BASIS OF THE RATIONAL SELECTION OF THE HYDROPHOBICITY AND CONCENTRATION OF THE ION-PAIRING REAGENT IN REVERSED-PHASE ION-PAIR HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHY

The retention of ionic solutes in ion-pair chromatographic separations can be controlled efficiently only when the surface concentration of the pairing ion, and the resulting surface potential, vary over a reasonably broad range. To achieve a broad operating range, the hydrophobicity and the mobile phase concentration of the pairing ion must be matched to the organic modifier concentration of the eluent. Preferred combinations of the eluent methanol concentrations and the commonly used alkylsulphonate and tetraalkylammonium pairing ions are reported, allowing for the rational selection of these parameters. © 1990.