高效液相色谱法分离及测定茶叶中的茶碱

Theophylline Separation and Analysis of Theophylline in Tea Samples by High Performance Liquid Chromatography

采用沸水提取-高效液相色谱法测定不同茶叶中的茶碱。流动相为甲醇-水,两者体积比为20:80,流速为0.7 mL/min,柱温35℃,检测波长270 nm。该方法的线性方程为Y=-0.094+1.24X,线性范围在0.05~15 mg/L,线性相关系数R 2=0.9991,检出限为0.017 mg/L。建立的分析方法能够有效检出茶叶样品中的茶碱,目标分析物不受干扰物质的影响,检出浓度在0.459~5.755 mg/L之间,加标回收率在88.9%~112.2%之间,相对标准偏差在1.1%~5.4%之间。

Theophylline in different tea samples was extracted by boiling extraction coupled with high performance liquid chromatography(HPLC)method.The mobile phase was methanol-water,with the volume ratio of 20:80.The flow rate was 0.7 mL/min.The column temperature was 35℃and the detection wavelength was 270 nm.The linear equation of the proposed method was Y=-0.094+1.24X,the linear range was 0.05~15 mg/L,the linear correlation coefficient R 2=0.9991,and the detection limit was 0.017 mg/L.The established analytical method could effectively detect theophylline in tea samples,and the target analyte was not affected by interfering substances.The detection concentration was between 0.459 and 5.755 mg/L.The recovery was between 88.9%and 112.2%,and the relative standard deviation was between 1.1%and 5.4%.