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Electrochemical Redox Behavior of Omeprazole Using a Glassy Carbon Electrode
Author(s) -
Jorge S. M. A.,
Pontinha A. D. R.,
OliveiraBrett A. M.
Publication year - 2010
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.200900377
Subject(s) - chemistry , redox , glassy carbon , electrochemistry , cyclic voltammetry , inorganic chemistry , sulfoxide , diffusion , differential pulse voltammetry , electrode , deprotonation , organic chemistry , ion , physics , thermodynamics
Abstract The electrochemical redox behavior of omeprazole (OMZ), a gastric acid pump inhibitor, was investigated at a glassy carbon electrode using cyclic, differential pulse and square‐wave voltammetry over a wide pH range. The pH‐dependent oxidation occurs in two irreversible consecutive charge transfer reactions. Adsorption of the nonelectroactive product was also observed. The first oxidation involves removal of one electron, followed by deprotonation and leads to the formation of a hydroxylated species. The second oxidation process is related to the hydroxyl and amino groups in the benzimidazole moiety. The reduction is irreversible, also pH‐dependent, and occurs in a single step at the sulfoxide group in a diffusion‐controlled mechanism. The diffusion coefficient of omeprazole was calculated to be D OMZ =2.31×10 −6 cm 2 s −1 .