Ion Exchange Chromatography (IEC) is a type of chromatography that separates ions and polar molecules based on their charge.
It is widely employed in various fields, including protein purification, water analysis, and diverse ion analyses.
Chromatography, as a technique, separates components of a mixture by passing them through a medium where they migrate at different rates due to differences in their interactions with the medium.
Principle
The fundamental principle of IEC involves the use of a charged stationary phase to separate ions present in the mobile phase.
Depending on the charge of the stationary phase:
Cation Exchange Chromatography: Utilizes a negatively charged stationary phase to attract and retain positively charged ions (cations).
Anion Exchange Chromatography: Utilizes a positively charged stationary phase to attract and retain negatively charged ions (anions).
Components of Ion Exchange Chromatography
1) Stationary Phase
Composition: Typically consists of a resin made from organic polymers with ionic functional groups.
Types:
Cation Exchangers: Contain negatively charged groups.
Anion Exchangers: Contain positively charged groups.
Function: Provides the charged sites for ion exchange.
2) Mobile Phase
Composition: Usually a water-based solution that transports the sample through the stationary phase.
Adjustability: The composition and pH can be modified to influence the separation process