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The Electrochemical Behavior of Iron(III) Incorporated in Zeolite Y‐Modified Electrode and the Catalytic Oxidation of Ascorbic Acid
Author(s) -
Jiang Yanxia,
Zou Mingzhu,
Yuan Kai,
Xu Hongding
Publication year - 1999
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/(sici)1521-4109(199904)11:4<254::aid-elan254>3.0.co;2-o
Subject(s) - ascorbic acid , chemistry , electrochemistry , inorganic chemistry , catalysis , ferrous , electrolyte , zeolite , amperometry , supporting electrolyte , redox , electrode , organic chemistry , food science
A new method is developed for the catalytic oxidation of ascorbic acid (AA) at a graphite‐zeolite‐modified electrode doped with iron(III) (Fe 3 +Y/ZCME), in which iron(III) exchanged in zeolite Y can act as catalyst to oxidize AA. First, the electrochemical behavior of iron(III) incorporated in the zeolite Y‐modified electrode was studied. The results illustrate that diffusion controls the ferric/ferrous redox process at the Fe 3 +Y/ZCME. The anodic current of this process increases with the supporting electrolyte concentration of non‐size‐excluded cation and was suppressed when using size‐excluded cation. Second, the catalytic oxidation of AA was explored at Fe 3 +Y/ZCME. With constant potential amperometric measurements optimal conditions for AA determination were obtained. The working potential was 0.55 V (vs. SCE); the supporting electrolyte was 0.1 M KNO 3 Or 0.05 M Na 2 HPO 4 ‐KH 2 PO 4 buffer solution (pH 6.8). The response current exhibits a linear relationship with the concentration of AA over the range of 1.58×10 –6 –2.15×10 –2 M. When samples of urine, and fruit were analyzed with Fe 3+ Y/ZCME, we obtained AA recovery of 98–102%, and a relative standard deviation lower than 3%. Meanwhile, interferences from other ions and organic substances were examined.