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The new technique of selected ion flow tube-mass spectrometry (SIFT-MS) has been applied to the measurement of Henry's Law constants for the volatile organic chemicals o-xylene and trichloroethylene that both have low solubility in aqueous solvents. The method is validated by measurements in water at 298 K using the equilibrium partitioning in closed systems (EPICS) methodology in which the equilibrium headspace concentrations for the volatile organic compounds (VOCs) are measured in two sealed bottles containing different liquid volumes of very dilute solutions of the VOC. The range of solvents is then extended to human body fluids at 309 K including urine, saline, whole blood, red cells in saline, and plasma. The dimensionless distribution coefficients for these solvents vary markedly in the different fluids. For o-xylene they range from k(H) = 0.12-0.15 for water, saline, and urine; 0.53 for red cells in saline; 1.9 for whole blood; to 2.4 for plasma. For trichloroethylene the distribution coefficients range from k(H) = 0.070-0.091 for water, saline, and urine; 0.28 for red cells in saline; 0.35 for plasma; to 0.48 in whole blood. The very different solubilities of organic solvents in body fluids influence the uptake of solvents in workers exposed to VOCs. Some implications of these measurements are briefly discussed.

In this paper we compare the amounts of ethanol in breath and in blood after ingestion of whisky using analysis by selected ion flow tube mass spectrometry (SIFT-MS). Blood ethanol concentrations were also obtained using standard hospital forensic procedures for blood alcohol analyses. We demonstrate the quantitative nature of SIFT-MS analysis by correlating the observed alcohol content of the headspace above 5-mL amounts of venous blood and aqueous solution to which known trace amounts of alcohol have been added. This procedure provides a Henry's Law coefficient for ethanol in aqueous solution at 298 +/- 3 K of 209 +/- 7 mol/kg*bar. We also demonstrate that measurement of the ethanol concentration in the alveolar portion of a single breath using the SIFT-MS technique gives an accurate measure of blood alcohol and could obviate the need for blood samples in forensic processing. The storage performance of breath samples in Mylar bags with a volume greater than 1 L has been shown to maintain the mixture integrity for ethanol but not for some other species.

The selected ion flow tube mass spectrometry (SIFT-MS) technique enables real time analysis of trace volatiles at ppb levels without preconcentration steps or chemical derivatization. Most previous studies of trace compounds on the breath were analyzed using gas chromatography where enhanced detection sensitivity was achieved by concentrating the breath using cryogenic or adsorption trapping techniques. In this paper, we have examined volatile organic substances, isoprene, acetone, ammonia and ethanol in breath before and after smoking a cigarette. It is interesting that isoprene levels increased in all the subjects after smoking one cigarette with a mean increase of 70%. The mean increase for acetone was found to be 22%. In contrast to isoprene, a decreasing ethanol level was observed in all the subjects except one with the negative mean decrease of 28%. Further SIFT-MS studies also have high-lighted some organic substances produced even by unburned cigarettes, US and New Zealand products. Certain US brands have shown much higher levels of volatile species than cigarettes produced in New Zealand.