The present invention relates to a method of separating a compound from a liquid, which method comprises providing a separation matrix comprising at least one uncharged ligand; providing a liquid wherein the compound to be separated is present in a positively charged state; contacting said matrix with said liquid to adsorb the compound; and removing the liquid. The uncharged ligands possess a quadrupole or dipole moment, allowing for a cation-p interaction between the compound and the ligand. The present invention also encompasses the use of a separation matrix, which comprises an uncharged group that possesses a quadrupole or dipole moment, in said method.