液相色谱-串联质谱测定饲料中7种硝基咪唑类药物

采用液相色谱-串联质谱法(LC-MS/MS)测定了饲料中甲硝唑(MNZ)、地美硝唑(DMZ)、洛硝唑(RNZ)、替硝唑(TNZ)、奥硝唑(ONZ)、异丙硝唑(IPZ)和塞克硝唑(SCZ)等7种硝基咪唑类药物。样品用乙酸乙酯提取,正己烷-磷酸溶液反萃取,MCX柱净化,以0.1%乙酸水溶液和乙腈作流动相进行梯度洗脱,电喷雾电离源正离子(ESI+)多反应监测(MRM)模式下检测。方法的检测限和定量限分别为0.03 mg/kg和0.1 mg/kg。添加浓度为0.1、1 mg/kg和10 mg/kg时的平均回收率为72.9%~98.8%,变异系数为4.9%~12.1%。

Determination of 7 Nitroimidazoles in Feed by Liquid Chromatography-tandem Mass Spectrometry

A liquid chromatography-tandem mass spectrometry method for the simultaneous determination of metronidazole,dimetridazole,ronidazole,tinidazole,ornidazole,ipronidazole,and secnidazole in feeds was developed.Samples were extracted with ethyl acetate,and purified by hexane-phosphoric acid solution.Then the acidic solution was applied to MCX cartridge for further cleanup.C18 column was used for separation with 0.1% acetic acid solution as mobile phase A and acetonitrile as phase B for elution.The equipment was operated in MRM mode.The limits of detection and quantification were 0.03 and 0.1 mg/kg,respectively.The average recoveries ranged from 72.9% to 98.8% with relative standard deviation 4.9%~12.1% at spiked levels of 0.1~10 mg/kg.