Evidence of sulfur mustard exposure in victims of chemical terrorism by detection of urinary β-lyase metabolites.

Sulfur mustard (SM) is a vesicant chemical warfare agent. Ocular, dermal, and respiratory systems are the primary targets of SM exposure. The aims of this study were to perform a quantitative analysis of β-lyase metabolites of SM as 1,1'-sulfonylbis[2-(methylthio) ethane] (SBMTE) in urine samples of chemical casualties and to investigate the relationship between the measured SBMTE levels and the severity of characteristic symptoms of SM poisoning. A bioanalytical method which is based on titanium (III) chloride reduction of β-lyase metabolites was employed to analyze urine samples of individuals ( = 13, collected 30 h after SM exposure) using gas chromatography-tandem mass spectrometry. Various levels of SBMTE were measured in urine samples of seven individuals, confirming SM exposure for each. There was a correlation observed between measured levels of SBMTE in human urine samples and severity of clinical findings including ocular, respiratory, and cutaneous lesions of SM. In combination with clinical examination, measurement of SBMTE levels in human urine could be used as a prognostic factor for clinical outcomes in victims of SM exposure. This bioanalytical verification is also important for the documentation of alleged use of SM. SBMTE is an unambiguous biomarker of potential SM poisoning as it does not exist in urine samples of an unexposed population. Quantitation of urinary SBMTE concentrations in victims of SM could be used in order to enable improved interpretation of clinical findings.