Evaluation of antimony microparticles supported on biochar for application in the voltammetric determination of paraquat

• Published in: Materials Science & Engineering C Vol. 62; pp. 123 - 129
• Main Authors: Gevaerd, Ava, de Oliveira, Paulo R., Mangrich, Antonio S., Bergamini, Márcio F., Marcolino-Junior, Luiz H.
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 01.05.2016
• Subjects: Antimony; Antimony - chemistry; Antimony microparticles; Beverages - analysis; Biochar; Carbon; Carbon paste electrode; Charcoal - chemistry; Electrochemical Techniques; Electrodes; Fresh Water - chemistry; Limit of Detection; Mathematical analysis; Microparticles; Paraquat; Paraquat - analysis; Pastes; Reproducibility; Reproducibility of Results; Paraquat; Carbon paste electrode; Biochar; Antimony microparticles
• ISSN: 0928-4931; 1873-0191
• DOI: 10.1016/j.msec.2016.01.020

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 2.9μmolL−1, with limit of detection and quantification of 34nmolL−1 and 113nmolL−1, respectively, after paraquat pre-concentration of 120s. 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. •Electrochemical procedure for growth of antimony microparticles anchored by biochar•Low cost and easy preparation of voltammetric sensor for paraquat determination•Low limit of detection, high sensitivity and stability of the proposed sensor•Promising analytical performance for paraquat determination in water and fruit juices