Amaze QR is a quaternary-modal reversed-phase column. It contains hydrophobic chain, aromatic fragments, and acidic and basic groups on the surface. All functionalities are carried within one ligand which is attached to the surface. The column is designed to separate a wide range of compounds within a single run. Compounds are retained and separated by a combination of reversed-phase, pi-pi, cation- and anion-exchange mechanisms. Retention time and selectivity can be adjusted by using various organic solvents (acetonitrile vs. methanol), buffer pH and buffer concentration. Multi-modal interaction allow to separate compounds that differ even slightly in chemical and physical properties. The synergy of multiple interaction makes much greater difference than single mode separations. All ingredients of mobile-phase composition are important in finding right conditions for toughest separations.