title: Simultaneous determination of metabolites of trimethylbenzenes, dimethylbenzylmercapturicacid and dimethylhippuric acid, in human urine by solid-phase extraction followed by liquid chromatography tandem mass spectrometry.
abstract: We describe a novel method for the determination of three kinds of dimethylbenzylmercapturic acids (DMM) and six kinds of dimethylhippuric acids (DMH), found in urine as metabolites of trimethylbenzenes, based on liquid chromatography/electrospray ionization tandem mass spectrometry. A solid-phase extraction procedure was used for the extractions of DMM and DMH from a urine sample, and the separation was performed on a reversed-phase C(30) column. The analytes were ionized by electrospray in the positive-ion mode. Operating in the multiple reaction monitoring mode, the linearity of the relative mass spectrometric responses to the internal standard versus analyte concentrations were established in the range 0.1-100 ng ml(-1). The extraction procedure was rapid and the relative standard deviations were below 5%. The detection limits of DMM and DMH in the urine by the proposed method were in the ranges 0.26-0.41 and 0.42-2.0 ng l(-1), respectively. Furthermore, DMM and DMH were detected in a urine sample from an individual who did not suffer from occupational exposure to trimethylbenzenes, by using this method.
authors.affiliation: Osaka City Institute of Public Health and Environmental Sciences, 8-34, Tojo-cho, Tennoji-ku, Osaka 543-0026, Japan. hiroshi.moriwaki@iphes.city.osaka.jp
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Moriwaki
authors.forename: Ayumi
authors.initials: A
authors.lastname: Watanabe
authors.forename: Ryuichi
authors.initials: R
authors.lastname: Arakawa
authors.forename: Yuji
authors.initials: Y
authors.lastname: Tsujimoto
authors.forename: Mitsuru
authors.initials: M
authors.lastname: Shimizu
authors.forename: Tsutomu
authors.initials: T
authors.lastname: Noda
authors.forename: Munehiro
authors.initials: M
authors.lastname: Warashina
authors.forename: Masanobu
authors.initials: M
authors.lastname: Tanaka
mesh_terms: D000111:Acetylcysteine / Q000031:analogs & derivatives* / Q000378:metabolism / Q000652:urine*; D000395:Air Pollutants, Occupational / Q000378:metabolism / Q000652:urine; D002853:Chromatography, Liquid / Q000379:methods*; D004781:Environmental Exposure; D006626:Hippurates / Q000378:metabolism / Q000652:urine*; D006801:Humans; D015394:Molecular Structure; D012680:Sensitivity and Specificity; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*; D016482:Urinalysis / Q000379:methods*; D014992:Xylenes / Q000378:metabolism / Q000652:urine*
chemical_list: D000395:Air Pollutants, Occupational; D006626:Hippurates; D014992:Xylenes; C030514:hippuric acid; D000111:Acetylcysteine; C029319:S-benzyl-N-acetyl-L-cysteine