Extracting caffeine from tea 從茶中提取咖啡因的實驗

劉昭辰

讀萬卷書不如行萬里路。從茶中提取咖啡因的實驗讓“我”了解了這類實驗的主要過程，也讓“我”明白，細心、耐心和毅力是打開成功之門的三把金鑰匙。

As is known to us all， China is the hometown of tea and the cradle of tea culture. But do you know that a substance in tea called caffeine is beneficial to our health？ And do you want to know what caffeine looks like？ Full of wonder and curiosity， I decided to do an experiment to extract caffeine from tea.

The experiment， to be honest， is a little complicated for me， so I teamed up with my deskmate to carry it out. To ensure the success of the experiment， we made full preparations. We surfed the Internet for relevant information， learning about the principles of the experiment. Also， we designed a detailed procedure and made a list of the experimental matters needing attention.

With great confidence and excitement， we entered the lab and started the experiment. Unexpectedly， a big challenge came out in the very beginning. The devices， made of glass， were so easily broken that we had to deal with them with extreme care and patience. Nearly a quarter had passed before we finally succeeded in installing the devices.

Everything ready， the experiment started. It was really amazing to see the color of the paper in the tube changing from white to different degrees of green， and then， white again！ In this process of color change， we observed that when the liquid rose to a certain height as the temperature went up， it would flow down in an instant. What a magic！

We felt increasingly nervous as it came to the last part. If this final step went wrong， all we had done would be fruitless. Fortunately， it went smoothly. At the sight of the white needle-like crystal （晶體） on the surface of the filter paper， we were relieved and then went wild with joy. We made it after nearly 4 hours' hard work！

Looking back on the whole experiment， I learned a lot. Carefulness， patience and perseverance were the keys to the final success. Finishing such an experiment requires so many qualities， let alone being a scientist. I will put my heart into study and try hard to become a qualified scientist in the future.

指導(dǎo)教師? 姜春陽