6533b822fe1ef96bd127d60d

RESEARCH PRODUCT

Effect of solute association on the apparent adsorption isotherm. A model of the separation of non-racemic mixtures of enantiomers in achiral chromatographic systems

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This article discusses the effect of solute association on the apparent adsorption isotherm and on the chromatographic peak profile. The modelling performed has shown that dimerization of a solute in a chromatographic system gives rise to an apparent adsorption isotherm of the non-linear type. This results first of all in peak broadening. Tailing or a fronting can be observed depending on the relative retention of the monomer and the dimer. Secondly, the retention of the solute depends on the amount of sample because of the non-linear character of the adsorption isotherm. As a result, an excess of one of two analytes with absolutely identical adsorption properties i.e. optical isomers, can be separated in such chromatographic systems by considering that the sample contains non-equal amounts of two analytes. The phenomenon is illustrated by simulated chromatograms of the separation of non-racemic mixtures of enantiomers.