Evaluation of solid-phase microextraction for sampling of volatile organic sulfur compounds in air for subsequent gas chromatographic analysis with atomic emission detection

The use of solid-phase microextraction (SPME) followed by GC-AED (atomic emission detection) for the analysis of volatile organic sulfur compounds (methanethiol, dimethyl sulfide, isopropanethiol and isobutanethiol) in spiked air samples was investigated. Gaseous standard mixtures were generated by means of a permeation apparatus with stopped flow facilities to permit sampling of the analytes with the SPME fiber. Detection limits between 4 ppt for dimethyl sulfide and isobutanethiol and 50 ppt (v/v) for methanethiol were achieved for extraction with the Carboxen-PDMS (polydimethylsiloxane) fiber followed by GC-AED analysis. The comparison of the performance of the 100 mu m PDMS and the 75 mu m Carboxen-PDMS fiber coating demonstrates the superiority of the latter in terms of sensitivity and repeatability. Despite the principal applicability of SPME to sampling of organosulfur compounds, artifacts ape observed during analysis. Furthermore, the low storage stability, the dependence of the extraction efficiency on the relative humidity and the pronounced differences in sensitivity between fibers limit the usefulness of the method for quantitative on-site analysis. (C) 1999 Elsevier Science B.V. All rights reserved.