Tuesday, November 14, 2006 - 10:15 AM
146-4

Measuring volatile sulfur compounds from animal feeding operations.

Steven Trabue, 2150 Pammel Dr, DuPont Ag. Products, USDA-ARS, National Soil Tilth Laboratory, Ames, IA 50011

Volatile sulfur compounds (VSCs) are a major class of odorants associated with animal feeding operations.  Identifying and quantifying VSCs in air is challenging due to their volatility, reactivity, and low concentrations.  In this study, a canister based method is presented that allows for the analysis of VSCs in ambient air at the sub-part-billion range.  This technique uses whole air sampling with fused silica lined (FSL) mini-canisters (1.4 L).  Sampled air was cryofocused, separated, and analyzed with a GC containing parallel MS (mass spectrometer) and PFPD (pulsed flame photometric detector) detectors.  Both hydrogen sulfide and methanethiol were unstable in canisters taken from humid environments with half-lives of less than one hour.  Decreases in methanethiol concentration correlated to increases in both dimethyl disulfide and dimethyl trisulfide concentrations.  Drying of the canisters air samples by either per-filling canisters with dry nitrogen or passing air samples through desiccants improve sample stability.  This method was used in measuring the emissions of hydrogen sulfide, carbonyl sulfide, carbon disulfide, dimethyl sulfide, dimethyl disulfide, dimethyl trisulfide, and methanethiol from swine manure holding tanks. 

Back to Symposium--Air Quality in the Agricultural Landscape: Measurements, Modeling, BMPs, and Emerging Regulations: III
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Back to The ASA-CSSA-SSSA International Annual Meetings (November 12-16, 2006)