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

The use of solid-phase microextraction (SPME) followed by GC-AED (atomic em ission detection) for the analysis of volatile organic sulfur compounds (me thanethiol, 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 samp ling of the analytes with the SPME fiber. Detection limits between 4 ppt fo r dimethyl sulfide and isobutanethiol and 50 ppt (v/v) for methanethiol wer e achieved for extraction with the Carboxen-PDMS (polydimethylsiloxane) fib er followed by GC-AED analysis. The comparison of the performance of the 10 0 mu m PDMS and the 75 mu m Carboxen-PDMS fiber coating demonstrates the su periority 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 stabil ity, the dependence of the extraction efficiency on the relative humidity a nd the pronounced differences in sensitivity between fibers limit the usefu lness of the method for quantitative on-site analysis. (C) 1999 Elsevier Sc ience B.V. All rights reserved.