title: Polarographic determination of berberine in the presence of H(2)O(2) in medicinal plants.
abstract: The mechanism of the parallel catalytic wave of berberine in the presence of H(2)O(2) was studied. The results showed that the reduction process of the C[double bond]N bond of berberine was two successive one-electron transfers, in which an intermediate free radical was involved. When H(2)O(2) was present, it oxidized the free radical to the original C[double bond]N bond, producing the parallel catalytic wave of berberine. In Na(2)B(4)O(7)-Na(2)CO(3) (pH 9.4, 0.08 M)-H(2)O(2)(4 mM) supporting electrolyte, the peak current of the catalytic wave was linear to the berberine concentration in the range of 1.0 x 10(-8)-3.0 x 10(-7) M. The limit of detection was 7.0 x 10(-9) M. The catalytic wave can be applied to direct determination of berberine in medicinal plant Coptis chinensis Franch, after sufficiently diluting the water extraction without preliminary separation.
authors.affiliation: Institute of Electroanalytical Chemistry, Northwest University, Xian 710069, People's Republic of China. songjunf@nwu.edu.cn
authors.forename: J-F
authors.initials: JF
authors.lastname: Song
authors.forename: Ying-Ying
authors.initials: YY
authors.lastname: He
authors.forename: Wei
authors.initials: W
authors.lastname: Guo
mesh_terms: D000465:Algorithms; D001599:Berberine / Q000032:analysis*; D002138:Calibration; D002384:Catalysis; D004563:Electrochemistry; D004566:Electrodes; D006861:Hydrogen Peroxide / Q000737:chemistry*; D007202:Indicators and Reagents; D010084:Oxidation-Reduction; D010946:Plants, Medicinal / Q000737:chemistry*; D011048:Polarography
chemical_list: D007202:Indicators and Reagents; D001599:Berberine; D006861:Hydrogen Peroxide