LC Enantioseparation of Tryptophan Analogs on α-Cyclodextrin Stationary Phase

Abstract

For the direct separation of enantiomers of tryptophan analogs, a native α-cyclodextrin-based Cyclobond III chiral stationary phase was examined. The separation conditions were optimized by variation of the different chromatographic parameters, and data are reported as retention factors, separation factors and resolutions. The nature and concentration of the buffers as mobile phase additivies exerted only slight effects on the retention and resolution. In all cases, the erythro isomers could be separated significantly better than the threo ones. With increasing hydrophobicity of the analytes, the retention time increased, but no clear trend could be observed between the resolution and the hydrophobicity. The sequence of elution of the enantiomers was in most cases determined by spiking the racemic samples with enantiorich analytes.