Novos materiais para aplicações analíticas nas determinações de compostos orgânicos de interesse farmacêutico e ambiental / New materials for analytical application in organic compound determination for pharmaceutical and environmental interests

AUTOR(ES)
DATA DE PUBLICAÇÃO

2009

RESUMO

Carbon film sensors, built from resistors of 2 Ω nominal resistance, were employed for application in the environment and pharmaceutical fields without previous modification of the electrode surface. When these sensors are electrochemically treated they obtain a wider potential window (both anodic and cathodic regions) than many other forms of carbon. Due to the fact that sensors are produced on industrial scale in Germany, the cost of each unit is very low, a feature that enables the use of these electrodes in disposable form. Moreover, they have great versatibility, reproducibility and stability. To prove the suitability of the carbon film electrodes as voltammetric sensors paraquat samples were analysed in river and drinking water. The association with the square wave voltammetry led to a detection limit below the allowed upper limit for herbicide analysis in drinking water. Previous results with cyclic voltammetry showed two peaks for paraquat reduction, in agreement with the literature data. The carbon film sensors were also adapted to the flow injection analysis system for amperometric determination of acetaminophen and ambroxol in pharmaceutical formulations. It was possible to obtain a wide linear working range, low detection limit and high sensitivity for both analytes. During the repeatabilty studies, acetaminophen and ambroxol showed relative standard desviations lower than 3% without any memory effect. The results obtained with a new amperometric sensor associated to FIA were in good agreement with those recommended by pharmacopoeias. In the appendices of this thesis are described other studies which have been developed for four years of PhD.

ASSUNTO(S)

organic compounds amperometria filmes de carbono sensors carbon films sensores electrochemistry eletroanálise pharmaceutical analyses electroanalyses eletroquímica (aplicações) análises de fármacos pesticides amperometry voltametria de onda quadrada compostos orgânicos (determinação) pesticidas square wave voltammetry

ACESSO AO ARTIGO

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