液相色谱-串联质谱法测定牛奶中万古霉素和去甲万古霉素残留

Simultaneous determination of vancomycin and norvancomycin in milk by liquid chromatography-tandem mass spectrometry

建立了牛奶中2种多肽类抗生素万古霉素和去甲万古霉素残留量的液相色谱-串联质谱(LC-MS/MS)检测方法。牛奶样品用三氯乙酸水溶液提取、沉淀蛋白,经混合型阳离子固相萃取柱Oasis MCX净化后,利用LC-MS/MS进行定性和定量分析。测定时样品溶液经ZORBAX SB-C18色谱柱分离,0.1%甲酸水溶液和乙腈作为流动相进行梯度洗脱,质谱测定采用正离子模式,多反应监测(MRM)。结果表明,万古霉素和去甲万古霉素的检出限为5μg/kg,回收率为72.5%～87.2%,相对标准偏差小于10%。

A simple, rapid and specific analytical methods for the determination of vancomycin and norvancomycin in milk had been developed based on liquid chromatography tandem mass spectrometry in a multiple reaction monitoring mode. Milk samples were extracted with 0.1% trifluoroacetic acid in water. Antibiotics in the extract were separated on a ZORBAX SB-C18 column using a gradient elution program of 0.1% formic acid aqueous solution and acetonitriie. Limits of detection for vancomycin and norvancomycin were 5μg/kg. Mean recoveries were 72.5%-87.2%,and the relative standard deviation（RSD） was less than 10%.