Multiresidue analysis of 63 veterinary drugs in meat by dispersive solid-phase extraction and high performance liquid chromatography-tandem mass spectrometry

A novel multiresidue analytical method has been developed and validated for the determination of five classes of veterinary drugs including 18 beta-lactams, 15 quinolones, 21 sulfonamides, 3 sulfonamide potentiators and 6 antiparasitics in meat using dispersive solid-phase extraction (dispersive-SPE) and high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). The analytes were extracted with a vortex mixer by 0.1 mol/L Na-2 EDTA solution and acetonitrile containing 1% (v/v) acetic acid, and then the extracts were purified using dispersive-SPE with C18 sorbent. Electrospray ionization mass spectrometry was operated in positive mode using dynamic multiple reaction monitoring (DMRM) for the qualitative and quantitative analysis of the 63 analytes after the separation on a Poroshell EC-C18 column (100 mm x 2.1 mm, 2.4 mu m). The correlation coefficients of linear calibration curves were over 0.99 in the corresponding concentration ranges. The average recoveries of the 63 analytes ranged from 62.2% to 112.0%, and the relative standard deviations (RSDs) were 3.1%-16.3% in spiked meat (pork, beef and chicken muscle) at three levels. The limits of detection (LODs, S/N >= 3) and the limits of quantification (LOQs, S/N >= 10) were 0.1-3.0 mu g/kg and 0.5-10.0 mu g/kg, respectively. The method is simple, rapid, sensitive, reliable and suitable for the determination of residues in animal products.