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 PM_2.5 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.