Modeling of the separation of two enantiomers using a microbore column

A microbore column packed with Chiralcel OB (cellulose tribenzoate coated silica) was used for the measurement of the single and competitive equilibrium-isotherm data of the 1-indanol enantiomers by frontal analysis. The amount of sample needed for the isotherm data acquisition was about 20 times less than that required with a conventional column. The data obtained were fitted to different single and competitive isotherm models. Both the single and the competitive data sets fitted best to the same Bilangmuir (BL) isotherm model with small differences in the numerical values of the parameters. The best fitted Bilangmuir single and competitive isotherm models were used to predict the overloaded experimental profiles of both pure enantiomers, of the racemic mixture, and of different enantiomeric mixtures. All the calculated profiles were in excellent agreement with the experimental ones. This agreement confirms that in many chiral separations, the competitive isotherms can be derived from data acquired from the mere racemic mixture with a sufficient accuracy for a correct prediction of the band profiles of all kinds of enantiomer mixtures, making possible the computer-assisted optimization of the experimental conditions.