title: Evaluation of antimony microparticles supported on biochar for application in the voltammetric determination of paraquat.
abstract: This work describes the construction and application of carbon paste electrodes modified with biochar and antimony microparticles (SbBCPE) for voltammetric determination of paraquat using a simple and sensitive procedure based on voltammetric stripping analysis. Some parameters such as amount of biochar and antimony used in the composition of the carbon paste and instrumental parameters were examined in detail. Under optimized conditions, an analytical curve was obtained for paraquat determination employing SbBCPE, which showed a linear response ranging from 0.2 to 2.9 μmol L(-1), with limit of detection and quantification of 34 nmol L(-1) and 113 nmol L(-1), respectively, after paraquat pre-concentration of 120 s. The repeatability study presented a RSD=2.0% for 10 consecutive measurements using the same electrode surface and the reproducibility study showed a RSD=2.7% for measurements with 10 different electrode surfaces. The proposed sensor was successfully applied for paraquat determination in tap water and citric fruit juice spiked samples and good recoveries were obtained without any sample pre-treatment, showing its promising analytical performance.
authors.affiliation: Laboratório de Sensores Eletroquímicos (LabSensE), Departamento de Química, Universidade Federal do Paraná (UFPR), CP 19081, CEP, 81531-990 Curitiba, PR, Brazil.
authors.forename: Ava
authors.initials: A
authors.lastname: Gevaerd
authors.affiliation: Laboratório de Sensores Eletroquímicos (LabSensE), Departamento de Química, Universidade Federal do Paraná (UFPR), CP 19081, CEP, 81531-990 Curitiba, PR, Brazil.
authors.forename: Paulo R
authors.initials: PR
authors.lastname: de Oliveira
authors.affiliation: Laboratório de Química de Húmus e Fertilizantes, Departamento de Química, Universidade Federal do Paraná (UFPR), CP 19081, CEP, 81531-990 Curitiba, PR, Brazil; Instituto Nacional de Ciência e Tecnologia de Energia e Ambiente (INCT/CNPq), Brazil.
authors.forename: Antonio S
authors.initials: AS
authors.lastname: Mangrich
authors.affiliation: Laboratório de Sensores Eletroquímicos (LabSensE), Departamento de Química, Universidade Federal do Paraná (UFPR), CP 19081, CEP, 81531-990 Curitiba, PR, Brazil.
authors.forename: Márcio F
authors.initials: MF
authors.lastname: Bergamini
authors.affiliation: Laboratório de Sensores Eletroquímicos (LabSensE), Departamento de Química, Universidade Federal do Paraná (UFPR), CP 19081, CEP, 81531-990 Curitiba, PR, Brazil. Electronic address: luiz1berto@ufpr.br.
authors.forename: Luiz H
authors.initials: LH
authors.lastname: Marcolino-Junior
mesh_terms: D000965:Antimony / Q000737:chemistry*; D001628:Beverages / Q000032:analysis; D002606:Charcoal / Q000737:chemistry*; D055664:Electrochemical Techniques; D004566:Electrodes; D005618:Fresh Water / Q000737:chemistry; D057230:Limit of Detection; D010269:Paraquat / Q000032:analysis*; D015203:Reproducibility of Results
chemical_list: C540010:biochar; D002606:Charcoal; D000965:Antimony; D010269:Paraquat
keywords: Antimony microparticles; Biochar; Carbon paste electrode; Paraquat