Determination of volatile sulfur compounds in water samples, beer and coffee with purge and trap gas chromatography-microwave-induced plasma atomic emission spectrometry
Résumé
A method for the determination of 13 volatile sulfur compounds including dimethyl sulfide, dimethyl disulfide (DMDS), carbon disulfide and other sulfides and thiols in water samples was developed. The analytes were stripped from the sample by a flow of helium and preconcentrated in a capillary cryogenic trap. This was followed by determination by gas chromatography-microwave-induced plasma atomic emission spectrometry. Detection limits ranged from 8 pg (0.4 ng l-1) for ethanethiol to 17 pg (0.9 ng l-1) for DMDS. The method was successfully applied to the quantitative analysis of fresh and sea water and after slight modifications also to different Belgian beer types and coffee powder. A system for the automated sample delivery was developed for liquid samples.