Abstract Isolation of caffeine from tea leaf is one of the classic experiments in organic chemistry experiments. In this study, the traditional sublimation apparatus was changed to be more simple and efficient. Meanwhile, the aggregation and growth of the crystal of caffeine can be observed directly. The amount of caffeine can be collected and calculated easily. The thin layer chromatography was used to determine the components in the extracting solution. The new experiment process enriches the experiment lesson and decreases the possibility of mistake. It is safer than the traditional one. Furthermore, the conjunctive use of microscopic melting point meter and smart phone successfully photographed the morphology of the caffeine crystal and bring the interest to this classic experiment.
MA Yun-Fei, SHU Ya-Jian, GAO Shi-Quan, ZHAO Zhi-Quan. Improvement of the Sublimation of Caffeine and Vivid Presentation[J]. Chinese Journal of Chemical Education, 2018, 39(10): 36-38.