Thin-layer chromatography enantioseparations on chiral stationary phases: a review

The current state of chiral separations by thin-layer chromatography using chiral stationary phases is reviewed. Both stationary phases essentially constituted by the chiral selector and those obtained by the impregnation of achiral plates with appropriate chiral selectors are described. Particular attention is paid to commercial and non-commercial cellulose and cellulose-derivative plates, as well as commercially available Chiralplate™, which are currently the most widely used. Some of the most important results obtained to date are reported and discussed; the examples provided illustrate the very wide range of structurally different solutes that can be readily resolved into their enantiomers by planar chromatographic methods. Special attention is paid to the discussion of the retention and resolution factors that influence chiral discrimination. The quantitative analysis of enantiomers is also discussed, especially from the point of view of determination of enantiomeric purity.