(i) Ion Exchange Chromatography: It is based on reversible exchange of ions in solution with ions electrostatically bound to some sort of insoluble support medium. Separation is obtained since different molecules have different degree of interaction with ion exchanger due to difference in their charges, charge densities and distribution of charge on their surface.
(ii) Partition Chromatography: Partition chromatography is the process of separation whereby the components of the mixture get distributed into two liquid phases due to differences in partition coefficients during the flow of mobile phase in the chromatography column. Here, the molecules get preferential separation in between two phases, i.e., both stationary phase and mobile phase are liquid in nature. So molecules get dispersed into either phases preferentially. Polar molecules get partitioned into polar phase and vice-versa. This mode of partition chromatography applies to liquid-liquid, liquid-gas chromatography and not to solid-gas chromatography. Because partition is the phenomenon in between a liquid and liquid or liquid and gas or gas and gas. But not in solid involvement.
