cation exchange chromatography

Cation exchange chromatography is a technique used to separate positively charged molecules, called cations, based on their affinity for a special resin. The resin contains negatively charged sites that attract and hold cations. When a mixture passes through, cations with a stronger attraction stay longer, while others wash out sooner. By changing the solution's conditions, such as pH or salt concentration, different cations can be selectively eluted and collected separately. This method is widely used in laboratories to purify proteins, amino acids, and metal ions effectively.