title: Dual derivatization-stir bar sorptive extraction--thermal desorption--gas chromatography-mass spectrometry for determination of 17beta-estradiol in water sample.
abstract: A novel method for the trace analysis of 17beta-estradiol (E2) in river water sample was developed, which involved stir bar sorptive extraction (SBSE) with in situ acylation (first derivatization) and thermal desorption (TD) with quartz wool assisted (QWA) in tube silylation (second derivatization), followed by gas chromatography-mass spectrometry (GC-MS), and is called the "dual derivatization method." The optimum conditions for SBSE with in situ acylation, such as the volume of acetic acid anhydride and the extraction time, were investigated. In addition, the optimum conditions for TD with QWA in tube silylation, such as the volume of N,O-bis(trimethylsilyl)trifluoroacetamide (BSTFA) and the TD temperature and hold time, were investigated as well. The detection limit (S/N = 3) and the quantitation limit (S/N>10) of E2 in the river water sample were 0.5 and 2 pg ml(-1) (ppt), respectively, by the dual derivatization method. In addition, the detection limit was 0.1 pg ml(-1) by using dual derivatization method with multi-shot mode. The calibration curve for E2 was linear in the range of 0.002-10 ng ml(-1) with correlation coefficients >0.999. The average recoveries of E2 (n = 6) at the concentrations of 0.05 and 1.0 ng ml(-1) from the river water sample were 93.1 (RSD: 1.4%) and 98.4% (RSD: 0.8%), respectively, with correction using the added surrogate standard, 17beta-estradiol-(13)C(4). This simple, accurate, sensitive and selective analytical method may be applicable to the determination of trace amounts of E2 in water samples.
authors.affiliation: Department of Analytical Chemistry, Faculty of Pharmaceutical Sciences, Hoshi University, 2-4-41 Ebara, Tokyo 142-8501, Japan.
authors.forename: Migaku
authors.initials: M
authors.lastname: Kawaguchi
authors.forename: Rie
authors.initials: R
authors.lastname: Ito
authors.forename: Norihiro
authors.initials: N
authors.lastname: Sakui
authors.forename: Noriya
authors.initials: N
authors.lastname: Okanouchi
authors.forename: Koichi
authors.initials: K
authors.lastname: Saito
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Nakazawa
mesh_terms: D000215:Acylation; D004958:Estradiol / Q000031:analogs & derivatives / Q000032:analysis*; D005618:Fresh Water / Q000737:chemistry; D008401:Gas Chromatography-Mass Spectrometry / Q000295:instrumentation / Q000379:methods*; D012680:Sensitivity and Specificity; D017655:Silicon Compounds / Q000737:chemistry; D014874:Water Pollutants, Chemical / Q000032:analysis*
chemical_list: D017655:Silicon Compounds; D014874:Water Pollutants, Chemical; D004958:Estradiol