Is ion-exchange chromatography is reverse phase chromatography?

Answer 1

The principal of ion exchange chromatography is the most popular method for purifying protein compounds.Other charged molecules are also called an ion exchange if of a protein nature.
[Fig 1. Principle of anionic and cationic exchangers.]

Biomolecular binding strength depends on solution pH, since it affects the number of ions available for exchange. Proteins can be zwitterions, so you'll need to use either an anionic or cationic exchanger. Whatever the conditions, we have to determine the isoelectric point of the protein at different pHs to see what charges the proteins can have and where it's electroneutral. When pH < pI of a given molecule, it will be positively charged and we'll need a cation exchanger; vice versa when pH > pI. The amphoteric character (ability to react as either acid or base) of proteins allows us to detect ionic interference of other substances and improve our own protein separation. The principle of ion exchange processes will be explained more clearly using an anionic exchange as an example. Today, most people use synthetic organic ion exchangers on a polystyrene base (DOWEX) or natural polymers like cellulose, dextran, or silicate. The macromolecules of the ion exchanger normally make up a 3D network, onto whose surface a huge number of ionizable groups are covalently bonded. Whereas the type of matrix material is generally flow characteristic (the type of ions used and their chemical/mechanical stability are more solid), the groups covalently-bonded to the matrix and the strength of those bonds determine what the exchangable ions can be: every group gives an exchange of very basic (anion exchanger) for very acidic (cation exchanger) character.

[Fig 2. Principle of an ion exchange process.]

Typical functional groups in an anion exchanger are quaternary amines such as diethyl aminoethyl groups (DEAE - non-denaturing, sorbents have good loading capacity), while those for cation exchangers include organic and inorganic acids like carboxymethyl groups (CMs) or sulfonates. These groups are covalently coupled to the matrix material (Fig. 3). Since exchange groups are only inserted in their ionic form, it's important to know their pK values. Such values can be found by a simple titration curve, as shown for a CM sephadex in Fig 4. Because so many biologically important substances contain ionizable functional groups (amino acids, proteins, nucleotides, nucleic acids, metabolites, etc), biochemical methods for the isolation and separation of charged compounds are quite valuable - some charged compounds are electrostatically bound to the exchanger and others are not.

Answer 2

Ion-exchange chromatography is a process that allows the separation of ions and polar moleculesbased on the charge properties of the molecules.

Answer 3

no reverse phase chromtography is a type of adsorption chromatography which is very much different from ion chromatography.they have different principles for separation of mixture.