Headspace solid-phase microextraction for the determination of volatile sulfur compounds in odorous hyper-eutrophic freshwater lakes using gas chromatography with flame photometric detection

A simple and efficient method based on headspace solid-phase microextraction (HS-SPME) followed by gas chromatography coupled to flame photometric detection was developed for the simultaneous determination of five volatile sulfur compounds (VSCs; hydrogen sulfide (H2S), methanethiol (MeSH), dimethyl sulfide (DMS), dimethyl disulfide (DMDS) and dimethyl trisulfide (DMTS)) in hyper-eutrophic freshwater lakes suffering from black water agglomerate. Carboxen/polydimethylsiloxane (CAR/PDMS) fiber was selected for the extraction of VSCs, and various parameters, such as the stirring rate, sample volume, ionic strength, duration and temperature of extraction and the duration and temperature of desorption, were optimized for extraction efficiency. The linearity spanned approximately three orders of magnitude for all of the studied compounds. The method detection limits (MDLs) and method quantification limits (MQLs) ranged from 1.6 to 93.5 ng L-1 and 10 to 500 ng L-1 respectively, depending on the analyzed compound. The reproducibility of the method was between 3.7 and 11.9%, and the recovery was approximately 100%. The developed analytical method was successfully applied to the determination of VSCs in odorous freshwater lakes, and the concentrations of the five target compounds were detected in the 0.33 to 166.60 mu g L-1 range. (C) 2012 Elsevier By. All rights reserved.