The relatively new technique of high-performance liquid affinity chromatography (HPLAC) has been plagued by very large plate heights. Here we show that the large plate heights observed in the concanavalin A (Con A) HPLAC system arise from the sluggish chemical kinetics of the Con A-sugar interaction, and that other mass transfer terms contribute much less to the observed plate height. The rate parameters for the association and dissociation of various sugar derivatives from silica-bound Con A are chromatography determined. The effects of isotherm non-linearity on both the thermodynamic and kinetic properties of immobilized Con A are described. The enhancement effect of mobile phase competing sugar on the kinetics of the immobilized Con A-sugar interaction is investigated in detail, and possible reasons for this effect are proposed.