Isolation by Ion-Exchange Methods

Historically, ion-exchange chromatography has been a popular technique for the isolation of natural products. This technique is used for the separation of ionized or charged substances, a characteristic of a majority of natural products. Ion-exchange chromatography was first reported in the late 1930s, and its application to natural products was first described in the late 1940s as a technique to isolate and separate amino acids from protein hydrolysates. It is still widely used today for the analysis and separation of proteins. As the name implies, the main factor contributing to retention and separation of components is the electrostatic attraction between ionized substances from the sample and ionized centers of opposite charge on the stationary phase. Ion-exchange chromatography is thus widely applicable to the purification and analysis of a large number of molecules.