大学化学 >> 2025, Vol. 40 >> Issue (8): 272-276.doi: 10.12461/PKU.DXHX202409137

化学实验 上一篇    下一篇

“可视化”助力从茶叶中提取咖啡因实验的关键步——升华

李龙平1, 李嘉莉2, 曲天歌1, 蔡佳庆3, 张楚钰1, 郭雯霁4, 李秋莲4, 罗钒4   

  1. 1 华中科技大学同济医学院口腔医学院, 武汉 430030;
    2 华中科技大学同济医学院公共卫生学院, 武汉 430030;
    3 华中科技大学同济医学院基础医学院, 武汉 430030;
    4 华中科技大学化学与化工学院, 武汉 430074
  • 收稿日期:2024-09-29 录用日期:2024-12-23 发布日期:2025-07-19
  • 通讯作者: 罗钒 E-mail:luofan16@hust.edu.cn
  • 基金资助:
    华中科技大学教学研究面上项目(2024106)

Sublimation: Application “Visualization” to the Key Step in Extracting Caffeine from Tea Leaves

Longping Li1, Jiali Li2, Tiange Qu1, Jiaqing Cai3, Chuyu Zhang1, Wenji Guo4, Qiulian Li4, Fan Luo4   

  1. 1 School of Stomatology, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China;
    2 School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China;
    3 School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China;
    4 School of Chemistry and Chemical Engineering, Huazhong University of Science and Technology, Wuhan 430074, China
  • Received:2024-09-29 Accepted:2024-12-23 Published:2025-07-19
  • Contact: Fan Luo E-mail:luofan16@hust.edu.cn

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摘要： 升华是“从茶叶中提取咖啡因”实验的关键步，这一步由于在蒸发皿里完成，学生在整个加热过程中不能直观地观察升华完成的全过程，并且由于加热温度不易控制导致部分学生的样品由于温度过低根本就没有开始升华，或者由于温度过高有色杂质跟着一起升华出来，甚至直接碳化，使得产品不纯和损失。本文在升华时用玻璃器皿代替蒸发皿，学生可以清楚地观察升华过程中的现象，并且利用温敏试纸监测找到升华的最佳温度。“可视化”的融入，不仅有助于学生观察、记录实验现象，将实验现象和升华的温度关联起来，更重要的是培养学生理论和实践相结合的能力和解决问题的能力。

关键词: 咖啡因, 升华, 温敏试纸, 可视化

Abstract: Sublimation is a critical step in the extraction of caffeine from tea leaves. In traditional methods, this process occurs within an evaporating dish, which limits students’ ability to visually monitor the entire sublimation process during heating. Additionally, the difficulty in controlling the heating temperature can lead to various issues: some students may not initiate sublimation due to insufficient heat, while others may inadvertently cause colored impurities to sublime alongside the desired product, or even result in carbonization when the temperature is excessively high. This study introduces the use of glassware in place of evaporating dishes, allowing students to clearly observe the phenomena associated with sublimation. Furthermore, temperature-sensitive test papers are employed to identify the optimal sublimation temperature. The integration of “visualization” in this context not only aids students in observing and documenting experimental phenomena, but also establishes a connection between these observations and sublimation temperature. More importantly, it fosters students’ ability to integrate theoretical knowledge with practical application, thereby enhancing their problem-solving skills.

Key words: Caffeine, Sublimation, Temperature sensitive test paper, Visualization