Determination of Cr(VI) in leather residues using graphite/paraffin composite electrodes modified with reduced graphene oxide nanosheets.

Autor: de Oliveira JPJ; São Paulo State University (Unesp), Faculty of Engineering and Sciences, Campus Rosana, 1881 dos Barrageiros, Av., 19274-000 Rosana, SP, Brazil; Brazilian Renewable Energies, School of Electrical and Computer Engineering, University of Campinas (Unicamp), Av. Albert Einstein 400, Campinas, SP 13083-852, Brazil., Hiranobe CT; São Paulo State University (Unesp), Faculty of Engineering and Sciences, Campus Rosana, 1881 dos Barrageiros, Av., 19274-000 Rosana, SP, Brazil., Torres GB; Instituto Tecnológico Metropolitano, Programa de Ingeniería de Diseño Industrial, Medellín, Antioquia, Colombia., Dos Santos RJ; São Paulo State University (Unesp), Faculty of Engineering and Sciences, Campus Rosana, 1881 dos Barrageiros, Av., 19274-000 Rosana, SP, Brazil., Paim LL; São Paulo State University (Unesp), Faculty of Engineering and Sciences, Campus Rosana, 1881 dos Barrageiros, Av., 19274-000 Rosana, SP, Brazil. Electronic address: leonardo.paim@unesp.br.
Jazyk: angličtina
Zdroj: The Science of the total environment [Sci Total Environ] 2022 Aug 15; Vol. 834, pp. 155318. Date of Electronic Publication: 2022 Apr 19.
DOI: 10.1016/j.scitotenv.2022.155318
Abstrakt: In this study, we determined the Cr(VI) in samples of tanned leather residues by differential pulse voltammetry (DPV) using graphite/paraffin composite electrodes modified with reduced graphene oxide nanosheets (referred to as GPEs/nsRGO). After the modification, the composite electrodes were characterized by two electrochemical techniques (i.e., cyclic voltammetry, CV, and electrochemical impedance spectroscopy, EIS), scanning electron microscopy, and Raman spectroscopy. The electroanalytical method was applied using the GPEs/nsRGO. An analytical curve was obtained in a Clark-Lubs buffer solution (pH = 1), with a linear concentration range from 25.0 to 392.0 μmol L -1 and a limit of detection (LOD) of 1.01 μmol L -1 . The GPEs/nsRGO showed good reproducibility in their manufacturing process and good response repeatability with an RSD of 4.59% over twelve measurements. These composite electrodes showed excellent selectivity, which was demonstrated by analyses in the presence of metal ions (Ca 2+ , Zn 2+ , Mg 2+ , Fe 3+ , Co 2+ , Na + , and Cu 2+ ) that did not interfere in the analysis of Cr(VI). The GPEs/nsRGO were applied to the determination of Cr(VI) in real samples of wet-blue leather and leather ash using DPV. This approach was validated using the sample recovery method, where it presented values from 95.6 to 108.2%. The proposed method showed satisfactory results compared to the literature and can be considered a good alternative for the determination of Cr(VI) in aqueous samples.
Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
(Copyright © 2022 Elsevier B.V. All rights reserved.)
Databáze: MEDLINE
Externí odkaz: