AAAR 31st Annual Conference
October 8-12, 2012
Hyatt Regency Minneapolis
Minneapolis, Minnesota, USA
Abstract View
Environmental Factors Influencing Peroxyhemiacetal Chemistry in SOA
LINDSAY YEE, Jill Craven, Katherine Schilling, Christine Loza, Xuan Zhang, Matthew Coggon, Paul Ziemann, John Seinfeld, California Institute of Technology
Abstract Number: 551 Working Group: Aerosol Chemistry
Abstract Peroxyhemiacetals (PHAs) form from the heterogeneous reaction of semi-volatile hydroperoxides and aldehydes. There is increasing evidence that peroxyhemiacetal formation contributes to the chemical composition of secondary organic aerosols generated from a variety of volatile organic compounds under low-NO$_x conditions. However, very little is known about the environmental conditions that affect PHA formation. In this study, we extend previously derived chemistry for the dodecane low-NO$_x mechanism and other alkane systems to explore the additional effects of varying relative humidity and aerosol acidity on PHA formation. We simulate these conditions in the Caltech Atmospheric Chamber and we examine the evolving aerosol chemistry comparing complementary information from chemical ionization mass spectrometry and high-resolution time-of-flight aerosol mass spectrometry measurements to elucidate PHA formation chemistry. We use these chemical frameworks as tools for extension of PHA formation chemistry in other VOC systems and to the atmosphere where primarily low-NO$_x and non-dry conditions exist.