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FIELD PERFORMANCE OF PM 2.5 FEDERAL REFERENCE METHOD SAMPLERS
Citation:
Peters, T., G A. Norris, R. W. Vanderpool, D B. Gemmill, R W. Wiener, R. W. Murdoch, F F. McElroy, AND M. Pitchford. FIELD PERFORMANCE OF PM 2.5 FEDERAL REFERENCE METHOD SAMPLERS. AEROSOL SCIENCE AND TECHNOLOGY 34(5):433-443, (2001).
Impact/Purpose:
The core aerosol research for FY01 includes evaluation of newly developed and developing methods for the chemical analysis and sampling of PM in ambient air, especially state-of-the-art continuous and non-invasive aerosol measurement methods, and the study of the aerosol sampling processes to better assess the true aerosol concentration and size distributions observed in the ambient environment. An additional emphasis is placed on integrated sampling for stable and semi-volatile organic aerosol species. This latter area addresses the state-of-the-art in this measurement area. This program supports Title I of the Clean Air Act in its mandate for performing research to support the NAAQS, GPRA goal 1.1.5, and ORD's main research objective on PM.
Much of this work directly supports OAQPS and may be applied within the Supersites Program managed jointly by OAQPS and ORD. This research also will support many of ORD's long-term research goals by providing more reliable information (decrease uncertainty) on ambient aerosols that can be utilized for characterizing risk.
Finally, an APM, has been established to develop measurement methods for causal factors, due in 2004. Currently, there are a number of causal factor hypotheses, but none have sufficient evidence to support developing one measurement/analytical method over another. The PM methods team will support and work with Joellen Lewtas on methods for the collection and analysis of semi-volatile and aerosol phase organic species to help address this APM. The PM methods team will continue to work within the Supersites program and with OAQPS and their new partners in ORIA to further evaluate continuous species specific methods and aerosol physical property measurement methods.
Description:
The results of several research field studies were evaluated to estimate the precision and bias of various designated PM2.5 Federal Reference Method (FRM) samplers. Precision was high in three carefully conducted research studies where all operational activities were strictly controlled, with an average coefficient of variation (CV) ranging from 2 to 6 percent. No significant bias was found between the method designations. Comparisons between the designated reference method samplers meet the EPA Equivalent Method Criteria for comparability except for one pair of samplers. In this instance, the y-intercept of the Andersen RAAS2.5-300 versus the Rupprecht & Patashnick Partisol-Plus 2025 was 1.07 ug/m3, slightly exceeding the y-intercept 1.0 ug/m3 limit. Non-designated PM2.5 samplers demonstrated strong linear relationships when compared to reference method samplers; however, the comparisons presented in this analysis did not meet the EPA Subpart C criteria. These results indicate that the currently designated reference method samplers should allow precision and bias objectives to be achieved for the National PM2.5 Network.
This work has been funded wholly or in part by the United States Environmental Protection Agency under Contract 68-D5-0040 to Research Triangle Institute. It has been subjected to Agency review and approved for publication.