AAAR 34th Annual Conference
October 12 - October 16, 2015
Hyatt Regency
Minneapolis, Minnesota, USA
Abstract View
Organosulfates in Centreville, Alabama: Quantification and Insights to Their Formation
ANUSHA PRIYADARSHANI SILVA HETTIYADURA, Thilina Jayarathne, Elizabeth Stone, University of Iowa
Abstract Number: 549 Working Group: Carbonaceous Aerosols in the Atmosphere
Abstract Organosulfates (R-O-SO$_(3)$^(-)) are suggested to be tracers of anthropogenically-influenced biogenic SOA that form under acidic conditions. Hydrophilic interaction liquid chromatography (HILIC) and tandem mass spectrometry (MS/MS) in combination with synthesized authentic standards were used to quantify organosulfates collected from Centreville, Alabama in summer 2013 during the Southeast Atmosphere Study (SAS). Glycolic acid sulfate, lactic acid sulfate and hydroxyacetone sulfate were the three most abundant organosulfates quantified in PM$_(2.5) collected from Centreville, Alabama from July 07 to 11, 2013. Their atmospheric concentrations ranged from 2.4 - 25.7 ng m$^(-3), 1.3 – 22.4 ng m$^(-3) and 0.4 - 7.5 ng m$^(-3) respectively. Average contributions of these organosulfates to PM$_(2.5) organic carbon were 0.09%, 0.10% and 0.04%, respectively. Positive artifacts during sample collection were found to have upper limits of 3%, 5% and 8% of the ambient concentration, respectively. In addition, organosulfates with major contributions to the observed bisulfate anion signal were identified using high-resolution and tandem mass spectrometry. These additional organosulfates were semi-quantified using structurally-matched organosulfate standards. Correlation analysis of organosulfates with one another and PM$_(2.5) constituents (e.g. water soluble organic carbon, sulfate, nitrate) was used to gain insights to formation of organosulfates in the atmosphere. In addition, time series analysis was used to examine the temporal and meteorological influences to their ambient concentrations.