15th Conf on Biometeorology and Aerobiology and the 16th International Congress of Biometeorology

Wednesday, 30 October 2002: 3:45 PM
Characterization of odors and evaluation of odor control techniques utilizing solid phase microextraction
Laura L. McConnell, USDA/ARS, Beltsville, MD; and H. Kim
Complaints due to odors are an important problem for the wastewater, composting and animal agriculture industries. Accurate, objective measurement techniques are needed to monitor emissions, to develop new waste handling procedures, and to reduce the production of these volatile gases. While olfactometry methods reflect actual human response to odors, they do not provide information on all the chemical components of a gas mixture. Solid phase microextraction was investigated as a technique for the determination of representative odorous gases. A flow-through Teflon chamber was used to expose the fibers to a certified gas standard. A 75 µm Carboxen-Polydimethylsiloxane (Car-PDMS) coating was used for trimethylamine (TMA), carbon disulfide (CS2), dimethylsulide (DMS) and dimethyldisulfide (DMDS), and an 85 µm polyacrylate coating was used for propionic acid (PA) and butyric acid (BA). Using a 1-hour fiber exposure time and a flow rate through the chamber of 72 ml/min, method detection limits were 2.38, 0.074, 0.150, 0.063, 1.85, and 1.32 ppbv for TMA, DMS, CS2, DMDS, PA, and BA, respectively. Enhanced detector response was observed for all analytes under flow conditions compared to static, and the porous nature of the Car-PDMS coating appears to increase the time needed for analytes to reach equlibrium under flow conditions.

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