ANALYSIS OF PARTIALLY METHYLATED CYCLODEXTRINS BY SUBCRITICAL FLUID AND LIQUID-CHROMATOGRAPHY

Liquid and subcritical chromatographic analyses using evaporative ligh t scattering detection were used to investigate the composition of var ious commercial dimethylated beta-cyclodextrins (beta-CD). The chromat ographic fingerprints better depict the complexity of each mixture tha n the degree of substitution. The elution order is reversed when subcr itical fluid chromatography is used instead of LC on apolar stationary phases (TMS and phenyl columns). Concerning the RPLC analysis of meth ylated beta-CD, a phenyl-bonded silica column offers selectivities tha t are different from those obtained using a classical C-18-bonded sili ca column. With regard to the more complex mixtures, SubFC allows one to obtain richer methylated beta-CD fingerprints than does LC.