Ion Exchange Chromatography (IEC) utilizes ion exchange ligands as the stationary phase, enabling separation based on the reversible exchange of ions between mobile phase components and stationary phase counter-ions, leveraging differences in binding affinity. This method offers high resolution, large working capacity, and operational simplicity, making it one of the most frequently used purification technologies for biopharmaceuticals, proteins, polypeptides, and other biomolecules. The IEC resin structure comprises three essential components: Cross-linked polymeric matrix (base matrix); Functional groups covalently attached to the matrix; Mobile ions carrying opposite charges to the functional groups, capable of undergoing ion exchange.