engleski

Adsorption and reduction of berberine at a mercury electrode

Adsorption and reduction of berberine are investigated by alternating current polarography and square-wave voltammetry in electrolytes of various pH. Both berberine and the product of its reduction canadine form condensed films on the mercury electrode surface. These processes limit the analytical application of square-wave voltammetry combined with adsorptive accumulation of berberine. Reduction of berberine is totally irreversible and occurs between - 0.95 V and - 1.35 V, depending on berberine concentration and pH of solution. Canadine is electroinactive and can not be reoxidized on mercury electrode. Its condensed film is very stable, even at - 0.5 V, and may prevent adsorption of berberine. The properties of square-wave voltammetric responses of berberine in acidic, neutral and basic electrolytes are reported and the conditions for their electroanalytical application are discussed.

berberine; canadine; tensametry; condensed film; square-wave voltammetry; adsorption

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