Chlorine, Free and Total by Colorimeteric DPD
Contents
1. SOP 30 CI DPD v5 docx Date Printed 12 17 2014 Accredited Test Method Name SOP 30 Chlorine Free amp Total by Colorimetric DPD v5 Analytical Services Branch Method Date November 4 2014 Environmental Standards Division Page 19 of 19 N Environmental Standards Analytical Services Document Control Archived Records The official MS Word document of this SOP is maintained in a secure controlled location N Environmental Standards Quality Assurance SourceDocs Current Word SOP 30_CI DPD_v5 docx SOP 30_CI DPD_v5 docx Date Printed 12 17 20142. Duplicate helps to determines if there is a problem with the DPD reagent dispenser p8 Weekly Vial Check amp Accuracy Check document the latter in LIMS as the CRM seseeeees p8 Non conformance and Corrective Action substitute the Specv blank with reagent grade water if two or more standards are outside of the control limits Run the Total Chlorine Accuracy Check Standard Run a sample blank sss p9 Using the Specv Standards they are used to verify the instrument not for calibration The actual instrument calibration is a factory setting that cannot be changed sssss p 10 Revision History includes a table for better historical documentation going forward it s much easier to note when a version number might be skipped and how often the revisions occur Appendices includes a new tab for Tab5 Meter Checks Tab 6 CRM Duplicates ssssse p 17 Endnotes new section referencing the file folder location of all referenced documents p 18 December 17 2014 reprint pages 5 11 amp 16 Interferences false positive readings caused by condensation and turbidity from DO P 5 False Positive RESO WS us qesitana Hire deus On d d ar dion Re P bte cR IN Eni doin a etu a er SE RiGee p 12 Procedure to use when traces of chlorine free or total occur with non chlorinated water Next Review No
3. Later than November 31 2015 SOP 30 CI DPD v5 docx Date Printed 12 17 2014 Accredited Test Method Name SOP 30 Chlorine Free amp Total by Colorimetric DPD v5 Analytical Services Branch Method Date November 4 2014 Environmental Standards Division Page 17 of 19 Use the following only if there are no changes required at the next review or there are minor handwritten amendments suitable for continued use i e the SOP does not have to be formally recompiled and distributed Annual Review includes verification ensuring that the laboratory has the most current version of all the referenced methods and manuals Method Binder tabs may appear in different order but are organized into the following sections Tab 1 COA amp Logs Certificate of Analysis and equipment calibration Tab 2 COA Total Certificate of Analysis Total Chlorine Tab 3 QC Standards Tab 4 Vial Cleaning Tab 5 Meter Checks Tab 6 CRM Duplicates Tab 5 Method Validation Certificates of Analysis are scanned to PDF in the COA Folder immediately upon receipt After confirmation of accuracy n missing or double scanned pages the hard copy is also Menus after expiration in accordance with the documented policy in the Quality Manual Completed QC Records Charts are moved from the clip board to the method binder tabs noted above Batch worksheets with Free CI Total CI amp Temperature are filed in the Chlorine Batch Worksheet Binder Each cal
4. amp Total by Colorimetric DPD v5 Analytical Services Branch Method Date November 4 2014 Environmental Standards Division Page 7 of 19 New amp Return to Use All new instruments or any instrument taken Out Of Service or OUT OF USE must be validated prior to its use The validation includes the repeated analysis of a Certified Reference Material and analysis of duplicates with the latter also analyzed on a valid instrument After completion the template Return To Use used to document is forwarded to the QA Officer for statistical analysis and validation Repair Service Authorization must be obtained from Hach Company before sending any items for repair Please contact the Hach Service Center serving your location Canada Mike Demkiw Senior Field Service Technician Manitoba and North Western Ontario Hach Sales and Service Canada Ltd Office 886 223 1793 Fax 866 806 6797 E mail mdemkiw hach com Tech Support 1 800 665 7635 www hach com servicecanada Website www hach com Thoroughly rinse the glass cells with the test water after each use Check the glassware for cleanliness Discard samples cells if there are any scratches pits or marks that could affect the measurement This is more pronounced with the high range plastic sample cells Perform a manual acid wash weekly by rinsing the sample cell with 50 HCI and rinsing with copious amounts of deionized water Afterwards inspect and match the cells as descri
5. to form a red solution The color intensity is proportional to the total chlorine concentration To determine the concentration of combined chlorine run a free chlorine test and a total chlorine test Subtract the results of the free chlorine test from the total chlorine test to obtain the combined chlorine concentration LIMS Test Codes TestCode Test Name Unit Chlorine Free Chlorine Residual Free mg L Chlorine Total Chlorine Residual Total mg L Sample History Holding Time Chlorine residuals are analyzed immediately after sampling Do not store samples Chlorine in water is not stable and will dissipate rapidly particularly in weak concentrations Sample Collection All chlorine testing must be done in situ and cannot be collected for later analysis Samples must be collected immediately prior to the conduct of the test specifically before the addition of the DPD reagents Taking samples is described in Test Procedure Taking Aliquots page 10 SOP 30 CI DPD v5 docx Date Printed 12 17 2014 Accredited Test Method Name SOP 30 Chlorine Free amp Total by Colorimetric DPD v5 Analytical Services Branch Method Date November 4 2014 Environmental Standards Division Page 5 of 19 Volume Required 10 mL each for free and total chlorine Interferences i Exposure to sunlight other strong light or agitation will accelerate the reduction of chlorine ii Very low temperatures as experienced all winters will slow the
6. 15 secs If the second reading is lower record this measurement SOP 30 CI DPD v5 docx Date Printed 12 17 2014 Accredited Test Method Analytical Services Branch Name SOP 30 Chlorine Free amp Total by Colorimetric DPD v5 Method Date November 4 2014 Environmental Standards Division location inform the laboratory supervisor immediately Read Taking Aliquots on page 10 Page 12 of 19 NOTE If the free chlorine is less than 0 10 mg L on any distribution system monitoring Note that the steps for the Free and Total Chlorine measurements are the same except a different reagent is used between the two Conduct the Free Chlorine First rinse several times and do the Total Chlorine test 1 Fill a 10 mL cell with sample the blank Cap Note Samples must be analyzed immediately ard cannot be preserved for later analysis 4 Press ZERO SCROLL The display will show then 0 00 Remove the blank from the cell holder 2 Press the POWER key to turn the meter on The arrow should indicate the low range channel LR Note See page 2 4 f r information on seleeting the correct rangeehanget 5 Fill a second 10 mL cell to the 10 mL line with sample Note Do not use the same sample cells for free and total chlorine analysis without thoroughly rinsing the cells with sample between free and total tests E ASD 3 Remoffe the meter cap Place the blank in the cell holder w
7. Accredited Test Method Name SOP 30 Chlorine Free amp Total by Colorimetric DPD v5 Analytical Services Branch Method Date November 4 2014 Environmental Standards Division Page 16 of 19 Wear plastic aprons and full face shields when acid washing Acid wash in acid washing fume hoods only Refer to each chemical MSDS for detailed hazards and handling instructions available on the City of Winnipeg s intranet site Wellness page Sewage samples contain pathogenic organisms Wear gloves eliminate contact above the chest while working and thoroughly wash hands with a disinfectant soap after handling Refer to Environmental Standards Division Health and Safety Manual and applicable safe work procedures in the SafeWorkProcedures manual Read all product labels and the material safety data sheets MSDS before using them Version No Issue Date Author Reviewers 4 1 G Levesque J Jones 5 0 October 28 2014 J Jones G Levesque x December 17 2014 G Levesque Revision details are documented in these historical versions Previous revisions are listed in the obsolete Version 4 1 which is maintained for historical and documentation reasons Current Version 5 0 Version 5 0 Reagents Total Chlorine Reference Standard preparation of the sealed ampoule std p6 Equipment and Supplies updated c ntact information for HACH ssssssesseeenen nemen p6 Method Quality Control
8. IR S 8 Method Quality Control A LLL nee nean 8 Weekly Vial and Accuracy Checks ecce e eese mese menemene meses 8 Acceptance Criterla i rere o aee eeiam kk Ran xara Raga 9 Non Conformance and Corrective Action M bie nemen menn nnn nnn 9 Proficiency Testing cot exe tell NV a EE XX ERRORES ERR ER URTA ARER UM X EUER EMEN 9 Test Procedure sorte odi Na d rrr ke nm eR REP ERRRE a E RET E YKAENFA FERREA 10 Documentation Requirements E AE cece recente eee emm nnn nnn 10 I puuprelge ER qi WIL IT IT EL UTILE 10 Using the Specv Standards 499 amp sesesssssesseseeeeesee nee nenne nenne raus ne rae rne rae rne rae nnn 10 Taking Aliquots Test Sampla 9J seee cessere mmn mene enne nnne ned 11 Chlorine Free and Total Low Range 0 02 to 2 00 mg L CI2 seeeeeennen 12 Chlorine Free and Total High Range 1 0 to 8 0 mg L CI2 seen 14 Data Analysis amp Cal amp ylatigRis Leeieeieeeieeeseeieeehe enn nn nnne anneau nena nhan aua nana 15 Ij ae A 15 ReVISIOID HISEOP V veu eiaax vid EH Nea a 4s SA REMO TI UUu DIR REEL ERU QUE PORE VVEU RETI ER EROR DE AE 16 Appendices Method Binder Tabs oiii ropa io Eee ae uy e eu Pres seTURET Ea gr RE EFII RP ERES 17 Tab 1 COA amp Logs Certificate of Analysis and equipment calibration c eceeeeee tees teen ees 17 Tab 2 COA Total Certificate of An
9. Q City of Winnipeg Environmental Standards Division Winnipeg Analytical Services Branch Standard Operating Procedure Field Testing Chlorine Free amp Total by Colorimetric DPD LIMS SOP 30 Procedure ID CI DPD Version 5 0 Appendices No 15 Issue Date November 4 2014 Total Pages 19 Approved By Courtney Diduck Analytical Services Branch Head Notice Two printed control copies are issued with one copy located in the Analytical Services Laboratory and the other at the Water Treatment Plant Laboratory Each copy is authorized by signature of the Analytical Services Branch Head Only the controlled copy documentation is to be used in the laboratory This controlled copy cannot be photocopied or reproduced without authorization Electronic copies are accessible in PDF format from the method folder and the intranet folder N Environmental Standards V Analytical Services SOP PDFs Hyperlinks to external documents and navigation within this document are highlighted and underlined in green font These links are functional in the electronic version of this document when the user has permission and the document is viewed within the City of Winnipeg s intranet site from the above mentioned folder All documents pertaining to this SOP are maintained in subfolders of the following Master Folder N Environmental Standards Methods Chlorine DPD SOP 30 Latest revisions are highlighted in blue print All hand written amen
10. alysis Total Chlorine sssesssseenm He 17 Taped OC Standards Gee cevotelosat ete nexu e AE xem DPSNM M E IERI m EE Ru E RYE DUE 17 X MBUI EeIT ec 17 Tab 5 Met r Checks cds aimed manta etuer eae Bat sue out Eae wid ea cw ERE TRE RED ME DUO ai 17 Tab 6 CRM D U pliCates icio ic eene vata eene aed erbe oe ot iq xa ak ax side actual KD ola sa sa PERRA RE A ga bende AE Ea ths 17 Tab 5 Method Validation esI er lds do GR OE Rv REO DRE RE Da D DERE ERERCR CE RDMEE 17 Document Controla ossa ee yXaaKYaz aR AE eRESGERIEMANNEEREEPEREGKTPNANEEATRA ERE POOEERTEKRARE ER EEE 17 Rerererces virens ou eror Vi Ti aAA Ree DEVIS PII AULUS IEEE d bDIUDEDI DEIN VPN DUDEN FERNER RER C E 17 Standard Operating Procedures sssssssssssessssessee emen eene eene 17 Equipment Instruction Manuals esssssssssesse emnes menie eene 18 Reference E duc M 18 Endnotes file and folder locations asesi cresine nania mme memes 18 SOP 30 CI DPD v5 docx Date Printed 12 17 2014 Accredited Test Method Name SOP 30 Chlorine Free amp Total by Colorimetric DPD v5 Analytical Services Branch Method Date November 4 2014 Environmental Standards Division Page 3 of 19 Chlorine is the most widely used drinking water disinfectant to destroy pathogenic organisms in water in order to prevent the spread of waterborne disease and to protect the water from recontamination during storage In addition chlorin
11. anufacturer supplier other than NSI 1 Fita 25 mL flask with about 10 15 mL of DI or MilliQ water 2 Take a tube and shake contents to bottom of tube 3 Snip off the top of the tube with scissors and invert tube into the opening of the cuvette 4 Squeeze the bottom of the tube 5 The contents will fully release into the vessel No rinSing is required The plastic contains a high content of Teflon or like material specific for that purpose 6 Fill the flask to the mark with DI water capj and mix by inverting several times then proceed immediately with analysis If the colorimeter doesn t turn on or appears to be not working check or replace the batteries For more information on the use of the Pocket Colorimeter II Error Codes Battery Replacement etc refer tofE u pMent Instruction Manuals listed in References page 18 e ilO0mLcells 25 X60 mm for low range e 1cm 10 mLcell for high range e SwiftTestTM Dispenser or packets e Timer minutes HACH Pocket ColorimeterII Lamp Light emitting diode LED Detector Silicon photodiode Photometric precision 0 0015 Abs Filter bandwidth 15 nm Wavelength 528 nm Absorbance range 0 2 5 Abs Operating conditions O to 50 C 32 to 122 F 0 to 90 relative humidity Power supply Four AAA alkaline batteries approximate life is 2000 tests SOP 30_CI DPD_v5 docx Date Printed 12 17 2014 Accredited Test Method Name SOP 30 Chlorine Free
12. bed in Glass Vial Maintenance amp Checks Record the work performed in the worksheet tab Glass Vials from the ChlorineForms xls workbook The hard copy is maintained on the Chlorine clipboard and filed in the method binder Cleaning vials after use with sewage and outfall samples Perform a manual acid wash every day that sewage or outfall samples are tested by rinsing the sample cell with 50 HCI and rinsing with copious amounts of deionized water Glass Vial Maintenance amp Checks Each kit contains two 10 mL sample cells for the low range method and one or two sample cells for use in the high range Each time that a sample cell is replaced both cells must be matched verified against each other Imperfections and variations stress in the glass can affect the absorbance of the sample or transmittance of the light Vials must be within 0 02 SOP 30_CI DPD_v5 docx Date Printed 12 17 2014 Accredited Test Method Name SOP 30 Chlorine Free amp Total by Colorimetric DPD v5 Analytical Services Branch Method Date November 4 2014 Environmental Standards Division Page 8 of 19 mg L of each other If over this amount then check against a third vial and reject the outlier that is over the limit Follow the instructions and use the printed Excel worksheet to record the findings See G ass Vials tab in Ch orineForms xlsx Weekly inspect and match the cells as described in Glass Vial Maintenance amp Checks Record the work performed i
13. dments except for spelling or grammatical errors must be approved immediately by the Analytical Services Branch Head or Quality Assurance Officer who shall initial and date the amendments The procedure shall be formally revised and reissued as soon as practicable SOP 30_CI DPD_v5 docx Date Printed 12 17 2014 Accredited Test Method Name SOP 30 Chlorine Free amp Total by Colorimetric DPD v5 Analytical Services Branch Method Date November 4 2014 Environmental Standards Division Page 2 of 19 All forms charts reagent logs located in the workbook ChlorineForms xlsx Control Charts are printed from ChartGenerator xIsm Table of Contents iecur aaa o d ORE EURO unl RRRGCOV CORR EORR RURERERK KR TOR RR LERRA RUN RIGEN 2 Introduction and SCOP Ge c teret E 3 Referenced Method e 3 SCODE e RETE 3 Fit FOr rre TUM 4 SUMMARY dou 4 Sample tseHz qrcgeee ER 4 Sample HIStory oet Ree Re ERREUR FERE nme athens A OPER as a pra ER PEDRO A MER een E ER EA 4 Ilaiai ig e PRM EUER UHDIISEETMS 5 REAQCIES tad rU UTE TUM E MS TM 5 Equipment amp SUDDINES rias vv vuv Y va VE EV wer E da v ra var a Nervi vic iv vec 6 New amp Return to Use eicere nnne re rina C NMM eorr enne 7 Repar SEVICE enninu diuinus ex R unen athens M eco A oe MS cls comes iens iso decus ee oer eet 7 Glassware Preparatiorni erre n erar nta 7 Quality Control Pla ioci uncos conor en A r aseo se aan ois nents ate E
14. e Maintain these non conformance records for audit and review Proficiency Testing The laboratory pursues both accreditation and proficiency for Free and Total Chlorine at the 2230 Main Street laboratory location through the Canadian Association of Laboratory Accreditation Since 2008 the laboratory participates in the CALA Proficiency Testing program for Free and Total Chlorine in January amp June which are included in the C 32 Chlorine Test Group SOP 30 CI DPD v5 docx Date Printed 12 17 2014 Accredited Test Method Name SOP 30 Chlorine Free amp Total by Colorimetric DPD v5 Analytical Services Branch Method Date November 4 2014 Environmental Standards Division Page 10 of 19 Documentation Requirements Chlorine testing of the City of Winnipeg s distribution system is done in conjunction with the bacteriological testing program whereby samples are collected and submitted to a contract lab for analysis The results of the free and total chlorine are documented on the chain of custody forms that are submitted to the contract lab A copy of those results as well as the bacteriological testing is automatically forwarded to the Manitoba Water Stewardship s Office of Drinking Water This is applicable to the routine monitoring of the distribution system and water treatment plant effluent The list of locations and the template are in the FORMS subfolder Settings Switching Ranges 1 Press the MENU key The display will sh
15. e reacts with iron ammonia manganese sulfide and some organic compounds to help improve the finished water quality Chlorine is applied to water in its molecular or hypochlorite form and initially undergoes hydrolysis to form free chlorine A portion initially reacts with ammonia iron manganese sulfide and some organic materials and is therefore not available for disinfection This is called the chlorine demand of the water The remaining chlorine concentration after the chlorine demand is the total residual chlorine Total residual chlorine is made up of combined chlorine amount that has reacted with nitrates and ammonia and is unavailable for disinfection and free chlorine Free chlorine is chlorine available to deactivate disease causing organisms and is thus used as a measure to determine if the water is potable The pH and temperature of the water affect the balance and ratio of all the chlorine compounds The City of Winnipeg s drinking water supply is chlorinated at the source at the water treatment plant and at the three pumping stations Sodium hypochlorite is either generated on site in the WTP either from NaCl or from chlorine gas or purchased and stored in holding containers and used to chlorinate the effluent treated water Free and total chlorine is measured at numerous locations and throughout the distribution system Combined chlorines are not measured by this method but can be calculated from the total and free Refere
16. endar year the QC Records are converted to PDF and filed in the method folder Methods Chlorine DPD QC RECORDS The Glass Vials and any additional maintenance records are combined converted to PDF and filed in the same QC RECORDS folder The batch worksheets are archived boxed filed and stored according to the policy described in the Quality Manual and documented in the Box_RecordList x sx 3 worksheet Standard Operating Procedures SOP 17 Sampling SOP 18 Bacteriological Monitoring and Sampling Program SOP 30 CI DPD v5 docx Date Printed 12 17 2014 Accredited Test Method Name SOP 30 Chlorine Free amp Total by Colorimetric DPD v5 Analytical Services Branch Method Date November 4 2014 Environmental Standards Division Page 18 of 19 Equipment Instruction Manuals Manual Pocket Colorimeter II pdf Reference Texts Method 4500 CI G Chlorine Residuals Standard Methods for the Examination of Water and Waste Water approved by Standard Methods Committee 2000 Editorial Revisions 2011 Endnotes file and folder locations All forms worksheets reagent logs located in N Environmental Standards Methods Chlorine DPD SOP 30 FORMS Control Charts are printed from ChartGenerator xlsm workbook in N Environmental Standards Analytical Services Charts 3 Standard Method for the Examination of Water and Wastewater are downloaded from the on line account and maintained as PDF document in a single folder N E
17. fore been listed to facilitate re ordering of these chemicals Purchased Reagents DescriptionPart No Free Chlorine Powder Pillows for 10mL Samples 21055 69 Total Chlorine Powder Pillows for 10mL Samples 21056 69 Free Chlorine Replacement Vials for the SwiftTest Reagent Dispenser 21055 60 Total Chlorine Replacement Vials for the SwiftTest Reagent Dispenser 21056 60 SPEC Secondary Standard for chlorine 26353 00 Total Chlorine Reference Standard sealed ampoules NSI Solutions Inc VWR Int NSQCI 123 SOP 30_CI DPD_v5 docx Date Printed 12 17 2014 Accredited Test Method Name SOP 30 Chlorine Free amp Total by Colorimetric DPD v5 Analytical Services Branch Method Date November 4 2014 Environmental Standards Division Page 6 of 19 Deionized MilliQ water required to dilute samples in the 2 3 mg range Prepare fill a small bottle each day in use Note there is currently only one routine location in this range Reagent Preparation Logs No reagents are prepared but all reagents in use are logged into the LIMS Chemicals and Standards Module and the use of the Secondary standards is recorded on worksheets found in the Ch orineForms xlsx Total Chlorine Reference Standard Accuracy Check The following instructions were taken from the certificate of analysis If future instructions differ then follow the Certificate of Analysis for that specific standard Instructions may differ if this standard is purchased from another m
18. ibution system or of the water that is in the water main If the temperature is still changing continue flushing until a stable reading is obtained Return the thermometer to its protective case location 3 Reduce the water flow to prevent over spilling and splashing 4 If the current location is a chlorine residual monitoring location a Record the temperature reading on your worksheet or in your field logbook b Measure and recordethe chlorine as described in the next sections False Positive Readings The number of false positive readings from condensation can occur at any time but are more problematic in summer in air conditioned environment and with very cold water The number of false positive readings from Turbidity caused by dissolved oxygen is more pronounced during the winter Cold water has a higher concentration of saturated oxygen Once the sample comes out of the tap the pressure is released causing the dissolved oxygen to dissipate This4ncreases the Turbidity of the sample and causes positive interference To minimize the interference and for all non chlorinated water showing traces of chlorine perform the test as normal then perform these additional steps Remove the sample from the sample compartment open the cap 5 seconds to release any build up of pressure and air bubbles close re wipe the cell to remove any condensation invert to mix and take a second reading This should only take 10
19. icates a problem with the standard or the instrument SOP 30 CI DPD v5 docx Date Printed 12 17 2014 Accredited Test Method Name SOP 30 Chlorine Free amp Total by Colorimetric DPD v5 Analytical Services Branch Method Date November 4 2014 Environmental Standards Division Page 11 of 19 After the field testing and immediately upon returning to the laboratory read record and plot the result of Standard 2 following the same steps as above Taking Aliquots Test Sample All chlorine testing must be done in situ and cannot be collected for analysis This section describes the procedure for collection of the sample aliquot from a tap immediately prior to the addition of the DPD reagents If samples are collected for additional testing at the laboratory or contract laboratory then read the corresponding procedure s SOP 17 Sampling and or SOP 18 Bacteriological Monitoring and Sampling Program Excerpt from SOP 18 Bacteriological Monitoring Routine Sampling Procedure p 7 1 Open the cold water tap fully and allow the water to run for a minimum of three minutes before collecting the sample Locations with low flow or larger buildings such as schools may require up to five minutes 2 Check the water temperature by inserting a thermometer in the flowing stream When the temperature is stable usually at its lowest reading and the minimum time 3 min has expired the water is considered to be representative of the distr
20. ith the diamond mark facing the keypad Fit the meter cap over the cell compartment to cover the cell Note Wipe excess liquid and finger prints off sample cells SOP 30_CI DPD_v5 docx Date Printed 12 17 2014 Accredited Test Method Name SOP 30 Chlorine Free amp Total by Colorimetric DPD v5 Analytical Services Branch Method Date November 4 2014 Environmental Standards Division Page 13 of 19 6 Add the contents of one DPD Free Chlorine Powder Pillow one SwiftTest dispension of DPD Free or one DPD Total Chlorine Powder Pillow one SwiftTest dispension of DPD Total 7 Cap and shake gently for 8 For free chlorine pl 20 seconds the prepared sample cell i the prepared sample in the Note Shaking dissipates the cell holder Cover cell holder and cover the cell bubbles that may form in with the instrument cap samples with dissolved Wait three to six minutes Gases after adding the DPD Total Pillow Note A pink colar will ng chara B Proceed to step 10 present 10 Press READ ENTER The instrument will show followed by the results in mg L chlorine SOP 30 CI DPD v5 docx Date Printed 12 17 2014 Accredited Test Method Name SOP 30 Chlorine Free amp Total by Colorimetric DPD v5 Analytical Services Branch Method Date November 4 2014 Environmental Standards Division Page 14 of 19 Using Powder Pillows 1 Fill a 1 cm 10 mL cell 2 Press the POWER key to 3 Re
21. mental Standards Division Page 4 of 19 Range and Bias The low range is from 0 02 to 2 0 mg L Any value at or greater than 2 mg L is re analyzed in the high range method The high range is from 1 0 to 8 0 mg L In house studies show a significant positive bias in the 2 3 mg L range Since there is no bias in the 1 2 mg L range any prepared samples measured at 2 3 mg L are immediately diluted to 10 mL mixed and re measured This value multiplied by two due to the dilution is recorded as the final result This eliminates the use of a correction factor due to bias Fit For Use This method is fit for its intended use for the Determination of Chlorine Free and Total by Colorimetric DPD in water in the range of 0 02 to 8 mg L Cl when using a HACH Pocket Colorimeter II Method Validation by Gerry Levesque Quality Assurance Officer July 31 2009 and updated November 4 2014 Chlorine can be present in water as free chlorine and as combined chlorine Both forms can coexist in the same solution and can be determined together as total chlorine Free chlorine is present as hypochlorous acid or hypochlorite ion Combined chlorine represents a combination of chlorine containing compounds including but not limited to monochloramine dichloramine nitrogen trichloride and other chlorine derivatives The combined chlorine oxidizes triiodide ion I3 to iodine I2 The iodine and free chlorine reacts with DPD N N diethyl p phenylenediamine
22. move the met r cap with sample the blank Cap turn the meter on Place the blank irito the Note Samples must be The arrow should indicate tne Cell holderawvith the analyzed immediately and high range channel HR diamond mark facing the back of the eell holder Cover tRe c ll with the cap Note Wipe liquid off Sample celis cannot be preserved for later Note See page 2 4 far anal ysis information on selecting the correct range chamel ff Y a 4 Press ZERO SCROLL 5 Fill another 1 cm 10 mL The display will show sample cell to the 5 mL line followed by OO with sample Cap Remove the blank Note Do not use the same sample cells for free and total chlorine without thoroughly rinsing the cells between the free and total tests 6 Add two pillows or two dispensations of DPD Free Chlorine gt reagent or DPD Total Chlorine reagent to the sample cell Cap the cell and shake gently for 20 seconds ba y cet SOP 30_CI DPD_v5 docx Date Printed 12 17 2014 Accredited Test Method Name SOP 30 Chlorine Free amp Total by Colorimetric DPD v5 Analytical Services Branch Method Date November 4 2014 Environmental Standards Division Page 15 of 19 7 For free chlorine place the 8 For total chlorine placethe 9 Press READ ENTER prepared sample cell in the cell prepared sample in the cell The instrument will holder and cover with the holder and cover with the show foll
23. n the worksheet tab Glass Vials from the ChlorineForms xls workbook The hard copy is maintained on the Chlorine clipboard and filed in the method binder Also run the Batch Creation Samples are analyzed in batches created using the LIMS Create Batch function see LIMS User Manual Each batch is assigned a unique identifier which is recorded with each test assigned to the batch Each instrument used shall have its own unique batch ID and set of quality control samples outlined in the next section Method Quality Control a UXq o LL AUUAEUUUE The following QC parameters are incorporated into every run e For each day in use measure and record all three secondary standards CalVer in the laboratory just prior to the field testing These secondary standards are not used to calibrate or to calculate the accuracy of the instrument but they are useful for measuring performance and stability of the instrument and can only be used on the low range Enter in the LIMS aS No 3 Calibration Verification Standard e Perform the first duplicate using the laboratory tap water prior to leaving Perform a second field duplicate in the field preferably in the second half of the work shift Record on the Chlorine Residual Duplicates worksheet This is useful in determining if there is a problem with the DPD reagent or the reagent dispenser Enter in the LIMS as QC No 7 Duplicate Sample Prep amp Analysis e Measure and record
24. nced Method This method is modified from Standard Methods for the Examination of Water and Wastewater 4500 CI G Chlorine Residuals approved by Standard Methods Committee 2000 Editorial Revisions 2011 with the following modifications e a portable single wavelength unit Hach Pocket Colorimeter II is used with the wavelength set at 528 nm NOT 515 nm e no calibration staridards are made nor a calibration curve produced as the meter is factory preset e Monochloramine and Dichloramine are not measured with the PocketColorimeter II e Based on in house method validation studies samples measured in the range of 2 to 3 mg L are read at the high range immediately diluted by 2 with DI water then re read at the low range Scope This method applies to field analysis of Free and Total Chlorine residuals Proficiency testing samples are analyzed by the exact same procedure but the field location is the laboratory at 2230 Main St All other field locations are conducted within enclosed structures and buildings at other sites which are listed in the LIMS Dictionaries Locations and in the corresponding projects Minimum Detection Limits The minimum detectable limit based on the instrument set to the low range is 0 02 mg L CI SOP 30 CI DPD v5 docx Date Printed 12 17 2014 Accredited Test Method Name SOP 30 Chlorine Free amp Total by Colorimetric DPD v5 Analytical Services Branch Method Date November 4 2014 Environ
25. nvironmental Standards Analytical ServiceS SOPS RDF Method Validation Data is located in N Environmental Standards Methods Chlorine DPD SOP 30 METHOD VALIDATION For a demonstration of the preparation of this Standard see Chlorine_Check_Standards_Snips mp4 orsin flv format N Environmental Standards Methods Chlorine DPD SOP 30 SOP Equipment Operation Manuals are available from the following two locations N Environmental Standards Methods Chlorine DPD SOP 30 MANUALS N Environmental Standards Analytical Services Instrument amp Software HACH_Pocketll_Colorimeters 7 All Standard Operating Procedure SOP 17 Sampling SOP 51 Glassware SOP 50 LIMS User Manual in N NEnvironmental Standards MAnalytical Services SOP PDFs Access MSDS from the City of Winnipeg intranet Wellness webpage at http citynet intrahom toc wellness stm Safety Manual located in N Environmental Standards Safety SafetyManual 1 Safe Work Procedures in N Environmental Standards Safety Safe Work Procedures Safe Work Procedures 11 Perform the review as described in the Method Validation Method Review section of the Quality Assurance Manual SOP 16 QAM in N Environmental Standards Methods Quality Manual SOP 16 t2 RECORDS MANAGEMENT BY LAW NO 86 2010 http www winnipeg ca clkdmis DocExt ViewDoc asp DocumentT ypeld 1 amp Docld 5220 amp DocType O 13 Document using the Excel Workbook Box RecordList xlsx located in
26. ow SEL A flashing arrow indicates the current range Press the READ ENTER key to toggle between ranges Press MENU again to accept and exit back to the measurement screen Setting the Time 1 Press the MENU key then press the ZERO SCROLL key until the display shows a time in the 00 00 format Press READ ENTER The digit to be edited will flash Use the ZERO SCROLL key to change the entry then press READ ENTER to accept and advance to the next digit The time is entered in 24 hour format Using the Specv Standards Prior to using the field meter perform the following in the laboratory 1 Place the colorless Spec blank into the cell holder with the alignment mark facing the keypad Tightly cover the cell with the instrument cap Press ZERO The display will show 0 00 Place the STD 1 cell into the cell holder Tightly cover the cell with the instrument cap 4 Press READ ENTER Record the concentration measurement Repeat steps 3 and 4 with cells labeled STD 2 and STD 3 Plot Standard 2 on the control chart Compare these measurements with previous measurements to verify the instrument is performing consistently If these are the first measurements record them for comparison with later measurements Note The Specv Standards are used to verify that the instrument is functioning correctly The actual instrument calibration is a factory setting that cannot be changed Any significant change with these standards ind
27. owed by instrument cap within one instrument cap Wait three to the results in mg L chlorine minute after adding the DPD six minutes after adding the C5 Free Pillow DPD Total Pillows Proceed to Proceed immediately to step 9 step 9 Note Wipe off sample cells 10 Due to a positive bias in the range of 2 to 3 mg Lvof Free or Total Chlorine samples within this range are diluted by half and then re measured Immediately open the prepared sample cell and dilute to the 10mL mark using deionized MilliQ water cap mix and re measure Multiply this value by two as the final result Record the first measurement in the margins or elsewhere Both Free Chlorine and Total Chlorine are direct measurements in mg L Combined Chlorine Total Free Cl Calculation of Duplicates or Repeats Difference Qlaupi lint X 100 Clinitiai Duplicate and Initiahas final calculated value Calculation of Recovery Applies to calibration verification standards calibration checks and Certified Reference Materials or HRM Recovery Result Certified Value x 100 as listed on the Certificate of Analysis or as prepared expected concentration Safety glasses must be worn at all times in the laboratory and field when handling chemicals Lab coat must be worn in the laboratory at all times Wear gloves when handling corrosive chemicals wastewater effluent and unknown samples SOP 30 CI DPD v5 docx Date Printed 12 17 2014
28. response of the colour development Ensure sufficient time is allowed iii Condensation on the sample cells will cause positive interferences iv Turbidity from dissolved gases and air bubble cause positive interferences chlorinated raw water samples Refer to False Positive Readings page 11 Although the following compounds may interfere in the quantities listed the levels are too low in any of the City of Winnipeg s raw or treated water to cause interferences They are listed for information only e Acidity greater than 150 mg L CaCO3 may not develop full color or color may fade instantly Neutralize to pH 6 7 with 1 N Sodium Hydroxide Determine amount to be added on a separate 10 mLsample and then add the same amount to the sample being tested Correct for the additional volume e Alkalinity greater than 250 mg L CaCO8 may not develop full color or color may fade instantly Neutralize to pH 6 7 with 1 N Sulfuric Acid Determine amount to be added on a separate 10 mL sample and then add the same amount to the sample being tested Correct for the additional volume e Bromine Br and Iodine I gt interfere at all levels but they are not present in our water supply e Hardness has no effect at less than 1 000 mg L as CaCO3 Both the powder pillows and SwiftTestTM are used in the laboratory and field All reagents must be purchased through a Hach approved vendor The following part numbers from Anachemia Science have there
29. the mid range secondary standard immediately after returning to the laboratory this shows your instrument drift See worksheet tab name CRM Check Std amp Chart e All results are recorded in a notebook and shall include sample information and date analyzed Initial each page and record the LIMS Equipment ID of the chlorine kit being used e Verify QC data against established upper and lower control limits If a QC standard is out of control treat as a non conformance Weekly Vial and Accuracy Checks Perform once a week for each Pocket Colorimeter II in use Prepare the standard as described in 7ota Ch orine Reference Standard Accuracy Check page 6 Record the results on the control chart and in the LIMS QC Module as QC No 8 Sample Reference Material SOP 30 CI DPD v5 docx Date Printed 12 17 2014 Accredited Test Method Name SOP 30 Chlorine Free amp Total by Colorimetric DPD v5 Analytical Services Branch Method Date November 4 2014 Environmental Standards Division Page 9 of 19 Acceptance Criteria The secondary standards shall be within the tolerance limits as described in the certificate of analysis A reference value is also given The duplicates shall be within the established control limits of 5 4 for total and free chlorine Non Conformance and Corrective Action If two or more standards are outside of the control limits then repeat the verification page 10 Using the Specv Standards but subs
30. titute the Specv blank with reagent grade water If the duplicate recovery is outside of the control limits then e Verify the measurement with another colorimeter If the colorimeter is determined to be a problem return it to HACH Instruments for servicing These instruments cannot be calibrated in house e Run the Total Chlorine Accuracy Check weekly check If the secondary standards are outside of the control limits then e Verify the measurement with another colorimeter e Runa sample blank DI amp reagents e If the standards fail on two instruments then one or more of the standards has degraded and should not be used Continue to use the good standards until replacement is available Always replac the set not one std If the Total Chlorine Accuracy Check CRM std fails then e Verify the measurement with another colorimeter If this other colorimeter passed then take discontinue the use of the first colorimeter Place an OUT OF USE label on it and investigate furtherawhen time permits e Run a sample blank DI amp reagents If none of the above recommended actions resolve the problem then further consultation with supervisor and or quality assurance officer is required including but not limited to e Notifying the Branch Head of the non conformance through an E Mail identifying the problem e Carry out corrective action to resolve the problem See Quality Manual for corrective action procedure
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