Extraction Of Caffeine Lab Template Page 2

Coffee is mostly water, so the solvent chosen for the extraction of caffeine must be immiscible

with water. Dichloromethane is a water-immiscible solvent that works well, because caffeine is

highly soluble in it (which means that most of the caffeine will easily move out of the coffee and

into the dichloromethane). Dichloromethane is also often called methylene chloride.

Structure of dichloromethane:

Also called methylene chloride

Once the caffeine has been extracted into the dichloromethane solvent, the dichloromethane will

need to be removed in order to obtain dry caffeine powder. This could be done by simply

allowing the dichloromethane to evaporate, but that would take a long time. Instead, distillation

will be used to remove the dichloromethane quickly. The distillation technique will be explained

in the prelab lecture.

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