title: Fast determination of flavonoids in Hippophae rhamnoides and its medicinal preparation by capillary zone electrophoresis using dimethyl-beta-cyclodextrin as modifier.
abstract: A fast capillary zone electrophoresis (CZE) method, using dimethyl-beta-cyclodextrin (DM-beta-CD) as modifier, has been developed for the determination of three flavonoids (quercetin (QU), kaempferol (KA) and isorhamnetin (IS)) in the Chinese herbal extract from Hippophae rhamnoides and its medicinal preparation (Sindacon tablet). Optimum separation was achieved with 20mM borate buffer at pH 10.0 containing 5mgml(-1) of DM-beta-CD. The applied voltage was 15kV and the capillary temperature was kept constant at 25 degrees C. Regression equations revealed linear relationships (correlation coefficients: 0.9973, 0.9992 and 0.9996) between the peak area of each compound (QU, KA and IS) and its concentration. The relative standard deviations of migration times and peak areas were <1.53 and 4.14%, respectively. The effects of several CE parameters on the resolution were studied systematically. The contents of three flavonoids in H. rhamnoides were successfully determined with 4.5min, with satisfactory repeatability and recovery. It was also tested that the possibilities of using this method for the determination of flavonoids in Chinese medicinal preparation.
authors.affiliation: Key Laboratory for Natural Medicine of Gansu Province, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000, PR China.
authors.forename: Mei-E
authors.initials: ME
authors.lastname: Yue
authors.forename: Ting-Fu
authors.initials: TF
authors.lastname: Jiang
authors.forename: Yan-Ping
authors.initials: YP
authors.lastname: Shi