HR: 0830h
AN: A51F-0748    [PDF]
TI: Studies of the Partitioning of Glyoxal into Atmospheric Particulates
AU: * Liggio, J
EM: jliggio@yorku.ca
AF: York University, Centre for Atmospheric Chemistry 4700 Keele St., Toronto, ON M3J 1P3 Canada
AU: McLaren, R
EM: rmclaren@yorku.ca
AF: York University, Centre for Atmospheric Chemistry 4700 Keele St., Toronto, ON M3J 1P3 Canada
AU: Li, S
EM: Shao-Meng.Li@ec.gc.ca
AF: Meteorological Service of Canada, Air Quality Research Branch 4905 Dufferin St., Toronto, ON M3H 5T4 Canada
AB: The organic composition of atmospheric aerosols is an area of very active research. Recent research has tried to elucidate possible mechanisms for incorporation of semi-volatile and volatile carbonyl products in particulates, almost all involving some sort of heterogeneous chemical reaction of carbonyl products to form less volatile species that are stabilized in the particle phase. These mechanisms include organic hydration, formation of hemiacetals and acetals, aldol condensations, and polymerization. In order to study the partitioning behaviour of volatile organic carbonyls, we have designed a 2 m3 teflon reaction chamber that uses a differential mobility analyzer - condensation nuclei counter for monitoring the physical properties of particles, an aerosol mass spectrometer (AMS) for monitoring the chemical composition of the particles and an automated DNPH cartridge/HPLC system for monitoring the gaseous composition inside the chamber. In this paper, we will discuss experiments that explore the physical and chemical characteristics of particles formed from the growth of seed particles ((NH4)2SO4, (NH4)HSO4, H2SO4, NaNO3, and NaCl) in the presence of gaseous glyoxal. The unique highlight of this system is the use of the AMS, which gives us a sensitive probe of changes in the chemical content of the particles as a function of time. The particle growth was rapid and significant and appears to be acid catalyzed, but is otherwise independent of the cationic content of the seed. Evidence is presented for the formation of hydrated glyoxal monomer, dimers, trimers and possibly higher order species. Possible mechanisms and mass spectrometric evidence will be discussed.
DE: 0305 Aerosols and particles (0345, 4801)
DE: 0317 Chemical kinetic and photochemical properties
SC: Atmospheric Sciences [A]
MN: 2003 Fall Meeting