Evaluation of selected-ion flow-tube mass spectrometry for the measurement of ethanol, methanol and isopropanol in physiological fluids: effect of osmolality and sample volume.

Selected-ion flow-tube mass spectrometry (SIFT-MS) is particularly suited for the analysis of volatile low molecular weight compounds. We have evaluated this technique for the assay of different alcohols in aqueous solutions, including blood plasma, and in particular whether the osmolality or sample volume affected vapourisation. Solutions of three different alcohols (methanol, ethanol and isopropanol) ranging from 0.

Combined use of gas chromatography and selected ion flow tube mass spectrometry for absolute trace gas quantification.

The value of the gas chromatography (GC) and selected ion flow tube mass spectrometry (SIFT-MS) combination for the analysis of trace gases is demonstrated by the quantification of acetone in air samples using the three precursor ions available to SIFT-MS, viz. H3O+, NO+ and O2+, and by the separation of the isomers 1-propanol and 2-propanol, and their analysis using H3O+ precursor ions. It is shown that the GC/SIFT-MS combination allows for accurate trace gas quantification obviating the regular, time-consuming calibrations that are usually required for the more commonly used detectors of GC systems, and the positive identification of isomers in mixtures that is often challenging using SIFT-MS alone.