Optimization of the separation of 1,1 '-bi-2-naphthol enantiomers in preparative liquid chromatography

The separation of enantiomers of 1-1'-bi-2-naphthol on Pirkle covalent D-ph enyl-glycine columns was investigated on the preparative scale. The adsorpt ion characteristics of each isomer, including the equilibrium and kinetic m odel parameters, were measured by the elution chromatographic method. The c ompetitive bi-langmuir model was adopted to correlate the adsorption equili brium isotherms of the binary mixture. The numerical solution of the equili brium-dispersive model of chromatography was used to predict the band profi les, where the isotherm parameters of the binary model were estimated by a model fitting method. The simulated band profiles can reasonably predict th e measured chromatograms for various cases of different operating condition s, e.g. mobile phase composition, flow rate and sample size. The optimum op erating conditions for the maximum production rate of either one of the two isomers were then found based on the theoretical model.