Reciclagem de componentes eletrônicos como alternativa para fabricação de microeletrodos e sua aplicação na determinação de isoniazida em formulações farmacêuticas

Abstract

The intensified technological progress, combined with the continuous obsolescence of electronic devices, has resulted in a significant increase in electronic waste. The lack of proper management hinders the recovery of valuable materials and contributes to the depletion of natural resources. Faced with this problem, it becomes necessary to seek efficient responsible management solutions for these wastes, aiming to reduce negative impacts and promote sustainable development. Thus, this study aims to highlight an alternative and sustainable methodology for the fabrication of a gold microelectrode array (AuMA) using the recycling of obsolete computer microchips, and to assess its applicability in the quantification of the antibiotic isoniazid in pharmaceutical formulations. Initially, the AuMA was fabricated and characterized using cyclic voltammetry and optical microscopy. Subsequently, the microelectrode array underwent an electrochemical modification using a sustainable approach involving the formation of a gold nanoporous film (NPGF). The device was also characterized using Scanning Electron Microscopy - SEM e Energy dispersive X-ray spectroscopy - EDX, detailing its morphology and composition. Relevant parameters were investigated, including the type of supporting electrolyte and modification time. Through optimization, it was determined that pH 5.0 phthalate buffer and a 20-minute electrode modification time were the ideal conditions. The linear range obtained was 1.37 - 48.00 ppm, while the calculated limits of detection (LOD) and quantification (LOQ) were 0.16 ppm and 0.49 ppm, respectively. The electroanalytical determination of isoniazid in tablets was carried out using the differential pulse voltammetry (DPV) technique. By using a standard addition calibration curve, a recovery rate of 103.69% was obtained. The developed analytical methodology was compared to results obtained with methodologies recommended by the Brazilian Pharmacopeia, which recommends obtaining recoveries of at least 90% and a maximum of 110%. Through UV-Vis molecular absorption spectrophotometry, a recovery of 91.2% of the active ingredient (isoniazid) was obtained from the declared drug content. The HPLC study showed a recovery of 82.7%. Therefore, electroanalysis can be considered a simple, fast, sustainable, and low-cost methodology capable of quantifying the active ingredient isoniazid in pharmaceutical formulations with excellent recovery rates.