ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

An ecologically correct electroanalytical method to determine the herbicide Picloram in Amazon waters using a miniaturized boron-doped diamond electrode and a 3D compact electrochemical cell

José Inácio Lopo da Silva, Vagner Bezerra dos Santos, Carlos Antonio Neves, and José Pio Iúdice de Souza

Faculty of Chemistry, Institute of Exact and Natural Science, Federal University of Pará, Belém, Brazil

E-mail: vagner.bsantos@ufpe.br

Received: 24 June 2020  Accepted: 12 September 2020

Abstract:

In this work, voltammetric methods were applied using a boron-doped diamond electrode (BDD) to detect Picloram (PCR), a very toxic and persistent herbicide. The method was applied to investigate environmental waters in the Amazon. In this context, an environmental-friendly method was developed using a miniaturized BDD electrode, and a compact electrochemical cell manufactured by a 3D printer using a polylactic acid biodegradable polymer to reduce the generated residue, leading to more sustainable research procedures with potential to be applied in field analysis. In addition, studies were carried out to establish the rate-limiting step of the reaction and the number of electrons and protons involved, being three protons and three electrons suggested for PCR electrochemical oxidation. For analytical purposes, the optimization of the square wave voltammetry (SWV) parameters and tests of precision, accuracy and sensitivity were performed. Thus, a low detection limit of 390 nmol L⁻¹ and values for the intra-day and inter-day repeatability tests of 8.65% and 4.64%, respectively, were obtained. Due to its biodiversity abundance, environmental waters in the Amazon should be better monitored and this method can contribute to this task quite efficiently.

Keywords: Polylactic acid (PLA); Amazon basin; Boron-doped diamond; Picloram; Square wave voltammetry; 3D printer

Full paper is available at www.springerlink.com.

DOI: 10.1007/s11696-020-01357-1

Chemical Papers 75 (3) 1055–1067 (2021)