[Niji]

Hello, everyone. I am a high school student from Japan, whose weakest subject is chemistry.
Does anyone here know several different ways to extract caffeine from tea leaves? I have found some experiments that use dichloromethane, carbon dioxide, and Soxhlet Extraction. If you know any other things, I would be happy if you tell me that.
In the introduction of my report, I have to state which methods succeed and fail. I am going to say that the method with carbon dioxide will fail because the high concentration of carbon dioxide can be harmful to humans in the science lab.
Also, the last thing: can ethanol be used to extract caffeine from tea leaves?

[AWK]

There are some inaccuracies in your statements - you combine industrial methods (carbon dioxide - high pressure, closed system) with laboratory methods. In the laboratory, extraction from leaves and ground seeds is carried out in a Soxhlet apparatus (methylene chloride or ethyl acetate solvent) or is washed out of the leaves or ground seeds with boiling water and after cooling, it is extracted into an organic solvent immiscible with water (preferably methylene chloride - the solution must be cooled before the addition of CH₂Cl₂). The organic layer is separated from the aqueous layer in the separating funnel.
Note that there are many plants that also contain caffeine in the leaves or seeds.
Details can be found on the internet.