Determination of flavonoids and alkaloids in the scute-coptis herb couple by capillary electrophoresis

A micellar electrokinetic capillary chromatographic (MEKC) method was developed for the simultaneous assay of six scute flavonoids (baicalin, wogonin 7-O-glucuronide, oroxylin A 7-O-glucuronide, baicalein, wogonin and oroxylin A) and four coptis alkaloids (berberine, palmatine, coptisine and epiberberine) in the scute-coptis herb couple. The carrier composed of a buffer solution (5 mM sodium borate, 15 mM sodium dihydrogenphosphate and 50 mM sodium cholate) and acetonitrile (3:2) was found to be the most suitable electrolyte for this separation, whereby the contents of these compounds in the herb couple and herb couple containing Chinese herbal preparations could be easily determined within 30 min. The effect of pH value, surfactant concentration and organic modifier (acetonitrile) concentration of the carrier on the migration and separation of the solutes were also studied.A micellar electrokinetic capillary chromatographic (MEKC) method was developed for the simultaneous assay of six scute flavonoids (baicalin, wogonin 7-O-glucuronide, oroxylin A 7-O-glucuronide, baicalein, wogonin and oroxylin A) and four coptis alkaloids (berberine, palmatine, coptisine and epiberberine) in the scute-coptis herb couple. The carrier composed of a buffer solution (5 mM sodium borate, 15 mM sodium dihydrogenphosphate and 50 mM sodium cholate) and acetonitrile (3:2) was found to be the most suitable electrolyte for this separation, whereby the contents of these compounds in the herb couple and herb couple containing Chinese herbal preparations could be easily determined within 30 min. The effect of pH value, surfactant concentration and organic modifier (acetonitrile) concentration of the carrier on the migration and separation of the solutes were also studied.