HR: 1340h
AN: A23D-1568    [Abstracts]
TI: Chemical Characterization of Secondary Organic Aerosol Formed Through Cloud Processing of Methylglyoxal
AU: * Altieri, K E
EM: altieri@marine.rutgers.edu
AF: Institute of Marine and Coastal Sciences, Rutgers University, 71 Dudley Rd., New Brunswick, NJ 08901, United States
AU: Seitzinger, S P
EM: sybil@marine.rutgers.edu
AF: Institute of Marine and Coastal Sciences, Rutgers University, 71 Dudley Rd., New Brunswick, NJ 08901, United States
AU: Seitzinger, S P
EM: sybil@marine.rutgers.edu
AF: Rutgers/NOAA CMER Program, Rutgers University, 71 Dudley Rd., New Brunswick, NJ 08901, United States
AU: Carlton, A G
EM: Carlton.Annmarie@epamail.epa.gov
AF: ASMD, ARL, NOAA, Mail Drop E-243-01, ResearchTrianglePark, NC 27711, United States
AU: Turpin, B J
EM: turpin@envsci.rutgers.edu
AF: Department of Environmental Sciences, Rutgers University, 14 College Farm Rd., New Brunswick, NJ 08901, United States
AU: Klein, G C
EM: geoffrey.klein@cnu.edu
AF: Department of Biology, Chemistry and Environmental Science, Christopher Newport University, 1 University Place, Newport News, VA 23606, United States
AU: Marshall, A G
EM: marshall@fsu.magnet.edu
AF: Ion Cyclotron Resonance Program, National High Magnetic Field Laboratory, Florida State University, 1800 East Paul Dirac Dr., Tallahassee, FL 32310, United States
AU: Marshall, A G
EM: marshall@fsu.magnet.edu
AF: Department of Chemistry and Biochemistry, Florida State University, Tallahassee, FL 32306,
AB: There is increasing evidence suggesting that secondary organic aerosol (SOA) forms as a result of low volatility product formation in atmospheric aqueous phase reactions. In this work aqueous phase photooxidation experiments between methylglyoxal (an isoprene oxidation product) and hydroxyl radical were conducted to simulate the cloud processing of methylglyoxal. The results verify that, as predicted, oxalic acid forms through cloud processing of methylglyoxal. This work adds to the growing body of literature (Altieri et al., 2006; Carlton et al., 2006; Carlton et al., 2007; Crahan et al., 2004; Warneck, 2003; 2005; Yu et al., 2005) supporting the hypothesis that cloud processing is a substantial source of oxalic acid to the atmosphere. Oxalic acid is the most abundant dicarboxylic acid in the atmosphere and a contributor to SOA. The formation of additional monomer products (e.g., malic acid, succinic acid, glycolic acid) and the development of an oligomer system were also identified through use of a combination of electrospray ionization mass spectrometry (ESI-MS) techniques: a quadrupole ESI-MS, an ion trap ESI-MS-MS, and an ultra-high resolution ESI FT-ICR MS. We propose a mechanism of oligomer formation through esterification of monomers with a hydroxy acid formed from hydroxyl radical initiated reactions. Oligomers were only recently identified as cloud processing products (Altieri et al., 2006), and this work is the first chemical characterization of oligomers formed through cloud processing reactions. The chemical characterization includes the distribution of molecular weights, elemental compositions, structure, and organic mass to organic carbon (OM:OC) ratio. Methylglyoxal is a water- soluble product of both biogenic and anthropogenic hydrocarbon oxidation. The varied and multiple sources of methylglyoxal suggest there is strong potential for these low volatility products (e.g., oxalic acid and oligomers) to significantly contribute to SOA.
DE: 0305 Aerosols and particles (0345, 4801, 4906)
DE: 0320 Cloud physics and chemistry
DE: 0365 Troposphere: composition and chemistry
DE: 3311 Clouds and aerosols
DE: 3322 Land/atmosphere interactions (1218, 1631, 1843)
SC: Atmospheric Sciences [A]
MN: 2007 Fall Meeting