提取咖啡因实验绿色化教学的实践

Practice of green chemistry teaching in extraction of caffeine

以铁观音碎茶为原料,通过综合改进实验考察得出从茶叶中提取咖啡因的实验条件,并和传统的水提取法、醇提取法进行对比。综合改进实验条件为:控温电热套加热,索氏提取器,95%乙醇为萃取剂,固液比1∶8(m/V),提取10次,蒸馏浓缩,水浴焙炒,200℃升华。咖啡因产率108 mg/10g,与市售绿茶产率相近。所得咖啡因结构经IR表征。在上述实验结果的基础上,提出了一种省时、绿色环保、实用的实验新方法。

Take Tie Guanyin tea fragments improved experimental method. The impact method and alcohol extraction method. The as raw material, caffeine was extracted by a comprehensive factors was compared with the traditional water extraction extraction conditions were as follows： controllable tempera- ture electronic heating mantle, soxhlet extractor, extraction agent 95% ethanol, solid-liquid ratio of 1 ： 8 （ m/V）, extraction ten times, distilling-condensing, water bath roasting, 200~C subliming. The rate of caffeine was 108mg/10g and roughly equaled with green tea. The structure was characterized by IR. Based on the experimental results, a new method for the extraction experiment was proposed in this pa- per. The method was green, time-saving and practicable.