Desenvolvimento e aplicação de eletrodos modificados com pseudocaule de bananeira (Musa sp) para detecção de íons Chumbo II

Abstract

The development of cheap and versatile methods for detection and quantification of chemical species, such as heav y metal ions present in tailings, is currently of great relevance in the academic world. Based on this, the project proposes to modify electrodes based on graphite powder with the biomass of the banana pseudocaule (Musa sp), which are generally discarded after harvesting the fruits, taking advantage of its biosorbent property, for the detection and quantification of lead ions (II) through of the Adsorptive Redisolution Voltammetry (ADSV) technique. For this, it was necessary to characterize the composition of the biomass and to study the electroanalytical parameters such as the adsorption time, the reduction potential, the electrolyte pH, the scanning speed and the ideal proportions for the formation of the working electrode composite to optimize the electroanalytical response. Repeatability and reproducibility tests of the modified electrode were performed to verify if the results obtained are reliable and can be used to determine a species of interest. The technique of voltammetry using the working electrode was applied in effluent media containing lead ions (Pb2+) for detection and based on the equation of the calibration curve, the concentration in the medium can be quantified. These values were confronted with the maximum allowed lead according to Resolution no. 357/2005, 430/2011 of CONAMA and Ordinance no . 518 of the Ministry of Health (MS). The results obtained in this work corroborated to the electroanalytical area, showing that the technique of electrode modification and the voltammetry is efficient is valid for application in different tests of identification and quantificat ion of studied chemical species, reaching a detection range of 1.0 x 10-9 mol. L-1. .