Title: Simultaneous Determination of Eight Quinolone Antibacterials in Meat and Fish by High Performance Liquid Chromatography
Abstract: A simple, rapid and reliable high performance liquid chromatographic (HPLC) method for the simultaneous determination of eight quinolones (oxolinic acid, nalidixic acid, flumequine, piromidic acid, benofloxacin, danofloxacin, enrofloxacin and ofloxacin) in meat and fish has been developed. The drugs were extracted with 0.2% metaphosphoric acid-acetonitrile (7:3), followed by a Bond Elut C18 clean-up procedure. The HPLC separation was carried out on a Wakosil II 5C18-HG column (150×4.6mm i. d.) with 0.05M phosphate buffer (pH 2.5)-ac-etonitrile (65:35) containing 3.5mM sodium dodecyl sulfate (SDS) as the mobile phase at a flow rate of 0.5ml/min. The drugs were detected by UV detection (at 282nm) and fluorescence detection (wavelength programing). The calibration graphs were rectilinear from 0.1 to 2ng for danofloxacin, and from 1 to 20ng for other drugs. The recoveries of the drugs from meat and fish fortified at the level of 0.2μg/g were 80.8-92.1%, with high precision. The limit of detection was 0.01μg/g for each drug. The method was applied in thermal stability studies of residual oxolinic acid. The thermal stability of oxolinic acid was excellent.