气相色谱-质谱联用法同时测定红枣中六种酚酸

摘要

采用气相色谱-质谱联用(GC-MS)分析方法同时测定红枣中6种酚酸(水杨酸、4-羟基苯甲酸、香草酸、2,5-二羟基苯甲酸、原儿茶酸和对香豆酸).并对色谱柱、升温程序及衍生化条件进行了优化.最终使用的色谱柱为Rtx-5毛细管色谱柱(0.25 mm×30 m,0.25 μm);升温程序为初始柱温100℃,以10℃/min升至200℃,然后再以5℃/min上升到250℃,保持5 min,总共运行时间为25 min;选择(双三甲基硅烷基)三氟乙酰胺(BST-FA,含1％的三甲基氯硅烷)为衍生化试剂,样品衍生化的温度为35℃,时间30 min.在此最优分析条件下,6种酚酸得到良好的分离,各酚酸含量与峰面积之间呈现良好的线性关系(r2≥92.6),方法的检出限为1 ～6μg/L,回收率为92.6％ ～ 104.3％,且相对标准偏差均小于5％.该方法可成功用于3种红枣样品中的此6种酚酸的测定,也为其他食品中这6种酚酸的测定提供新的检测方法.%GC-MS was used to simultaneously determine six kinds of phenolic acids in jujube including salicylic acid,4-hydroxybenzoic acid,vanillic acid,2,5-dihydroxybenzoic acid,protocatechuic acid and p-coumaric acid.Meanwhile,the column,temperature programmed and derivatized condition were optimized.Finally,the Rtx-5 capillary column (0.25 mm × 30 m,0.25 μm) was chosen.The temperature program was initially at 100 ℃,then raised to 200 ℃ at a rate of 10 ℃/min and then increased at 5 ℃/min up to 250 ℃ and held for 5 min.The total running time was 25 min.The samples were derivatized by BSTFA(containing 1％ TMCS) at 35 ℃ for 30min.Six kinds of phenolic acids were completely separated under this optimum condition.The phenolic acid content and the peak area showed a good linear relationship(r2≥ 92.6).The detection limits were 1-6 μg/L,the recoveries were 92.6％-104.3％,and the relative standard deviation were less than 5％.This method has been applied for the simultaneous determination of six kinds of phenolic acids in jujube.The study provides a reference to determine these six kinds of phenolic acids in other products as well.