Dimethyl disulphide residue analysis and degradation kinetics determination in soil using gas chromatography–mass spectrometry

Abstract

ABSTRACTDimethyl disulphide (DMDS) is a volatile sulphur compound and is used as a new type of soil fumigant. The objective of this study was to develop an effective method to extract and analyse DMDS residue in soil, then determine the degradation kinetics of DMDS in soil using the above method. The results showed that DMDS extraction from soil by ethyl acetate under static conditions for 60 min gave the best recovery. The extracted DMDS was analysed by gas chromatography–mass spectrometry (GC-MS), and the limit of quantification of DMDS in the soil was 5 μg/kg. The average recoveries of the DMDS at five different concentrations were in the range of 65.4–120.1% with all intra- and inter-day relative standard deviation less than 19.1 and 14.8, respectively. The degradation rates of DMDS in different soils were significantly different and were strongly influenced by the soil pH. The results in the present study will be useful for DMDS environmental behaviour study in future.