High Performance Ion-Exchange Chromatography

High-Performance Ion-Exchange Chromatography:  This method is used to separate 

mixtures of ions (organic or inorganic),  and finds its application mostly in protein 

separations. The stationary phase consists of very small polymer resin “beads” which have 

many ionic bonding sites on their surface, termed as Ion Exchange Resins. This resin can be 

either an anion exchange resin, which possesses positively charged sites to attract negative 

ions, or a cation exchange resin, which possesses negatively charge sites to attract positive 

ions. If the analyte mixture which contains mixture of ions is introduced into the column 

packed with suitable ion-exchange resin, selected ions will be attached or bonded on to the 

resin, thus being separated from other species that do not bond. Later, these attached ions can 

be dislodged from the column by repeated elution with a solution that contains an ion that 

competes for the charged groups on the resin surface, in other words, which has high affinity 

for the charged sites on the resin than the analyte ions. Thus the analyte ions get exchanged 

and separated from the column.