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REGION I, EPA-NEW ENGLAND - CLU-IN

1. 19 8 2 3 Standard Reference Material SRM 0 cece eee eee eee 20 9 0 10 0 11 0 12 0 13 0 SOP X MET 920 Rev 0 0 Date 10 29 96 Page 4 of 39 Calibration and Operation se eire iE eee E ee eee eee 21 9 1 Instrument Calibration 2 2 0 eee tne ene nae 21 9 1 1 Instrument Performance Check 0 0 e eee eee eee 22 9 1 2 Initial Calibration ICAL ceee sie ee eae 22 9 1 3 Initial Calibration Verification ICV oooooooooooooooooooooooo 23 9 1 4 Continuing Calibration Verification CCV 0 eee eee eee 23 9 2 Instrument Operation 2 4 aco bose e ro eee ene te 24 9 2 1 Filling the Probe Dewar with Liquid Nitrogen 004 24 9 2 2 Instrument Performance Check 0 0 eee eee eee 24 9 2 3 Empirical Calibration and Method Development 25 9 2 4 Checking and Updating an Existing Method 004 28 Quality Assurance and Quality Control 2 2 2 eee ene 28 10 1 Instrument Performance Check 0 2c eee ee ene ene 28 10 2 Sensitivity Method Detection Limit and Practical Quantitation Limit 28 IS PRECISION AAA A en Si Hoga pre Mace tf tess Del ahe ane uiage ae thee tse chan docks 29 10 3 1 Analytical Precision Test 2 0 0 0 eee cece eee nae 29 10 3 2 Laboratory Duplicates 0 0 2 ee ene 30 10 3 3 Field Duplicate 31 O de seh dne RA OA 31 10 4 1 Instrument blank L
2. 13 1 3 13 1 3 1 13 1 3 2 13 1 3 3 13 3 3 4 13 1 3 5 13 1 4 13 1 4 1 13 1 4 2 SOP X MET 920 Rev 0 0 Date 10 29 96 Page 40 of 39 Quality Control Results Tabulate the initial calibration data for each target element including the linear regression data indicating the correlation coefficient standard error of fit and the F test value Tabulate all ICV and CCV percent recovery data Include the true value found value recovery and control limits Tabulate all instrument and method blank results Tabulate all field and laboratory duplicate results Include the original result the duplicate result the mean the relative percent difference RPD the control limits and the flag qualifier for those results not meeting the control limits Note report duplicate results as separate field samples The sample ID for the duplicate samples shall contain the suffix FD or LD for field duplicate or laboratory duplicate respectively Element results not meeting the control limits for duplicate analyses shall be flagged in the tabulated sample results but only for the original and duplicate data result Tabulate all PE sample results Include the true value found value recovery and control limits Raw Data All raw data associated with the preparation and analysis of standards QC samples and field samples analyzed on the X MET 920 must be submitted with the final report The raw
3. SOP X MET 920 Rev 0 0 Date 10 29 96 Page 13 of 39 Table 1 Recommended Source and X ray Line Selection for Typical Elements of Environmental Concern Recommended Analysis Lines Isotope Half Life Primary Radiation Element K Line keV L Lines keV Cd 109 1 3 Years Ag K X ray 22 1 keV Loc sa sos mn so 649 re 640 706 co 692 76 NETA E cu eos so ze es os as lios ama gt 1 119 123 re ms 26 Am 241 433 Years Gamma Radiation 59 keV ere ee Es ee 1 a lao a EIA MEET a EE ee El 3 0 3 1 3 2 3 3 3 4 4 0 SOP X MET 920 Rev 0 0 Date 10 29 96 Page 14 of 39 elements in the energy spectra Quantitative determination of an element present is made by comparing the intensity of a characteristic peak in the sample to a calibration curve of the same peak developed from standards of similar matrix and known concentrations The analysis can either be performed in a quantitative or semi quantitative fashion depending on the DQOs of the project Quantitative analysis is performed by matching the matrix of the standards to that of the site These standards called site specific calibration standards SSCS are actual samples taken from the site that are representative of the matrix present and span the concentration range of the elements of interest The samples are sent to a fixed laboratory acid digested and analyzed by A
4. Concentration determined by XRF analysis Comparability criteria for confirmatory analysis must be established and documented in the QAPP or SAP Samples that exceed the criteria should be discussed in the final report Performance Evaluation Samples Performance evaluation PE samples should be submitted for analysis on the X MET 920 and to the fixed laboratory performing the full protocol EPA methods to provide information on the quality of the individual data packages in accordance with the EPA Region I Performance Evaluation Program Guidance PE samples are certified standard reference materials SRMs from a source other than that used to calibrate the instrument At least one PE sample should undergo both XRF analysis and confirmatory full protocol EPA method analysis to facilitate data comparability A copy of the certified values for the SRM must be submitted with the final data packages to facilitate data evaluation 10 7 10 8 10 8 1 10 8 2 11 0 SOP X MET 920 Rev 0 0 Date 10 29 96 Page 36 of 39 Data Verification and Validation Data should be verified daily by a person other than that performing the work to check for calculation and transcription errors and to ensure that all QC samples meet acceptance criteria All data must be validated in accordance with the Region I EPA New England Data Validation Functional Guidelines for Evaluating Environmental Analyses Audits Internal Audits As p
5. 9 2 4 10 0 10 1 10 2 SOP X MET 920 Rev 0 0 Date 10 29 96 Page 31 of 39 calibration After the calibration of the last element is set press F2 to save it to memory and move onto the next screen Screen 9 The final element screen will prompt you to Insert check sample number Choose a standard at the action level if possible or a mid point standard from the calibration curve and following the prompts Analyze this standard Note which standard is used This check sample standard can be used later to manually update a calibration curve for source decay After running the check standard the screen will show Calibration Finished Press F8 to quit calibration mode Checking and Updating an Existing Method Although the X Met 920 automatically updates calibration curves for source decay there are times when manual normalization may be needed This could be the case if unexpected results are obtained on a known sample used to measure the reliability of the instrument To do this go to the X Met 920 Main Menu arrow down to Maintenance and hit Enter Hit F2 for Method Update and arrow key down to the method to be checked updated Hit F7 for Check Standard and follow the screen prompts Place the Check Standard for the specific method into the probe hit F1 and the red button on the probe to run the check analysis At the end of the analysis a table of assay values and deviations will be displayed If the difference in
6. for site characterization This SOP should be uses in conjunction with the X MET 920 Reference Manual supplied by the instrument manufacturer Practical Planning for Projects Using Field XRF Figure 1 depicts a decision tree which outlines the process that project planners should follow to plan environmental projects utilizing XRF There are three basic steps which must be followed when planning projects that will utilize XRF analysis techniques 1 Project scoping and determination of project DQOs 2 Ascertaining XRF needs 3 Developing the project Quality Assurance Project Plan Sampling and Analysis Plan QAPP SAP Performing these three steps prior to sample collection will enable the project planner to ensure that the XRF analyses are correctly executed on site and that the resultant XRF data are suitable for their intended use in site decision making SOP X MET 920 Rev 0 0 Date 10 29 96 Page 6 of 39 Figure 1 Project Planning Decision Tree Will portable XRF analyses achieve DQOs Yes Will Project Scoping Review Site History Determine Data Quality Objectives DQOs Perform full protocol EPA methods No Will Semi Quantitative Screening No achieve DQOs Yes SEMI QUANTITATIVE SOP PROCESS Identify elements and areas of interest Prioritize elements of interest Establish possible interfering elements Create or modify calibration method Calibrate X MET 920
7. EPA NE specifications contained in the Training Manual for Reviewing Laboratory Data Package Completeness dated June 1994 Used properly with the appropriate QC procedures and a definitive QA program XRF can be a very effective tool Used without regard to QC requirements and QA process controls the resultant XRF data may be unusable or may not be able to be interpreted Method Summary Principles of Operation XRF is a nondestructive qualitative and quantitative analytical technique used to determine the chemical composition of a sample In an XRF analysis primary X rays emitted from an X ray tube or a sealed radioisotope source are utilized to irradiate a sample The primary X rays incident on the sample cause the elements present in the sample to emit that is fluoresce their characteristic X ray line spectra The elements may be identified by the energies of the wavelengths of their spectral lines The unit of energy of an X ray is the kilo electron volt keV The X ray energy is proportional to the frequency of the X ray waves and is inversely proportional to the wavelength Since it is a fluorescent process the energy of the fluorescent X rays will always be of lower energy than the primary X ray energy In addition to the fluorescent X rays there will be a backscattering of the primary X rays Energies of the fluorescent and scattered X rays are converted within the detector into a train of electric pulses the amplitudes of whic
8. MET 920 Rev 0 0 Date 10 29 96 Page 21 of 39 EPA methods and the other portion is archived for possible future use The stainless steel sieve and spoons must be decontaminated between samples by washing with soap and water and drying Semi Quantitative Calibration Standards When the site objectives require semi quantitative measurements the choice of an appropriate calibration standard must be determined Sections 8 2 1 8 2 3 Depending on the relative accuracy of the screening desired one or more calibration standards may be used Note due to the differences in representativeness between standards and samples as well as the other interference factors described in Section 5 0 semi quantitative calibrations may generate false positive and or negative results Site Typical Calibration Standards STCS STCS are SSCS from a different site that contain the target elements of interest in the approximate range and matrix as the site under investigation If possible STCS should be chosen to reflect any chemical matrix effects that may be present in the samples on site A new instrument calibration must be performed in accordance with Section 9 1 each time STCS are employed STCS data must be validated in accordance with the most recent version of the Region I EPA NE Data Validation Functional Guidelines for Evaluating Environmental Analyses prior to use and all raw data and information must be provided with the data package to ensure th
9. data shall include Instrument printouts from all standards QC samples blanks and field samples analyzed Instrument printouts shall include 1 Energy Spectra The energy spectra must be labeled with the appropriate standard or sample ID and be scaled appropriately such that the energy peaks of interest are easily visible 2 Data The data printout must indicate the standard or sample ID the analysis date and the peak energy information including the associated target elements and intensity and or concentration readouts Copies of all relevant standard QC and field sample Preparation Logbook pages The logbook must include 1 Site name CERCLIS number if available and EPA Site Manager Name and affiliation EPA Contractor company name etc of analyst preparing the samples 3 Preparation date 4 IDs of all standards QC samples and field samples prepared correlating to field location 5 IDs of SSCS and field samples sent to a fixed laboratory for confirmation analysis and 13 1 4 3 13 1 4 4 13 2 13 3 SOP X MET 920 Rev 0 0 Date 10 29 96 Page 41 of 39 6 Pertinent comments Comments shall include a description of the samples color particle size course fine clay organic vs sand sediment etc any problems encountered in preparation the resolution of those problems any deviations from the methodology and the reasons why and all pertinent information related to the preparation of L
10. day The sample chosen for testing should be analyzed a minimum of 7 times in replicate same sample cup 7 times It is extremely important if the site action level s are known that the sample used to determine method precision be at concentrations near the site action levels If several precision measurements will be made over time it is recommended that samples with varying concentration ranges be used to assess the effect of concentration on method precision Samples at the site s action levels should however dominate the precision measurement process Precision measurements must be made using the same analysis time as that used to analyze the other project samples To assess analytical precision calculate the relative standard deviation RSD of the replicate analyses using Equation 2 Field XRF data to be considered adequately precise should be lt 20 with the exception of chromium RSD values for chromium should be lt 30 Equation 2 10 3 2 SOP X MET 920 Rev 0 0 Date 10 29 96 Page 33 of 39 RSD x 100 Mean Where S Mean Standard deviation of the analyte concentration with n 1 degrees of freedom Mean concentration of the analyte Laboratory Duplicates The precision of the sample preparation and analytical methods is determined by performing a laboratory duplicate analysis Laboratory duplicates must be prepared and analyzed at a frequency of 1 per 20 samples or 1 per sample matrix whichever i
11. for target and matrix elements as well as for backscatter The measurement windows identify areas in the spectrum where analytical signals are measured for each element Note the spectra of the single element standards are also used to determine the interelement correction factors that are used to correct for spectral overlap The X MET 920 software automatically calculates these factors On the screen you are asked if you want to use the spectra in memory Press F1 for yes you will see the location of the analytes and then select the single element spectra If all spectra needed for calibration are not selected or present in memory the X MET 920 will then list the elements that need to be measured By pressing F1 the software will prompt for measurement of each single element standard Based on the element measured the software automatically selects the peak location K L etc and the measurement window to the peak width at half height Refer to the reference manual for instructions on manually selecting the window location and limits if required When measured the spectra from the single element samples are automatically stored to disk for use a at a later time If the measured spectrum is already in the library the new spectrum will replace the old X ray emission on the energy scale is in kilo electron Volts keV Press F7 to continue The next screen prompts you to enter the assay value for each element for your first calibration
12. initial peak calibration check at the beginning of the day for the Pb Lg line is not at 990 2 channels re set the peak calibration verify that it is correct and perform an initial calibration If the peak calibration check performed at the end of the analytical sequence or after eight hours does not meet the above criteria then re set the peak calibration re perform the initial calibration and re analyze all samples since the last compliant peak calibration check All samples must be analyzed within a valid analytical sequence Initial Calibration ICAL This SOP is specific to the use of empirical calibration The other calibration techniques for semi quantitative analysis fundamental parameters and Compton peak normalization are acceptable for use but will require modifications to this SOP Sections 9 1 2 and 9 2 3 and documentation of these changes in the QAPP SAP All other procedures discussed in this SOP are valid for these other calibration techniques and should remain implemented After the peak calibration check criteria are met and prior to the analysis of any samples the X MET 920 must be calibrated empirically for quantitative or semi quantitative analysis The instrument must be calibrated at a minimum of once every seven 7 days for the Cd 109 source once every thirty 30 days for the Am 241 source and any time the continuing calibration verification criteria below are not met The correlation coefficient of the calib
13. meet the control limits then the analysis must be terminated and the problem must identified and corrected An acceptable ICV must be obtained prior to sample analysis Continuing Calibration Verification CCV A CCY standard s must be analyzed at the beginning and end of an analysis sequence and after every 10 samples The CCV standard s is an ICAL standard that contains all of the target elements The concentration of the CCV should be near the site action level or if no action level has been determined the concentration should be near the level of interest or the mid point of the initial calibration Calculate the percent recovery for each target element in the CCV using Equation 6 The percent recovery for each target element in the CCV must be 80 120 inclusive If the true value of the CCV is gt MDL and lt PQL then the control limit is the true value MDL If the CCV does not meet the control limits then the analysis must be terminated the problem must be corrected and the CCV must be reanalyzed If the CCV reanalysis yields a result within the acceptance criteria then the analysis may continue and all samples analyzed since the last compliant CCV must be re analyzed If the reanalysis of the CCV still does not meet the acceptance criteria than the instrument must be recalibrated the ICV verified and all affected samples reanalyzed within a valid analytical sequence 9 2 9 2 1 9 2 2 SOP X MET 920 Rev 0 0
14. particles in which the element of interest is in the fine particles If two 5 3 5 4 SOP X MET 920 Rev 0 0 Date 10 29 96 Page 16 of 39 separate aliquots of the sample are prepared in such a manner that one sample receives a greater portion of the fine particles then the relative volume of the element of interest in each sample will be different Thus when these samples are analyzed a larger amount of the element of interest will be exposed to the source X rays in the sample containing the larger volume of fine particles This will then result in a higher intensity reading and a measured concentration in the sample that is biased high Chemical Matrix Effects Chemical matrix effects result from differences in concentrations of interfering elements These interelement effects appear as either X ray absorption or enhancement phenomena Both effects are common in soils contaminated with heavy metals For example consider a series of samples containing nickel Ni and chromium Cr Ni in the sample will absorb the fluorescent X ray of Cr If the concentration of Cr remained constant and the Ni concentration increased then the detected signal for Cr would decrease Thus basing the concentration solely on the Cr signal the Cr concentration would appear to decrease In order to correct for this absorption effect on Cr a term must be added to the regression equation for Ni Information on developing regression equations for instrum
15. selected according to the excitation efficiency of the elements of interest Sample Preparation Summary Samples are prepared in one of two ways depending on the type of analysis For semi quantitative screening analysis sticks stones and other matter that is non representative of the sample are removed the sample is then thoroughly homogenized and an aliquot is placed directly in a plastic XRF sample cup The sample cup is capped with a clear polypropylene film and the sample identification is clearly labeled prior to analysis For quantitative analysis sticks stones and other matter that is non representative of the sample are removed and the sample is thoroughly homogenized The sample is dried and then sieved through a No 60 mesh sieve The fraction of the sample that passes the No 60 sieve is then re homogenized and aliquoted into the XRF sample cup The sample cup is capped with a clear polypropylene film and the sample identification is clearly labeled prior to analysis Refer to section 12 0 for a complete discussion of sample preparation Sample Analysis Summary For measurement the cup is positioned in the sample holder and exposed to primary X rays from the selected radiation source The sample fluorescent and backscatter X rays are detected and the results are recorded by the data system Qualitative determinations of the elements present in the sample are based on the locations of characteristic peaks produced by individual
16. standard Type this information and press ENTER Press Fl to accept this information The next screen asks to place standard 1 in the SSPS and press Start To do this take the standard 1 XRF cup wipe the bottom of the cup with a dry tissue and place it over measurement window Close the cover radiation shield and press the small RED button at the base of the SSPS probe unit This will start the analysis of standard 1 Repeat this for each standard in the method After running all standards in the calibration curve the screen shows Selection of Regression Term s for Analytes Choose regression terms using the arrow keys and press ENTER on the chosen terms Press F1 to perform the regression You MUST press F4 Residuals to view and save calibration curve If you need to you can delete outlying points when viewing a calibration curve by pressing Fl Ideally the regression term chosen will give a linear regression with a correlation coefficient R close to 1 00 a standard error of fit S which is very low and a Fisher s factor F which is maximized Refer to reference manual for the discussion on choosing regression terms and establishing the best possible assay method When complete print out the calibration curve by pressing F3 Press F7 to continue If satisfied with the calibration curve for an analyte press F2 to move on to the Next Analyte Continue defining the regression terms for each target element s
17. steel spoon Re composite and repeat the quartering process three times Fill one or more XRF sample cups approximately 3 4 full with sample Cut and tension wrinkle free a piece of polypropylene film over the top of the cup and seal using the plastic film securing ring Label the sample cups appropriately The remaining sample may be placed in a clean labeled glass or plastic container to be archived or submitted for confirmatory analysis The stainless steel sieve and spoons must be decontaminated between samples by washing with soap and water and drying 12 2 12 3 SOP X MET 920 Rev 0 0 Date 10 29 96 Page 38 of 39 Sample Analysis From the main menu arrow up to ANALYSIS and press ENTER Arrow down to the method you wish to use Press F5 to toggle the printer on Press ENTER to chose the method On the top of the screen you will see NAME gt Near the bottom of the screen is the method name chosen the probe type the analysis time and print if the printer is activated At the very bottom of the screen there are numbers 1 8 with soft key functions To analyze the sample after NAME gt type the sample name and then ENTER Wipe the bottom of the sample cup to be analyzed with a tissue to remove any dirt dust or moisture and place cleaned sample cup into SSPS probe sample holder Close the sample holder protective cover On the computer press F1 to start screen says set probe in measurement position then pre
18. the amount of chemical added or final concentration must be adjusted to reflect this The clean soil or inert material used in LPCS preparation must be analyzed as a control blank following instrument calibration to verify that the elements of interest are not present If the soil or inert matrix contains an element of interest its concentration must be determined by the method of standard addition and the actual LPCS concentrations must be corrected for this amount A minimum of 3 LPCS and the unspiked matrix are required to perform the method of standards addition Once the base level concentration of the soil or inert matrix is determined the instrument must be recalibrated using the unspiked matrix as an additional calibration point along with the corrected LPCS concentrations Liquid Chemical Prepared LPCS Alternatively a standard may be prepared by adding a known amount of an aqueous standard to aknown amount of clean soil or inert material The clean soil or inert material must first be pre dried and sieved through a No 60 250 um sieve The volume of aqueous metals standard used must be sufficient to create a standard soil slurry where all parts of the soil come in contact with the liquid standard The slurry is then thoroughly mixed and dried at lt 105 C The dried standard must be ground in a mortar and pestle to thoroughly homogenize the standard to a uniform consistency and particle size To establish a calibration range for the
19. 0 2 2 1 Sample Preparation Summary 00 cee eee eee eee eee 10 2 2 2 Sample Analysis Summary 0 0 eee eee eee eae 10 Definitions 2 22525 rei waetas AAA ek aoa wae hee ie tte ts 12 Health and Safety os cccsmweetos diantaanerbi dane wanenbde wink wnnene wane we aaenbe AOE EOLA ERI MED ALD ALA 12 Interferences and Potential Problems 0 0 0c cee eee eee nae 13 5 1 Sample Representativeness 2 0 0 cette een eens 13 5 2 Physical Matrix Effects eee ca ek eee eae A A S Zils oa E 13 5 3 Chemical Matrix Effects 2 0 cence ene eens 14 5 4 X ray Spectrum Oyerlap rarna subs RARA ARA ka Masala 14 535 Moisture Content AAA oe oo ee Adie ee ee tes 15 Personnel Qualifications s scs s s 57e s7ec8 ers ek eid es NEUERE a RO ee er AEO 15 Equipment and Supplies 0 0 0 ene nee ene nae 15 7 1 Instrument Description 0 e e eee ene ene E 15 LEDS UPS tt Mey tet lta tattle ait bia tei tla E Gd A Wate Paging Daan a 16 Calibration Standards 16 8 1 Quantitative Analysis Using Site Specific Calibration Standards 17 8 1 1 Site Specific Calibration Standard Sampling 004 17 8 1 2 Site Specific Calibration Standard Preparation 004 18 8 2 Semi Quantitative Calibration Standards 0 0 0 0 tenes 19 8 2 1 Site Typical Calibration Standards STCS 0 000000 19 8 2 2 Laboratory Prepared Calibration Standards LPCS
20. 0 Solid State Probe Set SSPS contains two nuclear radiation sources cadmium 109 and Americium 241 During all measurements the sample lid on the probe must be closed over the sample to shield the user from exposure to nuclear radiation The probe must not be opened except by authorized personnel Proper training for the safe operation of the instrument and radiation training should be completed by the analyst prior to field operations Radiation safety information for the X MET 920 can be found in the operators manual Protective shielding should never be removed by the analyst or any personnel other than the manufacturer The analyst should be aware of the local state and national regulations that pertain to the use of radiation producing equipment and radioactive materials with which 5 0 5 1 5 2 SOP X MET 920 Rev 0 0 Date 10 29 96 Page 15 of 39 compliance is required Licenses for radioactive materials are of two types 1 general license which is usually provided by the manufacturer for receiving acquiring owning possessing using and transferring radioactive material incorporated in a device or equipment and 2 specific license which is issued to named persons for the operation of radioactive instruments as required by local state agencies The radiation safety officer is responsible for properly instructing all personnel maintaining inspection records and monitoring X ray equipment at regular intervals A copy of t
21. A or ICP in accordance with a full protocol EPA methods It should be noted that confirmatory results will vary depending on whether a partial digestion procedure or a total digestion procedure is used Confirmatory full protocol EPA methods should be chosen in the project scoping phase and meet the data quality objectives of the project It is essential that all SSCS and confirmatory sample analyses be performed using the same EPA methods for sample preparation and analysis These methods should be documented in the Quality Assurance Project Plan QAPP Sampling and Analysis Plan SAP and DQO Summary Form Once the SSCS results are validated in accordance with Region I EPA New England Data Validation Functional Guidelines for Evaluating Environmental Analyses and deemed usable they are considered the true values of the SSCS and can be used in calibrating the XRF analyzer SSCS are discussed in further detail in Section 8 1 For semi quantitative screening standards used to calibrate the analyzer are obtained from sources other than the project site These standards may be SSCS from another site standards prepared in house or NIST certified standard reference materials Screening standards are discussed further in Section 8 2 Definitions SSCS Site Specific Calibration Standards STCS Site Typical Calibration Standards LPCS Laboratory Prepared Calibration Standards SRM Standard Reference Material Health and Safety The X Met 92
22. Date 10 29 96 Page 27 of 39 Instrument Operation Filling the Probe Dewar with Liquid Nitrogen To operate the Solid State Probe Set SSPS the Si Li detector must be cooled with liquid nitrogen 1 Place the probe on its side on a flat surface Unscrew the dewar plug brass screw from the filling port 2 Slide the L shaped outlet tube of the funnel all the way into the filling port and hand tighten the brass knurled nut on top the filling port thread Arrange the funnel so that its cone faces upward 3 Pour liquid nitrogen slowly into a funnel and let it flow into the probe dewar It usually takes approximately three funnel volumes of liquid N to fill the probe dewar 0 45 liter capacity The dewar is filled when you see a cone like spray of liquid nitrogen from around the brass nut of the funnel connector 4 After the probe dewar is filled carefully unscrew the funnel nut holding the insulated sleeve and withdraw the funnel from the dewar port Quickly screw back in the dewar plug and hand tighten In a few seconds the pressure of the liquid nitrogen will build up inside the probe dewar and hissing sounds of escaping gas through relief valves will be heard Press the green switch on the probe to secure the radioactive sources from use until the probe reaches the proper operating temperature 5 Wait approximately thirty minutes for the probe to cool down before operating NOTE The threads on the dewar filling port will r
23. SOP X MET 920 Rev 0 0 Date 10 29 96 Page 1 of 39 REGION I EPA NEW ENGLAND STANDARD OPERATING PROCEDURE FOR ELEMENTAL ANALYSIS USING THE X MET 920 FIELD X RAY FLUORESCENCE ANALYZER U S EPA NEW ENGLAND Region I Quality Assurance Unit Staff Office of Environmental Measurement and Evaluation Prepared by Alan W Peterson Date 10 30 96 Reviewed by Moira M Lataille Date 10 30 96 Senior Technical Specialist Approvedby Nancy Barmakian Date 10 30 96 Branch Chief SOP X MET 920 Rev 0 0 Date 10 29 96 Page 2 of 39 1 0 2 0 3 0 4 0 5 0 6 0 7 0 8 0 SOP X MET 920 Rev 0 0 Date 10 29 96 Page 3 of 39 Region I EPA New England Standard Operating Procedure for Elemental Analysis Using the X MET 920 Field X ray Fluorescence Analyzer Table of Contents Scope and Applications pcre waren opereta cial a ie e aea Chih che Dn e Pee Pande ae 4 1 1 Practical Planning for Projects Using Field XRF 0 0 0 eee eee eee 4 1 1 1 Project Scoping and Determination of Project Data Quality Objectives 6 1 1 2 Ascertaining XRF Needs 0 eee ee tenes 6 1 1 3 Developing the QAPP SAP 6 ccc eee ee een nee 6 Method Summary 22a sanawax nana anes anne anes dadsadasrcasuca cara E 7 2 1 Principles of Operation 42 lt scars eo A 7 2 1 1 Eluorescent ATLAS rio ii a a Rda 8 2 1 2 Scattered A oa 10 2 2 X MET 920 XRF Analyze i aaa aa e aa a eee ene nae 1
24. The default time for standard analysis is 120 seconds Analysis Time 120 ENTER The default time for sample analysis is 120 seconds This time may be altered depending on the DQOs of the project Analysis times generally range from 60 300 seconds Longer count times improve the precision or reproducibility of the measurement however increasing the count time by a factor of 4 will provide only 2 times better precision so there is a point of diminishing returns Increasing the count time also decreases the detection limit and decreases sample throughput Standard and sample analysis times should be identical If you are satisfied with all entries press F7 to continue If you need to make changes to any entries press Fl and arrow key down to the entries you need to change When you are satisfied press F7 to continue Analytes selection Move the highlight bar with the arrow keys onto the elements you wish to analyze and press ENTER each time After the analytes are chosen press F7 Screen 4 Screen 5 Screen 6 Screen 7 Screen 8 SOP X MET 920 Rev 0 0 Date 10 29 96 Page 30 of 39 Units and standard concentrations Enter the concentration units for each element selected Then enter the high and low standard concentrations for each element When completed press F7 The next step in the calibration sets the measurement windows for each element in the method using single element samples The windows are set
25. Thus by reducing the number of target elements the number of required SSCS can be significantly reduced the complexity 8 1 SOP X MET 920 Rev 0 0 Date 10 29 96 Page 19 of 39 of the calibration can be simplified and a large cost savings can be realized by reducing the number of samples that require fixed laboratory analysis using full protocol EPA methods Note the X MET 920 can only analyzed ten 10 elements at one time in a calibration method Of those 10 elements only 6 elements may be reported quantitatively and of the remaining four elements one must always be the backscatter peak the Compton K peak from the source radiation Figure 1 Section 1 1 illustrates the typical sampling and analysis scheme for both quantitative and semi quantitative analyses Quantitative Analysis Using Site Specific Calibration Standards Site specific calibration standards SSCS are actual samples from the site under investigation that span the range of concentrations found on site for the elements of interest Elements of interest not only include the target elements under investigation but also those elements present that may create possible interference effects SSCS must be representative of the matrix under investigation refer to Section 5 1 If there are distinctly different matrices on site that require analysis separate SSCS must be sampled for each matrix The concentration of all target elements and any elements present t
26. aboratory Prepared Calibration Standards Copies of all relevant Analysis Logbook pages The Analysis Logbook must detail the exact sequence in which all standards QC samples blanks and field samples were analyzed The logbook must include 1 Site name CERCLIS number if available and EPA Site Manager Name and affiliation EPA Contractor company name etc of analyst preparing the samples Analysis date Radioisotope source used 5 Report peak calibration results for the Pb L line Indicate the peak energy reading and any recalibration steps taken including a list of any samples requiring reanalysis 6 IDs of all standards QC samples and field samples analyzed include pertinent concentrations of standards and QC samples 7 Data file IDs if different than samples IDs and any data disk storage identification and 8 Pertinent comments related to the analysis Comments shall include any problems encountered during the analysis the resolution of those problems any deviations from the methodology and the reasons why and all pertinent information related to analysis decisions made during the run sequence aS Copies of all other relevant Field Logbook pages ICP AA Confirmatory Data Package and Data Validation Report for SSCS For full protocol EPA method analyses complete data packages should be provided in accordance with the Region I EPA NE specifications contained in the Training Manual for Reviewing Laborato
27. analysis additional standards may be prepared from aqueous standards of different concentrations or by preparing serial dilutions of the first standard All serial dilutions must mixed in the identical manner as described in Section 8 2 2 1 For example to prepare a 10 000 mg kg antimony standard pipet 10 mL of a 10 000 mg L antimony AA ICP standard into a beaker containing 10 g of dry clean soil or inert material Mix to a uniform slurry dry in an oven at lt 105 C and re mix grind until the standard is thoroughly homogenized 10 000 mg L Sb 0 010 L 0 010 kg 10 000 mg kg Sb The clean soil or inert material used in LPCS preparation must be analyzed as a control blank following instrument calibration to verify that the elements of interest are not present If the soil or inert matrix contains an element of interest its concentration must be determined by the method of standard addition and the actual LPCS concentrations must be corrected for this amount A minimum of 3 LPCS and the unspiked matrix are required to perform the method of standards addition Once the base level concentration of the soil or inert matrix is determined the instrument must be recalibrated using the unspiked matrix as an additional calibration point along with the corrected LPCS concentrations Standard Reference Material SRM NIST or other commercially available certified standard reference materials may be used A copy of the certified result
28. ard calibration and can reduce the problems associated with varying sample matrices Use Equation 5 to calculate Compton peak normalized sample results SOP X MET 920 Rev 0 0 Date 10 29 96 Page 25 of 39 Equation 5 A Sx So Sample Concentration mg Kg ee Ay S Where A Baseline corrected sample intensity Ax Baseline corrected sample Compton K intensity Sx Baseline corrected standard Compton K intensity S Baseline corrected standard intensity Sc Standard concentration mg Kg Certified standards used in Compton peak normalization calibrations may include either SSCS STCS LPCS or SRM For optimum results the certified reference standards should be of similar matrix as the samples and should contain the elements of interest at concentrations near those expected in the samples Although the X MET 920 software can be adapted to supply the line intensities to manually calculate Compton peak normalized results it is not a routine procedure accommodated by this instrument and will thus not be addressed further in this SOP Instrument Performance Check Prior to the analysis of any standards or samples the peak calibration of the X MET 920 must be verified The channel for the Pb Lg line on the multi channel analyzer of the XPCU board must be verified at the beginning of the day prior to the initial calibration and at the end of the analysis sequence or every 8 hours whichever is more frequent If the
29. art of the Quality Assurance Quality Control Program for an XRF project a series of internal audit checks should be instituted to monitor and maintain the integrity of the data A daily QC review will insure that all QC samples met acceptance criteria and monitor any corrective actions taken and or institute corrective action that should have been taken and were not All corrective actions taken as part of an internal audit must be documented in the appropriate logbooks and if these corrective actions impact the final data reported then they must also be documented in the final report narrative External Audits The Agency reserves the right to perform periodic field audits to ensure compliance with this SOP Sample Collection Preservation and Storage Soil and sediment samples may be collected in either glass or plastic containers or plastic zip lock bags Approximately 8 ounces of sample volume should be collected This is equivalent to a sampling area approximately 4 inches by 4 inches square by 1 inch deep in size Initial homogenization of the sample and removal of non representative material should take place at the time of sampling To maintain sample integrity chain of custody procedures must be implemented at the time of sampling to 1 document all sample locations and associated field sample identification numbers 2 document all quality control samples taken including field duplicates split samples for confirmatory analyses and PE sa
30. ation Report for Field Samples 38 14 0 1 0 1 1 SOP X MET 920 Rev 0 0 Date 10 29 96 Page 5 of 39 References sacs ds 39 Region I EPA New England Standard Operating Procedure for Elemental Analysis Using the X MET 920 Field X ray Fluorescence Analyzer Scope and Application The following Standard Operating Procedure SOP describes the procedures used to operate the EPA Region I X MET 920 portable X ray Fluorescence XRF analyzer for the analysis of metals in soils and sediments The SOP describes two methods of calibration and analysis quantitative analysis and semi quantitative screening to be used depending on the data quality objectives DQOs of the project For example projects involving comprehensive extent of contamination studies or site clean up to a defined action level will require the quantitative technique of analysis while the semi quantitative screening technique would be more appropriate for site investigation work or initial delineation of site hot spots Whichever calibration technique is chosen the analyst should always strive to prioritize the number of elements under investigation typically 1 3 elements are recommended This strategy will not only simplify instrument calibration but will minimize the time effort and cost of the project If the precision accuracy and detection limits of the field XRF analyzer meet the project DQOs then XRF is a fast powerful cost effective technology
31. e scientific defensibility of the calibration standards Laboratory Prepared Calibration Standards LPCS If satisfactory STCS are not available for all elements at appropriate concentrations it may be necessary to prepare quantitative standards from laboratory stock chemicals Such standards may be prepared by mixing finely ground dry chemicals or liquid standards with a clean soil silica sand or other inert material e g Somar Mix from Somar Laboratories NY NY or equivalent Solid Chemical Prepared LPCS Prepare the high LPCS first by adding a known weight of dry chemical s to a known weight of clean dry soil or inert material The clean soil or inert material must first be pre dried and sieved through a No 60 250 um sieve Following the addition of the dry chemical the combined mixture must be ground in a mortar and pestle to thoroughly homogenize the standard to a uniform consistency and particle size Serial dilutions of the high standard may then be prepared to establish the calibration range for the analysis All serial dilutions must mixed in the identical manner as the initial standard For example to prepare a 10 000 mg kg antimony standard add 0 60 g of Sb O to 49 4 g of dry clean soil and mix grind thoroughly 600 mg Sb O 83 5 Sb 10 000 mg kg Sb 0 050 kg 8 2 2 2 8 2 3 SOP X MET 920 Rev 0 0 Date 10 29 96 Page 22 of 39 Note if the purity of the dry chemical is lt 97 then
32. ee Oe ee al 31 10 4 2 Method blank sasae Wa ene BR da NS Rnd WE BLES BALA aL 31 10 4 3 Control Blank nanasa nea Ga wettest dete aaa 32 10 5 Confirmatory Sample Analyses 0 0 0000s 32 10 6 Performance Evaluation Samples 0 0 eee eee ena 32 10 7 Data Verification and Validation 2 2 0 0 0 eee cece eens 33 10 8 Audison RS a E Seed eh hed i hed bg Eee 33 10 8 1 Internal AUS a oe tee oye oe oe ue tee Me we a 33 10 8 2 External Audits 00 5 0 0 ee eee eee eee eee wet ee eet 33 Sample Collection Preservation and Storage 2 20 eee ee eee 33 Sample Preparation and Analysis 0 0 0 cece eee nen eee n nee 34 12 1 Sample Preparation An a ta td HAA AAA ATA OA OA etait 34 12 1 1 Quantitative Analysis Preparation 0 0 0 eee eee eee eee 34 12 1 2 Semi Quantitative Screening Preparation 0 0 e eee eee eee 34 12 2 Sample Analysis tte waco ete Wate eee ee la 35 12 3 Analysis Sequence sta oes gee abba 35 Documentation Reporting Results and the Final Report 0 0 000000000 ee 36 13 1 Field XREF Final Report cccceuneescesiwe see aa er 36 13 1 1 Report Narrative arios dat dea Ate e tei det tn Ie a 36 13 1 2 Sample Results 000 O O A A eee ete 36 13 1 3 Quality Control Results 2 0 0 eee eens 37 13 1 4 Ra Data ee ae en 37 13 2 ICP AA Confirmatory Data Package and Data Validation Report for SSCS 38 13 3 ICP AA Confirmatory Data Package and Data Valid
33. ent calibration is discussed at length in the X MET 920 reference manual As a general guideline elements that may cause chemical matrix effects are 1 near the target element 4 or 5 atomic numbers 2 excited by the source 3 at a concentration greater than 10 of the target element s concentration and 4 present in varying concentrations in the area under investigation It is essential to define the chemical matrix effects on the elements of interest prior to instrument calibration X ray Spectrum Overlap Certain emitted X ray lines from different elements when present in the sample can be very close in energy and therefore interfere by producing an overlapping spectrum Typical spectrum overlaps are caused by the Kg line of element Z 1 overlapping the K line of element Z where Z the atomic number of the element Note in heavier elements the Kg line of elements Z 2 or Z 3 may create the spectral overlap of the K line of element Z This is called the K Kg interference Since the K Kg intensity ratio for a given element usually varies from 5 1 to 7 1 the interfering element must be present at a large concentration to disturb the measurement of element Z For example a large concentration of vanadium Z 23 could interfere with chromium Z 24 Vanadium V has K and Kg energies equal to 4 951 and 5 427 keV respectively Chromium Cr has a K energy equal to 5 41 keV Since the resolution of the Si Li detector i
34. equire periodic lubrication on a semi annual basis or as needed Lubricate with DOW Corning 33 Lubricant or equivalent While the Si Li Solid State Probe is cooling turn on the computer and monitor Type either SSPSA for the Cd 109 Source or SSPSB for the AM 241 source Follow the prompts and press ENTER After thirty minutes the instrumentation is ready for use Instrument Performance Check The Lead Pb Lg peak optimum must be checked before instrument calibration or analysis is performed and at the end of the analytical sequence or every eight hours whichever is more frequent To assure proper peak assignment and identifications you must check to make sure the Pb Lg peak right side large Pb peak is at channel 990 two channels To do this place the pure element Pb standard into the SSPS probe sample holder 9 2 3 SOP X MET 920 Rev 0 0 Date 10 29 96 Page 28 of 39 The Main Menu for X Met 920 Software Version 1 33 November 1994 consists of 1 ANALYSIS 2 CALIBRATION 3 MAINTENANCE From the main menu of the computer arrow down to MAINTENANCE and press ENTER Press F3 for Instrument Press F3 for Test Measurement Press F3 for Time When in Time type 30 for 30 second analysis time and press ENTER The screen message says Probe in Reference position Press Start to begin On the base of the SSPS probe push the red start button and then Press F1 on the keyboard to start acquisition When ac
35. er MCA that records the spectra during measurements The SSPS houses the sample holder the Cd 109 and Am 241 radioisotope sources and the Si Li detector The Si Li detector is a silicon drifted with lithium semi conductor crystal diode which is reversely polarized and cooled by liquid nitrogen The detector is capable of resolution equal to 0 170 keV 7 2 7 2 1 7 2 2 7 2 3 7 2 4 1 2 5 7 2 6 7 2 7 8 0 SOP X MET 920 Rev 0 0 Date 10 29 96 Page 18 of 39 Instrument Transport The X MET 920 computer monitor probe etc MUST be handled with care during transport The original shipping containers should be used at all times to avoid damage in transit The shipping container for the SSPS must be properly labeled in accordance with regulations governing the shipment of radioactive materials Supplies Sieve No 60 250 um stainless steel Nylon or equivalent mesh sieve Polyethylene XRF sample cups Film for sample containment Mylar Kapton Spectrolene polypropylene or equivalent 2 5 or 6 0 um thick Stainless steel spoons Mortar and pestle glass agate or aluminum oxide Aluminum drying pans Drying oven Calibration Standards The appropriate choice of calibration standards is made based on the project DQOs When definitive quantitation is required site specific calibration standards must be used refer to Section 8 1 When semi quantitative results are required the choice of the appropriate se
36. generate a minimum 5 point calibration curve for each target element that spans the range of concentrations found in the area under investigation The high and low SSCS for each target element will determine that element s linear calibration range The remaining standard concentrations should be roughly distributed throughout this range Note additional SSCS near the concentration range of interest or site action level will improve the accuracy of the calibration at that level For each interfering element present increase the number of SSCS for the element being interfered with by 5 For example consider an analysis in which Pb and Cr are the target elements To develop the two 5 point calibration curves it required a combination of 7 SSCS to span the range of 8 1 2 SOP X MET 920 Rev 0 0 Date 10 29 96 Page 20 of 39 concentrations found on site Unfortunately Ni was also present in high enough concentrations to cause a chemical matrix effect with the Cr X ray In order to improve the calibration model and reduce the chemical matrix effects 5 more Cr SSCS which contain Ni are added to the Cr calibration curve Thus a total of 12 SSCS are now needed to calibrate the instrument for the two target elements SSCS collected for an interfering element should reflect the variability of that element s concentration found in relation to the concentration of the target element Note mixing of high and low concentration soils to p
37. gic variability can occur when more than one type of matrix exists on site i e one part of the site is a rich organic soil while the other part of the site is a course sand In this case quantitative analysis may require two sets of site specific calibration standards to minimize error Contaminant concentration variability is an issue that must be dealt with at each site For example if the contamination on site is due to a liquid waste dumped in the soil the dispersion in the area of concern is more likely to be uniform and thus the samples more likely to be representative of the area If however the contamination is due to a solid waste of varying size and shape the likelihood of samples being representative of the area is lower and thus the error in results is greater In this latter case the error can be minimized by homogenizing a large volume of sample prior to analyzing an aliquot or by analyzing several samples at each sampling point and averaging the results Preparation and analytical variability are minimized by using consistency in technique and by matching standard and sample matrices Physical Matrix Effects Physical matrix effects are the result of variations in the physical characteristics of the sample including particle size uniformity homogeneity and surface condition Thorough and consistent sample preparation is critical to minimizing these effects For example consider a sample composed of a mix of fine and coarse
38. h are linearly proportional to the energy An electronic SOP X MET 920 Rev 0 0 Date 10 29 96 Page 9 of 39 multichannel analyzer measures the pulse amplitudes which is the basis of qualitative X ray analysis The number of counts at a given energy per unit of time is representative of the element concentration in a sample and is the basis for quantitative analysis Fluorescent X rays During interaction of the primary source X rays with samples they may either undergo scattering or absorption by sample atoms in a process known as the photoelectric effect This latter analytical phenomenon illustrated in Figure 2 occurs when incident radiation knocks an electron from the inner most shells of an atom The atom now in an excited state releases its surplus energy almost instantly by filling the vacancy created with an electron from one of the outer energy shells This rearrangement of electrons is associated with the emission of an X ray with a wavelength characteristic in terms of energy of the given atom Primary X ray eee ray gt e Ejected from K shell Figure 2 Electron rearrangement in an atom exposed to X ray radiation generating a characteristic fluorescent X ray X rays are created in the inner most shells of an atom the K L and M atomic shells Each characteristic X ray line is defined with the letter K L or M which signifies which shell had the original vacancy and by a subscript alpha
39. hat may cause chemical matrix effects refer to Section 5 3 must be determined by independent AA or ICP analysis in accordance with the full protocol EPA methods specified in the QAPP SAP The same method must be used to perform all confirmatory analyses to ensure data comparability Independent SSCS analyses must be performed in triplicate and the average result for each element is to be used in the instrument calibration SSCS data must be validated in accordance with the most recent version of the Region I EPA NE Data Validation Functional Guidelines for Evaluating Environmental Analyses prior to use and all raw data and information must be provided with the data package to ensure the scientific defensibility of the calibration standards The X MET 920 reference manual uses the term modeling to describe the process of modifying the regression equation of an element s calibration curve to correct for chemical matrix effects and backscatter from the X ray source To properly model a regression equation and compensate for these effects a series of SSCS containing both interfering and target elements at known and varying concentrations are required The total number of SSCS required increases significantly with each target and interfering element Again by reducing the number of target elements in the analysis the number of SSCS required may be greatly reduced Site Specific Calibration Standard Sampling Collect sufficient SSCS to
40. he radioactive material license and leak tests should be present with the instrument at all times and available to local and national authorities upon request Radiation monitoring equipment should be used with the handling of the instrument The operator and the surrounding environment should be monitored continually for analyst exposure to radiation Thermal luminescent detectors TLD in the form of badges and rings are used to monitor operator radiation exposure The TLDs should be worn in the area of most frequent exposure The maximum permissible whole body dose from occupational exposure is 5 Roentgen Equivalent Man REM per year Possible exposure pathways for radiation to enter the body are ingestion inhaling and absorption The best precaution to prevent radiation exposure is distance and shielding Interferences and Potential Problems Generally the instrument precision is the least significant source of error in XRF analysis User or application related error is more significant and will vary with each site and the completeness of instrument calibration The components of user or application error are the following Sample Representativeness To accurately characterize site conditions samples collected must be representative of the site or area under investigation Variables affecting sample representativeness include geologic variability contaminant concentration variability and sample collection and preparation variability Geolo
41. ject planner decides that XRF techniques may be applicable to project DQOs then the planner must answer the following questions e What type of XRF data are required quantitative or semi quantitative e What detection levels and or action levels must be met for each target element e What full protocol EPA methods will be used for confirmatory and or site specific calibration standard SSCS analyses e Will the resultant XRF data meet project objectives Section 2 0 discusses the basic principles of XRF analysis so that project planners will be familiar with the technology Developing the QAPP SAP The XRF project planner must develop a QAPP SAP that details the following e Project description and DQOs e Project personnel and their responsibilities e Sampling protocols sampling locations and numbers of samples to be collected e Quality Assurance QA and Quality Control QC elements required including frequency requirements acceptance criteria and corrective actions refer to Sections 8 and 10 2 0 2 1 SOP X MET 920 Rev 0 0 Date 10 29 96 Page 8 of 39 e SSCS analytical protocols for quantitative analysis including frequency requirements QC acceptance criteria and corrective action measures e Confirmational analytical protocols with frequency requirements QC acceptance criteria and corrective action measures note these protocols should be the same as the SSCS protocols when quantitative analysis is
42. ler sieve size may be used if the DQOs of the project dictate Note the identical sieve size must be used to prepare all samples and standards Deviations in the sieve size and the reason for the change must be recorded in the sample preparation log and noted in the final report Homogenize the sieved sample by placing 150 200 grams of sample on a piece of kraft or butcher paper about 1 5 by 1 5 feet in size Each corner of the paper should be lifted alternately rolling the soil over on itself and toward the opposite comer The soil should be rolled on itself 20 times Fill one or more XRF sample cups approximately 3 4 full with sample Cut and tension wrinkle free a piece of polypropylene film over the top of the cup and seal using the plastic film securing ring Label the sample cups appropriately Place the remaining sample in a clean labeled glass or plastic container for archival and possible confirmation analysis The stainless steel sieve and spoons must be decontaminated between samples by washing with soap and water and drying Semi Quantitative Screening Preparation For semi quantitative screening analysis the collected sample is spread out in a pan clumps are broken up with a stainless steel spoon and sticks stones and other matter non representative matter are removed from the sample The sample is then thoroughly homogenized in the pan by dividing it into quarters and physically mixing opposite quarters with a clean stainless
43. me the project planner must establish the project DQOs Prior to DQO development the project planner should obtain and evaluate as much historical information as possible about the site conditions and history including the results of any previous investigations at the site so that the following questions can be answered e What and where is the contamination on the site e What is the source of contamination on the site e What is the purpose of sampling and analysis data collection e What are the target elements of interest e What are the Action Level concentrations for the elements of interest e What non target metals or site conditions may be present that could create possible interference problems e What is the intended use of the data If the project planner can answer these questions completely then the project DQOs have been developed properly and are understood For assistance refer to the Agency document Guidance for the Data Quality Objective Process EPA QA G 4 which describes the informational needs and critical decision processes that must be addressed during DQO development Ascertaining XRF Needs Once the project target elements action levels and intended data uses have been established during DQO development the project planner can proceed with ascertaining XRF needs for the project The project planner should first determine whether the project DQOs can theoretically be met using XRF techniques If the pro
44. meter approach to generate a calibration This calibration technique may only be used for semi quantitative screening analyses This calibration relies on the ability of the liquid nitrogen cooled Li Si solid state detector to separate the coherent Rayleigh backscatter peaks from the incoherent Compton backscatter peaks of primary radiation These peak intensities are known to be a function of sample composition and the ratio of the Compton to Rayleigh peak is a function of the mass absorption of the sample The calibration procedure is explained in detail in the ACES user s manual The ACES program is not presently available on the Region I X MET 920 and thus the fundamental parameters calibration procedure is beyond the scope of this SOP and will not be addressed further Compton Peak Normalization The last calibration technique Compton peak normalization is a manual calibration technique used for semi quantitative screening analyses It is based on the analysis of one or more certified standards where the intensities of the lines of interest i e target elements in the sample are ratioed against those in the standard following normalization of the Compton peaks The Compton peak intensity changes with differing matrices Generally matrices dominated by lighter elements produce a larger Compton peak and those dominated by heavier elements produce a smaller Compton peak Normalizing to the Comptom peak is similar to using internal stand
45. mi quantitative calibration standards is made refer to Section 8 2 The first step in selecting the calibration standards is to determine the target elements of interest The basic rule is to prioritize the target elements and then reduce the number of elements to be analyzed in the field to the minimum amount required to perform the task For example suppose the site requiring cleanup was a metals plating facility which contained a waste lagoon known to be contaminated with high concentration of several metals and cadmium was the element present with the highest risk i e lowest action level In this case the amount of target elements required to monitor the cleanup could be reduced to 1 element cadmium Here by simplifying the calibration procedures and using only one radioisotope source sample throughput for the project can be maximized Note confirmatory samples taken throughout the cleanup and a final round of confirmatory sampling following completion of the project will help ensure that cleanup action levels for all target elements of interest were obtained Another reason to reduce the number of target elements to be analyzed in the field applies directly to quantitative analysis using site specific calibration standards SSCS In order to properly model the regression equation for an element additional SSCS must be included for each element that may cause possible chemical matrix effects approximately five per interfering element
46. mples and 3 document the transfer of field samples from field sampler to field chemist and from field chemist to the fixed laboratory Samples may be stored at room temperature and have an indefinite shelf life Mercury analysis has a six month holding time 12 0 12 1 12 1 1 12 1 2 SOP X MET 920 Rev 0 0 Date 10 29 96 Page 37 of 39 Sample Preparation and Analysis Sample Preparation Quantitative Analysis Preparation Samples for quantitative analysis must be prepared in the identical manner as the SSCS Field samples are spread out in a drying pan clumps are broken up with a stainless steel spoon and the sample is oven dried at lt 150 C for 2 to 4 hours to remove moisture If mercury is to be analyzed a separate sample must be air dried until the moisture content is lt 20 as heating may volatilize the mercury After drying all large organic debris and non representative material sticks twigs leaves roots insects asphalt rocks etc are removed and the sample is transferred to a mortar and pestle and ground to a uniform consistency The dried and ground sample is then sieved through a No 60 250 um mesh stainless steel sieve At no time should the material be forced through the sieve Pebbles and organic matter remaining on the sieve should be discarded The under sieve fraction of the material constitutes the sample Although a maximum final particle size of 60 mesh is normally recommended a smal
47. n the X MET 920 is approximately 0 170 keV large amounts of vanadium in the sample will result in spectral overlap of the V Kg with the Cr K peak and the measured X ray spectrum will include total counts for Cr plus V lines Other spectral interferences can occur between K L K M and L M lines An example is the As K Pb L interference In this case the lead can be measured from the Pb Ly line and arsenic from either the As K or As Kg line in this way the interference can be overcome The X MET 920 uses correction factors obtained from the analysis of single element standards to correct for spectrum overlap It is 5 5 6 0 7 0 7 1 SOP X MET 920 Rev 0 0 Date 10 29 96 Page 17 of 39 essential to define all possible spectral overlaps for the target elements and create and or update the overlap correction factor table during instrument calibration refer to Section 9 2 3 and the X MET 920 reference manual for further details Note whenever spectral overlap is an issue measurement sensitivity is reduced Moisture Content Sample moisture content will affect the accuracy of the sample results The measurement error may be minor when the moisture content is small 5 20 or it may be significant when measuring the surface of soils that are saturated with water For quantitative analysis moisture content will not be an issue because all samples are dried as part of the sample preparation However for semi quantitative
48. o time should the material be forced through the sieve Pebbles and organic matter remaining on the sieve should be discarded The under sieve fraction of the material constitutes the sample Although a maximum final particle size of 60 mesh is normally recommended a smaller sieve size may be used if the physical characteristics of the sample or DQOs of the project dictate Note the identical sieve size must be used to prepare all SSCS and samples Deviations in the sieve size and the reason for the change should be documented in an amendment to the QAPP SAP and must be recorded in the sample preparation log and noted in the final report Homogenize the sieved sample by placing 150 200 grams of sample on a piece of kraft or butcher paper about 1 5 by 1 5 feet in size Each corner of the paper should be lifted alternately rolling the soil over on itself and toward the opposite corner The soil should be rolled on itself 20 times Fill one or more XRF sample cups approximately 3 4 full with sample Cut and tension wrinkle free a piece of polypropylene film over the top of the cup and seal using the plastic film securing ring Label the sample cups appropriately The remainder of the sample is then split into two portions and placed in clean labeled glass or plastic containers One portion of the sample is submitted to the approved laboratory for analysis of the requested element s by the full protocol 8 2 8 2 1 8 2 2 8 2 2 1 SOP X
49. or beta B which indicates the higher shell from which an electron fell to fill the vacancy and produce the X ray For example a K line is produced by a vacancy in the K shell filled by an L shell electron whereas a Kg line is produced by a vacancy in the K shell filled by an M shell electron Figure 3 is a schematic which illustrates of the production of K and L X rays Since the electrons producing the fluorescent X rays are not valence outer shell electrons the X ray energy is not affected by the chemical or physical form of the atom Thus elemental sulfur and CaSO give the same sulfur X ray Since there are few allowed transitions and thus relatively few X ray lines the X rays for a specific element are SOP X MET 920 Rev 0 0 Date 10 29 96 Page 10 of 39 Figure 3 Production of K and L X rays L series L series well defined K lines have the shortest wavelengths and therefore the highest energies L lines have longer wavelengths and thus lower energies and M lines have very long wavelengths and thus even lower energies An X ray source can excite characteristic X rays from an element only if the source energy is greater than a threshold energy associated with a particular line group K L or M This energy threshold called the absorption edge 1 e K absorption edge L absorption edge or M absorption edge is greater than the corresponding line energy Actually the K absorption edge energy is approximately e
50. performed e Split sampling comparability acceptance criteria and e How the QC and field sample data will be used to determine whether project DQOs have been met Data Quality Assessment The QAPP SAP should reflect the complexity of the XRF project It must sufficiently address all of the relevant elements detailed in the Region I EPA New England Quality Assurance Project Plan Guidance Draft October 1996 Detailed standard operating procedures SOPs for the sampling and analysis protocols can be referenced in the QAPP SAP as long as the applicable SOPs are appended to that QAPP SAP All SOPs that are pertinent to project operations should be developed in accordance with EPA QA G 6 Guidance for the Preparation of Standard Operating Procedures for Quality related Operations The QAPP SAP must describe or reference documentation requirements for the resultant XRF and split sample confirmation data Documentation that all key QC elements were performed and met project requirements is essential regardless of intended data use For XRF techniques the preparation and analysis of each batch of samples including related standards QC samples and blanks should be recorded in a field or laboratory notebook run logs and or tabulated forms Section 13 0 of this SOP offers a detailed reporting format for XRF projects For conventional full protocol analytical methods complete data packages should be produced in accordance with the Region I
51. qual to the sum of the K L and M line energies The L absorption edge energy is approximately equal to the sum of the L and M line energies Also the closer the absorption edge energy of an element is to the source energy but not greater than the source energy the more efficient is the excitation and the more sensitive is the element s detection For example if a source energy is sufficient enough to excite the K lines for both Zn atomic number 30 and Ni atomic number 28 then the Zn K lines will be more sensitive than the Ni K lines i e the higher the atomic number the higher the line energies and the closer the line energy is to the source energy If the source energy is sufficient to excite the K lines then they will always be accompanied by the L and M lines of the same element If there is insufficient energy to excite the K lines but enough to excite the L line then just the L and M lines will appear XRF analyzers most commonly measure X ray lines originating from the K and L shells only elements with an atomic number greater than 57 have measurable M shell emissions SOP X MET 920 Rev 0 0 Date 10 29 96 Page 11 of 39 2 2 2 2 1 2 2 2 SOP X MET 920 Rev 0 0 Date 10 29 96 Page 12 of 39 Scattered X rays Scattered or backscattered radiation is simply the reflection of the primary X rays off the sample The source radiation is scattered from the sample by two physical reactions coherent scatte
52. quisition is complete check to see that Pb Lg peak is at channel 990 two channels To do this move the yellow cursor to the Pb Lg peak second large peak on screen which is shaded and read the channel number where the area count is at the maximum If the Pb Lp peak is at 990 two channels press F8 to quit If not press F8 again and type the letter O to optimize After optimization repeat the above procedure to make sure the Pb Lg peak assignment is proper The Instrument is now ready for use In order to perform sample analysis using empirical calibration a new calibration method must be developed or an existing calibration method must be updated Empirical Calibration and Method Development Refer to the reference manual for more complete information on software operation Particular attention must be given to the calibration sections in the manual describing the setting of regression terms to establish the best possible instrument calibration for analyzing field samples NOTE Since sources decay net count rates for elements will vary as time passes Therefore calibration standards must be analyzed and the calibration updated at a minimum of once every seven 7 days for the Cd 109 source and once every thirty 30 days for the Am 241 source Calibration records must be maintained during an ongoing project to insure that the X MET 920 is calibrated at the proper frequency To perform an empirical calibration for either quantitati
53. ration curve for each target element must be gt 0 98 If the correlation coefficient is less than 0 98 the problem must be identified and corrected prior to sample analysis If a correlation coefficient of gt 0 98 is SOP X MET 920 Rev 0 0 Date 10 29 96 Page 26 of 39 unattainable due the chemical matrix effects the best possible calibration must be established for analysis and the problems associated with the calibration documented in the report narrative Initial Calibration Verification ICV The ICV is an independent standard or standards from a source other than that used in the initial calibration that contains all the target elements of interest The ICV may be an STCS LPCS or SRM or for quantitative analysis using SSCS an additional SSCS not used in the ICAL may be used for the ICV The ICV must be analyzed immediately after the initial calibration is completed ICV target element concentrations should be near the site action levels or if no action level has been determined they should be near the level of interest or the mid point of the initial calibration Calculate the percent recovery for each target element in the ICV using Equation 6 Equation 6 Percent Recovery Bowie Vali x 100 True Value The percent recovery for each element in the ICV must be 50 150 inclusive If the true value of an ICV element is lt 2 times the MDL then the control limit is the true value MDL If the ICV does not
54. re and after analyses are conducted and once per 20 samples In addition an instrument blank should be analyzed whenever contamination is suspected by the analyst The analysis time must match that of the other project samples Element concentrations must be below their respective MDLs If concentrations exceed these limits then the probe window and the check sample should be checked for contamination If contamination is not the problem then the instrument must be zeroed by following the manufacturer s instructions The instrument blank analyses must meet criteria in order for the analysis to continue All samples analyzed since the last compliant instrument blank must be re analyzed in an analysis sequence which meets blank criteria Method blank A method blank is used to monitor for sample preparation induced contaminants or interferences The method blank can be clean silica sand or lithium carbonate that undergoes the same preparation procedure as the samples Method blanks must be prepared at a frequency of 1 per group of samples prepared or 1 per 20 samples whichever is more frequent The method blank must not contain element concentrations greater than their respective MDLs If concentrations 10 4 3 10 5 10 6 SOP X MET 920 Rev 0 0 Date 10 29 96 Page 35 of 39 exceed these limits then the cause of the problem must be determined and corrected and all samples associated with that method blank must be re p
55. repared and reanalyzed Control Blank The clean soil or inert material used in LPCS preparation must be analyzed as a control blank in accordance with Sections 8 2 2 1 and or 8 2 2 2 immediately after the initial calibration Confirmatory Sample Analyses Confirmation of XRF sample results using standard EPA method protocols is required and should support the project s data quality objectives Confirmatory samples are splits of the thoroughly homogenized material obtained following sample preparation In general a frequency of a minimum of 1 per 20 samples or 1 per sample matrix whichever is more frequent is recommended The confirmatory samples should be selected to include samples with element concentrations at or near site action levels The choice of digestion and analysis methods the frequency of confirmation sampling and the comparability criteria for confirmatory analyses should be established at the scoping phase of the sampling and analysis event Confirmation results should be validated in accordance with the most recent revision of the Region I EPA NE Data Validation Functional Guidelines for Evaluating Environmental Analyses and accompany the XRF final report upon their completion XRF field data shall be compared to the confirmatory results using Equation 4 Equation 4 Confirmatory Analyses IC z C Difference x 100 C Where C Concentration determined by full protocol confirmatory analysis C
56. ring no energy loss and incoherent or Compton scattering small energy loss Thus for each line of primary radiation incident on the sample two scattered X ray lines close together are returned The coherent scatter lines being equal to the source energy and the Compton scatter lines being slightly less than the source energy The amount of scattering 1s due to the sample matrix The two primary factors are particle size and average atomic number of the sample Larger particle sizes and lighter matrices lower average atomic number produce more backscatter The scattered X rays have the highest energies in the spectrum X MET 920 XRF Analyzer The EPA Region I X MET 920 XRF analyzer has two radioisotope sources Cadmium 109 and Americium 241 available for the production of primary X rays Each source emits a specific energy range of primary X rays that cause a corresponding range of elements in a sample to produce their fluorescent X rays Table 1 provides a listing of the recommended source and analysis line energies for typical environmental elements The K or L line is always the most intense line in their respective line group and for that reason is usually the line of choice for analysis note the intensity ratio between K and Kg lines is approximately 7 1 respectively while the ratio between L and Lg lines is approximately 3 2 respectively When more than one source can excite the same element of interest the appropriate source is
57. rovide a full range of target element concentrations is not recommended because the ratio of the interfering element to the target element will remain the same and the interelement effect in the calibration will be skewed in one direction All target and interfering element concentrations in each of the SSCS collected should be included as calibration points Outliers can later be eliminated when the regression equations are being developed refer to developing regression equations in the reference manual To assist in determining appropriate SSCS for laboratory analysis sample points may be pre screened with the instrument calibrated using semi quantitative calibration standards refer to Section 8 2 Site Specific Calibration Standard Preparation The SSCS samples collected in the field must be oven dried at lt 150 C for 2 to 4 hours to remove moisture The entire sample should be spread out in a drying pan and clumps broken up with a stainless steel spoon If mercury is to be analyzed a separate sample must be air dried until the moisture content is lt 20 as heating may volatilize the mercury After drying all large organic debris and non representative material sticks twigs leaves roots insects asphalt rocks etc are removed and the sample is transferred to a mortar and ground with a pestle to a uniform consistency The dried and ground sample is then sieved through a No 60 250 um mesh stainless steel sieve At n
58. ry Data Package Completeness dated June 1994 Confirmation results should be validated in accordance with the most recent revision of the Region I EPA NE Data Validation Functional Guidelines for Evaluating Environmental Analyses The complete confirmatory data package and validation report should accompany the XRF final report ICP AA Confirmatory Data Package and Data Validation Report for Field Samples Confirmation results should be provided and validated as specified in Section 13 2 In addition confirmation results should be compared in tabular format against the XRF results as specified in Section 8 5 and these results checked against the comparability criteria established during the DQO phase of the project The complete confirmatory data package validation report and tabulated comparability results should accompany the XRF final report upon their completion 14 0 SOP X MET 920 Rev 0 0 Date 10 29 96 Page 42 of 39 References 1 2 3 4 5 6 7 8 9 Test Methods for Evaluating Solid Waste Physical Chemical Properties SW 846 Method 6200 Draft Revision March 1996 X MET 920 User s Manual Metorex X MET 880 Field Portable X Ray Fluorescence Operating Procedures U S EPA Environmental Response Team SOP 1707 Rev 0 0 December 1994 McGraw Hill Encyclopedia of Science and Technology X ray Fluorescence Analysis Volume 14 1971 Guidance for the Data Quali
59. s greater Laboratory duplicates are two aliquots of the same sample that are prepared homogenized and analyzed in the same manner Note proper sample homogenization is critical in producing meaningful results Calculate the RPD between the sample and its duplicate using Equation 3 Equation 3 RPD 1 D 100 S D 2 Where S Original sample result D Duplicate sample result Laboratory duplicates must meet the following criteria e If both the original and laboratory duplicate values are gt PQL then the control limit for RPD is lt 35 If one or both values are lt PQL then do not assess the RPD If duplicate criteria are not met then re prepare and reanalyze both the original and laboratory duplicate samples If duplicate criteria are still not met then flag that target element with an on the final report for both the original and duplicate samples Note report both the original and duplicate analyses do not report the average The sample ID for laboratory duplicate samples shall contain the suffix LD 10 3 3 10 4 10 4 1 10 4 2 SOP X MET 920 Rev 0 0 Date 10 29 96 Page 34 of 39 Field Duplicates Field duplicates measure cumulative effects of both the field and method precision and hence provide an indicator of overall precision Sample field duplicates must be prepared and analyzed at a frequency of 1 per 20 samples or 1 per sample matrix whichever is greater Field duplicates are
60. s must be included in the final data package SOP X MET 920 Rev 0 0 Date 10 29 96 Page 23 of 39 9 0 9 1 SOP X MET 920 Rev 0 0 Date 10 29 96 Page 24 of 39 Calibration and Operation Instrument Calibration The X MET 920 may be calibrated using one of several techniques available depending on the data quality objectives of the project e For quantitative field analysis empirical calibration procedures must be used that incorporate site specific calibration standards e For semi quantitative screening one of three calibration procedures empirical calibration fundamental parameters calibration or Compton peak normalization calibration may be used to calibrate the instrument depending on the standards and instrument software available Empirical Calibration The standard software package supplied with the X MET 920 supports the empirical calibration technique This calibration technique is used for all quantitative analyses and for semi quantitative analysis using a series of either site typical calibration standards laboratory prepared calibration standards or standard reference materials Refer to Instrument Operation Section 9 2 of this SOP and X MET reference manual for information on performing an empirical calibration Fundamental Parameters Alternatively an optional software package called ACES Automated Contaminant Evaluation Software is available which uses a modified fundamental para
61. samples collected adjacent to each other at the same sample location not two aliquots of the same sample Calculate the Relative Percent Difference RPD between the sample and its duplicate using Equation 3 If the field duplicate criteria specified below are not met then flag that target element with an on the final report for both the original and field duplicate samples Note report both the original and field duplicate analyses do not report the average The sample ID for field duplicate samples shall contain the suffix FD e If both the original and field duplicate values are gt PQL then the control limit for RPD is lt 50 e If one or both values are lt PQL then do not assess the RPD If more rigorous field duplicate criteria are needed to achieve the project DQOs then the criteria should be documented in the QAPP SAP Blanks Two types of blank samples instrument blanks and method blanks must be analyzed with every XRF analysis A third type of blank the control blank used in the preparation of laboratory prepared calibration standards LPCS must be analyzed whenever LPCS are used in instrument calibration Instrument blank The instrument blank is used to verify that no contamination exists in the spectrometer or on the probe window The instrument blank can be silicon dioxide a Teflon block a quartz block clean sand or lithium carbonate This instrument must be analyzed on each working day befo
62. screening analysis drying is not required therefore moisture content should be a practical concern in sample preparation In general air drying oven drying or some other mechanical technique of drying is recommended to reduce moisture content to within 5 of the calibration standard s moisture content Microwave drying is not recommended Personnel Qualifications Sample analysis must be performed by qualified personnel either experienced in the operation of the XRF analyzer and knowledgeable in X ray fluorescence or under the direct supervision of an experienced and knowledgeable individual The analyst must be thoroughly familiar with this SOP and the X Met 920 Reference Manual supplied by the instrument manufacturer Equipment and Supplies Instrument Description The X Met 920 is a PC based energy dispersive X ray analyzer which consists of three major units 1 Computer and Software 2 X Met PC Unit XPCU 3 Solid State Probe Set SSPS The X MET 920 software version 1 33 is MS DOS based and provides total control of the instrument The minimum computer configuration recommended for operation of the software is a 33 MHZ 486 DX computer with 2 MB RAM 1 floppy drive and an 80 MB hard drive The XPCU board goes into an expansion slot inside the computer It is the interface between the analysis probe and the computer and software In addition to other electronic functions this board contains a 2048 channel Multi Channel Analyz
63. ss the red start button on the base of the probe This starts the acquisition The screen shows measurement in progress and in the top right corner is the analysis time countdown When sample acquisition is complete assay results and standard deviations are shown on the screen Analysis sequence 1 Verify instrument peak calibration by checking the Pb Lg line Section 9 2 2 2 Perform initial calibration using either quantitative or semi quantitative calibration standards Section 9 1 3 Analyze the initial calibration verification ICV standard s Section 9 1 2 4 Analyze continuing calibration verification CCV standard s Section 9 1 3 5 Analyze 10 samples maximum Note control blanks used in preparing LPCS Section 8 2 2 should be analyzed at the beginning of the run sequence prior to sample analysis 6 Analyze CCV continue 10 samples CCV sequence 7 Analyze last sample 8 Analyze CCV 9 Verify instrument peak calibration by checking the Pb Lg line SOP X MET 920 Rev 0 0 Date 10 29 96 Page 39 of 39 13 0 Documentation Reporting Results and the Final Report 13 1 13 1 1 13 1 2 Field XRF Final Report Report Narrative The final XRF data package must contain a report narrative that includes the following The narrative must list all the sample numbers for the sample results being reported and include any pertinent information related to their sampling location sampling map or writ
64. ten description The narrative must identify the SSCS and field samples sent to the fixed laboratory for confirmation analysis and must reference the full protocol EPA digestion and analysis methods The narrative must also include any comments related to problems encountered in sample preparation or analysis any technical or administrative problems and the corrective actions taken and or the resolution of the problem Discuss precision in terms of the daily precision tests performed and field duplicate analyses Evaluate the impact on sample results Discuss accuracy in terms of PE samples analyzed and confirmatory analysis results Discuss sensitivity in terms of calibration response and evaluate the impact on sample results Discuss data completeness in terms of the number of samples analyzed and successfully analyzed Evaluate the impact on sample results Discuss contamination in terms of blank contamination and evaluate the impact on sample results Sample Results Tabulate all sample results Quantitative results shall be reported in mg Kg dry weight and semi quantitative results shall be reported in mg Kg wet weight Results lt 1000 mg Kg are reported to two significant figures and results gt 1000 mg Kg are reported to three significant figures All values lt MDL shall be reported as the MDL and flagged with the letter U All values gt MDL and lt PQL shall be reported as is and flagged with the letter B
65. terly there after If there are distinctly different matrices on site MDLs and PQLs must be determined for each matrix For quantitative analysis the MDLs are generated by preparing and analyzing a minimum of seven aliquots i e sample cups of the lowest SSCS for each target element in accordance with 40 CFR Part 136 Appendix B For semi quantitative screening a low concentration sample STCS LPCS or SRM may be used Element concentrations should be approximately 3 5 times the expected MDL to generate accurate MDLs and PQLs Calculate the MDL using Equation 1 10 3 10 3 1 SOP X MET 920 Rev 0 0 Date 10 29 96 Page 32 of 39 Equation 1 MDL Un 1 1 0 0 99 S Where tint 1 0 0 99 the students t value appropriate for a 99 confidence level and a standard deviation estimate with n 1 degrees of freedom See Table 2 S standard deviation of the replicate analyses Table 2 Students t Values at the 99 Percent Confidence Level Number of Degrees of tint 1 a 0 99 replicates freedom n 1 7 6 Calculate the PQL for each element by multiplying the MDL by 3 Precision Analytical Precision Test The precision of the analytical method is determined by performing multiple analyses on a field sample with low moderate or high concentrations of target elements The frequency of precision measurements will depend on the DQOs of the project At a minimum one analytical precision test must be performed per
66. the results is within 3 standard deviations no correction is required If the difference in results is within the range of greater than 3 but less than 20 standard deviations the regression equation is corrected If the difference in results is off by more than 20 standard deviations the instrument must be recalibrated Quality Assurance and Quality Control Instrument Performance Check The instrument peak calibration must be verified at the beginning of the day prior to the initial calibration and at the end of the analysis sequence or every 8 hours whichever is more frequent If the initial peak calibration check at the beginning of the day for the Pb Lg line is not at 990 2 channels re set the peak calibration verify that it is correct and perform an initial calibration If the peak calibration check performed at the end of the analytical sequence or after eight hours does not meet the above criteria then re set the peak calibration perform an initial calibration and re analyze all samples since the last compliant peak calibration check within a valid analytical sequence Sensitivity Method Detection Limit and Practical Quantitation Limit The site specific method and quantitation limits must be determined for each target element during the initial stages of a project Site specific method detection limits MDLs and practical detection limits PQLs must be determined for each project and on long term projects must be repeated quar
67. ty Objective Process QA G 4 EPA 600 R 96 055 September 1994 Region I EPA New England Quality Assurance Project Plan Guidance Draft October 1996 Guidance for the Preparation of Standard Operating Procedures for Quality related Operations QA G 6 EPA 600 R 96 027 November 1995 Region I EPA New England Data Validation Functional Guidelines for Evaluating Environmental Analyses July 1996 Training Manual for Reviewing Laboratory Data Package Completeness June 1994 10 EPA Region I Performance Evaluation Program Guidance July 1996 11 U S EPA Code of Federal Regulations 40 CFR Part 136 Appendix B Revised as of July 1995
68. ve analysis or semi quantitative screening follow the steps below Screen 1 To begin a new calibration follow the prompts 1 At the Main Menu arrow down to CALIBRATION and press ENTER 2 Press F1 for New Method Screen 2 Screen 3 SOP X MET 920 Rev 0 0 Date 10 29 96 Page 29 of 39 Answer the questions at the prompt which are as follows Method Name Up to 8 alphanumeric characters ENTER Calibration Date Computer fills this in for you ENTER Operator Type the two initials of your name ENTER Number of Measurement Windows Type the number of elements you will be analyzing for in this method and ADD one for the backscatter peak For example if you were analyzing Pb and Cr you would type 3 ENTER Number of Standards Number of standards to be used in the calibration ENTER Probe Arrow down to SSPS ENTER Window 1 Computer automatically puts in BS Backscatter for you Window 2 Type in one element symbol for an analyte of interest i e Pb ENTER Continue entering the remaining elements of interest both target elements and matrix elements in the additional window slots up to 10 total Window Time 60 Leave at 60 ENTER This is the default analysis time used to measure single element standards for setting each element s measurement window From this information the software automatically calculates the overlap correction factors Standard Time 120 ENTER
69. with semi quant stds Optimize calibration method for linearity Prep samples and provide splits for possible confirmatory analysis Analyze all field samples including blanks and QC samples within a valid calibration sequence Submit confirmatory samples for lab analysis by full protocol EPA Methods Validate results Assemble data package Write final report Assess confirmatory data comparability and achievement of DQOs Quantitative Analysis achieve DQOs Yes QUANTITATIVE SOP PROCESS Identify elements and areas of interest Prioritize elements of interest Establish possible interfering elements Collect SSCS spanning conc ranges Provide SSCS for fixed lab analysis by full protocol EPA Methods Create X MET 920 calibration method Calibrate using fixed laboratory SSCS results Optimize calibration method for linearity Prep samples and provide splits for possible confirmatory analysis Analyze all field samples including blanks and QC samples within a valid calibration sequence Submit confirmatory samples for lab analysis by full protocol EPA Methods Validate results Assemble data package Write final report Assess confirmatory data comparability and achievement of DQOs SOP X MET 920 Rev 0 0 Date 10 29 96 Page 7 of 39 Project Scoping and Determination of Project Data Quality Objectives Before Field XRF analysis can be integrated into a project s sampling and analysis sche

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