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Electrocatalytical of chlorophenoxycarboxylic acids at a protoporphyrin IX cobalt(III) chloride modified glassy carbon electrode
Author(s)
Chaiyasith, Suwan
Tangkuaram, Tanin
Chaiyasith, Pachernchai
Date Issued
July 15, 2005
Type
Article
Abstract
Protoporphyrin IX cobalt(III) chloride (Co(ProP)Cl) was immobilized on a glassy carbon electrode (GCE) to facilitate the electrocatalytical determination of 2,4-dichlorophenoxycarboxylic acids (2,4-D) and three of its derivatives 2-(2,4-dichlorophenoxy) propionic acid (2,4-DP), 2-(2,4,5-trichlorophenoxy) propionic acid (2,4,5-TP) and 4-(2,4-dichlorophenoxy)butyric acid (2,4-DB) in aqueous solution. Co(ProP)Cl was immobilized by a spontaneous adsorption method. The electrocatalytic reduction peak of 2,4-D and its three derivatives was found at -1.12 V (vs. Ag/AgCl). Employing chronoamperometry, the highest limiting current was found for a modified GCE with 1 mM Co(ProP)Cl in acetonitrile|water (1:3; v/v) containing 0.1 M KCl at -1.15 V. Good linear response of the modified electrode was found in 10-400 μM for 2,4-D, 2,4-DP and 2,4,5-TP; and in 10-300 μM for 2,4-DB. The detection limits were estimated as 0.98, 1.14, 0.89, and 2.77 μM for 2,4-D, 2,4-DP, 2,4,5-TP and 2,4-DB, respectively. The lifetime of the Co(ProP)Cl-GCE was seven times for 2,4-D; eight times for 2,4,5-TP; and six times for 2,4-DP and 2,4-DB. © 2005 Elsevier B.V. All rights reserved.
Citation
Journal of Electroanalytical Chemistry, 581(1), 104-110, 2005