Voltammetric and spectroscopic studies of the interaction between copper (II) ions with the pesticide carbendazim and its effect in the soil

• Published in: Journal of solid state electrochemistry 2018-05, Vol.22 (5), p.1563-1570
• Main Authors: Costa, Isis Marques, Codognoto, Lúcia, Valle, Eliana Maíra Agostini
• Format: Article
• Language: English
• Subjects: Absorption spectra; Analytical Chemistry; Characterization and Evaluation of Materials; Chemistry; Chemistry and Materials Science; Complex formation; Condensed Matter Physics; Copper; Electrochemistry; Energy Storage; Metal ions; Original Paper; Oxidation; Pesticides; Physical Chemistry; Reduction; Reduction (metal working); Silver chloride; Soil analysis; Species diffusion; Voltammetry
• ISSN: 1432-8488; 1433-0768
• DOI: 10.1007/s10008-017-3746-5

The pesticide carbendazim (MBC) has nitrogen and oxygen in their structure which can interact with metal ions. This work evaluated the interaction between copper (II) ions with the pesticide carbendazim. The results obtained by cyclic voltammetry (CV) in 0.4 mol L −1 Britton-Robinson (BR) buffer (pH 4.0), under glass carbon electrode (GCE) to the MBC, showed an oxidation peak at 1.02 V and a reduction peak at 0.78 V vs Ag/AgCl, with characteristics of a quasi-reversible process controlled by the diffusion of the species in solution. For the Cu 2+ metal ions, two reduction peaks were observed at − 0.26 and − 0.11 V and an oxidation peak at 0.04 V vs Ag/AgCl, with characteristics of a quasi-reversible process, controlled by the diffusion of the species in solution. In the interaction between carbendazim and copper metal ion, the formation of an oxidation peak around 0.60 V vs Ag/AgCl and a reduction peak around 0.08 V was observed, in a 1:1 ratio (Cu 2+ :MBC) in solution, suggesting that a new compound was formed. Complex formation was confirmed by UV-Vis spectroscopy, where changes were observed in the MBC absorption band and Cu 2+ d-d band, suggesting the formation of a MBC-Cu complex. Analyses with the soil samples showed that after 30 min of the presence of the carbendazim solution in the soil, the pesticide had around 80% of its initial concentration adsorbed. When carbendazim is in the presence of the Cu 2+ ion, about 62% of the pesticide is adsorbed, indicating that complexation influences adsorption of the species in the soil studied.