OPTIMIZING THE SAMPLE-SIZE AND THE RETENTION PARAMETERS TO ACHIEVE MAXIMUM PRODUCTION-RATES FOR ENANTIOMERS IN CHIRAL CHROMATOGRAPHY

The optimum experimental conditions (sample size and mobile phase composition) are calculated for maximum production rate of either one of two enantiomers contained in feeds of different compositions (1/1, 1/10, and 10/1). The products are obtained at 99% purity. The calculations use the equilibrium-dispersive model of chromatography and the equilibrium isotherms determined experimentally from the rear, diffuse boundary of overloaded elution profiles. The production rate measured experimentally under the optimum conditions calculated agree within 4% of the calculated values. There is an optimum value for the retention factor which is higher than predicted by a model assuming constant separation factor, because both separation factor and retention decrease with increasing organic solvent concentration in the mobile phase.