title: Microwave-assisted extraction followed by capillary electrophoresis-amperometric detection for the determination of antioxidant constituents in Folium Eriobotryae.
abstract: A method based on capillary electrophoresis-amperometric detection has been developed for the determination of catechin, rutin, kaempferol, gentistic acid, and quercetin in Folium Eriobotryae with the aid of microwave-assisted solvent extraction. The effects of the acidity and the concentration of the running buffer, separation voltage, injection time, detection potential, and irradiation time were investigated to acquire the optimum analysis conditions. The detection electrode was a 300-mum-diameter carbon disc electrode at a detection potential of +0.90 V. The five analytes could be well separated within 12 min in a 40-cm length fused-silica capillary at a separation voltage of 12 kV in a 50-mM borate buffer (pH 9.0). The relation between peak current and analyte concentration was linear over about three orders of magnitude with detection limits (S/N=3) ranging from 2.1 to 4.5 microM for all the analytes.
authors.affiliation: School of Pharmacy, Fudan University, 138 Yi-Xue-Yuan Road, Shanghai 200032, China.
authors.forename: Zhi
authors.initials: Z
authors.lastname: Chen
authors.forename: Luyan
authors.initials: L
authors.lastname: Zhang
authors.forename: Gang
authors.initials: G
authors.lastname: Chen
mesh_terms: D000975:Antioxidants / Q000032:analysis*; D004563:Electrochemistry; D019075:Electrophoresis, Capillary / Q000379:methods*; D008872:Microwaves; D018515:Plant Leaves / Q000737:chemistry*; D015203:Reproducibility of Results; D027824:Rosaceae / Q000737:chemistry*; D012680:Sensitivity and Specificity
chemical_list: D000975:Antioxidants