实验室中一种高纯度咖啡因提取方法的研究

摘要

Caffeine is a main purine base from ordinary tea. In this paper, through adjusting the experimental procedure of organic chemistry experiment to extract caffeine from tea by the sublimation method, the extracting process was optimized by changing tea type and ethanol water solution concentration,improving experiment installation and experiment time. The experiment results show that when using black tea as raw material,ratio of ethanol to water solution is 1 1∶ ,the time is 40 min , the extraction rate is the best. Comparing with traditional way,improved method can increase the extraction rate by 20%, and attain analytically pure caffeine.%咖啡因是茶叶中所含的多种嘌呤碱中最主要的一种。通过改进经典有机化学教学实验“从茶叶中提取咖啡因”实验步骤，在保持升华法提取的前提上通过对茶叶品种、乙醇溶剂比、实验提取装置、实验控制时间等角度改进实验。实验结果表明溶剂比为1∶1的乙醇水溶液提取率较高，提取最控制时间为40 min，发酵程度较高的红茶类茶叶的咖啡因含量较高，改进后的恒压提取法与索氏提取法相比咖啡因平均提取率提高20%，提取后的产品经过色谱分析确定为咖啡因、纯度为98.5%达到分析纯级样品。