AAAR 32nd Annual Conference
September 30 - October 4, 2013
Oregon Convention Center
Portland, Oregon, USA
Abstract View
Quantification of Organosulfate Formation in the SOA with Preexisting Acidic Sulfate Aerosol
ROSS BEARDSLEY, Jiaying Li, Myoseon Jang, University of Florida
Abstract Number: 533 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.