【摘要】 <正> 红茶中茶黄素类[Theaflavins]物质的含量对茶叶的品质和市场价格影响很大。茶叶中茶黄素类物质含量的测定,最常用的方法是溶剂萃取—分光光度法测定其总量,后来逐步发展了纸色谱法和经典柱色谱法,也有人采用气相色谱法进行测定,但样品需经过复杂的预处理和衍生化处理Hoefler和Coggon首先将高效液相色谱用于茶黄素的分离,但定量工作未见报道。更多还原

【Abstract】 A separation and quantitative determination method of thea-flavins in black tea by isoctratic elu-tion HPLC has been developed. By using a 150mm×2.6mm stainless steel column packed with YWG-CH (10μ) as stationary phase and UV detector (λ-310nm) , theafiavin(TF) , theaflavin monogallate (TFG) and thcaflavin disgallate (TFDG) were quantitatively determined within 25 minutes. The mobile phase composition used was acetone-water-acetic acid (31:68 :1). Black tea was infused by boiling distilled water for 10 minutes. The infusion was extracted with ethyl acetate. After washing by 0.05M Tris-HCl buffer (pH 8.0) , the extract was evaporated to dry. The residue was dissolved in mobile phase solution and determined by HPLC.In this method, the average recoveries of TF, TFG and TFD Gare 85.1%, 89.2% and 95,4%, respectively. The variation coefficient arc 5.53%, 5.54% and 6.51%,the minimum detectable quantities are 0.32μg, 0.29μg and 0.36μg, respectively.更多还原