title: [Simultaneous determination of four mercapturic acids in human urine using solid phase extraction and liquid chromatography-tandem mass spectrometry].
abstract: A method was developed for the simultaneous extraction and determination of four mercapturic acids (MAs), N-acetyl-S-(3,4-dihydroxybutyl)-L-cysteine (DHBMA), N-acetyl-S-(3-hydroxypropyl)-L-cysteine (3-HPMA), N-acetyl-S-(2-carboxyethyl)-L-cysteine ( CEMA) and S-phenylmercapturic acid (SPMA), in human urine using solid phase extraction and high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). Frozen urine samples were thawed at room temperature, and centrifuged to remove any settled precipitate. The supernatant was then purified and concentrated by a C18 solid phase extraction column, and analyzed by HPLC-MS/MS in the multiple reaction monitoring (MRM) mode for the quantitative analysis. The ranges of recovery for DHBMA, 3-HPMA, CEMA and SPMA spiked in human urine matrix at three concentration levels were 105.6%-124.4%, 102.7%-106.5%, 103.2%-103.9% and 101.7%-104.3%, respectively, with the relative standard deviations of 2.6%-7.7%. The limits of detection (LOD, S/N > or = 3) were 0. 062, 0. 031, 0. 020 and 0. 003 microg/L for DHBMA, 3-HPMA, CEMA and SPMA, respectively. The method was successfully used to detect 4 MAs in 37 human urine samples from smokers and non-smokers. It was found that the contents of 3-HPMA, CEMA and SPMA in the urines from cigarette smokers were about three to six-fold more than those in the urines from the non-smokers.
authors.affiliation: China National Tobacco Quality Supervision & Test Centre, Zhengzhou 450001, China. hou_hongwei@yahoo.com.cn
authors.forename: Hongwei
authors.initials: H
authors.lastname: Hou
authors.forename: Wei
authors.initials: W
authors.lastname: Xiong
authors.forename: Na
authors.initials: N
authors.lastname: Gao
authors.forename: Dongkui
authors.initials: D
authors.lastname: Song
authors.forename: Gangling
authors.initials: G
authors.lastname: Tang
authors.forename: Qingyuan
authors.initials: Q
authors.lastname: Hu
mesh_terms: D000111:Acetylcysteine / Q000652:urine*; D002853:Chromatography, Liquid / Q000379:methods*; D006801:Humans; D012907:Smoking / Q000652:urine; D052616:Solid Phase Extraction / Q000379:methods*; D053719:Tandem Mass Spectrometry / Q000379:methods*
chemical_list: D000111:Acetylcysteine