Determination of five major anthraquinoids in Chinese herbal preparations by micellar electrokinetic capillary electrophoresis

A micellar electrokinetic capillary electrophoretic (MEKC) method was developed for the simultaneous assay of three anthraquinones (rhein, emodin and aloe-emodin) and two anthrones (sennoside A and sennoside B) in Chinese herbal preparations. The carrier composed of a buffer solution (10 mM sodium dodecyl sulfate, 12.5 mM sodium dihydrogenphosphate and 15 mM sodium borate) and acetonitrile (3:1) was found to be the most suitable electrolyte for this separation, whereby the contents of these anthraquinoids in rhubarb-containing Chinese herbal preparations could be easily determined within 30 min. The effects of surfactant concentration and organic modifier (acetonitrile) concentration of the carrier on the migration and separation of the solutes were also studied.