Record Display for the EPA National Library Catalog
RECORD NUMBER: 33 OF 1037
|OLS Field Name||OLS Field Data|
|Main Title||Acid aerosol measurement methods studies of extraction and analytical effects.|
|Author||Ellestad, T. G. ; Hodson, L. L. ; Randtke, S. J. ; Thurston, G. D. ; Koutrakis, P.|
|CORP Author||Environmental Protection Agency, Research Triangle Park, NC. Atmospheric Research and Exposure Assessment Lab. ;Research Triangle Inst., Research Triangle Park, NC. ;Kansas Univ., Kansas City. ;New York Univ. Medical Center, Tuxedo Park. ;Harvard School of Public Health, Boston, MA.|
|Publisher||Atmospheric Research and Exposure Assessment Laboratory, Office of Research and Development, U.S. Environmental Protection Agency,|
|Subjects||Aerosols--Analysis. ; Air--Pollution--United States--Measurement. ; Acid deposition--United States. ; Air--Pollution--Measurement.|
|Additional Subjects||Aerosols ; Acidity ; Interlaboratory comparisons ; Quality assurance ; Air pollution sampling ; Acid rain ; Statistical analysis ; Hydrogen ions ; Precision|
|Collation||8 pages : illustrations ; 28 cm|
Following a major intercomparison of acid aerosol measurement methods, an additional study was held to investigate the sources of variability among labs. In addition, it was felt important to do this comparison with atmospheric aerosol. The first test was of spiked filters in triplicate at six different levels; each lab had to extract and analyze its filters. The second test was of atmospheric samples collected under carefully controlled sampling conditions; two or more filters for three sampling periods were extracted and analyzed by each lab. The third test was of atmospheric samples that were all extracted by one lab with the resulting extract solutions for each day combined, spiked, and divided among the labs for analysis. All labs reported hydrogen, ammonium, and sulfate ion for each sample. Results indicate that atmospheric aerosols gave a precision comparable to spiked samples, that interlaboratory precision was about 10 percent for H+, and that a minimum sample of about 400 nanomoles of H+ is required to obtain good interlaboratory results.
"June 1992." Includes bibliographical references. "EPA/600/A-92/120." Microfiche.