INFLUENCE OF TEMPERATURE ON RETENTION AND SELECTIVITY IN REVERSED-PHASE LIQUID-CHROMATOGRAPHY

The influence of temperature on retention and selectivity in reversed- phase liquid chromatography using a porous organic polymer stationary phase is quantitatively characterized using the solvation parameter mo del, The predominant influence of increasing temperature (20-60 degree s C) is to decrease the relative difference in the ease of cavity form ation between the aqueous mobile phase and solvated sorbent and to dec rease the hydrogen-bond acidity of the aqueous mobile phase, with othe r polar interactions affected to a lesser extent, Temperature variatio n and composition variation produce similar trends in retention, but w ithin the easily accessible range for both variables, the capacity to change retention is much greater for composition variation than temper ature variation, Temperature variation is a useful parameter for fine tuning an isocratic separation with an outcome that is easily predicte d using the solvation parameter model.