Objective To establish a high performance liquid chromatography (HPLC ) method for the determination of the content of theanine ,theophylline and caffeine in the various tea leaves .Methods Various tea leaves were extracted heating and refluxing to ex -tract by using water as the solvent .HPLC with gradient elution was used to determine theanine ,theophylline and caffeine .Results ①Theanine showed good linear relationship in the concentration range of 0 .026 4-1.762 0 mg · mL (r=0 .999 7) ;the RSD of precision of control article was 0 .98% (n=6) ;the average rate of recovery was 98 .96% ,and RSD was 1.01% (n=5),respectively .②Theophylline showed good linear relationship in the concentration range of 0 .014 3-0 .954 0 mg · mL (r=0 .999 8) ;the RSD of precision of control article was 1 .21% (n=6) ;the average rate of recovery was 98 .43% ,and RSD was 0 .74% (n= 5) respectively .③Caffeine showed good linear relationship in the concentration range of 0 .077 6-5 .168 0 mg · mL-1 (r=0 .999 6) ;the RSD of precision of control article was 1.03% (n= 6) ;the average rate of recovery was 99.43% ,and RSD was 0 .91% (n=5), respectively .④ The content of theanine ,theophylline and caffeine were 0 .46% -12 .70% ,0 .53% -32 .78% and 8 .78% -24 .12% , and the average content was 6 .08% ,10 .43% ,19 .04% respectively .Conclusion The method proved to be simple and easy to implement ,and could be used to tea's quality control.%目的 建立测定茶中茶氨酸、茶碱与咖啡因含量的方法,并测定其在不同茶中的含量.方法 茶叶采用水作为溶剂加热回流提取,采用高效液相色谱法及梯度洗脱法.结果 ①茶氨酸对照品在0.026 4～1.762 0 mg·mL-1质量浓度范围内线性关系良好(r=0.999 7);精密度的RSD值为0.98%(n=6);测得平均加样回收率为98.96%,RSD值为1.01%(n=5).②茶碱对照品在0.014 3～0.954 0 mg·mL-1质量浓度范围内线性关系良好(r=0.999 8);精密度的RSD值为1.21%(n=6);测得平均加样回收率为98.43%,RSD值为0.74%(n=5).③咖啡因对照品在0.077 6～5.168 0 mg·mL-1质量浓度范围内线性关系良好(r=0.999 6);精密度的RSD值为1.03%(n=6);测得平均加样回收率为99.43%,RSD值为0.91%(n=5).④茶氨酸、茶碱与咖啡因含量(mg·g-1)范围分别为0.46%～12.70%,0.53%～32.78%和8.78%～24.12%,平均含量分别为6.08%,10.43%,19.04%.结论 该方法简便易行,可用于茶叶的质量控制.
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