Hydrophilic and hydrophobic quaternary amines, along with sodium ion, were separated by mixed-mode chromatography on a Primesep 200 column. Mechanism of retention for sodium and tetramethylammonium ions is cation exchange, while the tetrabutylammonium ion is retained by combination of reversed-phase and cation-exchange mechanisms. All three compounds are not UV-active and monitoring is done by ELSD/CAD.