Caffeine is one of many naturally occurring chemicals in tea plants that plays two important roles: protecting the plant from pr
edators while making its flowers appealing to pollinators such as bees. It is known to be soluble in both pure water and pure dichloromethane, but exhibits a preference towards one solvent over the other. Describe the procedural steps to perform a liquid-liquid extraction and isolation of solid caffeine from a sample of one commercial tea bag.
Caffeine is more soluble in dichloromethane and the both are separated by evaporating the solvent.
Caffeine is an organic plant material which is more soluble in non-polar solvents than in polar solvents. As such, caffeine is more soluble in dichloromethane than in pure water.
In order to carry out a liquid-liquid exaction of dichloromethane from a commercial teabag, the dichloromethane is mixed with water. The caffeine is found to be more soluble in the organic dichloromethane layer than in water.
The two solvents can now be separated using a separating funnel and the solution is evaporated to obtain the caffeine.
