从茶叶中提取咖啡因实验方法的改进

针对采用传统的实验方法从茶叶中提取咖啡因存在着产率较低、产物色泽不好等问题，奉课题从脱色、滤液浓缩和升华等实验过程进行了深入的探索研究，发现了实验中成败的关键步骤——升华温度的控制方法,通过改进不仅提高了茶叶中咖啡因的收率和产品纯度，而且缩短了实验反应时间．用电热套代替砂浴，95％工业乙醇作溶剂，萃取时间为1．5h，15g绿茶中咖啡因的最高收率可迭160mg．

Improvement on the Experimental Method of Extracting Caffeine from Tea

The traditional method of extracting caffeine from tea has much difficult in contents and purify of products. In this paper, we deeply studied the effect of decolorization, concentrated filtrate, and sublimation. The results showed that the key steps were the controls of sublimation temperature and time. By improving this process, not only the contents and the purity of the products were assured, but also the experiment time was saved. That is, the highest results efficiency of caffeine reached 160 mg from 15 g green tea, when the sand bath was replaced by electric jacket, 95% anhydrous alcohol was used as solvent, and the extraction time was 1.5 h.