气相色谱-质谱联用法测定巧克力中香兰素、特丁基对苯二酚、咖啡因

GC-MS Determination of Vanillin, TBHQ, Caffeine in Chocolate

样品经乙酸乙酯提取蒸干,用饱和乙腈溶解,再经正己烷脱脂后,以气相色谱-质谱联用法同时测定巧克力中的香兰素、特丁基对苯二酚、咖啡因的含量。在样品的气相色谱分离中用HP_5MS毛细管柱作为固定相,在质谱测定中采用选择离子检测模式。香兰素、特丁基对苯二酚、咖啡因的检出限(3S/N)分别为0.04,0.05,0.02 mg·kg^(-1)。用标准加入法做回收率试验,测得回收率在86.1%～99.9%之间,相对标准偏差(n=11)分别为2.01%,1.10%,1.68%。

The chocolate sample was extracted with ethyl acetate and dried, and dissolved with saturated acetonitrile and defatted with n：hexane, The contents of vanillin, TBHQ and caffeine in sample solution were determined by GC-MS. The HP-5MS capillary column was used for C,-C separation and the SIM mode was adopted in MS determination. The values of detection limit （3S/N） of vanillin, TBHQ and caffeine found were 0. 04, 0. 05, 0. 02 mg· kg-1. Recovery was tested by standard addition method, giving values of recovery in the range from 86.1% to 99. 9%, with their RSD＇s （n=11） 2.01%, 1.10% and 1.68%, respectively.