title: Gas chromatographic-mass spectrometric determination of oxolinic acid in fish using selected ion monitoring.
abstract: A gas chromatographic-mass spectrometric (GC-MS) method is described for the determination of oxolinic acid in fish tissues. oxolinic acid is reduced with sodium tetrahydroborate to permit GC analysis. The sample is homogenized with phosphate buffer (pH 6) and extracted with ethyl acetate. The extract is partitioned between sodium hydrogencarbonate solution and the aqueous phase is acidified and re-extracted with ethyl acetate. The residue from the ethyl acetate extract is dissolved in methanol and reduced with sodium tetrahydroborate. The reduction product is extracted with diethyl ether and analysed by GC-MS in the selected ion monitoring mode for the ions at m/z 204, 219 and 176. The detection limit is 0.001 mg/kg and the recoveries were 95.6% [relative standard deviation (R.S.D.) 7.7%] at 0.1 mg/kg and 72.9% (R.S.D. 13.3%) at 0.01 mg/kg fortification levels in fish.
authors.affiliation: Miyagi Prefectural Institute of Public Health and Environment, Sendai, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Takatsuki
mesh_terms: D001894:Borohydrides; D005396:Fish Products / Q000032:analysis*; D005504:Food Analysis; D008401:Gas Chromatography-Mass Spectrometry; D007202:Indicators and Reagents; D007477:Ions; D010084:Oxidation-Reduction; D010093:Oxolinic Acid / Q000032:analysis* / Q000737:chemistry
chemical_list: D001894:Borohydrides; D007202:Indicators and Reagents; D007477:Ions; C025364:sodium borohydride; D010093:Oxolinic Acid