Studies on the behaviour of α-, β- and γ-cyclodextrins and some derivatives under reversed-phase liquid Chromatographic conditions

The separation processes of α-, β- and γ-cyclodextrins and their various methyl derivatives have been investigated with Knauer polarimetric (Chiralyser) and refractive index (RI) detectors. RP18 and RP8 hydrocarbon packings and an NH₂ bonded phase were applied as stationary phases. Aqueous methanolic or ethanolic solutions were used as mobile phases. It has been found that the Chiralyser detector response is approximately linear at low concentrations of solutes and that its detection capabilities are about 40 times better than those of the RI detector. Differences in the order of elution of α-, β- and γ-cyclodextrins have been observed for various stationary phases as well as for various mobile phase compositions. The optimal conditions for analytical determinations of cyclodextrins and their derivatives have been discussed.