title: Stir bar sorptive extraction with in situ derivatization and thermal desorption-gas chromatography-mass spectrometry in the multi-shot mode for determination of estrogens in river water samples.
abstract: A novel method for the trace analysis of natural and synthetics estrogens, such as estrone (E1), 17beta-estradiol (E2) and 17alpha-ethynylestradiol (EE), in river water sample was developed, which involved stir bar sorptive extraction (SBSE) with in situ derivatization followed by thermal desorption (TD)-gas chromatography-mass spectrometry (GC-MS). The derivatization conditions with acetic acid anhydride and the SBSE conditions such as sample volume and extraction time were investigated. In addition, the single and multi-shot modes in TD were investigated. The detection limits of E1, E2 and EE in river water sample were 0.2, 0.5 and 1 pg ml(-1) (ppt), respectively, in the multi-shot mode using five stir bars. The calibration curves for E1, E2 and EE were linear and had correlation coefficients >0.99. The average recoveries of E1, E2 and EE from all sample volumes were higher than 90% (R.S.D. < 10%) with correction using an added surrogate standard such as estrone-13C4, 17beta-estradiol-13C4 or 17alpha-ethynylestradiol-13C4. This simple, accurate, sensitive and selective analytical method may be applicable to the determination of trace amounts of estrogens in water samples.
authors.affiliation: Department of Analytical Chemistry, Faculty of Pharmaceutical Sciences, Hoshi University, 2-4-41 Ebara, Shinagawa-ku, Tokyo 142-8501, Japan.
authors.forename: Migaku
authors.initials: M
authors.lastname: Kawaguchi
authors.forename: Yumiko
authors.initials: Y
authors.lastname: Ishii
authors.forename: Norihiro
authors.initials: N
authors.lastname: Sakui
authors.forename: Noriya
authors.initials: N
authors.lastname: Okanouchi
authors.forename: Rie
authors.initials: R
authors.lastname: Ito
authors.forename: Koichi
authors.initials: K
authors.lastname: Inoue
authors.forename: Koichi
authors.initials: K
authors.lastname: Saito
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Nakazawa
mesh_terms: D000465:Algorithms; D004968:Estrogens, Non-Steroidal / Q000032:analysis*; D005618:Fresh Water / Q000032:analysis*; D008401:Gas Chromatography-Mass Spectrometry; D007202:Indicators and Reagents; D012015:Reference Standards; D014874:Water Pollutants, Chemical / Q000032:analysis*
chemical_list: D004968:Estrogens, Non-Steroidal; D007202:Indicators and Reagents; D014874:Water Pollutants, Chemical