Identification and quantitative determination of mercapturic acids formed from Z- and E-1,3-dichloropropene by the rat, using gas chromatography with three different detection techniques

Z- and E-1,3-dichloropropene, mutagenic geometric isomers and major constituents of commercial soil fumigants, were found to be metabolized to mercapturic acid derivatives by the rat. Extremely small quantities of mixtures of the parent compounds were administered intraperitoneally to the rat and the isomeric urinary mercapturic acids were quantified in three ways. Gas chromatographic procedures with nitrogen selective, sulphur selective and mass spectrometric detection, using negative chemical ionization with single ion detection, were evaluated with respect to selectivity and sensitivity. Applying the former two techniques, urinary mercapturic acids could still be quantified following 5 micrograms doses of each of the dichloropropene isomers. With gas chromatography-negative chemical ionization mass spectrometry, only mercapturic acid metabolites arising from 25 micrograms doses and higher could be quantified because of interference from endogenous compounds. These results suggest that all three analytical methods can be used to determine exposure of men to soil fumigants containing low levels of 1,3-dichloropropene.