高效液相色谱法测定砖茶中儿茶素和生物碱含量的研究

Simultaneous determination of catechins and alkaloids in brick-tea by high performance liquid chromatography-diode array detection

目的建立测定砖茶中儿茶素和生物碱的色谱分析方法，同时寻找出砖茶中儿茶素和生物碱的较优提取条件。方法采用高效液相色谱法分离检测砖茶中儿茶素和生物碱，并进行回收率、精密度、稳定性实验。分别采用水、乙醇作为提取溶剂对砖茶中儿茶素和生物碱提取情况进行正交实验。再比较水和醇的提取效果，以获得提取砖茶中儿茶素和生物碱的较优提取条件。结果高效液相色谱法可同时分离并检测出砖茶中儿茶素、表儿茶素、表没食子儿茶素、表没食子儿茶素没食子酸酯、没食子儿茶素、表儿茶素没食子酸酯6种儿茶素以及咖啡碱、可可碱2种生物碱。各组分的峰面积和浓度之间具有良好的线性关系，决定系数（R：）范围为0．9990—0．9999；加标回收率范围为83．78％一106．35％。精密度较好[峰面积相对标准偏差（RSD）范围为0．50％-1．51％]。砖茶中儿茶素和生物碱较优提取条件为：乙醇浓度80％、料液比1：10、温度80℃、时间30mino结论乙醇作为提取剂的高效液相色谱法的较优提取条件，对砖茶中6种儿茶素和2种生物碱分离度较好，定性准确，快速灵敏。

Objective To develop a method for determination of catechins and alkaloids in brick-tea by high performance liquid chromatography（HPLC） with diode array detection（DAD）, and to explore optimum extraction conditions for catechins and alkaloids components in brick-tea. Methods Catechins and alkaloids were separated and detected by HPLC. Orthogonai experiment and paired t test was carried out to compare the effect of water and alcohol as extraction solvents and to obtain optimum extraction conditions for extracting catechins and alkaloids components in brick-tea. Results Six kinds of catechins of catechin, epicatechin, galloeatechin, epigallocatechin, epicatechin gallate, epigallocatechin gallate and two kinds of alkaloids of caffeine and theobromine were separated and detected simultaneously. Calibration curves between peak areas and concentration of each component in brick- tea were linear within a suitable concentration range, and coefficients of determination （R2） were between 0.9990 - 0.9999; spiked recoveries were from 83.78% to 106.35%, and relative standard deviations（RSD） were between 0.50% - 1.51%. The optimum extraction condition for catechins and alkaloids was 80% ethanol, solid-liquid ratio of 1 ： 10, temperature 80 ~C and extraction time 30 min. Conclusion Alcohol as extraction solvents with optimal combination on HPLC, six kinds of catechins and two kinds of alkaloids are separated accurately, qualitatively, rapidly and sensitively.