Determination of Amprolium Residues in Bovine Tissues by Liquid Chromatography with Tandem Mass Spectrometry
A method was developed for determining residual amprolium in bovine tissues by liquid chromatography with tandem mass spectrometry.The samples were extracted with phosphate buffer solution.Then the extract was directly purified through HLB cartridge after centrifugation.The elution was dried under nitrogen and residues were dissolved in 0.1% formic acid solution/ methanol(9∶1,V/V).The samples were analyzed by LC-MS/MS on a XBridge TM C18 column with a mixture of 0.1% formic acid solution and methanol(90∶ 10,V/V) as the mobile phase.The samples were quantified with the external standard calibration curve method.Good linearity was obtained for amprolium at the concentration of 5-2000 mg/L with the linear relative coefficient more than 0.999.The recoveries in three kinds of bovine tissues were 81.6%-92.8% at the fortified levels of 25-750 mg/kg with the limit of detection of 3.50 mg/kg and the limit of quantitation of 11.7 mg/kg.The relative standard deviations were less than 15.0%.