Classification of Ion exchange chromatography

1. Based on the Charge of the Stationary Phase:

a) Cation Exchange Chromatography:

• Uses a stationary phase with negatively charged groups.

• Positively charged cations from the solution will be attracted to and exchanged with the stationary phase.

b) Anion Exchange Chromatography:

• Uses a stationary phase with positively charged groups.

• Negatively charged anions from the solution will be attracted to and exchanged with the stationary phase.

Here's a color diagram illustrating the classification of Ion Exchange Chromatography:

2. Based on the Type of Stationary Phase:

a) Gel Type Resins:

• These are cross-linked polymers with a three-dimensional network.

• Their porous structure allows the exchange of ions. Examples include dextrans and agarose.

b) Macroporous or Beaded Resins:

• These resins have larger pores and offer a higher surface area which results in increased capacity and faster exchange rates.

3. Based on the Functional Groups Present:

a) Strong Acid Resins (SAR):

• Contain sulfonic acid groups (-SO₃H). They can exchange all types of cations across a wide pH range.

b) Weak Acid Resins (WAR):

• Contain carboxylic acid groups (-COOH). Their exchange capacity is pH dependent.

c) Strong Base Resins (SBR):

• Contain quaternary ammonium groups. They can exchange all types of anions.

d) Weak Base Resins (WBR):

• Contain primary, secondary, or tertiary amine groups. Their exchange capacity for anions is pH dependent.

Here's a diagram illustrating the classification of Ion Exchange Chromatography (IEC):