CORRELATION BETWEEN THE CHROMATOGRAPHIC PROPERTIES OF SILICA PHENYL PACKING MATERIALS AND THE RETENTION BEHAVIOR OF METHYLATED BETA-CYCLODEXTRINS

The chromatographic properties of five columns packed with phenyl-bond ed phases were characterized by an approach based on Tanaka's method f or column to column comparisons in order to develop an LC analysis of partially methylated beta-cyclodextrins. The retention behaviour of be ta-cyclodextrin, heptakis(2,6-di-O-methyl)-beta-cyclodextrin and hepta kis(2,3,6-tri-O-methyl)-beta-cyclodextrin was examined in order to eva luate the different interactions between phenyl stationary phase and t his family of compound. Chromatograms show that the residual silanol a ctivity of the packing materials plays a beneficial role in the partia lly methylated beta-cyclodextrins separation process. It is concluded that knowledge of the interactions involved allows one to make a reaso ned choice of the stationary phase in order to obtain the best possibl e analysis of three different commercial samples of partially methylat ed beta-cyclodextrins.