title: Identification and quantitative determination of 3-chloro-2-hydroxypropylmercapturic acid and alpha-chlorohydrin in urine of rats treated with epichlorohydrin.
abstract: Epichlorohydrin (ECH) is used in many industrial processes. Different toxic effects of ECH were found in rodents. The metabolism of ECH was investigated before in rats using [14C]ECH. The aim of this investigation was the development of non-radioactive quantitative analytical methods for measuring two urinary metabolites of ECH, namely 3-chloro-2-hydroxypropylmercapturic acid (CHPMA) and alpha-chlorohydrin (alpha-CH). The identity of CHPMA and alpha-CH excreted in urine of rats treated with 5 to 35 mg/kg ECH was confirmed by GC-MS. The quantitative analysis of CHPMA, involving ethyl acetate extraction from acidified urine and subsequent methylation and analysis by gas chromatography-flame photometric detection (GC-FPD), showed a method limit of detection of 2 micrograms/ml. The analysis of alpha-CH based on ethyl acetate extraction and subsequent analysis by GC-ECD, showed a method limit of detection of 2 micrograms/ml. CHPMA and alpha-CH derivatives could be determined quantitatively down to concentrations of 0.5 and 0.4 micrograms/ml urine, respectively, by selected-ion monitoring GC-MS under EI conditions. Cumulative urinary excretion of CHPMA and alpha-CH by rats treated with ECH were found to be 31 +/- 10 and 1.4 +/- 0.6% (n = 13) of the ECH dose, respectively. For CHPMA, the dose-excretion relationship suggested partially saturated ECH metabolism. For alpha-CH, the doe-excretion relationship was linear. With fractionated urine collection it was found that approximately 74 and 84% of the total cumulative excretion of CHPMA and alpha-CH, respectively, took place within the first 6 h after administration of ECH. From these investigations it is concluded that the GC-FPD and GC-ECD based methods developed are sufficiently sensitive to measure urinary excretion of CHPMA and alpha-CH in urine from rats administered 5 to 35 mg/kg ECH. It is anticipated that the analysis of CHPMA and alpha-CH based on GC-MS may be sufficiently sensitive to investigate urinary excretion from humans occupationally exposed to ECH.
authors.affiliation: Leiden-Amsterdam Center for Drug Research (LACDR), Department of Pharmacochemistry, Free University, Amsterdam, Netherlands.
authors.forename: B M
authors.initials: BM
authors.lastname: De Rooij
authors.forename: J N
authors.initials: JN
authors.lastname: Commandeur
authors.forename: J R
authors.initials: JR
authors.lastname: Ramcharan
authors.forename: H C
authors.initials: HC
authors.lastname: Schuilenburg
authors.forename: B L
authors.initials: BL
authors.lastname: Van Baar
authors.forename: N P
authors.initials: NP
authors.lastname: Vermeulen
mesh_terms: D000111:Acetylcysteine / Q000031:analogs & derivatives* / Q000737:chemistry / Q000652:urine; D000818:Animals; D002273:Carcinogens / Q000008:administration & dosage / Q000378:metabolism*; D002728:Chlorohydrins / Q000737:chemistry / Q000652:urine*; D002849:Chromatography, Gas / Q000379:methods*; D004305:Dose-Response Relationship, Drug; D004811:Epichlorohydrin / Q000008:administration & dosage / Q000378:metabolism*; D007274:Injections, Intraperitoneal; D008297:Male; D051381:Rats; D017208:Rats, Wistar; D012997:Solvents / Q000008:administration & dosage / Q000378:metabolism*; D013997:Time Factors
chemical_list: D002273:Carcinogens; D002728:Chlorohydrins; D012997:Solvents; D004811:Epichlorohydrin; C104663:3-chloro-2-hydroxypropylmercapturic acid; D000111:Acetylcysteine