Choosing extraction conditions for isolation of a product from its natural source depends
on both the properties of the compound and the composition of the source. In our case
caffeine is soluble in both water and organic solvents. It is possible to extract caffeine
from leaves by solid/liquid extraction to hot water. The medium polarity of caffeine
implies that it can be further separated from water soluble compounds by extraction to a
polar non-protic solvent like methylene chloride (KCH2Cl2/H2O~10).
Designing an efficient extraction scheme requires analyzing the major components of tea
leaves. These include cellulose, proteins and amino acids, tannins, pigments and
saponins.