DESCRIPTION OF THE RETENTION BEHAVIOR OF SOLUTES IN MICELLAR LIQUID-CHROMATOGRAPHY WITH ORGANIC MODIFIERS - COMPARISON OF 2 METHODS

Two methods for the description of the retention behaviour of solutes in micellar liquid chromatography are compared. One of them divides the parameter space into triangular subspaces, fitting a different equation in each subspace. The second method makes use of a unique equation, valid in the whole parameter space. In both cases, equations of the type log k = f (mu, phi), and 1/k = f (mu, phi), (mu and phi are the concentration of surfactant and alcohol, respectively), were used to describe the retention. The use of the hyperbolic function, 1/k=c(0)+c(1) mu+c(2) phi+c(3) mu phi, to describe the whole parameter space yielded the best prediction. When a small portion of the parameter space was modelled, a simpler hyperbolic function, lacking the mu phi term often led to good results. The logarithmic equations usually gave the poorer predictions.