Improved methodology for the detection and quantitation of urinary metabolites of sulphur mustard using gas chromatography-tandem mass spectrometry.

Gas chromatography-tandem mass spectrometry (GC-MS-MS) with selected-reaction monitoring was applied to the analysis of urinary metabolites of sulphur mustard, derived from the beta-lyase pathway and from hydrolysis. In the case of beta-lyase metabolites, a limit of detection of 0.1 ng/ml was obtained, compared to 2-5 ng/ml using single stage GC-MS with selected-ion monitoring. GC-MS-MS methodology was less useful when applied to the analysis of thiodiglycol bis(pentafluorobenzoate) using negative-ion chemical ionisation although selected-reaction chromatograms were cleaner than selected-ion chromatograms. The advantage of using GC-MS-MS was demonstrated by the detection of low levels of beta-lyase metabolites in the urine of casualties who had been exposed to sulphur mustard.