A novel amperometric method for antioxidant activity determination using DPPH free radical
2005; Elsevier BV; Volume: 68; Issue: 2 Linguagem: Inglês
10.1016/j.bioelechem.2005.06.005
ISSN1878-562X
AutoresStjepan Milardović, Damir Iveković, Božidar S. Grabarić,
Tópico(s)Advanced Chemical Sensor Technologies
ResumoA new method for the determination of antioxidant activity based on the amperometric reduction of 2,2-diphenyl-1-picrylhydrazyl (DPPH) at the glassy carbon electrode is proposed. All experiments were done in three-electrode electrochemical cell at 140 mV vs. Hg(2)Cl(2) | 3 M KCl using ethanolic solution (phi=40%) and 0.033 M KCl in 0.033 M phosphate buffer, pH=7.4. The linear range obtained for Trolox in 100 microM DPPH ethanol-water solution was up to 30 microM, with a limit of detection of 0.05 microM. The developed method was applied for the evaluation of antioxidant activity of some water or ethanol soluble pure compounds of antioxidants and of the samples of tea, wine and some other beverages. The good correlation of measurements (R(2)=0.9993) expressed as Trolox equivalent was obtained between the proposed amperometric method and classic spectroscopic method.
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