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CHARACTERIZATION OF FINE PARTICLE ASSOCIATED ORGANIC COMPOUNDS:

CHARACTERIZATION OF FINE PARTICLE ASSOCIATED ORGANIC COMPOUNDS:. INTERLABORATORY COMPARISON AND DEVELOPMENT OF STANDARD REFERENCE MATERIALS (SRM). Joellen Lewtas , US EPA, National Exposure Research Laboratory Michele M. Schantz and Stephen A. Wise , NIST, Analytical Chemistry Division.

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CHARACTERIZATION OF FINE PARTICLE ASSOCIATED ORGANIC COMPOUNDS:

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  1. CHARACTERIZATION OF FINE PARTICLE ASSOCIATED ORGANIC COMPOUNDS: INTERLABORATORY COMPARISON AND DEVELOPMENT OF STANDARD REFERENCE MATERIALS (SRM) Joellen Lewtas, US EPA, National Exposure Research Laboratory Michele M. Schantz and Stephen A. Wise, NIST, Analytical Chemistry Division

  2. PM2.5 Organic Speciation Working Group EPA PM Supersites & Related Sites EPA PM Centers National Labs & other Research Centers Regional and State Laboratories NIST, ORNL/NARSTO

  3. GOAL • Improve the Characterization and Quantification of Organic Compounds Associated with PM2.5 (Aerosols) • Standard Reference Materials • Inter-Laboratory Trials • Common Analysis of Key Analytes

  4. SRM 1649 & 1649a, Urban Dust • Collected in Washington, DC (1976-77) • Baghouse with no size selective inlet • Sieved to <125 microns • >160 certified and reference values published • >50 publications characterizing SRM 1649

  5. Intercomparison Trials: Reference Materials • Trial I (Feb-July, 2001) • SRM 1649a sieved to <63 microns • Extract of sieved SRM 1649a • Trial II (Winter 2002) • Interim Reference Material Baltimore PM2.5 • Trial III (Goal: 2003-2004) • Bulk Baltimore PM2.5 for new SRM (goal to collect 200g)

  6. Target Analytes Labs • 36 PAH 14 Labs • 7 Nitro PAH 2 Labs • 12 Alkanes & Alkenes 6 Labs • 13 Hopanes, Colestanes, & Sterols 5 Labs • 18 Carbonyls & Acids 5 Labs • Aldehydes, Ketones, Lactones, etc. • 8 Phenols none

  7. Participating Laboratories California Air Resources Board Rice Univ. (Houston Supersite) Mike Poore Matt Fraser Desert Research Institute (Fresno SS) UCLA (So. Cal SS/ PM Center) Barbara Zielinska Tony Miguel Florida Int. U. (Baltimore & Pittsburg SS) Univ. of Miami (Atlanta SS) Wolfgang Rogge Rod Zika Lovelace Respiratory Research Institute U.S. EPA-RTP/Univ NC Jake McDonald Mike Tolocka & John Volckens Environmental Technology Center Univ.Washington (Seattle PM Center) Gary Poole/Chung Chiu Chris Simpson NIST-Maryland U.S. EPA-Region 10 Michele Schantz Steve Reimer NIST-South Carolina U.S. EPA-ORD-NRMRL John Kucklick Dean Smith/Mike Hays

  8. Range of Analysis Methods • Extraction solvents including: • Dichloromethane • Benzene • Isopropanol • Hexane • Acetone • Acetonitrile • Ethylacetate • Hydroxytoluene • Phenol • Extraction techniques including • sonication • soxhlet • microwave-assisted • pressurized fluid extraction

  9. Range of Analysis Methods, continued • Extraction times ranging from 15 minutes to 20 hours • Extract clean-up including: • filtering • concentration by blowdown or evaporation • solid-phase extraction • solvent exchange • HPLC fractionation • Analysis Techniques • GC/MS - Electron Ionization • GC/MS – Negative Chemical Ionization • HPLC • Standards • Internal versus external • Calibration from 3 to 10 points

  10. Results • Good data return and agreement for many PAH • - Surprisingly, agreement better for SRM1649a • than for the extract • Poor data return for more exotic compounds • - Not sufficient information for a consensus value

  11. Next Inter-Laboratory Trial • Trial II (Winter 2002) • New Interim Reference Particles • Baltimore PM2.5 • Collected in 2000-2001 • Calibration Standards • Requirement to report Trial I results • Expanding Target Analytes where possible

  12. Interlab Trial I: Design • Samples Prepared and Shipped by NIST • NIST SRM 1649a: 500 mg particles • Air Particulate I (SRM 1649a sieved to <63 microns): 500 mg particles • Air Particulate Extract I (Extract of sieved SRM 1649a): 5 ampoules of 1.2 ml each • Extracted by Pressurized Fluid Extraction using Dichloromethane • Labs Requested to analyze each of 3 replicate samples and to concurrently analyze the NIST SRM 1649a Urban Dust

  13. +30% CL +95% CL Certified value

  14. z=+3 z=+2 z=+1 (+25%) assigned value z= -1 z= -2 z= -3 75% 50% 25% Assigned value

  15. Summary of Accuracy of PAH Data • Air Particulate Extract • Eliminating 1 lab with z-scores generally >3 • Remaining labs z-scores: • Less than 10% of the data had z-scores > 2 • Air Particulate • Eliminating 1 lab with z-scores > 3 • Remaining labs z-scores: • Less than 10 % of the data had z-scores >2 • 7/13 Labs had less than 3% of the z-scores >2

  16. Summary of Accuracy of PAH Data • Air Particulate Extract • Eliminating 1 lab with z-scores generally >3 • Remaining labs z-scores: • Less than 10% of the data had z-scores > 2 • Air Particulate • Eliminating 1 lab with z-scores > 3 • Remaining labs z-scores: • Less than 10 % of the data had z-scores >2 • 7/13 Labs had less than 3% of the z-scores >2

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