MULTIFUNCTIONAL ZWITTERION-EXCHANGE STATIONARY-PHASE FOR HPLC

A zwitterion-exchange stationary phase (ZIXSP) was prepared for the se paration of the mixture of organic bases, organic acids and amino acid s by high performance liquid chromatography (HPLC). It was synthesized by the reaction of cyanuric chloride with sulfanilic acid and then bo nded onto the silica gel on which the silane coupling agent was prebon ded. The chromatographic behaviours of the prepared ZIXSP revealed tha t the capacity factors of each analyte varied with the pH value of the mobile phase. By applying the concept of acid-base equilibrium the co rrelation between the capacity factor on the ZIXSP and pH of the mobil e phase could be explained reasonably. Based on our results, it is con cluded that ZIXSP is a zwitterion exchanger that additionally provides pi-pi charge-transfer interaction and hydrophobic interaction functio ns.