DETECTION OF VOLATILE ORGANIC SULFUR-COMPOUNDS IN WATER BY HEADSPACE GAS-CHROMATOGRAPHY AND MEMBRANE INLET MASS-SPECTROMETRY

Two gas chromatographic methods, GC-FID (flame ionization detection) a nd GC-ELCD (electrolytic conductivity detector) are compared in the an alysis of volatile organic sulfur compounds (VOSCs) in water samples w ith a membrane inlet mass spectrometry (MIMS) technique. Carbon disulf ide, ethanethiol, dimethyl sulfide, ethyl-methyl sulfide, thiophene, a nd dimethyl disulfide were used as test compounds, Linear dynamic rang es were found to be two decades with the GC-ELCD method and four decad es,vith the GC-PID and MIMS methods. Detection limits were at low mu g /l levels with the two gas chromatographic methods and clearly below m u g/l level with the MIR IS method, Analysis of one sample takes 40 mi n with the gas chromatographic methods and five minutes with the MIMS method. The selectivity was good, especially with the GC-ELCD and the MIMS method, In addition, quantitative results obtained with spiked ma ter samples by the three methods are compared.