Fine particulate (PM2.5) composition in Atlanta, USA: assessment of the particle concentrator-Brigham Young University organic sampling system, PC-BOSS, during the EPA supersite study

Aerosol concentrations of carbonaceous material, sulfate, and nitrate for samples obtained using a newly designed PC-BOSS are reported. The results indicated that PM2.5 composition in Atlanta was dominated by sulfate and organic material, with low concentrations of particulate nitrate. Observed average particulate component concentrations for the 26-day study period were: sulfate, 12.2 μg/m3 (17.0 μg/m3 as ammonium sulfate); non-volatile organic material, 11.4 μg OM/m3 (assumes organic material, OM, is 61% C); semi-volatile organic compounds (SVOC) lost from particles during sampling, 5.3 μg OM/m3; filter retained nitrate, 0.1 μg/m3 (0.2 μg/m3 as ammonium nitrate); nitrate lost from particles, 0.3 μg/m3 (0.4 μg/m3 as ammonium nitrate); and soot (elemental carbon), 1.5 μg/m3. The PC-BOSS particle concentrator efficiency was obtained by comparison of the PC-BOSS sulfate data with sulfate data obtained from the Federal Reference Method (FRM) sampler. A modification of the PC-BOSS design to allow independent determination of this parameter is recommended.