DETERMINAÇÃO ELETROANALÍTICA E ESTUDO DA REDUÇÃO ELETROQUÍMICA DO RODENTICIDA BROMADIOLONA USANDO ELETRODO DE GRAFITE DESCARTÁVEL

Abstract

Rodenticides are chemical agents intended for the extermination of rodents. Bromadiolone is an anticoagulant rodenticide that acts as a vitamin K antagonist. Bromadiolone poisoning has been reported in the literature and also by police forces, either accidentally or intentionally (suicide attempts or intentional poisoning). Thus, it is necessary to use fast and efficient methods for monitoring bromadiolone, both in commercial and forensic samples. A wide range of analytical methods have been used for this purpose, with high performance liquid chromatography (HPLC) being the most commonly used. However, although efficient, these methods have some disadvantages, such as long sample preparation times and high instrumentation costs. As an alternative, electroanalytical methods have been gaining space due to advantages such as simpler operation, possibility of miniaturization, high sensitivity, relatively low cost and detection limits comparable to those found in chromatographic techniques. The present work presents a low-cost analytical methodology for the determination of bromadiolone, in commercial and forensic samples, using for the first time its electrochemical reduction and mechanical pencil graphite electrodes. For this purpose, square wave voltammetry (SWV) was used. The limits of detection (LD) and quantification (LQ) were 0.5 and 1.65 nM, respectively. An analytical curve was built in the concentration range from 1.65 to 100 nM, obtaining a correlation coefficient (R) of 0.991. The proposed methodology was used qualitatively in forensic sample of powdered chocolate and quantitatively in commercial samples, where the recoveries found were 72 and 78 %. Recovery tests were also performed with bromadiolone standard, in two different concentrations, obtaining recoveries between 93 and 98 %. Thus, the proposed methodology for the determination of bromadiolone demonstrated efficiency for applications in quality control and forensic analysis.