APPLICATION OF NONLINEAR-REGRESSION FUNCTIONS FOR THE MODELING OF RETENTION IN REVERSED-PHASE LC

The feasibility of simple nonlinear regression models to describe the effects of pH and organic modifier concentration on retention is investigated. Different functions, derived by combining the model of Horvath and co-workers with the model of Snyder and co-workers or by simplifying the model of Schoenmakers and co-workers, are compared for modeling the retention of tetra- and pentachlorophenols, dichlorophenols, sulfonamides, and adrenergic blocking drugs in a feasible restricted retention region. A sequential strategy is shown to work satisfactorily. It is based on a combination of the following: a retention boundary map to determine a feasible region; the Kennard and Stone algorithm to select a set of experiments; and nonlinear regression models. © 1994 Oxford University Press.