Caffeine (C8H10N4O2) is an example of a type of organic weak base called an alkaloid – alkaloid means ‘alkali-like’. Caffeine is a stimulant and is found naturally in tea, coffee and kola nuts. Organic compounds tend to be soluble in organic solvents. Polar materials, such as salts tend to be more soluble in polar solvents, such as water.
In general, an organic compound and an inorganic salt can be easily separated using these solubility differences. We can tell which phase is aqueous and which is organic by checking the density of the liquids. Swirling the separatory funnel is a better technique to mix the liquids. The rotary evaporator is used to evaporate the solvent that your chemical compound of interest is solubilized in.
We must ensure that the filtrate(filtrated liquid) is in room temperature as caffeine is more soluble in dichloromethane than water. Remember to place a Stopper to the separating funnel and gently invert it. You must not shake it too vigorously.