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Use of DPPH⋅|DPPH Redox Couple for Biamperometric Determination of Antioxidant Activity
Author(s) -
Milardovic Stjepan,
Iveković Damir,
Rumenjak Vlatko,
Grabarić Božidar S.
Publication year - 2005
Publication title -
electroanalysis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.574
H-Index - 128
eISSN - 1521-4109
pISSN - 1040-0397
DOI - 10.1002/elan.200503312
Subject(s) - trolox , dpph , chemistry , antioxidant , redox , detection limit , electrochemistry , phosphate buffered saline , nuclear chemistry , inorganic chemistry , organic chemistry , electrode , chromatography
A novel electrochemical method for selective determination of antioxidant activity based on 2,2‐diphenyl‐1‐picrylhydrazyl | 2,2‐diphenyl‐1‐picrylhydrazin (DPPH⋅|DPPH) redox couple and biamperometric technique is proposed. Two identical glassy carbon disk electrodes were mounted in a classic electrochemical cell and the tested working potential difference was between 50 and 200 mV. The DPPH⋅|DPPH redox couple exhibited a high degree of reversibility. Selectivity of detector was tested by different antioxidant compounds in ethanol‐phosphate buffer solution, pH 7.40. The results of antioxidant activity of pure antioxidant compounds and of actual samples of beverages, expressed as Trolox equivalents and determined by proposed biamperometric and spectroscopic measurements, were in good correlation ( R =0.9959). The detection limit for Trolox established by the applied biamperometry was 0.05 μM while the resulting current was linear up to 25 μM of Trolox.