What is ion exchange chromatography?

Ion exchange chromatography (IEC) is a separation technique that separates molecules based on their net surface charge. It is commonly used in water treatment, food and beverage analysis, pharmaceutical production, and biochemistry to purify and analyze ions and charged molecules like proteins and amino acids. The stationary phase carries an electrical charge, and molecules with an opposite charge are attracted to it. Molecules are then eluted by changing the ionic strength or pH of the mobile phase.