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Analysis of nitromethane from samples exposed in vitro to chloropicrin by stable isotope dilution headspace gas chromatography with mass spectrometry
Author(s) -
Halme Mia,
Pesonen Maija,
Grandell Toni,
Kuula Matti,
Pasanen Markku,
Vähäkangas Kirsi,
Vanninen Paula
Publication year - 2015
Publication title -
journal of separation science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.72
H-Index - 102
eISSN - 1615-9314
pISSN - 1615-9306
DOI - 10.1002/jssc.201500457
Subject(s) - nitromethane , chromatography , isotope dilution , chemistry , mass spectrometry , chloropicrin , gas chromatography , gas chromatography–mass spectrometry , dilution , ecology , physics , fumigation , organic chemistry , biology , thermodynamics
Chloropicrin (trichloronitromethane) is a widely used soil fumigant and an old chemical warfare agent. The metabolism of chloropicrin is not well known in mammals but nitromethane has been shown to be one of its main metabolites. Here, a fast and simple headspace gas chromatography with mass spectrometry method was applied for the measurement of nitromethane from aqueous samples. The analytical method was validated using stable isotope labeled internal standard and a small sample volume of 260 μL. No conventional sample preparation steps were needed. The method was accurate (relative standard deviations ≤1.5%) and linear ( R 2 = 0.9996) within the concentration range of 0.1−6.0 μg/mL. This method was used to measure nitromethane in in vitro incubations with human and pig liver cell fractions containing enzymes for xenobiotic metabolism, exposed to chloropicrin. The results indicate that the presence of glutathione is necessary for the formation of nitromethane from chloropicrin. Also, nitromethane was formed mostly in liver cytosol fractions, but not in microsomal fractions after the incubation with chloropicrin. Our results suggest that although nitromethane is not the unequivocal biomarker of chloropicrin exposure, this method could be applied for screening the elevated levels in humans after chloropicrin exposure.