Fast separation of warfarin and 7-hydroxywarfarin enantiomers by cyclodextrin-assisted capillary electrophoresis

The enantioseparation of warfarin and its main metabolite has been achieved using several cyclodextrin types and buffers at different pH, including conditions that have not been attempted so far. Methyl-beta-cyclodextrin, highly sulfated-beta-cyclodextrin and highly sulfated-gamma-cyclodextrin were the most efficient chiral selectors. The pHrange, within which particular cyclodextrins support chiral separation, has been approximately determined for the first time. By shortening the effective capillary length to 10 cm, the time of analysis has been vastly reduced <2 min. Hence, baseline separations of warfarin and 7-hydroxywarfarin enantiomers have been achieved in times unreported for those species until now. The established conditions are promising for the further development of new highly selective and fast methods involving warfarin, its derivatives, as well as the same cyclodextrin types.