Question

In ion-exchange chromatography, the charge on the anion exchangers is

• A. Positive
• B. Negative
• C. Zwitter ionic
• D. Iso-ionic

Hint:

To avoid confusion, remember:
- Anion exchangers carry a positive charge to attract negatively charged anions.
- Cation exchangers carry a negative charge to attract positively charged cations.

Answer 1

The Correct Option is A

Step 1: Understanding the Concept:
Ion-exchange chromatography separates biomolecules based on their net charge.
Anion-exchange chromatography specifically binds negatively charged molecules (anions).

Step 2: Detailed Explanation:
1. In anion-exchange chromatography, the stationary phase (resin) is chemically modified with functional groups that carry a permanent or pH-dependent positive charge.
2. Negatively charged anions in the mobile phase bind to these positively charged functional groups through electrostatic attraction, while cations pass through.
3. Common positively charged functional groups used in anion exchangers include Diethylaminoethyl (DEAE) and Quaternary Ammonium (Q) groups.

Step 3: Final Answer:
The charge on the anion exchangers is positive.