2. Development of Time Resolved Thermal Desorption Gas Chromatography/Mass Spectrometry of Particulate Matter in Resuspended Soil

We investigated a method for identifying semivolatile organic compounds in resuspended soil samples representative of fugitive dust from unpaved roads and wind erosion. The objective was to test the feasibility of using organic compounds as part of the source profile for Chemical Mass Balance (CMB) source apportionment of fugitive dust. The method consists of analyzing samples of dust collected on quartz filters by a thermal desorption gas chromatograph mass spectrometer. Polar compounds were analyzed by simultaneous derivatization (using tetramethylammoniumhydroxide) and thermal desorption. A 1mm x 37mm filter sliver is placed in a custom made curie point thermal inlet and desorbed onto a GCMS where it is analyzed for organic semivolatiles. The method was validated for accuracy and precision. Dust samples collected from various military and civilian sites exhibited distinct fingerprint chromatograms that were unique enough to help differentiate among the various sites. The method is extremely sensitive and can easily detect compounds in the 200 nanogram range per filter. The method generates highly reproducible peaks that can be quantified by proxy with an internal standard and therefore used as input in Chemical Mass Balance source apportionment simulations (CMB). This paper is a report on an ongoing study; more sampling, analysis and statistical manipulation are needed to obtain a better understanding of this technique. Some of the target peaks have been identified by name, further identification of other peaks can help us isolate their source and further understand what makes each site different. Some peaks may have biological decay origins while others are generated by atmospheric pollution. This study may lead to the quantification of some double counting of atmospheric pollutants that have adhered to dust.