iHILIC columns are designed for the separation and purification of polar and hydrophilic compounds using Hydrophilic Interaction Liquid Chromatography (HILIC). The packed stationary phases are charge-modulated amide silica or polymer particles which are covalently bonded with neutral, positively charged, and negatively charged hydrophilic functional groups. Therefore, the separation mechanism with iHILIC columns is based on a combination of hydrophilic interaction, hydrogen bonding, and weak electrostatic interactions. They have unique separation selectivity and high separation efficiency. iHILIC columns are available in three different surface chemistries, providing complementary selectivity.