HR: 0800h
AN: A41C-06    [Abstracts]
TI: Accretion Reactions of Glyoxal, Methylglyoxal, and Amines in Evaporating Cloud Droplets
AU: * De Haan, D O
EM: ddehaan@sandiego.edu
AF: University of San Diego, Dept of Chemistry & Biochemistry 5998 Alcala Park, San Diego, CA 92110, United States
AU: Corrigan, A L
EM: corriganashley-09@sandiego.edu
AF: University of San Diego, Dept of Chemistry & Biochemistry 5998 Alcala Park, San Diego, CA 92110, United States
AU: Hanley, S W
EM: swhanley@gmail.com
AF: University of San Diego, Dept of Chemistry & Biochemistry 5998 Alcala Park, San Diego, CA 92110, United States
AU: Lee, F E
EM: animalcookies43@yahoo.com
AF: University of San Diego, Dept of Chemistry & Biochemistry 5998 Alcala Park, San Diego, CA 92110, United States
AB: Glyoxal and methyl glyoxal (G+MG) are secondary pollutants produced by the atmospheric oxidation of aromatic compounds, isoprene and terpenes. They are known to partition efficiently into tropospheric water droplets, reaching micromolar concentrations. While G+MG hydrates are quite unreactive, we show that cloud droplet evaporation triggers accretion acid-catalyzed reactions between G+MG and nucleophiles present in the cloudwater, especially amines. The imine products of the reactions between G+MG and the three most common free amino acids in cloudwater (glycine, serine and arginine) are characterized by NMR, ATR, and electrospray- MS. Unlike the acetal-linked oligomers formed from the self-reactions of G+MG, these imine products are stable, resisting hydrolysis over many weeks. The formation of long-lived, non-volatile products from acid-catalyzed G+MG reactions during cloud processing suggests that this may be a significant source of secondary organic aerosol in the troposphere.
DE: 0305 Aerosols and particles (0345, 4801, 4906)
DE: 0320 Cloud physics and chemistry
DE: 0345 Pollution: urban and regional (0305, 0478, 4251)
DE: 0365 Troposphere: composition and chemistry
DE: 3311 Clouds and aerosols
SC: Atmospheric Sciences [A]
MN: 2007 Joint Assembly