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2007 Changes to the NELAC Proficiency Testing Program Accreditation Analytes, Experimental Analytes and Evaluation Crite

2007 Changes to the NELAC Proficiency Testing Program Accreditation Analytes, Experimental Analytes and Evaluation Criteria FSEA May 2007. I’m the NELAC PT Board. And I’m an environmental lab!. It’s not as bad as you may think. Four Key Areas of Change – primarily Soil and UST analytes

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2007 Changes to the NELAC Proficiency Testing Program Accreditation Analytes, Experimental Analytes and Evaluation Crite

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  1. 2007 Changes to the NELAC Proficiency Testing Program Accreditation Analytes, Experimental Analytes and Evaluation Criteria FSEA May 2007

  2. I’m the NELAC PT Board.... And I’m an environmental lab! It’s not as bad as you may think.........

  3. Four Key Areas of Change – primarily Soil and UST analytes • Additions to the Accreditation Analyte list • New Experimental Analytes • Ways that PT data is evaluated • Analyte Concentration Ranges

  4. This presentation is available on line at: www.wibby.com click on the “Papers and Presentations” link

  5. Additions to the Accreditation List • Fifteen analytes added to existing lists utilizing current methods • Seven new analyte sets or lists that utilize techniques or methods not currently in accreditation tables

  6. Experimental Analytes • Thirty eight analytes added to existing lists utilizing current methods • Seven new analyte sets or lists that utilize techniques or methods not currently used in accreditation

  7. Evaluation Changes • Some analytes are now evaluated by regression equation coefficients derived from historical data • The “10% Rule” • The “110% Rule”

  8. Don’t Freak Out Yet..

  9. So What’s The Document? 2007 NELAC SW/Soil Fields of Proficiency Testing (FoPT) Table

  10. So Where’s The Document? www.nelac-institute.org 2007 NELAC SW/Soil Fields of Proficiency Testing (FoPT) Table

  11. Analyte Lists Evaluation Criteria NELAC Code PT Reporting Limit Concentration Range What’s in the table that’s helpful?

  12. Footnotes in the Tables

  13. Accreditation Table Changes

  14. New Inorganic Analytes Accreditation • Strontium • Ignitability • Corrosivity • Oil and Grease (n-hexane extractable, IR or gravimetric) • Total Petroleum Hydrocarbons (non-polar extractable material, IR or gravimetric)

  15. New Organic Analytes Accreditation

  16. New Organic Analytes Accreditation • VOAs – Acetone,1,2-Dichloropropane, MEK, MTBE, Naphthalene, 1,2,4-Trichlorobenzene, 1,1,2-Trichloroethane, 1,2,3-Trichloropropane • BNAs - 1,2-DCB, 1,3-DCB, 1,4-DCB • Pesticides – alpha Chlordane, gamma Chlordane, Endrin Ketone

  17. New Organic Analytes and Methods for Accreditation • Medium Level VOAs - 19 “traditional” analytes and 4 ketones • Low Level PAHs - 16 “traditional” PAHs, levels set for HPLC • Diesel Range Organics - C10 - C28 • Gasoline Range Organics - C5 - C10

  18. Potential Problems • Aroclor 1016 and 1242 separated as individual analytes in PCBs in Oil PTs • Medium Level vs. Low Level VOAs: Which one do I run? • Acetone in Low Level VOAs and Medium Level VOAs

  19. Some good news Low end of concentration ranges for analytes generally higher. • Example: • Old range for acids in BNA standards were generally 500 - 10,000 µg/kg, now they are 1,500 - 15,000 µg/kg

  20. New Experimental Table for Soil PTs

  21. New Experimental Inorganic Analytes • Boron - Trace Metals • Minerals (anions) • Nutrients (Ammonia, TKN, Total P) • TOC

  22. New Experimental Organic Analytes • VOAs - 15 additionals, including the light gases, 2-Hexanone, DBCP, EDB • Medium Level VOAs - 17 additionals, including light gases, DBCP, EDB, Styrene, iso-Propylbenzene • BNAs - 12 additional analytes, typical 8270C analytes • Herbicides - 2,4-DB, Dinoseb

  23. New OrganicAnalytes - Experimental • Pesticides - 8141A OPP’s, nine compounds at 100 - 1000 ug/kg • Explosives/Nitroaromatics - 8330 list of eleven compounds, 1500 - 15,000 ug/kg

  24. Potential Problems • Light Gases in the VOAs? • Medium Level & Low Level VOAs • “Results to be used for historical data establishment only” I believe you have my stapler!

  25. Evaluation Criteria

  26. The 10% Rule • Lower Acceptance Limit for any analyte that has been spiked in a sample is set at 10% of assigned value. • Lower limit will no longer include zero • Could present problems for poorly recovered organic analytes • Choice of digestion used for Metals in Soil • Sb, Ag

  27. The 10% Rule If the lower acceptance limit generated by the statistical evaluation of the data for a spiked analyte is below 10% of the actual made-to value or below the PTRL, the lower acceptance limit will be set to 10% of the made-to value or the PTRL, whichever is higher.

  28. The 10% Rule • Example: Dicamba spiked at 120 ug/kg, stats for the study set the range at 0 - 210 ug/kg for acceptance. • Now, range will have to be set to 20 - 210 ug/kg • PTRL is 20 ug/kg, greater than the 10% of the spiked value which is 12 ug/kg

  29. The 10% Rule: Difficulties Presented (i.e. “The Bad”) • A < result reported for a spiked analyte is now unacceptable. • Labs will now have to be acutely aware of the PTRL and the 10% “worst case scenario” and establish MDLs accordingly.

  30. The 10% Rule: Helpful Outcomes (i.e. “The Good”) • Knowing the PTRL and the 10% “worst case scenario” will help eliminate false positive reporting. • The NELAC PT Board raised the lowest concentration range possible for most analytes. • Does not apply to experimental extractable organics.

  31. The 110% Rule: more Good • If the upper limit is <110% of the assigned value, then the upper limit is set at 110% of the assigned value. 100% should always be Acceptable.

  32. New Regression Equation Criteria for Soil PTs Data is currently evaluated using: Study Mean + 3x Study Standard Deviation generated using robust statistics (Ref: Kafadar, Karen Journal of the American Statistical Association June 1982, Volume 77, Number 378, Theory and Methods Section)

  33. Evaluation Criteria New Regression Equation Criteria New Soil FoPT Tables contain regression equation coefficients for most analytes.

  34. Calculating Acceptance Limits When a, b, c, and d coefficients are provided, data is evaluated using the following: Mean = (a*T) + b Standard Deviation = (c*T) + d where T = Assigned Value (made-to value) Acceptance Limits = Mean + 3 SD

  35. Mean = (100 µg/kg *0.9843) - 0.0327 = 98.4 µg/kg S.D. = (100 µg/kg *0.1213) + 0.7969) = 12.9 µg/kg Acceptance Limits = 98.4 + (3*12.9) µg/kg = 59.6 µg/kg to 137 ug/kg or 59.6% - 137% Recovery Range Example: Benzene in VOC PT Standard spiked at 100 µg/kg :

  36. Calculating Acceptance Limits, cont. When only c and d coefficients are listed, data are evaluated as shown below: Mean = Statistically Derived from study data Standard Deviation = (c*T) + d where T = Assigned Value (made to conc.) Acceptance Limits = Study Mean + 3 SD

  37. Calculating Acceptance Limits • Accreditation Analytes now using a, b, c, and d coefficients: • VOAs, Medium Level VOAs, PCBs in Oil • Accreditation Analytes now using c and d coefficients: • Metals, BNAs and Pesticides • All Experimental Analytes use the study mean + 3 x study standard deviation except for 2,4-Dinitrophenol and 2-Methyl-4,6-dinitrophenol which have c and d coefficients

  38. When does all of this go into affect? All PT Studies that start on or after July 1st, 2007

  39. It will make us a better lab.... It’s just more to do.... You be the judge: Good or Bad........

  40. You can’t make me run those analytes, Mr. Arms! More Good News You only have to run and report PT analytes if the analytes are in the NELAC PT tables and on your scope of accreditation.

  41. Reporting PT Results Often a prime source of errors • Different from how you report your routine results • Filling in hardcopy data reporting sheets and faxing back to PT Provider • Entering in results manually into the PT Provider’s on line site • Uploading an Electronic Data Deliverable (EDD)

  42. Reporting PT Results via EDD

  43. Reporting PT Results via EDD

  44. Reporting PT Results via EDD

  45. Reporting PT Results via EDD

  46. If I were a lab….. Things that are unique to PTs • Double check before reporting a quantitative value less than the PTRL. • Double check before reporting a “<“ value for an inorganic analyte. • Double check before reporting more than one Aroclor in a PCB sample. • Double check before reporting a “>” value.

  47. If I were a lab….. • Double check before reporting a value less than 10% of the lowest allowed concentration. • Double check WS Micro results that don’t include the required number of results • Three + total /+ fecal • Three + total /- fecal • Two – total /- fecal • Two blanks • Double check results outside of maximum acceptable range

  48. Thank you. Questions? More information? cwibby@wibby.com 1-866-WibbyPT (866-942-2978) www.wibby.com

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