Determinação eletroanalítica de zinco e cádmio, em amostras aquosas reais, utilizando eletrodo de grafite modificado com cortiça

Abstract

The presence of potentially toxic metals in aquatic bodies has increased considerably in recent years. Among these chemical elements we can highlight the potentially toxic metals zinc (Zn) and cadmium (Cd), these have received a certain amount of attention due to the significant increase in industrial activities. In human health and in some animals, the existence of zinc and cadmium, even in low concentrations, can cause concern. This concern is particularly relevant in effluents from the oil industry, where the significant presence of organic and inorganic substances, with diverse composition, can represent a considerable environmental challenge. These potentially toxic metals have received a certain amount of attention due to the impacts they can generate on terrestrial and aquatic ecosystems, where they have received regulations established by resolution number 401 of 11/04/2008 of the National Environmental Council (CONAMA) in Brazil to mitigate these impacts and assign minimum and maximum quantities to certain effluents and consequently minimize and control their contamination. This work sought to carry out a study on the use of graphite / cork electrode 50% (m/m) to quantify zinc and cadmium in real samples of produced water, tap water and catchment pond water using the pulse voltammetry technique. differential. The results obtained clearly demonstrated that the application of this electrode proved to be quite efficient in detecting the metals Zn and Cd with a detection sensitivity of 0.095 µg L-1 and a quantification limit of 0.317 µg L-1 for Zinc and detection sensitivity of 82,824 µg L-1 and limit of quantification of 876,080 µg L-1 for Cadmium. In water recovery tests, the results for zinc and cadmium ions are within the acceptable range (105% to 118%), which suggests that the proposed methodology is reliable. And in general, we can highlight the ease of creating the electrode, as well as the electroanalytical method due to its low consumption of reagents, speed of analysis and characteristics that lead to the use of this technique in a safe and reliable way in the determination of zinc and cadmium. applied to real samples.