LC-MS/MS测定果汁饮料中乳酸链球菌素

该试验旨在建立LC-MS/MS测定果汁饮料中乳酸链球菌素的分析方法。通过含0.1%甲酸的20%乙腈水溶液超声提取样品中的乳酸链球菌素,C₁₈色谱柱分离,0.1%甲酸水溶液和乙腈进行梯度洗脱,经质谱法检测,外标法定量。结果表明,最佳提取条件为提取溶剂乙腈、超声提取时间15 min。乳酸链球菌素的线性范围在0~100μg/L之间,线性相关系数为0.9996。方法的检出限为20μg/kg,定量限为50μg/kg;在50,100和500μg/kg三个水平下进行加标试验,其加标回收率在79.5%~111.5%之间,相对标准偏差(RSD)<10%,符合GB 27404—2008相关规定。该方法简单、便捷,适用于饮料中乳酸链球菌素含量的测定。

Determination of Nisin in Fruit Juice Drinks by Liquid Chromatography-Tandem Mass Spectrometry

To establish a method for detection of nisin in fruit juice drinks by liquid chromatography-tandem mass spectrometry(LC-MS/MS),nisin was extracted by ultrasonic with 20%acetonitrile containing 0.1%formic acid from samples,separated by an a C₁₈chromatographic column using 0.1%formic acid water solution-acetonitrile as mobile phase for gradient elution,and then detected by tandem mass spectrometry with external standard method for quantification.The results showed that the optimum extracting conditions were extraction solvent of acetonitrile and ultrasonic extraction time of 15 min.The linear range of nisin was 0-100 ng/mL,and the linear correlation coefficient was 0.9996.The detection limit of the method was 20μg/kg,and the limit of quantification was 50μg/kg.When spiked at three levels of 50,100 and 500μg/kg,the recovery range of the method was 79.5%-111.5%,and relative standard deviation(RSD)was less than 10%,which were in line with GB 27404—2008 standard.This method was simple and convenient,which was suitable for the determination of nisin in fruit juice drinks.