AAAR 31st Annual Conference
October 8-12, 2012
Hyatt Regency Minneapolis
Minneapolis, Minnesota, USA
Abstract View
Quantification of Organosulfate Formation in the SOA with Preexisting Acidic Sulfate Aerosol
JIAYING LI, Myoseon Jang, University of Florida
Abstract Number: 664 Working Group: Aerosol Chemistry
Abstract In this study, organosulfates were produced in the secondary organic aerosol (SOA) from the photooxidation of various volatile organic compounds (VOCs), such as α-pinene, toluene, and isoprene, in the presence of NOx and acidic sulfate aerosols using an outdoor Teflon film chamber. The aerosol proton concentration ([H+], mol/L) of the SOA collected on the filter was measured using colorimetry integrated with a reflectance UV-Visible spectrometer (C-RUV). As the organosulfates form in the aerosol, the C-RUV data showed a decrease of aerosol acidity due to the consumption of preexisting acidic sulfate. The reduction of aerosol acidity measured by the C-RUV technique was used to quantify the organosulfates production in the SOA. FTIR equipped with a small flow chamber that holds an optical window for aerosols collected by impaction was used to characterize functional groups of organic compounds in the SOA. The reactivity of a certain functional group (e.g., hydroxyl, carbonyl, keto) to form organosulfates in the SOA will be investigated. Hydroxy and carbonyl groups are expected to give high organosulfates yields.