AAAR 32nd Annual Conference
September 30 - October 4, 2013
Oregon Convention Center
Portland, Oregon, USA
Abstract View
Reactive Uptake and Aqueous Chemistry of Isoprene Epoxydiols (IEPOX) and Glycolaldehyde in Aerosol Liquid Water
TRAN NGUYEN, Matthew Coggon, Kelvin Bates, Rebecca Schwantes, Xuan Zhang, Katherine Schilling, Christine Loza, Richard Flagan, Paul Wennberg, John Seinfeld, California Institute of Technology
Abstract Number: 150 Working Group: Aerosol Chemistry
Abstract The atmospheric oxidation of isoprene (C5H8) forms many water-soluble oxidation products that may partition into the liquid water of inorganic particles. The fates of the dissolved organic compounds include dark aqueous reactions (like hydration and imine formation), aqueous photooxidation, aqueous direct photolysis, and evaporation of water – reactions that may contribute to the formation of secondary organic aerosol (SOA). In this work, we studied the aqueous chemistry of isoprene photooxidation products glycolaldehyde (GLYAL) and isoprene epoxydiol (IEPOX) using a photochemical smog chamber and a photochemical flow reactor. Gas-phase compounds were measured with a chemical ionization mass spectrometer (CIMS) and particle-phase compounds were measured with a time-of-flight aerosol mass spectrometer (ToF-AMS), alongside traditional aerosol instrumentation. Offline composition analyses were performed using electrospray ionization mass spectrometry (ESI-MS). The reactive uptake of GLYAL and IEPOX onto neutral AS seed particles will be described as a function of particle liquid water content. The composition of particle-phase organics and key mechanisms involved in the aqueous dark chemistry and photochemistry will be discussed.