Organo-Sulfur Concentrations in the Southeastern U.S

Eric Edgerton (1), Mike Fort (1), Karsten Baumann (1) John Jansen (2), Justin Walters (2)

(1) Atmospheric Research & Analysis, Inc., (2) Southern Company

     Abstract Number: 413
     Last modified: November 10, 2009

Abstract
Sulfate, typically in the form of mixed ammonium sulfates, is well established as the dominant form of sulfur in PM2.5 over much of the U.S. Recent work, however, has identified numerous organo-S and organo-S/N compounds in the southeastern U.S., especially in the summer months. These results are based on a limited number of direct measurements on material extracted from high-volume air samples. This poster will present estimates of total organo-S concentrations using archived low-volume filters from the Southeastern Aerosol Research and Characterization (SEARCH) network. Organo-S concentrations will be estimated indirectly by comparing sulfate and methansulfonic acid (MSA) concentrations based on ion chromatography (IC) with total-S concentrations from x-ray fluorescence and total water-soluble S concentrations from ICPMS. Total water-soluble S will be quantified as sulfur monoxide (SO) on the same filter extract used to quantify sulfate and MSA. Archived filters will be selected to develop urban-rural and inland-coastal contrasts and seasonal comparisons, and to investigate organo-S concentrations when aerosol concentrations are characterized by high C/S ratios (biomass and mobile sources) and low C/S ratios.