| A high performance liquid chromatography tandem mass spectrometric（HPLC-MS/MS） method was developed for the simultaneous determination of 8 penicillins（e.g.amoxicillin,ampicillin,penicillin G,penicillin V,oxacillin,cloxacillin,nafcillin and dicloxacillin） residues in fishery products．The penicillin G-D7,as an internal standard,was added into the sample before the extraction.The samples were extracted with acetonitrile-water（80∶20，by volume），and then cleaned up by dispersive solid-phase extraction with C18 dispersant sorbent and filtered through a Mr 10000 cut-off ultrafree microcentrifuge filter.The separation of 8 penicillins were performed on a HyPURITY C18 （2.1 mm×150 mm，3.5 μm） column using a mixture of 0.1% formic acid and acetonitrile containing 0.1% formic acid as mobile phase.The qualitative and quantitative analysis for the analyte were carried out under the selective reaction monitoring（SRM） mode with positive electrospay ionization．Under the optimal conditions,the calibration curves were linear in the range of 1.0-50.0 μg/L for ampicillin，penicillin G and nafcillin,2.5-100.0 μg/L for penicillin V,oxacillin,cloxacillin and dicloxacillin,and 5.0-200.0 μg/L for amoxicillin,respectively,with detection limits of 0.6 μg/kg,1.5 μg/kg and 3.0 μg/kg,respectively.The average spiked recoveries for 8 penicillins were between 74%and 98% with relative standard deviations（RSDs）less than 10%．The proposed method is accurate，sensitive and high-efficient,and is applicable for the determination of penicillins in fishery products． |