高效液相色谱法测定绿茶中茶多酚及咖啡因

应用高效液相色谱法测定绿茶中没食子酸(GA)、咖啡因(CAF)及5种儿茶素类化合物,包括儿茶素(C)、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)、没食子儿茶素没食子酸酯(GCG)。对国家标准方法GB/T 8313-2008中流动相组成进行了调整,用0.5%乙酸代替2%的乙酸,在AT.Lichrom ODS色谱柱(4.6mm×250mm,5μm)上进行分离,流量为1.0mL.min-1,在波长278nm处进行紫外检测。7种组分在40min内达到完全分离。7种组分的质量浓度分别在一定的范围内与其峰面积呈线性关系。方法用于绿茶的分析,7种组分的加标回收率在96.0%～102.8%之间。

HPLC Determination of Tea Polyphenols and Caffeine in Green Tea

HPLC was applied to the determination of gallic acid(GA),caffeine(CAF) and 5 catechinic compounds,namely: catechin(C),epicatechin(EC),epigallocatechin gallate(EGCG),epicatechin gallate(ECG) and gallocatechin gallate(GCG),in green tea.Readjustment of composition of the mobile phase used in GB method of GB/T 8313-2008 was made by reducing the concentration of acetic acid from 2% to 0.5%.The 7 components were separated on AT.Lichrom ODS column(4.6 mm×250 mm,5 μm).Flow rate of the mobile phase was set at 1.0 mL·min-1 and UV-detection at 278 nm was adopted in the determination.Seven components were completed separated within 40 min.Linear relationships between values of peak area and mass concentration of the 7 components were obtained in definite ranges.The proposed method was used in the analysis of green tea,giving values of recovery obtained by standard addition method in the range of 96.0%-102.8%.