M. J. Legorburu, R. Alonso, R. Jiménez
Mar 1, 1996
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Influential Citations
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Journal
Electroanalysis
Abstract
The electrochemical oxidation of the 3-(Aminosulfonyl)-4-chloro-N-(2,3-dihydro-2-methyl-1H-indol-1-y1)benzamide, Indapamide, was studied in aqueous alcoholic media (9:91 MeOH+H2O, pH range 1–13) and two different ionic media (KNO3 and KCl) at carbon electrodes. The oxidation processes attributed to indoline ring and benzamide moiety have been shown to be irreversible and diffusion-controlled over the entire pH range in both media. A differential-pulse voltammetric method was developed upon the basis of the voltammetric peak due to indoline ring, at pH around 2.3 (phosphate buffer) and using KNO3 as ionic medium. The peak current ip, showed a linear relationship with concentration in the range 5.92 × 10 −7 M–1.86 × 10 −5 M with a detection limit of 9.87 × 10−8 M (37 ppb) and a reproducibility (in terms of relative standard deviation) of 4.8% and 9.3% for 10 determinations of 2.67 × 10−6 M and 1.07 × 10−6M concentrations, respectively. The differential-pulse voltammetric method for Indapamide was applied to assays of pharmaceuticals (Tertensif, 2.5mg) and urine samples.