TSKgel HIC-ADC Butyl columns utilize a novel polymer-based resin functionalized with increased ligand densities targeted specifically for Antibody-Drug Conjugates (ADCs) and monoclonal antibody separations. TSKgel HIC-ADC Butyl columns are packed with 5.0 µm non-porous particles, enhancing the separation performance for calculating Drug-to-Antibody Ratios (DAR) for ADCs.