Enantiomer separation by strong anion-exchange capillary electrochromatography with dynamically modified sulfated beta-cyclodextrin

A novel mode of capillary electrochromatography (CEG) based on a dynamicall y modified stationary phase was presented for chiral separation. The capill ary column was packed with strong anion-exchange (SAX) stationary phase pac king; the sulfated beta -cyclodextrin (S-CD), which was added to the mobile phase, was dynamically adsorbed to the packing surface. Separation of enan tiomers was achieved by their different abilities to farm an inclusion comp lex with the adsorbed S-CD. The enantiomers of tryptophan, praziquantel, at ropine, metoprolol, and verapamil were successfully separated in this syste m with a column efficiency of 36000-412000 plates/m. The resolution value o btained for atropine was as high as 11.23. The superiority of CEC with a dy namically modified stationary phase over that with a physically adsorbed st ationary phase was demonstrated. The influence of ionic strength, S-CD conc entration, and methanol content on separation was also studied.