Chemically bonded multifunctional stationary phases for high-performance liquid chromatography

Summary A new class of stationary phases for high-performance liquid chromatography (HPLC) are described which simulate in their retention chracteristics ion-pair separations. The phases consist of mixtures of chemically dissimilar ligands chemically bonded to silica supports. These phases are largely reversed-phase in nature, but also contain significant ion-exchange properties, at levels similar to those demonstrated to occur in ionpairing. By bonding both ionic and hydrophobic groups in the correct proportions, mixed retention mechanisms are created, resulting in unique selectivities, while retaining the excellent stabilities and efficiencies characteristic of bonded phases. The ratio of hydrophobic to ionic character can be controlled during the synthesis, and is used as a tool to vary the stationary phase, rather than only the mobile phase, to effect the separation desired. The synthesis and behavior of both anionic and cationic/reversed-phase materials are described, and are applied to the simultaneous separation of nucleosides and nucleotides, and to the separation of the catecholamines.Presented at the 14th International Symposium on Chromatography London, September, 1982.