分光光度法测定茶叶中的茶氨酸

Spectrophotometric Determination of Theanine in Tea

热水萃取茶氨酸,浓盐酸水解为乙胺,建立了分光光度测定茶叶中茶氨酸含量的新方法。最大吸收波长为570nm。茶氨酸浓度在1.6-10.0mg·L-1范围内与△A呈线性关系,检出限为3×10-7g·mL-1。方法分析结果准确、操作比较简单、可排除茶叶中其它氨基酸的干扰。直接测定茶叶样品中的茶氨酸获得了满意的结果。

Theanine was extracted by hot water, hydrolyzed with concentrated hydrochloric acid to form ethylamine, and determined spectrophotometrically at 570nm. The linear range is 1. 6-10. 0mg·L-1. The detection limits is 3×10-7g·mL-1. The method is simple, credible, and effective to avoid interference of other amino acids in tea, and was used for determination of theanine in tea with satisfaction results.