SILICA-BONDED CALIXARENES IN CHROMATOGRAPHY .2. CHROMATOGRAPHIC RETENTION OF METAL-IONS AND AMINO-ACID ESTER HYDROCHLORIDES

The chromatographic behaviour of alkali and alkaline earth metal ions on a silica-bonded macrocyclic calix[4]arene tetradiethylamide phase i s reported. Selective retention of Na+ over other alkali metal ions an d of Ca2+ over Mg2+ ions is found using water as the mobile phase and conductivity detection. A series of amino acid ester hydrochlorides ar e shown to be retained in order of their hydrophobicity on a silica bo nded calix[4]arene tetraester phase with aqueous mobile phases contain ing lithium perchlorate and acetonitrile. Retention of metal ions and organic solutes on these new silica-bonded functionalised calixarene p hases is dependent on the organic modifier concentration.