Ion exchange is an extremely robust and adaptable technique allowing the extraction from a liquid of a charged molecule, which is then exchanged for an ion initially bound to the resin. This is the most widely used process for producing sugars of all origins. Once a resin is saturated, it must be regenerated by the application of salt, an acid, or a base depending on its purpose.
Adsorption refers to the ability of certain materials to make molecules adhere to their surface, more or less reversibly. The substrates used (resins) have a porous structure, giving them a very large specific surface area. Once the resin is saturated, the adhering molecules are eluted by applying a suitable solvent, in some cases a simple sodium solution.
Chromatography makes it possible to separate the molecules in a mixture, according to their affinities with the resin used. Differences in affinity are reflected in different velocities of displacement through a resin bed: this difference in velocity is used to continuously separate the slow constituents from the fast constituents, without the need to use chemicals or a solvent to regenerate the resin.