Simultaneous Determination of 2 Penicillins and Their 5 Major Metabolites in Bovine Muscle by Ultra Performance Liquid Chromatography Tandem Mass Spectrometry
A comprehensive analytical method based on ultra performance liquid chromatography tandem mass spectrometry has been developed for the simultaneous determination of 2 penicillins(amoxicillin and penicillin G) and their 5 major metabolites.Penicillin V was used as the internal standard in this method.Bovine muscle sample was prepared by precipitation of proteins with acetonitrile.The penicillins was analyzed on an ACQUITY UPLC HSS T3 column 100 mm×2.1 mm,1.8 μm using a mixture of 0.15% formic acid in water with 5 mmol/L ammonium acetate(pH 2.8) and acetonitrile as the mobile phase and a gradient program with a cycle time of 8 min,and detected by positive electrospray ionization tandem mass spectrometry in the MRM mode,and quantified by matrix-match internal standard solution.The standard curves were linear in the range of 25-2500 μg/kg for bovine muscle.The average recoveries were 91%-106% with RSDs of 2%-9%(n=6).The detection limits(S/N3) of the 8 analytes were 0.05-3.0 μg/kg,the limits of quantitation(S/N10) were all 25 μg/kg.The method is sensitive and repeatable,and can be applied to the field of residue analysis about penicillins and their metabolites.