BIDENTATE SILANE STATIONARY PHASES FOR REVERSED-PHASE HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHY

A family of new silica-based bidentate silane stationary phases shows distinct advantages as reversed-phase chromatography column packings. Column efficiency, reproducibility, and selectivity characteristics ar e equivalent to those of conventional monofunctional silane stationary phases, but column stability is measurably improved. A silica-based b identate-C18/C18 column packing exhibits excellent stability with both low- and intermediate-pH mobile phases, but is especially notable for high-pH separations. Highly basic compounds such as basic drugs can b e separated routinely at high pH as free bases. Ou studies have define d how the structure of this bidentate silane should be designed to pos ition C18 ligands for optimum solute interaction and column efficiency . The characteristics of these new phases have been determined to desc ribe areas of most useful chromatographic applications.