分散固相萃取-离子色谱质谱法测定乳制品中硫氰酸盐含量

摘要

A method for the determination of thiocyanate in dairy products by ion chromatography mass spectrometry was established.Dairy products thiocyanate was extracted by water ultrasound,protein was precipitated by 3％ acetic acid,dispersive solid phase extraction was used for purification;extraction solution was filed by 0.22 M aqueous membrane,ion chromatography mass spectrometry detection was combined with external standard method for quantitative analysis.The purification methods,ion chromatography and mass spectrometry connection,spray cone voltage were optimized.The linear range was 0.01 ～ 0.5mg/L,the correlation coefficient was 0.996,determination limit (3S/N) was 0.2mg/kg and the detection limits (10S/N) was 0.6mg/kg.Recoveries were 91.0％ ～ 96.9％ with RSD (n =10) of 5.78％ ～ 9.81％ at the three different standard levels of 2.0,5.0,10.0 mg/kg.The method is simple,sensitive,accurate,low cost,and could be applied in the determination of chlorfluazuron in food.%建立了离子色谱质谱法测定乳制品中硫氰酸盐含量的方法.乳制品中硫氰酸盐经水超声提取后,用3％乙酸沉淀蛋白,以分散固相萃取法进行样品净化,提取液过0.22μm水相滤膜,离子色谱质谱联用仪检测,外标法定量.同时对样品净化方式,离子色谱-质谱连接方式,喷雾温度和锥孔电压等条件进行了优化.结果表明:硫氰酸盐在0.01 ～ 0.5mg/L范围内线性良好,相关系数为0.996,测定限(以信噪比S/N≥3计)为0.2mg/kg,定量限(以信噪比S/N≥10计)为0.6mg/kg.在2.0、5.0、10.0 mg/kg3个添加水平下进行了回收率和精密度试验,加标回收率在91.0％ ～ 96.9％之间,相对标准偏差RSD (n=10)为5.78％ ～ 9.81％.该方法操作简单、抗干扰能力强、灵敏度高、稳定性好、成本低廉,可用于乳制品中硫氰酸盐的日常检测.