Odor profiling efforts were directed at applying to high-density livestock operations some of the lessons learned in resolving past, highly diverse, odor-focused investigations in the consumer product industry. Solid-phase microextraction (SPME) was used for field air sampling of odorous air near and downwind of a beef cattle feedyard and a swine finisher barn in Texas. Multidimensional gas chromatography-olfactometry (MDGC-O) was utilized in an attempt to define and prioritize the basic building blocks of odor character associated with these livestock operations. Although scores of potential odorant volatiles have been previously identified in high-density livestock operations, the odor profile results developed herein suggest that only a very few of these may constitute the preponderance of the odor complaints associated with these environments. This appeared to be especially true for the case of increasing distance from both cattle feedyard and swine barn facilities, with p-cresol consistently taking on the dominant odor impact role with ever increasing distance. In contrast, at- or near-site odor profiles were shown to be much more complex, with many of the well-known lower tier odorant compounds rising in relative significance. For the cattle feedyard at- or near-site odor profiles, trimethylamine was shown to represent a significantly greater individual odor impact relative to the more often cited livestock odorants such as hydrogen sulfide, the organic sulfides, and volatile fatty acids. This study demonstrates that SPME combined with a MDGC-O-mass spectrometry system can be used for the sampling, identification, and prioritization of odors associated with livestock.

An evaluation of the chemical and/or physical involvement of a number of matrix modifiers and procedures Is presented for the determination of Pb In blood by graphite furnace atomic absorption. In particular, the roles of HN03, NH4H2P04, 02 ashing, and surfactants (such as Triton-X 100) have been studied. Appearance time shifts and changes In peak shape are also presented. A rapid method for the determination of Pb In human whole blood by graphite furnace atomic absorption spectrometry is also described. Sample preparation involves dilution of whole red cells 1:4 with 1% Trlton-X 100 solution, followed by an air ash. Oxygen ashing was used at 900 °C without any loss of Pb, no reduction In furnace lifetime, and negligible background scatter.

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A method for the determination of arsenic in whole human blood is presented. To decrease the matrix effects from this complex sample, the blood was prediluted with a matrix modifier solution. The modifier solution contained a surfactant, Triton X-100, which homogenized the sample and allowed accurate pipetting by an autosampler. The modifier also contained nickel nitrate which stabilized the arsenic and allowed ash temperatures of 1400 degrees C without loss of the arsenic. The method exhibited a sensitivity of 5 micrograms/L (concentration/1% absorption) which was sufficient for the forensic evaluation of elevated arsenic levels in the blood.