Determination of six major flavonoid glycosides in Saussurea mongolica by capillary electrophoresis.

A new capillary electrophoresis (CE) method was established for simultaneous assay of six flavonoid O-glycosides, asebotin (AS), kaempferol 3- O-beta- D-glucopyranoside (KG), kaempferol 3- O-alpha- L-rhamnopyranoside (KR), 7-methoxykaempferol 3- O-alpha- L-rhamnopyranoside (KMR), quercetin 3- O-beta- D-glucopyranoside (QG) and quercetin 3- O-alpha- L-rhamnopyranoside (QR) obtained from Chinese herbal plant extract of Saussurea mongolica. The optimum buffer system was 30 mmol/L borate buffer (Na2B4O7/HCl, pH 9.00) with 40 % (v/v) methanol. Voltage was 15 kV and detection at 270 nm. The application of this method for the separation and determination of the six flavonoid O-glycosides in S. mongolica is reported. The relative standard deviations of migration times and peak areas were < 2.61 and 4.41%, respectively. The contents of six natural products ranged from 0.043 to 0.60 mg/g and recoveries ranged from 92.4 to 104.4%. The effects of pH value, buffer concentration, surfactant, beta -cyclodextrin and organic modifier on the separation were investigated.