气相色谱-质谱／选择离子法测定牛奶中的香兰素

Determination of vanillin in milk by GC-MS/SIM

应用气相色谱-质谱联用(GC-MS)技术建立了牛奶中香兰素(Vanillin)的测定方法。利用香兰素在pH>8的环境中以离子形式存在的性质,排除牛奶中乳脂等成分的干扰,然后以乙醚为萃取剂提取样品中的香兰素,采用选择离子(SIM)模式,根据保留时间和特征离子丰度比进行确证后进行定量分析。结果表明,本法可消除复杂基质的干扰,简便快速、准确可靠,相对标准偏差小于7%(n=6),回收率在83%～95%;方法的检出限为0.006μg/g。本文利用此法对市售12个不同厂家的UHT纯奶样品中香兰素进行了测定,检出率达到83.8%。

The method for the determination of Vanillin in milk by GC-MS was described in this paper. Vanillin was ion form for removing the interference with butterfat in milk when it was pH〉8, which was extracted by ethyl ether. Analysis was performed by selected ion monitoring （SIM） mode, retention time and characteristic ion ratios. Result shows that this method could eliminate the interference with complex base material, conveniently, quickly; exactly. The spiked recovery is between 83% and 95%.The RSD is less than 7%.The limit of detection is 0.006 μg/g. The investigation for 12 different market UHT milk were completed by the method and the results were acquired that the detection rate of Vanillin was 83.3%.