APPLICATION OF MODIFIED CYCLODEXTRINS IN CAPILLARY ELECTROPHORESIS FOR ENANTIOMERIC RESOLUTION OF PROPRANOLOL AND ANALOGS

The enantio-resolution of propranolol and four derivatives was examine d by free solution capillary electrophoresis (FSCE) using various cycl odextrin molecules. Of the three modified cyclodextrins investigated, hydroxyethyl-beta-cyclodextrin provided the largest chiral resolution values for all five analytes. This may be linked to its extended hydro gen bonding chains on the cyclodextrin rim. Methyl-beta-cyclodextrin a nd heptakis(2,3-di-O-acetyl) beta-cyclodextrin gave lower maximum anal yte resolutions, probably due to differences in their macrocyclic stru cture and hydrogen bonding ability. The presence of a bulky, non-polar alkyl group on the analytes was found to enhance chiral recognition. Methanol was found to have a varied effect on chiral resolutions, depe ndent on the type of cyclodextrin and structure of the analyte.