HR: 09:00h
AN: A11E-05    [Abstracts]
TI: The Use of Solid Phase Extraction and Size-Exclusion Chromatography to Characterize the Fine Particle Carbonaceous Aerosols Soluble in Water
AU: * Sullivan, A P
EM: asullivan@eas.gatech.edu
AF: Georgia Institute of Technology, ES&T Building - Dept. EAS, 311 Ferst Drive, Atlanta, GA 30332 United States
AU: Weber, R J
EM: rweber@eas.gatech.edu
AF: Georgia Institute of Technology, ES&T Building - Dept. EAS, 311 Ferst Drive, Atlanta, GA 30332 United States
AB: A new two-step method has been developed to speciate the ambient organic aerosol based on chemical functional groups. In the first step, water-soluble organic carbon (WSOC) aerosols are extracted from integrated filters and separated by use of XAD-8 resin into its hydrophilic and hydrophobic fractions. In the second step, size-exclusion chromatography (SEC) is used to chromatographically separate by organic functional groups the WSOC hydrophilic and recovered hydrophobic fractions. During this step, the hydrophilic fraction is further separated into aliphatic acids with less than four carbons, neutrals, and bases. The recovered hydrophobic fractions can be separated into aromatic acids and phenols or compounds with similar hydrophobic properties. The fractions obtained in both steps are quantified directly with Total Organic Carbon analysis. The results have been confirmed by C-NMR (Carbon - Nuclear Magnetic Resonance). Data will be presented comparing urban Atlanta summer, urban Atlanta winter, and biomass burning samples. During the summer in Atlanta, approximately 20% of the organic carbon (on a carbon mass basis) is due to the aliphatic and aromatic acids. These aliphatic acids are additional correlated with the aromatic acids (R2=0.74), elemental carbon (R2=0.64), carbon monoxide (R2=0.73), and VOCs (Volatile Organic Compounds) expected from mobile source emissions. Biomass burning samples, however, were dominated by neutrals (e.g. saccharides) and phenolic compounds. In the winter, when the WSOC is much lower, the samples tended to a combination of the other two sample types.
DE: 0305 Aerosols and particles (0345, 4801, 4906)
DE: 0394 Instruments and techniques
SC: Atmospheric Sciences [A]
MN: Fall Meeting 2005