HR: 0800h
AN: A41C-04    [Abstracts]
TI: Analysis of Limonene-Derived Secondary Organic Aerosol via High-Resolution Mass Spectrometry
AU: * Walser, M L
EM: mwalser@uci.edu
AF: University of California, Irvine, Department of Chemistry, Irvine, CA 92697-2025, United States
AU: Dessiaterik, Y
EM: yury.desyaterik@pnl.gov
AF: Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, Richland, WA 99354, United States
AU: Laskin, J
EM: julia.laskin@pnl.gov
AF: Chemical Sciences Division, Pacific Northwest National Laboratory, Richland, WA 99354, United States
AU: Laskin, A
EM: alexander.laskin@pnl.gov
AF: Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, Richland, WA 99354, United States
AU: Nizkorodov, S
EM: nizkorod@uci.edu
AF: University of California, Irvine, Department of Chemistry, Irvine, CA 92697-2025, United States
AB: Aerosol particles have a major impact on atmospheric chemistry, climate, and human health. Up to 90% of urban aerosol has been shown to be organic in nature, and a significant fraction of such organic aerosol particles are formed as secondary organic aerosol (SOA) by condensation of partially-oxidized volatile organic compounds (VOC). Monoterpenes are a class of VOC that have been shown to form SOA in impressively large yields. Once such SOA particles are formed, they age via physical transformations and heterogeneous atmospheric chemistry, often with profound effects on the physical and chemical properties of the particles. This research focuses on secondary organic aerosol (SOA) particles formed from the ozone-induced oxidation of limonene. Artificial SOA particles are generated in the laboratory by reacting limonene and ozone in a Teflon reaction chamber. The resulting particles are collected on glass fiber filters for analysis with high-resolution mass spectrometry. Mass spectra obtained in both the positive and negative electrospray modes show evidence for the formation of oligomers. Elemental compositions were assigned to more than 90% of peaks less than 500 amu. Kendrick and van Krevelen plots, common tools in the analysis of mass spectra of complex mixtures, are applied to the analysis of SOA for the first time. Additionally, a mechanism for the formation of first generation SOA molecular components and their oligomers is proposed. Implications for photochemical aging of organic aerosol will also be discussed.
DE: 0305 Aerosols and particles (0345, 4801, 4906)
DE: 3311 Clouds and aerosols
SC: Atmospheric Sciences [A]
MN: 2007 Joint Assembly