固相萃取/超高效液相色谱-串联质谱法测定乳与乳制品中万古霉素、去甲万古霉素残留

Determination of Vancomycin and Norvancomycin Residues in Milk and Dairy Products by Solid Phase Extraction/UPLC-MS/MS

建立了固相萃取/超高效液相色谱-串联质谱法(UPLC-MS/MS)同时测定乳和乳制品中万古霉素、去甲万古霉素残留量的分析方法。样品经乙腈-水溶液提取,三氯乙酸沉淀蛋白,二氯甲烷去除脂肪等杂质,Strata-X-C SPE小柱净化,以乙腈和0.1%甲酸水溶液作为流动相进行梯度洗脱,采用电喷雾离子源(ESI)在正离子多反应监测(MRM)模式下进行测定。万古霉素、去甲万古霉素在4～5 000μg/L范围内呈良好的线性关系,相关系数(r2)大于0.99。空白基质样品在15、60、150μg/kg加标水平的平均回收率均大于80%,相对标准偏差均小于5%。万古霉素、去甲万古霉素的方法检出限(LOD)分别为0.5、0.8μg/kg,定量下限(LOQ)分别为2.0、3.0μg/kg。该方法实用性强、准确性好、灵敏度高,适用于乳和乳制品中万古霉素、去甲万古霉素残留量的测定。

A method was established for the simultaneous determination of vancomycin and norvancomycin residues in milk and dairy products by solid-phase extraction and ultra performance liquid chromatography coupled with tandem mass spectrometry（UPLC-MS/MS）.The sample was extracted with a mixed solution of acetonitrile and water.Then the protein was precipitated with trichloroacetic acid, the fat and other impurities were eliminated with dichloromethane.The extration solution was purified with Strata-X-C solid phase extraction（SPE） column.The target compounds were separated on a reversed phase column by gradient elution of acetonitrile and 0.1% formic acid water solution,and then detected with positive electrospray ionization under multiple reaction monitoring（MRM） mode.The SPE conditions and UPLC-MS/MS parameters were optimized.Under the optimized conditions,the calibration curves for two target compounds were linear in the range of 4-5 000 μg/L with correlation coefficients（r2） greater than 0.99.The average recoveries of blank matrix sample at three spiked levels of 15,60, 150 μg/kg were all more than 80%,and the relative standard deviations（RSDs）were less than 5%.The limits of detection（LODs）for vancomycin and norvancomycin were 0.5 μg/kg and 0.8 μg/kg,respectively.The limits of quantitation（LOQs）were 2.0 μg/kg and 3.0 μg/kg,respectively.The method was practical，accurate and sensitive,and was suitable for the determination of vancomycin and norvancomycin in milk and dairy products.