Influence of column characteristics on retention and selectivity in RP-HPLC

Summary Eight commercially available reversed-phase (RP) columns of widely different characteristics were evaluated and compared using the linear solvation energy relationships (LSER). Retention factors of 32 solutes of different types were determined under isocratic conditions using an acetonitrile-water (30∶70) mobile phase. Stationary phase properties were compared by the fitting coefficients of the LSER-based regression equations which are characteristic of the individual stationary phases and represent the extent of various molecular interactions contributing to the retention process. The good agreement between the calculated and measured logk values for different type of compounds support the adequacy and applicability of the LSER model to describe chromatographic retention. Characterization of column performance for the separation of various type of compounds was established by the determination of the different selectivity factors representing hydrophobic selectivity, polar selectivity and specific selectivity.