Determination of Tetradifon in Brazilian Green Bell Pepper by Differential Pulse Voltammetry

Abstract

Tetradifon, a potentially carcinogenic and mutagenic pesticide, can contribute to environmental and human contamination when applied to green bell pepper crops. In this context, in this work, a reliable and sensitive method for determination of tetradifon in Brazilian green bell pepper samples involving a differential pulse voltammetry (DPV) technique on a glassy carbon electrode is proposed. The electrochemical behavior of tetradifon as followed by cyclic voltammetry (CV) suggests that its reduction occurs via an irreversible five-electron transfer vs. Ag|AgCl, KCl 3 M reference electrode. Very well-resolved diffusion controlled voltammetric peaks have been obtained in a supporting electrolyte solution composed of a mixture of 40% dimethylformamide (DMF), 30% methanol, and 30% NaOH 0.3 mol L −1 at −1.43, −1.57, −1.73, −1.88, and −2.05 V. The proposed DPV method has a good linear response in the 3.00 -10.0 μmol L −1 range, with a limit of detection (L.O.D) of 0.756 μmol L −1 and 0.831 μmol L −1 in the absence and in the presence of the matrix, respectively. Moreover, improved L.O.D results (0.607 μmol L −1 ) have been achieved in the absence of DMF from the supporting electrolyte solution. Recovery has been evaluated in five commercial green bell pepper samples, and recovery percentages ranging from 91.0 to 109 have been obtained for tetradifon determinations. The proposed voltammetric method has also been tested for reproducibility, repeatability, and potential interferents, and the results obtained for these three analytical parameters are satisfactory for electroanalytical purposes.

An Electrochemical Application of MnO2Decorated Graphene Supported Glassy Carbon Ultrasensitive Electrode: Pb2+and Cd2+Analysis of Seawater Samples

“…Electrode modification and characterization.-Bare GC, GC/GO, and GC/GO-MnO 2 surfaces were performed by using a Fe(CN) 6 3− redox probe in 0.1 M KCl aqueous and cyclic voltammograms as shown in Figure 1a. To confirm that the modification of GO-MnO 2 and GO has occurred, the CVs of the redox probe taken at the modified surfaces were compared to those obtained at the bare GC surface and at the electrochemically treated GC in the absence of films.…”

“…The electrochemical methods such as stripping voltammetry, amperometry, and impedimetry on modified electrodes are most commonly used for analysis of electroactive groups in environmental 3 and food samples. [4][5][6] The structure of graphene and its derivatives, such as graphene oxide (GO) and reduced graphene oxide (RGO), is a flat monolayer of sp 2 -carbon atoms covalently attached and arranged as a honeycomb lattice. 7 GO contains hydroxyl and epoxide functional groups on the top and bottom of the sheet, whereas the sheet edges are mostly arranged with carboxyl and carbonyl groups.…”

Sensitive and Selective Electrochemical Biosensor Based on ELP-OPH/BSA/TiO2NFs/AuNPs for Determination of Organophosphate Pesticides withp-Nitrophenyl Substituent

“…[1][2][3][4] Due to their high chemical stability in ambient conditions, they can maintain toxicity in water and/or soil for a long time, thus posing long-term environmental and health hazard. [5][6][7][8][9] Therefore, detection methods with advantages like fast response, low cost, high sensitivity, and high selectivity and reliability are highly desired for OPs determination. Previously, OPs measurement is available using conventional detection equipment, including gas or liquid chromatography, chemiluminescence, capillary electrophoresis, mass spectrometry and high-performance liquid chromatography.…”