Determinação potenciométrica de paracetamol em formulações farmacêuticas através da reação oscilante de Belousov-Zhabotinsky por pertubação do padrão de oscilação

• Autor(a) principal: Maia, Luiz Fernando Oliveira
• Data de Publicação: 2009
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: LOCUS Repositório Institucional da UFV
• Texto Completo: http://locus.ufv.br/handle/123456789/2076
• topic: Paracetamol; Determinação; Reação química oscilante; Potenciometria; Perturbação; Paracetamol; Determination; Oscillating chemical reaction; Potentiometry; Disturbance; CNPQ::CIENCIAS EXATAS E DA TERRA::QUIMICA::QUIMICA ANALITICA

This present work proposes the development of an analytical procedure for paracetamol determination in samples of drugs using a system of continuous flow analysis associated with potentiometric detection allowing the study of the Belousov- Zhabotinsky (BZ) oscillating reaction. This method is based on paracetamol determination using the effect of this substance in the oscillation standard of the BZ reaction. The system was composed by a microcomputer interfaced to a potentiometer connected to a reaction cell. To detect the signal of the oscillating reaction two electrodes were used, a platinum electrode as indicator electrode and a double-layer Ag/AgCl electrode as a reference electrode. The experimental conditions such as reagent concentration, temperature and flow rate of the system were optimized and allowed the production of regular oscillations. An analytical curve was obtained for the paracetamol determination. The linear range covers concentrations from 3.69 x 10-6 to 3.69 x 10-5 mol L- 1 of paracetamol, with a correlation coefficient of 0.9956. The detection limit for this range was 3.69 x 10-6 mol L-1. The relative standard deviation (n = 6) of the standard solution containing 6.0 x 10-3 mol L-1 of paracetamol was 2.34%. The analysis of real samples by the proposed procedure and by the official method (spectrophotometry/UV) showed similar results. The method was successfully applied for the determination of paracetamol in drug and proved to be a simple, practical and with low cost, and provides results with adequate sensitivity for purposes of quality control and good accuracy of experimental results. The mechanism of action of paracetamol in the BZ reaction system was also discussed.