NEUTRAL AND ANIONIC CYCLODEXTRINS IN CAPILLARY ZONE ELECTROPHORESIS -ENANTIOMERIC SEPARATION OF EPHEDRINE AND RELATED-COMPOUNDS

Two methods for the enantiomeric separation of chiral ephedrine alkalo ids (ephedrine, methylephedrine, methylpseudoephedrine and norephedrin e) by capillary zone electrophoresis in uncoated capillaries were deve loped. Both methods were optimized to more than 100 000 theoretical pl ate numbers. The first method used a neutral cyclodextrin (CD) derivat ive: heptakis (2,6-di-O-methyl)-beta-cyclodextrin at an acidic pH of 2 .5 (20 mM phosphate buffer) at an 18 mM concentration. The second used a newly developed acidic CD derivative, the tetrakis[6-O-(4-sulfobuty l)]-beta-cyclodextrin sodium salt. The benefits of this new reagent fo r the chiral separation are a wide range of basic pH available for the enantiomeric resolution. It is also useful for other cases, e.g. prev enting adsorption without additives.