高效液相色谱快速测定茶叶中儿茶素的含量

A Rapid Detection of Catechins and Caffeine in Tea-leaves by Hi gh Performance Liquid Chromatograph

分析了酸的种类及 pH对高效液相色谱 (HPLC)法测定表儿茶素 (EC)、表没食子儿茶素没食子酸酯(EGCG)、表儿茶素没食子酸酯 (ECG)、表没食子儿茶素 (EGC)、儿茶素 (C)和咖啡因的影响 ,实验表明 :酸尤其是乙酸不仅能改善各组分的峰形 ,而且对保留时间和出峰顺序均有较大的影响。确定了简单、快速分析 5种儿茶素及咖啡因的高效液相色谱分析方法。采用C18反相柱 ,水 -甲醇 -乙酸 ( 73. 0 / 2 3. 0 / 2 . 0 )为流动相 ,在流速为 1. 0mL·min-1,柱温 30℃ ,检测波长 2 80nm时等度洗脱分析样品 ,分析时间仅为 2 5min ,线性范围为 0 . 8～ 90mg·mL-1(r =0 998～ 0 999) ,回收率为 98. 2 %～ 10 0 . 3%,检测限为 5～ 10ng。

Effects of acid and pH on high performance liquid ch ro matograph (HPLC) for (-)-epigallocatechin 3-gallate(EGCG), (-)-epicatechin(E C), (-)-epicatechin-3-gall ate(ECG), (+)-catechin, (-)-epigallocatechin(EGC ) and caffeine was discussed. Effect of acid especially acetic acid on not only peak shape of composition but retention time and elution order was resulted. A s imple and fast HPLC method using an ODS column (4.6×250 mm) and water-methanol -acetic acid (73.0/25.0/2.0) mobile phase system was developed. The separation w as carried out within 25 min by isocratic elution with flow rate 1.0 mL·min~ -1, column temperature at 30℃ and detection wavelength at 280 nm. The rec overy of all compounds of method is 98.2%～100.3%, the linear is 0.8～90 mg·mL ~ -1 (r=0.998～0.999) and detection limits 5～10 ng respectively.