title: Stir bar sorptive extraction with in situ de-conjugation and thermal desorption gas chromatography-mass spectrometry for measurement of 4-nonylphenol glucuronide in human urine sample.
abstract: 4-Nonylphenol glucuronide (NP-G) in human urine samples was analyzed using stir bar sorptive extraction (SBSE) with in situ de-conjugation by beta-glucuronidase and thermal desorption (TD)-gas chromatography-mass spectrometry (GC-MS). Distilled water (1 ml), 1.0 M ammonium acetate solution (100 microl) and beta-glucuronidase (10,000 units ml(-1), 10 microl) were added to human urine sample (1 ml), and extraction was commenced for 90 min at 37 degrees C while stirring at 250 rpm with a stir bar coated with a 500-microm-thick polydimethylsiloxane (PDMS) layer. Then, the stir bar was subjected to TD-GC-MS in the selected ion monitoring (SIM) mode. The calibration curve was made by SBSE method using 4-nonylphenol (NP) as the standard solution. The method showed good linearity and the correlation coefficients were 0.999 over the concentration range of 5-500 nM. Moreover, to optimize the conditions for SBSE with in situ de-conjugation and the recovery test, NP-G was synthesized by a biochemical technique in our laboratory. The limits of detection (S/N = 3) and quantitation (S/N > 10) for NP were 0.2 ng ml(-1) (1.0 nM) and 1.1 ng ml(-1) (5.0 nM), respectively. The average recoveries in the human urine samples (n = 6) spiked with NP-G at levels of 20 and 100 nM were 104.1 (R.S.D. 7.1%) and 100.6% (R.S.D. 9.2%), respectively, with correction using the added internal standard, 4-(1-methyl) octylphenol-d(5). The method enabled the precise determination of the standard and was applicable to the detection of trace amounts of NP-G in human urine samples.
authors: Department of Analytical Chemistry, Faculty of Pharmaceutical Sciences, Hoshi University, 2-4-41 Ebara, Tokyo 142-8501, Japan.
authors: Migaku
authors: M
authors: Kawaguchi
authors: Rie
authors: R
authors: Ito
authors: Yoshio
authors: Y
authors: Hayatsu
authors: Hisao
authors: H
authors: Nakata
authors: Norihiro
authors: N
authors: Sakui
authors: Noriya
authors: N
authors: Okanouchi
authors: Koichi
authors: K
authors: Saito
authors: Hiroshi
authors: H
authors: Yokota
authors: Shun-ichiro
authors: S
authors: Izumi
authors: Tsunehisa
authors: T
authors: Makino
authors: Hiroyuki
authors: H
authors: Nakazawa
mesh_terms: D000085:Acetates / Q000737:chemistry; D000328:Adult; D001671:Biochemistry / Q000379:methods; D002138:Calibration; D002626:Chemistry, Pharmaceutical / Q000379:methods*; D004129:Dimethylpolysiloxanes / Q000737:chemistry; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods*; D005965:Glucuronates / Q000652:urine*; D006358:Hot Temperature; D006801:Humans; D013058:Mass Spectrometry; D008956:Models, Chemical; D009596:Nitrophenols / Q000652:urine*; D015203:Reproducibility of Results; D012107:Research Design; D012828:Silicones / Q000737:chemistry; D014874:Water Pollutants, Chemical
chemical_list: D000085:Acetates; D004129:Dimethylpolysiloxanes; D005965:Glucuronates; D009596:Nitrophenols; D012828:Silicones; D014874:Water Pollutants, Chemical; C049288:p-nitrophenol glucuronide; C013830:baysilon; C018824:ammonium acetate