高效液相色谱-串联质谱法测定牛奶中9种青霉素类药物的残留量

目的:建立一种HPLC-MS/MS方法快速测定牛奶中9种青霉素类药物的残留量。方法:前处理方法采用乙腈沉淀蛋白,正己烷液液萃取除脂;经高效液相色谱C18柱分离,选用pH 3.1甲酸水溶液和乙睛-pH3.1甲酸水溶液为流动相,11 min内在线梯度洗脱;在优化的质谱条件下,采用多反应监测(MRM),外标法定量。结果:方法的线性范围为0.4～400μg/L,9种青霉素类药物在牛奶基质中均有良好的线性关系(r>0.990);方法最低检测限为0.1～0.8μg/L,定量限为0.3～2.6μg/L;方法回收率均在80%以上,重复性良好,日内精密度<8.5%。结论:该方法测定9种青霉素药物的残留量简便、快速、准确,可以满足对青霉素残留的监测要求。

Determination of nine penicillin residues in milk by high-performance liquid chromatography-mass spectrometry

Objective: To establish a high-performance liquid chromatography-mass spectrometry(HPLC-MS/MS) method for detection of nine penicillin residues in milk.Methods: The samples were precipitated with acetonitrile and degreased with n-hexane for pre-processing.The chromatography was performed by reversed-phase HPLC in a C18 column and eluted gradiently on line for 11 min.The mobile phases were water with formic acid(pH 3.1) and acetonitrile-water with formic acid(pH 3.1).By optimizing the mass condition,the method was operated by multiple-reaction monitoring(MRM) and quantitated by external standard calibration.Results: The standard curves were linear in concentration range of 0.4~400 μg/L and all nine penicillins showed a good linear relationship in the milk matrix(r>0.990).The detection limit of the method was from 0.1 to 0.8 μg/L while the limit of quantification was from 0.3 to 2.6 μg/L.The average recoveries were higher than 80%.The within-day precisions were less than 8.5%.Conclusion: The established method is convenient,rapid and accurate and meets the requirement of monitoring penicillin residues in milk.