Quantification of N-(3-chloro-2-hydroxypropyl)valine in human haemoglobin as a biomarker of epichlorohydrin exposure by gas chromatography–tandem mass spectrometry with stable-isotope dilution

• Published in: Journal of chromatography. B, Analytical technologies in the biomedical and life sciences Vol. 877; no. 13; pp. 1402 - 1415
• Main Authors: Bader, Michael, Rosenberger, Wolfgang, Gutzki, Frank-Mathias, Tsikas, Dimitrios
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 01.05.2009
• Subjects: Acetylation; Biomarkers - chemistry; Biomonitoring; Calibration; Deuterium-labelling; Epichlorohydrin; Epichlorohydrin - toxicity; Gas Chromatography-Mass Spectrometry - methods; GC-tandem MS; Globin; Hemoglobins - chemistry; Humans; Isotopes; Protein adducts; Reference Standards; Reproducibility of Results; Sensitivity and Specificity; Tandem Mass Spectrometry - methods; Globin; Epichlorohydrin; Deuterium-labelling; Biomonitoring; Protein adducts; GC–tandem MS
• ISSN: 1570-0232; 1873-376X; 1873-376X
• DOI: 10.1016/j.jchromb.2008.11.028

Epichlorohydrin (ECH) is an important industrial intermediate for the production of polymers and surface coatings. Animal experiments support the classification of ECH as a carcinogen, and a significant contribution to the cancer risk of ECH exposed humans has to be considered. Upon uptake, epichlorohydrin reacts with nucleophilic moieties of N- and S-containing macromolecules to form stable adducts, e.g. with haemoglobin. In this article, we describe a GC–tandem MS method for the quantitative analysis of the primary ECH adduct to the N-terminal amino acid of human haemoglobin, i.e. of N-(3-chloro-2-hydroxypropyl)valine (CHPV), using a globin labelled with d 5-ECH as the internal standard. Incubation of erythrocyte lysate from human blood with ECH or d 5-ECH yielded two reaction products, with CHPV being the major component. The GC–tandem MS method is based on a modified Edman degradation procedure with subsequent O-acetylation. The limits of detection and quantification of this method are 10 and 25 pmol/g globin, respectively. Intra- and inter-assay imprecision of the method was about 12 and 15%, respectively, and the mean recovery was 105 and 96% at the levels of 25 and 100 pmol of CHPV per g globin, respectively. The present study reports for the first time on the analysis of CHPV as a haemoglobin adduct of ECH using GC–tandem MS and a stable-isotope labelled internal standard. By this method we quantified haemoglobin adducts of ECH in the blood of subjects potentially exposed to ECH after a freight train accident. Our study points to CHPV in human haemoglobin as a possible biomarker for epichlorohydrin exposure.