonia ammonium hydroxide in solutions used for chloramination of drinking water for determining aqua ammonia feed pump rates or applications requiring the determination of high concentrations g L of aqua ammonia CAUTION Handling chemical samples standards and reagents can be dangerous Review the Material Safety Data Sheets before handling chemicals Wear eye protection and protective gloves when sampling Measuring Hints and General Test Information Wash all labware between tests Contamination may alter test results Rinse with clean water preferably deionized water Hach recommends that reagent accuracy and analyst technique be checked using a standard solution Use the Ammonium Hydroxide solution listed on page 53 and follow the procedure in the Accuracy Check section on page 52 Ammonia Titration Procedure To ensure accurate results read carefully before proceeding 1 Insert a clean delivery tube into the 8 00 N Sulfuric Acid Titration Cartridge Attach the cartridge to the titrator body Note See section 1 2 on page 13 for assembly instructions 2 Flush the delivery tube by turning the delivery knob to eject a few drops of titrant Reset the counter to zero and wipe the tip Note For added convenience use the TitraStir Stir Plate See section 1 2 step 4 on page 14 3 Fill a clean 125 mL Erlenmeyer flask to about the 75 mL mark with deionized water
132. ned a standard deviation of 1 5 g L 0 15 CL Under acidic conditions hypochlorite reacts with iodide to produce an equivalent amount of triiodide 147 The released Iz is titrated with standard thiosulfate solution to a colorless end point The number of digits of thiosulfate required is proportional to the hypochlorite concentration in the original bleach sample 145 HYPOCHLORITE Bleach continued REQUIRED REAGENTS HR Hypochlorite Bleach Reagent Set about 100 tests 26870 00 Includes 1 349 32 1 1042 99 1 20599 96 1 26869 01 Description Unit Cat No Acid Reagent Powder Pillows eee 100 pkg 1042 99 Potassium Iodide Powder Pillows eene 50 pkg 20599 96 Sodium Thiosulfate Standard Titrant Solution 2 26 N sss each 26869 01 Starch Indicator Solution eese 100 mL MDB 349 32 REQUIRED APPARATUS Clippers daria each 968 00 Delivery Tubes R ISER Ee sn ove 5 pkg 17205 00 Digital Titrator Assembly nennen each 16900 02 Flask Erlenmeyer 125 Mesias e P eter rc iter ocius each 505 43 Pipet TenSette 0 1 1 0 ML nennen each 19700 01 Pipet Tips for 19700 01 TenSette Pipet esse 50 pkg 21856 96 OPTIONAL REAGENTS Potassium Iodide Iodate Standard Solution O OI285N Ips AA 14
133. ntration of chlorine standard mg L certificate value V volume of standard added in mL 6 Calculate the percent spiked recovery E Spiked sample result in mg L APIKE Recovery Theoretical concentration calculated in mg L SE Example Sample result C 120 ug L or 0 120 mg L Spiked sample result 185 ug L or 0 185 mg L Volume Sample Vu 200 mL Volume Standard V 0 2 mL Chlorine Standard C 68 1 mg L e _ 0 120 x 200 68 1 x 0 2 _ Theoretical concentration 200 40 2 0 188 mg L an Ge _ 0 185 mg L n Spike recovery 0 188 mg L x 100 98 Ideally the percent recovery should be 100 Generally results from 80 120 recovery are considered acceptable The standard additions technique is not applicable for samples containing excess reducing agents such as sulfur dioxide sulfite or bisulfite 90 CHLORINE FREE continued Precision In a single laboratory using a standard solution of 338 ug L chlorine a single operator obtained a standard deviation of 5 2 ug L chlorine Detection Limit With good operator technique the estimated detectable concentration is approximately 15 ug L chlorine using 0 00564 N PAO Sampling and Storage Chlorine is rapidly lost from water Avoid exposure to sunlight or other strong light Avoid excessive agitation Analyze samples immediately Interferences e Silver ions poison the electrode Copper ions interfere Interferences are sometime
134. nvenience use the TitraStir Stir Plate See General Description Step 3 in Step by Step OXYGEN DISSOLVED continued 9 Use a graduated cylinder to measure the sample volume from Table 1 Transfer the sample into a 250 mL Erlenmeyer flask Digits Required mg L Dissolved Oxygen 13 Calculate Digits Required x Digit Multiplier mg L Dissolved Oxygen 10 Place the delivery tube tip into the solution and swirl the flask while titrating with sodium o 11 Add two 1 mL droppers of Starch Indicator Solution and swirl to mix 12 Continue the titration to a colorless end point Record the number of digits 156 thiosulfate to a pale Note A dark blue color required yellow color will develop Digit Multiplier Table 1 Range Sample Mer Catalog Digit mg L D O Volume mL N Na2S 05 Number Multiplier 1 5 200 0 200 22675 01 0 01 2 10 100 0 200 22675 01 0 02 gt 10 200 2 000 14401 01 0 1 OXYGEN DISSOLVED continued Using a 60 mL BOD Bottle Method 8332 ode dedi i 1 Collect a water sample in a clean 60 mL glass stoppered BOD Bottle Note Allow the sample to overflow the bottle for 2 3 minutes to ensure air bubbles are not trapped Note If samples cannot be analyzed immediately see Sampling and Storage on page 158 5 Remove the stopper and add the contents of one Dissolved Oxygen 3 Powder Pillow Replace the stopper
135. o account for the reduction in sample size to give the true equivalent buret milliliters of 20 5 mL If the buret method called for multiplying the number of milliliters of titrant by a factor to calculate the concentration of a sample component then multiply 20 5 by that factor Equivalent Buret Milliliters 1 5 Using PermaChem Powder Pillows 1 Tap the PermaChem on a hard surface to collect the powdered reagent in the bottom 2 Tear across on the dotted pillow line marked TEAR holding the pillow away from your face gt gt 23 GENERAL DESCRIPTION continued 1 6 Safety 3 Using two hands Push both sides toward each other until thumbs and forefingers form a diamond Make sure to Crease the foil pack so that it forms a spout 4 Pour the pillow contents into the sample The polyfilm lining is specially formulated to deliver all the powder necessary for accurate results no tapping on the vessel edge is necessary N n vol Safety is the responsibility of each individual when performing analysis procedures and the analyst must develop and maintain good safety habits Because many of the procedures in this methods handbook use potentially hazardous chemicals and apparatus it is important that the analyst practice good laboratory techniques to minimize accidents The following paragraphs present several techniques applicable to water analysis in the laboratory and in the field They are not all inclusive
136. o not occur refer to Appendix A Accuracy Check and Standard Additions Interferences Higher room temperatures tend to lead to higher free chlorine residual due to reaction of chloramines Higher room temperatures also result in increased color fading If the sample contains more than 250 mg L alkalinity or 150 mg L acidity as CaCO the sample may not develop the full amount of color or it may instantly fade To overcome this interference adjust the pH of a separate 25 mL sample to a 6 to 7 pH by adding 1 N Sulfuric Acid Standard Solution or 1 N Sodium Hydroxide Standard Solution in small increments and using a pH meter Record the amount of acid or base required Add this amount of acid or base to the sample to be tested and proceed with step 4 76 CHLORINE FREE AND TOTAL continued Bromine iodine ozone and oxidized forms of manganese and chromium will also react and read as chlorine To compensate for the effects of manganese Mn or chromium Cr9 add three drops of Potassium Iodide 30 g L to 25 mL of sample Mix and wait one minute Add three drops of Sodium Arsenite 5 g L and mix Analyze this solution as described above If chromium is present allow exactly the same reaction period in step 7 with the DPD for both analyses Subtract the result from the original analysis to correct for the interference Summary of Method The DPD FEAS method provides a titrimetric procedure for determining free available chlorine and for
137. ocedure Use safety equipment such as pipet fillers protective clothing and ventilating hoods appropriate for the test being conducted Wipe up all spills promptly Do not smoke or eat in an area where toxic or irritating chemicals are used Use reagents and apparatus only as they were meant to be used and use them only as directed in the test procedure Do not use damaged labware and malfunctioning equipment 25 26 D TITRATION PROCEDURES 28 ACID BASE 10 to 4000 mg L as meq L Acid Determination 1 Select the sample volume corresponding to the expected acid concentration in milliequivalents meq L or normality N from Table 1 Note See Sampling and Storage following these steps P 5 Add the contents of one Phenolphthalein Indicator Powder Pillow and swirl to mix The solution should be colorless Note Four drops of Phenolphthalein Indicator Solution may be substituted for the Phenolphthalein Indicator Powder Pillow 2 Insert a clean delivery tube into the appropriate Sodium Hydroxide Titration Cartridge Attach the cartridge to the titrator body See General Description Step by Step for assembly instructions 6 Place the delivery tube tip into the solution and swirl the flask while titrating with sodium hydroxide until a light pink color forms and persists for 30 seconds Record the number of digits required 3 Flush the delivery tube by turning the delivery knob to
138. olonged exposure to air Samples may be stored at least 24 hours by cooling to 4 C 39 F or below ifthey cannot be analyzed immediately Warm to room temperature before analyzing Accuracy Check Standard Additions Method This accuracy check should be performed when interferences are suspected or to verify analytical technique 1 Snap the neck off an Acidity Voluette Ampule Standard 0 500 N 37 ACIDITY continued Interferences Summary of Method Bromphenol blue pH 3 7 or phenolphthalein pH 8 3 indicator is used to titrate the sample with sodium hydroxide to a Use a TenSette Pipet to add 0 1 mL of standard to the sample titrated in step 6 for methyl orange acidity or step 3 for phenolphthalein acidity Resume titration back to the same end point Note the number of digits required Repeat using two more additions of 0 1 mL Titrate to the end point after each addition Each 0 1 mL addition of standard should require 25 additional digits of 1 600 N titrant or 250 digits of 0 1600 N titrant If these uniform increases do not occur refer to Appendix A Accuracy Check and Standard Additions Highly colored or turbid samples may mask the color change at the end point Use a pH meter for these samples Chlorine may interfere with the indicators Add one drop of 0 1 N Sodium Thiosulfate to eliminate this effect To determine the phenolphthalein acidity of samples containing hydrolyzable metals such as
139. olor Note Four drops of Phenolphthalein Indicator Solution may be substituted for the Phenolphthalein Indicator Powder Pillow Digits Required Digit Multiplier mg L as CaCO P Alkalinity 6 If the solution turns pink titrate to a colorless end point Place the delivery tube tip into the solution and swirl the flask while titrating with sulfuric acid Record the number of digits required Note If the solution is colorless before titrating with sulfuric acid the Phenolphthalein P Alkalinity is zero proceed with step 8 42 7 Calculate Digits Required x Digit Multiplier mg L CaCO P Alkalinity 8 Add the contents of one Bromcresol Green Methyl Red Indicator Powder Pillow to the flask and swirl to mix Note Four drops of Methyl Purple Indicator Solution may be substituted for the Bromcresol Green Methyl Hed Indicator Powder Pillow Titrate from green to a gray end point pH 5 1 Note Four drops of Bromcresol Green Methyl Red Indicator Solution may be substituted for the Bromcresol Green Methyl Red Indicator Powder Pillow ALKALINITY continued Total Digits Required Digit Multiplier mg L as CaCO Total T or M Alkalinity 9 Continue the 10 Calculate titration with sulfuric acid to a light greenish Total Digits Reguired x Digit Multiplier blue gray pH 5 1 a Ger as Gate Total light violet gray PH T or M Alkalinity 4 8 or a light pink pH
140. olution 0 100 N esses 1000 mL OPTIONAL APPARATUS Bottle wash poly 2O0 ml esses ener enne nnne each Clamp 2 prong extension 28 mm each Clamp Te e eee efie pe bee enean each Demineralizer Assembly 473 mL eene nene each Delivery Tubes with 180 book S pkg Delivery Tubes 90 with hook for TitraStir Stir Plate S pkg Pipet volumetric Class A Tom each Pipet volumetric Class A 2 mlt eccccessecessceceeeeceeeecsaeceeaeceeaeeceeeeeeeeeenaees each Pipet volumetric Class A 5 1 oe aia e E EESE each Pipet volumetric Class A 10 mL eese each Pipet volumetric Class A 20 mL eese teretes each Pipet volumetric Class A 50 mL esee each Pipet volumetric Class A 100 mL eese ene each Support Ring Stand s eec an eisen tte ieget ent te ken each TitraStir Stir Plate 115 Nac rennen sennen nnn each TitraStir Stir Plate 230 Nac each Contact Hach for larger sizes 33 Cat No 14390 01 41578 00 14515 35 14515 36 14515 37 14515 38 14515 20 14515 41 34 Methods 8201 and 8202 ACIDITY 10 to 4000 mg L as CaCO Methyl Orange and Phenolphthalein Total Methods Methyl Orange Method Method 8201 fa Lb ov 1 Select a sample 2 Insert a clean 3 Turn the delivery 4 Use a graduated volume and a Sodium delivery tube into the knob to eject a few drops cylinder or pipet to Hydroxide NaO
141. on discusses the chemical reaction taking place and information that applies to the entire procedure The Reagents and Apparatus list concludes the procedure All the items required to perform the test are listed first and are available from Hach The items listed in the notes or interferences sections are included in the optional listings 1 Select a sample volume and titration cartridge corresponding to the expected sample concentration from the table given in each procedure If the expected sample concentration is not known start with one of the smaller sample volumes and determine its approximate concentration Retest with the appropriate sample size 2 Slide the cartridge into the titrator receptacle and lock in position with a slight turn See Figure 2 Figure 2 Sliding the Cartridge into Place 3 Remove the polyethylene cap and insert a clean delivery tube into the end of the cartridge until it is tight See Figure 3 Use a straight tube with a hook at the end for hand held titrations use a 90 tube with a hook at the end for stationary setups 13 GENERAL DESCRIPTION continued Do not insert tube past cartridge extension see illustration below In some instances it might be necessary to remove a small burr on the leading edge of the tube before insertion Figure 3 Inserting the Delivery Tube Do not insert past this point HAC H ZS CARTRIDGE 4 For stationary titrations use a Titra
142. on factor to obtain the correct sodium nitrite concentration Sampling and Storage Accuracy Check Summary of Method Collect samples in clean plastic or glass bottles Prompt analysis is recommended If prompt analysis is impossible store samples for 24 to 48 hours at 4 C 39 F or lower Warm to room temperature before analysis Do not use acid preservatives Dissolve 1 000 gram of fresh sodium nitrite in 100 mL of deionized water Dilute to 1000 mL with deionized water to prepare a 1000 mg L sodium nitrite standard solution Use a 5 0 sample of the standard solution and start with step 4 of the titration procedure The analysis should yield 1000 mg L for step 8 of the titration procedure Sodium nitrite is titrated with tetravalent cerium ion a strong oxidant in the presence of ferroin indicator After the cerium oxidizes the nitrite it oxidizes the indicator causing a color change from orange to pale blue The concentration of sodium nitrite is proportional to the amount of titrant used 153 NITRITE continued REQUIRED REAGENTS Description Unit Cat No Ceric Standard Solution Titration Cartridge 0 5 N sss each 22707 01 Ferroin Indicator Solution eene 29 mL DB 1812 33 Sulfuric Acid Standard Solution 5 25 N 100 mL MDB 2449 32 REQUIRED APPARATUS Digital Tittatot EE each 16900 01 Flask Erlenmeyer EE each 505 43 Select one or mor
143. onal digits of titrant If these uniform increases do not occur refer to Appendix A Accuracy Check and Standard Additions Other acid components in the sample will be titrated and interfere directly in this determination Sodium hydroxide standard solutions tend to lose strength slowly with age and should be checked periodically by titrating a known standard Check the solution frequently monthly by titrating 50 mL of Potassium Acid Phthalate Standard Solution 100 mg L CO using Phenolphthalein Indicator Solution The titration should require 5 00 mL of titrant If the volume required for this titration is greater than 5 25 mL discard the sodium hydroxide and replace it with a fresh supply 57 CARBON DIOXIDE continued REQUIRED REAGENTS varies with sample characteristics Description Unit Carbon Dioxide Reagent Set about 100 tests essen Includes 1 942 99 1 14378 01 1 14380 01 Phenolphthalein Powder Pillows eee 100 pkg Sodium Hydroxide Titration Cartridge 0 3636 NA each Sodium Hydroxide Titration Cartridge 3 636 N sess each Water deon Ze E AL REQUIRED APPARATUS Digital Dittatot 2t esee ote cedet each Select one or more based on sample concentration Flask Erlenieyet 250 mL iste GO ERBE each Flask Erlenmeyer 125 Md Rr ee ee en each OPTIONAL REAGENTS Carbon Dioxide Standard Solution Voluette Ampules 10 000 mg L as CO 10 ML eee 16 pkg Phenolphthalein Indicato
144. onvenience 189 190 REPLACEMENT PARTS AND ACCESSORIES REPLACEMENT PARTS FOR MODEL 16900 DIGITAL TITRATOR Description Unit Cat No Digital Titrator including delivery tubes manual and case each 16900 01 Delivery Tubes 180 book esee 5 pkg 17205 00 CASE ibi titer ptg tate eee re ibl d Deest pb pie Eois each 46602 00 pike Sorin Ss of bree id oo EROR EU each 16900 08 191 192 HOW TO ORDER By Telephone By Mail 6 30 a m to 5 00 p m MST Hach Company Monday through Friday P O Box 389 800 227 HACH Loveland CO 80539 0389 800 227 4224 U S A By FAX 970 669 2932 Ordering information by E mail orders hach com Information Required e Hach account number if available Billing address e Your name and phone number e Shipping address e Purchase order number e Catalog number e Brief description or model number Quantity Technical and Customer Service U S A only Hach Technical and Customer Service Department personnel are eager to answer questions about our products and their use Specialists in analytical methods they are happy to put their talents to work for you Call 1 800 227 4224 or E mail techhelpO hach com International Customers Hach maintains a worldwide network of dealers and distributors To locate the representative nearest you send E mail to intl hach com or contact In Canada Latin America Africa Asia
145. ould be an uncommon situation and results are probably correct unless unusual interferences are possible Refer to the Interferences section in the specific procedure 185 APPENDIX A continued Figure 2 Multiple Standard Additions Graph mg L titrated Extrapolated result for sample tested a V N N IN N DER N a N gt DO gt Peo OT RS EN EN aie ez au EN Bp P s ar _ Y 4 TINNY LM 11 Pt ttt tt tt tT BEEBBRBBBZEBE Pa AR Co 125 100 75 50 25 0 25 50 75 100 mg L Actually Present gt mg L Standard Added Branch H Check operation of the apparatus used in the performance of the test Verify the correct volumes of sample and standard were used Check glassware used in the procedure making sure that it is scrupulously cleaned Dirty pipets and graduated cylinders are a source of contamination and will not deliver the correct volume If a defect is found in the apparatus repeat Branch B after repair or replacement of apparatus If the apparatus is found to be in good working order proceed with Branch I BranchI After demonstrating that the procedure reagents and apparatus are correct and operating properly the only possible cause for standard additions not functioning properly in deionized water is the standard used in performing the standard additions Prepare or obtain a new set of standards and repeat Branch B 186 APPENDIX
146. perior accuracy and stability To use titration standards follow these steps 1 Select the procedure of interest and order the appropriate standard Use the given catalog numbers 2 Measure the volume of standard to be used as the sample in the procedure using a TenSette Pipet or Class A pipet 3 Perform the procedure as written adding deionized water as necessary 4 After titrating the required number of digits should approximately equal the expected digits Call Hach Technical and Customer Service 1 800 227 4224 for additional help 19 GENERAL DESCRIPTION continued Table 1 Titration Standards Procedure Standard Description un Titration Cartridge Expected Parameter Cat No mL Cat No Digits Acid Base 0 500 N H2SO 2121 26 1 0 1 600 N NaOH 250 Acid 14379 01 5 0 8 00 N NaOH 250 14381 01 Base 0 500 N Na COz 1 0 1 600 N H SO 250 14278 10 14389 01 5 0 8 00 N H SO 250 14391 01 Acidity 0 500 N H2SO 2121 26 0 1 0 1600 N NaOH 250 14377 01 1 0 1 600 N NaOH 250 14379 01 Alkalinity 0 500 N Na2COs 14278 10 0 1 0 1600 N H2SO 250 14388 01 1 0 1 600 N H SO 250 14389 01 Calcium 10 000 mg L CaCO 0 1 0 0800 M EDTA 100 mg L CaCO3 2187 10 14364 01 1 0 0 800 M EDTA 100 14399 01 G d h 10 000 mg L CaCO 0 2 0 1428 M EDTA 112 2187 10 14960 01 1 0 0 714 M EDTA 112 14959 01 Carbon 10 000 mg L CO 14275 10 0 2 0 3636 N NaOH 100 Dioxide
147. que the estimated detectable concentration is approximately 15 ug L chlorine using 0 00564 N PAO Sampling and Storage Interferences Chlorine is rapidly lost from water Avoid exposure to sunlight or other strong light Avoid excessive agitation Analyze samples immediately e Silver ions poison the electrode e Copper ions interfere Interferences are sometimes found in highly turbid water and those containing surface active agents Oxidized manganese and other oxidizing reagents give positive interferences e Some uncertainty in the end point may be observed with samples containing high organic content e Samples containing excess reducing agents such as sulfur dioxide sulfite and bisulfite do not contain free chlorine or chloramines and can not be titrated under the conditions of the test Highly buffered samples or extreme sample pH may exceed the buffering capacity of the buffer reagent If necessary add additional buffer and check pH of sample prior to titration 109 CHLORINE TOTAL continued Summary of Method In the amperometric forward titration procedure for total chlorine a small electrical current is applied across two identical platinum electrodes No current can flow between the electrodes unless a substance that can be oxidized at the anode and a substance that can be reduced at the cathode are both present In the case of the total chlorine an equivalent amount of iodine forms from the reaction
148. r Assembly 473 ML eene each 21846 00 Delivery Tubes with 180 book sese S pkg 17205 00 Delivery Tubes 90 with hook for TitraStir Stir Plate 5 pkg 41578 00 Flask volumetric Class B 100 mL een each 547 42 Pipet TenSette 0 1 to 1 0 ML AAA ee each 19700 01 116 CHROMATE continued OPTIONAL APPARATUS continued Description Unit Cat No Pipet Tips for 19700 01 TenSette Pipet sse 50 pkg u 21856 96 Pipet volumetric Class A 23 ml each 14515 03 Pipet volumetric Class A 3 ml nenn each 14515 37 Pipet volumetric Class A IO mt each 14515 38 Pipet volumetric Class A 20 mL esee each 14515 20 Pipet volumetric Class A SO ml essere each 14515 41 Pipet Piller Safety bulb nir eit e Pete Ege Kane each 14651 00 Spoon measuring 1 0 gram sess eren nennen each 510 00 Support Ring Stand BE Te nel 563 00 TitraStir Stir Plate 115 Vae oos doeet A each 19400 00 TitraStir sur Plate 230 Vac tret re eS OS ae A e each 19400 10 117 118 HARDNESS DECISION TREE There are several hardness procedures presented in this manual Use the following decision tree to select the appropriate procedure for your application Are you determining calciu
149. r Solution 5 g L 100 mL MDB Potassium Acid Phthalate Standard Solution 100 mg L as CO 100 mL Potassium Acid Phthalate Standard Solution 400 mg L as CO 500 mL OPTIONAL APPARATUS Clamp 2 prong extension 38 mm esee ener each Clamp Holder reete te die a pa each Delivery Tubes with 180 hook eene S pkg Delivery Tubes 90 with hook for TitraStir Stir Plate S pkg Pipet TenSette 0 1 to 1 0 ML ue ie apte dettes each Pipet Tips for 19700 01 TenSette Pipet esses 50 pkg Pipet Filler safety bulbo diia each sensilon Basic Portable pH Meter with electrode ee each Support Ring Staid nnne e RERO a s each id MUA ens d dg each TitraStir Stir Plate 230 VAC se ne ee vedo eaten dane eat each Voluette Ampule Breaker Kit c cccccssssssessssssesssesscssscssseseessssssseeessassees each Contact Hach for larger sizes 58 Cat No 22727 00 ae 14275 10 o 162 32 uiis 2261 42 TERN 1885 49 ra 21145 00 leeren 326 00 Bn 17205 00 dep 41578 00 ju 19700 01 RER 21856 96 Sones 14651 00 Gert 51700 10 su 563 00 A 19400 00 seri 19400 10 Ge 21968 00 Method 8352 CHELANT FREE 0 to 20 0 mg L as CaCO3 Using Magnesium Chloride Ny 1 Insert a clean 2 Hold the Digital 3 Use a graduated 4 Using the 1 mL delivery tube into the Titrator with the cylinder to measure the calibrated dropper a
150. rength of the Thiosulfate Standard Solution can be checked using Potassium Iodide Iodate Standard Solution 1 Use a Class A pipet to transfer 50 00 mL of 0 0125 N Potassium Iodide Iodate Standard Solution to a clean 125 mL Erlenmeyer flask 2 Add the contents of one Potassium Iodide Powder Pillow to the flask and swirl to mix 3 Add the contents of three Acid Reagent Powder Pillows to the flask and swirl to mix Swirl until all powder is dissolved 144 HYPOCHLORITE Bleach continued Interferences Precision Summary of Method 4 Continue the titration starting at step 9 of the procedure It should take 217 227 digits of 2 26 N Thiosulfate Standard Solution to reach the end point The iodometric method is relatively free of interferences The test will determine chlorite ion ClO gt in addition to the hypochlorite ion C107 However the amount of chlorite in commercial bleach is insignificant typically less than 0 2 A large excess of caustic in the bleach sample may lead to low results After adding the Acid Reagent Powder Pillow step 5 check the pH of the solution with pH paper The pH should be less than 3 If not add additional Acid Reagent one pillow at a time until the pH drops below 3 For most accurate results the temperature of the dilution water step 3 should be less than 20 C 68 F In a single laboratory using a commercial bleach sample of 91 2 g L 9 12 Cl a single operator obtai
151. ret merece each Support Ring Stand vee Pata dea aka hte eerte e ge ien each TitraStir Stir Plate ke each TitraStir Stir Plate 230 Vac entere each Voluette Ampule Breaker Kit s scsscssssssssscscseesenssesesssecsssssesssneneesees each 166 24093 53 14267 10 2038 32 19700 01 21856 96 14515 37 14515 38 14515 20 14515 41 19400 00 19400 10 21968 00 TURBIDITY STANDARDS Preparing Turbidity Free Water Phase 1 Filtration Assembly CC 1 Attach the filter funnel stem to a 1000 mL filtering flask 5 Attach the vacuum hose to the sidearm 2 Using plastic tweezers position a 0 45 micron membrane filter on top of the funnel stem A 6 Pour a total of about 800 mL in three portions of deionized water through the filter funnel and wait until it passes through the filter Discard this rinse water Method 8217 3 Cover the stem with 4 Attach a vacuum the filter housing hose to the water aspirator and turn on water JI ls 7 Again add 800 mL 8 Use this filtered of deionized water deionized water for all through the filter funnel formazin dilutions and collect in a filter flask Remove vacuum hose from sidearm and turn off water 167 TURBIDITY STANDARDS continued Phase 2 Preparing Standards using a Formazin Cartridge HOWH 1 Shake the Formazin 2 Attach a clean Cartridge vigorously for
152. riodate one Sulfosalicylic Acid tube tip into the solution Powder Pillow and swirl Powder Pillow and swirl Powder Pillow and swirl and swirl the flask while to mix to mix to mix A red color will titrating the sample until Note A yellow color develop if iron is the color changes from indicates the presence present red to the original of iron yellow Record the number of digits required Digits Digit Required Multiplier mg L Iron Fe 9 Calculate Digits Required x Digit Multiplier mg L lron Fe 148 IRON continued Accuracy Check This accuracy check should be performed when interferences are suspected or to verify analytical technique 1 Use a TenSette Pipet to add 0 5 mL of 1000 mg L as Fe standard to the sample in step 7 Resume titration back to the same end point Record the number of additional digits required 2 Repeat using two more additions of 0 5 mL Titrate to the end point after each addition 3 Each 0 5 mL addition of standard should require 10 additional digits of 0 716 M titrant or 100 digits of 0 0716 M titrant If these uniform increases do not occur refer to Appendix A Accuracy Check and Standard Additions Summary of Method Iron Fe is oxidized by sodium periodate to the ferric ion Fe When sulfosalicylic acid is present the ferric ion forms a red complex coloring the solution The red complex is destroyed by titration with EDTA Citric acid is used to buffer the solut
153. s found in highly turbid water and those containing surface active agents Oxidized manganese and other oxidizing reagents give positive interferences e Some uncertainty in the end point may be observed with samples containing high organic content e Samples containing excess reducing agents such as sulfur dioxide sulfite and bisulfite do not contain free chlorine and can not be titrated under the conditions of the test Highly buffered samples or extreme sample pH may exceed the buffering capacity of the buffer reagent If necessary add additional buffer and check pH of sample prior to titration Summary of Method In the amperometric forward titration procedure for free chlorine a small electrical current is applied across two identical platinum electrodes No current can flow between the electrodes unless a 91 CHLORINE FREE continued substance that can be oxidized at the anode and a substance that can be reduced at the cathode are both present In the case of the free chlorine titration with phenylarsine oxide PAO chlorine is reduced at the cathode to chloride due to the addition of PAO and PAO is oxidized from the 3 oxidation state to the 5 oxidation state at the anode Prior to the end point of the titration both free chlorine and chloride are present in solution allowing current to flow even with a very small applied potential At the end point no free chlorine remains and the solution cannot conduct even if ex
154. s in German degrees of hardness G d h Note One German degree hardness equals 17 9 mg L hardness as CaCOs Note If sample cannot be analyzed immediately add 1 5 mL Nitric Acid per liter of sample to preserve the sample and to prevent adsorption of the calcium to the container walls Store in a refrigerator Samples preserved in this manner are stable for one week Neutralize to pH 7 before running the test 2 Insert a clean delivery tube into the titration cartridge Attach the cartridge to the titrator body See General Description Step by Step for assembly instructions 3 Turn the delivery knob to eject a few drops of titrant Reset the counter to zero and wipe the tip Note For added convenience use the TitraStir Stir Plate See 4 Use a graduated cylinder or pipet to measure the sample volume from Table 1 or Table 2 Transfer the sample into a clean 250 mL Erlenmeyer flask Dilute if necessary General Description to about the 100 mL Step 3 in Step by Step mark with deionized water if necessary Table 1 Range mg L as Sample Titration Cartridge Catalog Digit olume ES CaCO3 M EDTA Number Multiplier mL 10 40 100 0 0800 14364 01 0 1 40 160 25 0 0800 14364 01 0 4 100 400 100 0 800 14399 01 1 0 200 800 50 0 800 14399 01 2 0 500 2000 20 0 800 14399 01 5 0 1000 4000 10 0 800 14399 01 10 0 Table 2 Sample TN f ET Titration Cartridge Catalog D
155. ss as CaCO4 Total Digits Required x Digit Multiplier Table 2 Gd h 10 g L as CaCOs Table 1 Range mg L as Sample Heston Catalog Digit CaCO volume Cartridge Number Multiplier 3 mL M EDTA P 10 40 100 0 0800 14364 01 0 1 40 160 25 0 0800 14364 01 0 4 100 400 100 0 800 14399 01 1 0 200 800 50 0 800 14399 01 2 0 500 2000 20 0 800 14399 01 5 0 1000 4000 10 0 800 14399 01 10 0 Table 2 Sample Titration wu Range G d h Volume Cartridge d uL mL M EDTA P 1 4 100 0 1428 14960 01 0 01 4 16 25 0 1428 14960 01 0 04 10 40 50 0 714 14959 01 0 1 25 100 20 0 714 14959 01 0 25 gt 100 10 0 714 14959 01 0 5 122 HARDNESS CALCIUM continued Hardness Relationships Accuracy Check Interferences WARNING Potassium cyanide is toxic Always add it after the potassium hydroxide Excess potassium cyanide does not affect results All cyanide wastes should be disposed of by adding an excess of strongly alkaline sodium hypochlorite solution bleach with stirring Use good ventilation Allow to stand for 24 hours before disposal mg L Ca Ca Hardness mg L as CaCO x 0 40 Standard Additions Method This accuracy check should be performed when interferences are suspected or to verify analytical technique 1 Snap the neck off a Hardness Standard Solution Voluette Ampule 10 000 mg L as CaCO Use a TenSette Pipet to add 0 1 mL of standard to the solution titrated in step 7
156. strate the effect of interferences upon the standard addition and upon substances in the sample The plots were made by graphing the Total Standard Added mg L on the X axis and the Total Parameter Found mg L on the Y axis as shown in Figure 2 on page 186 Table 5 PlotA Total Total Standard Total Number Total Standard Parameter Added mL of Digits Used Added mg L Found mg L 0 100 0 100 0 1 113 25 Ma 0 2 123 50 123 0 3 129 75 Table 6 Plot B Total Total Standard Total Number Total Standard Parameter Added mL of Digits Used Added mg L Found mg L 0 0 0 0 0 1 25 25 9 0 2 50 50 29 0 3 75 75 90 183 APPENDIX A continued Both of these plots show that the four data points do not lie on a straight line Plot A illustrates an interference which becomes progressively worse as the concentration of the standard increases This type of interference is not common and may be caused by an error or malfunction of the procedure reagents or apparatus Perform Branch B to ensure that the supposed interference is present Plot B illustrates a common chemical interference which becomes less or even zero as the concentration of the standard increases The plot shows the first standard addition was consumed by the interference and the remaining additions gave the correct increase of 25 mg L for each additional 0 1 mL of standard added The apparent interference in Plot B could be the result o
157. t volumetric Class A 25 mL essere each 14515 40 Pipet volumetric Class A 50 mL eese each 14515 41 Pipet volumetric Class A LO each 14515 42 Pipet Filler safety bulb eee as each 14651 00 sension 1 Basic Portable pH Meter with electrode s555111111155011110 each 51700 10 Spoon measuring 0 1 gram essere nennen nennen each 511 00 Spoon measuring 0 5 gram sse rennen nennen each 907 00 Spoon measuring 1 0 gram sese ener each 510 00 Support Ring Stand A each 563 00 TitraStir Stir Plate 115 Vac ccececcecsssssceccecccsscsecsecsccssesseceeceaceaseeseeseees each 19400 00 TitraStir Stir Plate 230 Vac an unse each 19400 10 Voluette Ampule Breaker Kit essent tette tette nnns each 21968 00 133 134 Method 8329 HARDNESS TOTAL SEQUENTIAL 10 to 4000 mg L as CaCO3 Sequential Titration Procedure Limited Sample Scope and Application To determine total and calcium hardness in samples with limited sample size follow this procedure Calculate magnesium hardness by difference 1 Select a sample size and an EDTA Titration Cartridge corresponding to the expected calcium as calcium carbonate CaCO3 concentration Use Table 1 for concentrations in mg L or Table 2 for concentration
158. t Cat No Acetate Buffer Solution pH AU 100 mL MDB 14909 32 Potassium Iodide Powder Pillows eene 100 pkg 1077 99 Standard Iodine Titrant Solution 0 028 N sse each 23333 01 Sodium Thiosulfate Standard Solution 0 00564 N 100 mL 24088 42 REQUIRED APPARATUS Amperometric Titrator Assembly esee each 19299 00 Beaker low form 2Z 0 ml esee eene each 500 46 Cylinder graduated 2230 ml seen each 508 46 Digital Ditrator eee em dte em dations each 16900 01 Delivery Tubes 90 with book S pkg 41578 00 Pipet volumetric Class A L mt eese each 14515 35 Probe Assembly Amperometric Titrator eee each 19390 00 Stir Bar octagonal Teflon coated 50 8 x 7 9 mm each 20953 55 TitraStir Stir Plate 115 Vac ssesseeeeeeeen eren each 19400 00 TitraStir Stir Plate 230 Nac retener tenerent each 19400 10 OPTIONAL REAGENTS Chlorine Standard Solution PourRite Ampules 30 1591 Elo 2 mb s oer ur ot repo RPM RUD UR E 20 pkg 14268 20 Phenylarsine Oxide Solution 0 00564 NA 100 mL 1999 42 Water delOntzed s rot rre Lage eros Rein n ie ri oda AL EE 272 56 OPTIONAL APPARATUS Bottle BOD 300 mL 5 2 chiede i eer am Te san an ns each 621 00 Pipet TenSette 0 1 to 1 0
159. t into sample Counter Reset Knob Resets counter to zero after completion of titration SN Cartridges Simply slide in and lock with a slight turn Plunger Release Button Releases plunger from the main threaded Handgrip drive screw so that it can be manually Braces titrator against palm advanced or retracted to engage the of hand for comfortable piston with the cartridge hand held operation 11 GENERAL DESCRIPTION continued Both portable and fixed position titrations are possible with the Digital Titrator The instrument has a grip for hand held operation or it can be clamped to a TitraStir Stir Plate or laboratory stand for stationary setups See Figure 1 Each Digital Titrator comes with five delivery tubes and a methods manual which covers the most commonly tested parameters and the corresponding titrant cartridges Right angle ninety degree delivery tubes for stationary setups are available as an optional accessory 1 1 1 Following a Procedure for the First Time Each method is divided into five sections Procedure Accuracy Check Interferences Summary of Method and Reagents and Apparatus For more information about how to select a procedure or for answers to chemical questions see Hach s Water Analysis Handbook literature 8376 For more information about chlorine measurement also see the technical booklet titled Current Technology of Chlorine Analysis for Water and Wastewater literature 7019
160. tep 5 adding the Dissolved Oxygen 3 Powder Pillow The titration should take 10 mL If 158 OXYGEN DISSOLVED continued more than 10 5 mL is required to reach the end point replace the Sodium Thiosulfate Solution Interferences Nitrite interference is eliminated by the azide in the reagents Other reducing or oxidizing substances may interfere If these are present use an alternate method such as the High Range Dissolved Oxygen Method colorimetric in this manual or a dissolved oxygen electrode Summary of Method Samples are treated with manganous sulfate and alkaline iodide azide reagent to form an orange brown precipitate Upon acidification of the sample this floc reacts with iodide to produce free iodine as triiodide in proportion to the oxygen concentration The iodine is titrated with sodium thiosulfate to a colorless end point REQUIRED REAGENTS FOR 300 ML BOD BOTTLE Varies with sample characteristics Dissolved Oxygen Reagent Set about 50 tests esee 22722 00 Includes 1 349 32 2 1071 68 2 1072 68 1 22675 01 2 20762 68 Description Unit Cat No Alkaline Iodide Azide Powder Pillows eese 25 pkg 1072 68 Manganous Sulfate Powder Pillows eene 25 pk 1071 68 Sodium Thiosulfate Titration Cartridge 0 2000 N sss each 22675 01 Sodium Thiosulfate Titration Cartridge 2 00 N sss each 14401 0
161. ting 1 Assemble the Amperometric Digital Titrator System according to the instructions in the Amperometric Titrator Instruction Manual 2 Install the 0 00564 N Phenylarsine Oxide PAO cartridge Flush the Digital Titrator delivery tube by turning the delivery knob to eject a few drops of titrant Reset the counter to zero and wipe the tip Note When a new probe is placed in service or when the probe has not been used recently prepare it according to the Probe Stabilization instructions in the Amperometric Titrator Instruction Manual 3 With minimum agitation measure 200 mL of sample with a clean graduated cylinder Transfer the sample to a clean 250 mL beaker containing the 50 mm stirring bar supplied with the system Note An improper stirring bar size can result in volatilization of chlorine instability of readings and loss of sensitivity Method 10024 4 Add 1 mL of pH 7 Phosphate Buffer Solution Note If the sample pH is between 6 5 and 7 5 it is not necessary to add the buffer Procedure is equivalent to Standard Methods for the Examination of Water and Wastewater 18th ed 4500 CI D for drinking water 87 CHLORINE FREE continued 5 Place the beaker on the TitraStir Stir Plate and immerse the tips of the probe and delivery tube in the solution The probe s platinum wires must be submerged Turn on the stirring motor 6 Note the LED reading on the Ampero
162. tion Step 3 in Step by Step OXYGEN DISSOLVED continued Digits oi Required mg L Dissolved Oxygen 9 Titrate the prepared 10 Calculate solution with 0 2000 N Sodium Thiosulfate until the sample changes from yellow to colorless Record the number of digits Digits required x 0 1 mg L Dissolved Oxygen Sampling and Storage Sampling and sample handling are important in obtaining meaningful results The dissolved oxygen content of the sample changes with depth turbulence temperature sludge deposits light microbial action mixing travel time and other factors A single dissolved oxygen test rarely reflects the over all condition of a body of water Several samples taken at different times locations and depths are recommended for most reliable results Collect samples in clean BOD Bottles see step If storage is necessary run steps 1 5 of the procedure and store in the dark at 10 20 C Seal the bottle with water by pouring a small volume of water into the flared lip area of a stopper bottle Snap a BOD Bottle Cap over the flared lip Samples preserved like this can be held 4 8 hours Begin with step 6 when analyzing Accuracy Check Check the strength of the Sodium Thiosulfate Solution by using an Iodate Iodide Standard Solution which is equivalent to 10 mg L dissolved oxygen For the 300 mL procedure begin at step 5 adding the Sulfamic Acid Powder Pillow For the 60 mg L procedure begin the analysis at s
163. trator delivery knob reading on the arm from the beaker and and immerse the tips of add 50 digits of Standard Amperometric Titrator rinse the platinum wires the probe and delivery Iodine Titrant Solution Unlock the BIAS control with deionized water tube in the solution The and adjust the BIAS Adjustment of the probe s platinum wires control knob until a electrode response slope must be submerged stable reading between is complete Turn on the stirring 0 50 0 60 is obtained motor Lock the BIAS control Phase 2 Standardization of the Iodine Titrant B 1 Set up the 2 Using a graduated 3 Using a Class A 4 Add 1 mL of pH 4 Amperometric Digital cylinder measure 200 pipet transfer 1 00 mL Acetate Buffer Solution Titrator System as in mL of deionized water of 0 00564 N Sodium and the contents of one Phase 1 Adjusting the into a clean 250 mL Thiosulfate Solution to Potassium Iodide Electrode Response beaker Place the 50 mm the beaker Swirl to mix Powder Pillow Slope if it has not stirring bar supplied Note Alternatively use already been done Reset with the system into the o 90564 N Phenylarsine the Digital Titrator beaker Oxide PAO Cat No counter to zero and wipe 1999 instead of Note An improper size of stirring bar can result in volatilization of iodine instability of readings and loss of sensitivity the tip thiosulfate 94 CHLORINE TOTAL continued 5 Place the beaker on the TitraStir Stir
164. tte Pipet to add 0 1 mL of standard to the sample titrated in step 7 Resume titration back to the same end point Record the number of digits required 3 Repeat using additions of 0 2 and 0 3 mL titrating to the end point after each 4 Each 0 1 mL addition of standard should require 25 additional digits of titrant If these uniform increases do not occur refer to Appendix A Accuracy Check and Standard Additions A standard solution equivalent to 40 mg L sulfite can be prepared by diluting 10 0 mL of 0 025 N Sodium Thiosulfate Titrant to 250 mL in a volumetric flask Titrate a 50 mL sample using the above procedure Interferences Sulfide organic matter and other oxidizable substances will cause positive error in the titration Nitrite will react with sulfite to cause low results Some metals especially copper catalyze the oxidation of sulfite to sulfate Addition of one Dissolved Oxygen 3 Powder Pillow per liter of sample immediately upon sampling will help eliminate the effects of nitrite and copper Summary of Method Sulfite ion is titrated with potassium iodate iodide standard solution under acidic conditions to a blue starch end point The volume of titrant used is proportional to the sulfite concentration REQUIRED REAGENTS Sulfite Reagent Set about 100 reste 22723 00 Includes 1 349 32 1 987 99 1 14961 01 Description Unit Cat No Dissolved Oxygen 3 Reagent Powder Pillows esses 100 p
165. um 3 710 Barium 0 729 Cobalt 1 698 Copper 1 575 lron 1 792 Manganese 1 822 Nickel 1 705 Strontium 1 142 Zinc 1 531 139 HARDNESS TOTAL SEQUENTIAL continued REQUIRED REAGENTS Calcium and Magnesium Hardness Reagent Sets about 100 tests each 10 100 G d h includes 1 282 32 1 424 32 1 928 99 1 947 99 1 2449 32 1 1400 01 10 160 mg L includes 1 282 32 1 424 32 1 928 99 1 947 99 1 2449 32 1 14364 01 isses 100 4 000 mg L includes 282 32 1 424 32 1 928 99 1 947 99 1 2449 32 1 14399 01 eeeeeneeeesensnnenessneeennnseensnnneeneene nennen Description Unit CalVer 2 Indicator Powder Pillows eese 100 pkg Hardness 1 Buffer Solunon 100 mL MDB ManVer 2 Hardness Indicator Powder D Uows 100 pkg Potassium Hydroxide Standard Solution 8 00 N 100 mL MDB S lf ric Acid 5 2 Noia dto 100 mL MDB Ee e E DEE EE 4L Select one or more based on sample concentration EDTA Titration Cartridge 0 0800 M A each EDTA Titration Cartridge 0 1428 M A each EDTA Titration Cartridge 0 714 NM each EDTA Titration Cartridge 0 800 M A each REQUIRED APPARATUS Digital lira eii tirar each Flask Erlenmeyer 250 ml each Select one or more based on sample concentration Cylinder graduated 10 ml eese each CyImder graduated 25 Micra eeh ergeet Elte each Cylinder graduated 50 ml each Cylinder graduated 100 ml each OPTIONA
166. water to remove any hardness present on the plastic or glass Run reagent blanks occasionally using deionized or distilled water in place of the sample Subtract the value of the blank from the sample value before recording the final answer 61 CHELANT FREE continued REQUIRED REAGENTS Description Unit Hardness 1 Buffer Solution eene 100 mL MDB ManVer 2 Hardness Indicator Powder Pillows ses 100 pkg Magnesium Chloride Titration Cartridge 0 0800 M sss each REQUIRED APPARATUS Cylinder graduated 100 mL eese each Digital A ee Pete si Pe ete det ty keke each Flask Brlenmeyet 125 mL eite toe eet reri te eee each OPTIONAL REAGENTS EDTA Standard Solution 0 035 N sene 100 mL MDB ManVer 2 Hardness Indicator Powder 113g ManVer 2 Hardness Indicator Solution sss 100 mL MDB Phenolphthalein Indicator Solution 5 g L 100 mL MDB Sulfuric Acid Standard Solution 5 25 N 100 mL MDB Water deionized eee p EPA 4L OPTIONAL APPARATUS Clamp 2 prong extension 38 mm each Clamp Hold t 2 ee eerte AE e each Clippers shears 7 25 inch eee eee eee each Delivery Tubes with 180 hook serene 5 pkg Delivery Tubes 90 with hook for TitraStir Stir Plate 5 pkg Eiter Paper folded 12 5 emi erint ted edes deet 100 pkg Flask Erlenmeyer
167. wing formulas to cal culate the final concen tration Digits Required x Digit Multiplier Table 1 mg L Total Hardness as CaCO ManVer Hardness Note Titrate slowly near ni u Indicator Solution ora 0 1 the end point because the Pigits Required x Digit g scoop of ManVer 2 reaction is slow especially Multiplier Table 2 Hardness Indicator G d h Powder Cat No 280 14 may be substituted for the in cold samples Note The magnesium concentration may be de powder pillow termined by subtracting the results of the calcium determination from total hardness Table 1 Sample Titration n Ran h tal Digit mg L ie Caco Volume Cartridge NUR Multiplier mL M EDTA 10 40 100 0 0800 14364 01 0 1 40 160 25 0 0800 14364 01 0 4 100 400 100 0 800 14399 01 1 0 200 800 50 0 800 14399 01 2 0 500 2000 20 0 800 14399 01 5 0 1000 4000 10 0 800 14399 01 10 0 Table 2 Sample Titration Range G d h Volume Cartridge LE e mL M EDTA 1 4 100 0 1428 14960 01 0 01 4 16 25 0 1428 14960 01 0 04 10 40 50 0 714 14959 01 0 1 25 100 20 0 714 14959 01 0 25 gt 100 10 0 714 14959 01 0 5 128 HARDNESS TOTAL continued Hardness Relationships Accuracy Check Interferences mg L Total Hardness as Ca mg L Total Hardness as CaCO x 0 400 mg L Total Hardness as CaCO mg L Ca as CaCO mg L Mg as CaCO3 Standard Additions Method To verify analytical technique use 20 mL of t
168. without trapping air in the bottle and invert several times to mix Note The floc will dissolve and leave a yellow color if oxygen is present 2 Add the contents of one Dissolved Oxygen 1 Reagent Powder Pillow and one Dissolved Oxygen 2 Reagent Powder Pillow 6 Accurately measure 20 mL of the prepared sample and transfer it to a 125 mL Erlenmeyer flask 3 Immediately insert the stopper so air is not trapped in the bottle Invert several times to mix Note A flocculent precipitate will form It will be orange brown ifoxygen is present or white if oxygen is absent The floc settles slowly in salt water and normally requires 5 additional minutes before proceeding to step 5 Ce 7 Attach a clean straight stem delivery tube to a 0 2000 N Sodium Thiosulfate Titration Cartridge Twist the cartridge onto the titrator body See General Description Step by Step for assembly instructions if necessary 157 4 Wait until the floc in the solution has settled and the top half of the solution is clear Again invert the bottle several times and wait until the floc has settled Note Results are not affected if the floc does not settle or if some of the reagent powder does not dissolve 8 Flush the delivery tube by turning the delivery knob to eject a few drops of titrant Reset the counter to zero and wipe the tip Note For added convenience use the TitraStir Stir Plate See General Descrip
169. xists in the sample resulting in a measurable polarization current The end point is estimated by continued addition of titrant recording of the current at each titrant addition and graphing the data points Where the best line between the data points intersects with the null current the number of digits from the Digital Titrator at the end point can be determined and the concentration of chlorine calculated It is necessary to adjust the electrode sensitivity by using the bias control prior to performing the analysis The bias adjustment is set by adding a known amount of standard iodine titrant to deionized water and adjusting the bias control to a given value on the display The electrode sensitivity will vary depending on the probe conditioning Adjustment should be made at least daily or before each series of samples Although the iodine titrant solution is formulated and packaged to be quite stable it is recommended the iodine be routinely standardized against standard thiosulfate or phenylarsine oxide The number of digits determined for the iodine standardization is recorded and used in the calculation of the sample s chlorine concentration 102 CHLORINE TOTAL continued To preserve the strength of the iodine titrant solution always remove the delivery tube from the Digital Titrator cartridge and replace the cap when not in use Protect the iodine titrant solution from direct sunlight REQUIRED REAGENTS Description Uni
170. y check The Total Standard Added mg L is determined for each addition by the following equation Total Standard Added mE x Standard Concentration mg L Sample Volume mL Total Standard Added mg L The Total Parameter Found mg L is determined by following the calculation step of the procedure used Use the same volume of deionized water as used for the sample The addition of standard will not change the digit multiplier If steps between each addition are roughly uniform i e 25 digits or 25 mg L difference between each addition proceed to Branch 181 APPENDIX A continued G If the results are not uniform i e 13 10 and 6 mg L proceed to Branch F For example a sample of water was analyzed for chloride with the result being 100 mg L The analyst suspecting interferences made one standard addition of 0 10 mL of 12 500 mg L chloride standard to 50 0 mL of sample Rather than an increase of 25 mg L as expected the analyst found an increase of 13 mg L The analyst added a second and third addition of 0 1 mL of standard The titrations were made and the results tabulated The increments were 10 123 minus 113 and 6 129 minus 123 mg L respectively The analyst proceeded to Branch F Table 4 Total Parameter Found mg L Total Standard Total Number Total Standard Added mL of Digits Used Added mg L 0 100 0 100 0 1 113 25 113 0 2 123 50 123 0 3 129 75 129 To

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