毛细管电泳法同时分析茶黄素类和儿茶素类化合物

为了建立一种快速、准确、简便的同时分析茶黄素类和儿茶素类化合物的毛细管电泳方法以满足茶黄素体外氧化制备过程监测和茶多酚酶促氧化动力学研究的需要，研究了毛细管电泳同时分析4种茶黄素类和6种儿茶素类化合物的最佳分析条件，并将建立的方法进行应用评价。结果表明:以含有200 mmol/L H3BO3(pH 7.7)、10 mmol/L KH2PO4、9 mmol/L β-环糊精和27.5%乙腈为电泳介质,在电压25 kV、柱温30 ℃下分离和200 nm波长处检测,可在8 min内将10种待测组分全部分离,且各组分的浓度与峰面积呈良好的线性关系,相关系数r为0.9907～0.9998,检测限为0.39～0.88 μg/mL,各组分的加标回收率为91.5%～113.5%,相对标准偏差小于5%。

Simultaneous Analysis of Theaflavins and Catechins by Capillary Electrophoresis

In order to monitor the changes of theaflavins and catechins during the process of tea polyphenol oxidation, a rapid, accurate, sensitive and convenient analytical method was established. The optimum analytical conditions for simultaneous analysis of four theaflavins (TFs) and six catechins by capillary electrophoresis were investigated. The electrolyte solution consisted of 200 mmol/L boric acid (pH 7.7), 10 mmol/L potassium dihydrogenphosphate, 9 mmol/L beta-cyclodextrin and 27.5% acetonitrile. The experimental conditions of the instrument were selected as follows: voltage 25 kV, column temperature 30 degrees C, and detection wavelength 200 nm. Ten constituents could be separated from each other completely within 8 min and each one had a good linear relationship between its peak area and corresponding concentration (nu = 0.990 7 - 0.999 8). Furthermore, their detection limits were from 0.39 to 0.88 microg/mL, the mean recoveries varied from 91.5% to 113.5%. The relative standard deviations were less than 5%. All the above results showed that the developed method is especially suitable for the analysis of theaflavins and catechins.