title: Simultaneous determination of flavonoids in chrysanthemum by capillary zone electrophoresis with running buffer modifiers.
abstract: Despite the separation efficiency of capillary electrophoresis (CE) is much higher than other chromatographic methods, it is sometimes difficult to perfectly separate the complex ingredients in biological samples. One possible and simple way to develop the separation effect in CE is to add some modifiers in the running buffer. In this paper, the suitable running buffer modifiers were explored to simultaneously separate and detect six typical flavonoids (apigenin, luteolin, kaempferol, quercetin, (+)-catechin and (-)-epicatechin) which are the main active ingredients in chrysanthemum by capillary zone electrophoresis with amperometric detection (CZE-AD). It was found that when beta-cyclodextrin (beta-CD) and the mixture of methanol and ethanol were used as running buffer modifiers, a baseline separation of the six analytes could be accomplished in less than 20 min and the detection limits were as low as 10(-7) or 10(-8)gm l(-1). Other factors affecting the CZE separation, such as working potential, pH value and ionic strength of running buffer, separation voltage and sample injection time were extensively investigated. Under the optimum conditions, a successful practical application on the determination of chrysanthemum samples confirmed the validity and practicability of this method.
authors.affiliation: Department of Chemistry, East China Normal University, Shanghai 200062, China.
authors.forename: Shan
authors.initials: S
authors.lastname: Zhang
authors.forename: Shuqing
authors.initials: S
authors.lastname: Dong
authors.forename: Langzhu
authors.initials: L
authors.lastname: Chi
authors.forename: Pingang
authors.initials: P
authors.lastname: He
authors.forename: Qingjiang
authors.initials: Q
authors.lastname: Wang
authors.forename: Yuzhi
authors.initials: Y
authors.lastname: Fang
mesh_terms: D002021:Buffers; D002623:Chemistry Techniques, Analytical / Q000295:instrumentation / Q000379:methods*; D031202:Chrysanthemum / Q000378:metabolism*; D019075:Electrophoresis, Capillary / Q000295:instrumentation* / Q000379:methods*; D005419:Flavonoids / Q000032:analysis* / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D008956:Models, Chemical; D015203:Reproducibility of Results; D012997:Solvents / Q000737:chemistry; D013997:Time Factors; D047392:beta-Cyclodextrins / Q000737:chemistry
chemical_list: D002021:Buffers; D005419:Flavonoids; D012997:Solvents; D047392:beta-Cyclodextrins; C031215:betadex