Electroanalysis of formetanate hydrochloride by a cobalt phthalocyanine functionalized multiwalled carbon nanotubes modified electrode: characterization and application in fruits

Author(s)

Paulino Ribeiro, Francisco Wirley ^[1] ; de Souza Lucas, Francisco Willian ^[1] ; Mascaro, Lucia H. ^[1] ; Morais, Simone ^[2] ; da Silva Casciano, Paulo Naftali ^[3] ; de Lima-Neto, Pedro ^[3] ; Correia, Adriana N. ^[3]

Affiliation

^[1] Univ Fed Sao Carlos, Dept Quim, LIEC, Rodovia Washington Luis Km 235, Caixa Postal 676, BR-13560970 Sao Carlos, SP - Brazil

^[2] Inst Politecn Porto, Inst Super Engn, REQUIMTE LAQV, Rua Dr Antonio Bernardino de Almeida 431, P-4200072 Oporto - Portugal

^[3] Univ Fed Ceara, Ctr Ciencias, Dept Quim Analit & Fis Quim, GELCORR, Bloco 940 Campus Pici, BR-60455970 Fortaleza, CE - Brazil

• Document type: Journal article
• Source: Electrochimica Acta; v. 194, p. 187-198, MAR 10 2016.
• Web of Science Citations: 11

Abstract

This study characterizes the electroanalytical behavior of the carbamate pesticide formetanate hydrochloride (FMT) at a cobalt phthalocyanine (CoPc) functionalized multiwalled carbon nanotubes (fMWCNT) modified glassy carbon electrode (CoPc-fMWCNT/GCE). Nafion (R) was used to improve solubility and dispersibility of fMWCNT. The construction of the developed electrode was characterized by high-resolution field-emission gun scanning electron microscopy, Raman spectroscopy, cyclic voltammetry and electrochemical impedance spectroscopy. FMT exhibited a behavior consistent with a three-step reaction of the electrochemical-chemical-electrochemical mechanistic type at CoPc-fMWCNT/GCE (three anodic peaks at 0.26, 0.55 and 1.2 V, and two cathodic peaks at 0.35 and 0.50 V vs. Ag/AgCl/3 M KCl). Highly reproducible and well-defined peaks were obtained at the optimum experimental conditions (Britton-Robinson buffer at pH 5.0, accumulation potential 1.55 V, accumulation time 5 s, frequency 100 s(-1), amplitude 30 mV, and scan increment 3 mV). Peak currents were found to be proportional to the FMT concentrations in the range of 9.80 x 10(-8) to 3.92 x 10(-6) mol dm(-3) with a detection limit (LOD) of 9.7 x 10(-8) mol dm(-3). The modification of GCE with CoPc-fMWCNT enhanced the electrocatalytic activity and provided high sensitivity (3.51 A mol(-1) dm(3)). The developed electroanalytical methodology was successfully applied to FMT residue analysis in mango and grape samples with recoveries in the range of 94.2 +/- 4.5 to 105.7 +/- 1.8%. The proposed electroanalytical approach represents a reliable, sensitive and environmental friendly analytical alternative for determination of FMT. (C) 2016 Elsevier Ltd. All rights reserved. (AU)

• FAPESP's process: 08/57872-1 - National Institute for Materials Science in Nanotechnology
• Grantee: Elson Longo da Silva
• Support type: Research Projects - Thematic Grants
• FAPESP's process: 14/06704-2 - SYNTHESIS AND CHARACTERIZATION OF BISMUTH VANADATE FOR WATER SPLITTING AND DEGRADATION OF THE ORGANIC MOLECULES
• Grantee: Francisco Wirley Paulino Ribeiro
• Support type: Scholarships in Brazil - Post-Doctorate
• FAPESP's process: 12/10947-2 - Preparation and characterization of MBSe thin films (M = Ag or Cu; B = In, Ga, Sb or Tl; and S = S or Se) for application in photovoltaic cells"
• Grantee: Francisco Willian de Souza Lucas
• Support type: Scholarships in Brazil - Doctorate