Principles of Ion Exchange Chromatography

Ion Exchange Chromatography: Key Concepts

• Primary Function: Separating and purifying charged molecules based on their affinity for a stationary phase (resin) with opposite charges.
• Step Not Involved: Centrifugation.
• Factors Affecting Ion Exchange: pH, ionic strength, temperature, and the concentration of mobile phase.
• Type of Ion Exchange: Anion exchange binds negatively charged ions to positively charged functional groups on the resin.
• Strong Interactions: Stronger interactions between the analyte and the resin lead to slower elution because the analyte spends more time bound to the resin, delaying its movement through the column.
• Applications: Purification of proteins, peptides, and other biomolecules, water softening, and removing impurities from various solutions.
• Common Limitations: Limited capacity for large molecules and potential for irreversible binding.
• Mobile phase: A liquid solution that carries the analytes through the column, often containing buffers, salts, or other compounds to modulate the separation.