建立了超高效液相色谱-串联质谱法（UPLC-MS/MS）测定牛肉组织中地美硝唑（DMZ）、甲硝唑（MNZ）、洛硝达唑（RNZ）和替硝唑（TNZ）残留量的检测方法。样品经乙酸乙酯提取，正己烷除脂，PLS（亲水亲脂平衡柱）固相萃取柱净化后，以C18反相色谱柱为分析柱，0.1%甲酸水-乙腈为流动相，采用电喷雾电离源（ESI+），选择反应监测模式（SRM）进行检测。结果表明，4种硝基咪唑类药物响应值与其质量浓度在1.00～25.00ng/mL范围内线性良好，相关系数r2在0.9986以上；在0.2、1.0和2.0μg/kg添加水平下DMZ、MNZ、RNZ和TNZ回收率在64.4%～96.6%范围内，批内、批间变异系数小于15%；4种药物检测限（LOD）为0.1μg/kg，定量限（LOQ）为0.2μg/kg。方法满足于牛肉中上述单种或多种种硝基咪唑类药物残留检测。% A method was established for determining residues of dimetridazole,metronidazole, ronidazole and tinidazole in beef with UPLC-MS/MS. The sample was extracted with ethyl acetate and the fat was removed by hexane. A PLS solid phase extraction (SPE) cartridge was used to clean up the extract. These compounds were determined by reversed-phase LC using a C18 column with fomic acid solution –acetonitrile as the mobile phase,and MS detection in positive mode by applying selected reaction monitoring (SRM). Good accuracy,precision and sensitivity were obtained with the method. The calibration curves of 4 nitroimidazoles was linear between the peak areas and the concentrations in the range of 1~25μg/L and the correlation coefficients (r2) was 0.998 6 at least.The recoveries of DMZ,MNZ,RNZ and TNZ were in the range of 64.4%~96.6% at three spiked concentration of levels of 0.2,1 and 2μg/kg,with the intra-and inter-batch variation coefficients less than 15%. The limit of detection(LOD) for 4 nitroimidazoles was 0.1μg/kg and the limit of quantitation (LOQ) was 0.2μg/kg. The study revealed that the method is suitable for the determination of nitroimidazoles in beef.
展开▼
