Ion exchange (IEX)

Ion exchange (IEX) chromatography involves interactions between a charged stationary phase and the oppositely charged mobile analytes. In cation exchange chromatography positively charged molecules are attracted to a negatively charged stationary phase. Likewise, in anion-exchange chromatography negatively charged molecules are attracted to a positively charged stationary phase.

Ion exchange (IEX) chromatography is useful for a wide variety of compounds, from acidic (anionic) and basic (cationic) small molecules up to peptides and proteins.

Ion exchange columns are essential components in ion exchange chromatography, with cation exchange chromatography specifically focusing on the separation of positively charged molecules using columns with negatively charged functional groups. The selection of the appropriate column, buffer pH, and salt concentration are critical factors in the successful application of cation exchange chromatography.