Speciated Organic Composition of Atmospheric Aerosols: A New In-Situ Instrument

70753 Energy production and combustion of fossil fuels are sources of organic aerosols that have been linked to environmental degradation, human health problems, and changes in the radiative transfer properties of earth¿s atmosphere. New techniques are needed for the time-resolved in-situ characterization of the organic composition of atmospheric aerosols in order to understand their sources, sinks, and transformations. This project will develop a new automated in-situ instrument for the routine identification and quantification of organic compounds in atmospheric aerosols. The instrument will allow measurements to be made either in one size fraction (PM2.5) with hourly time resolution, or simultaneously in three size fractions with two-hour time resolution. Phase I will conduct laboratory studies to: (1) evaluate the capability of direct impaction thermal desorption/gas chromatography/mass spectrometry for compound separation and identification; (2) determine detection limits and reproducibility for specific marker compounds; and (3) prove the ability to quantitatively measure ambient samples. Commercial Applications and Other Benefits as described by the awardee: A commercially viable instrument for routine, hourly monitoring of organic composition of atmospheric aerosols should substantially lower the cost per sample and increase the time resolution compared to current methods of filter collection, solvent extraction, and analysis.