Simultaneous determination of (fluoro)quinolones antibacterials residues in bovine milk using ultra performance liquid chromatography-tandem mass spectrometry

The ultra performance liquid chromatography-tandem mass spectrometry (UPLC) method had been developed for 22 (fluoro)quinolone(QNs) antibacterials in milk with multiple reaction monitoring (MRM) as acquisition mode. The analytes were extracted from the sample using Mcllvaine buffer by ultrasonic bath, and purified by solid-phase extraction (SPE) cartridge. The residue were dried under nitrogen and dissolved in mobile phase before UPLC-MS/MS final analysis. The calibration curve of six concentrations for 22 QNs showed good linearity and the good correlation coefficients (r >= 0.9851) were achieved. The limit range of quantification was 0.008-0.339 mu g/kg. The recovery range was 63.1-94.6% except flumequine, nalidixic acid and nadifloxacin. The method was precise: the relative standard deviations of the method for milk were not more than 13.12%. The accuracies and sensitivity of the method were good for simultaneous determination of 22 QNs. (C) 2008 Elsevier B.V. All rights reserved.