A Graphite-Polyurethane Composite Electrode for the Analysis of Furosemide

A graphite-polyurethane composite electrode has been used for the determination of furosemide, a antihypertensive drug, in pharmaceutical samples by anodic oxidation. Cyclic voltammetry and electrochemical impedance spectroscopy were used to characterize the electrooxidation process at +1.0 V vs. SCE over a wide pH range, with the result that no adsorption of analyte or products occurs, unlike at other carbon-based electrode materials. Quantification was carried out using cyclic voltammetry, differential pulse voltammetry, and square-wave voltammetry. Linear ranges were determined (up to 21 mu mol L-1 with cyclic voltammetry) as well as limits of detection (0.15 mu mol L-1 by differential pulse voltammetry). Four different types of commercial samples were successfully analyzed. Recovery tests were performed which agreed with those obtained by spectrophotometric evaluation. The advantages of this electrode material for repetitive analyzes, due to the fact that no electrode surface renewal is needed owing to the lack of adsorption, are highlighted.

Brazil/Portugal Bilateral Agreement

Brazil/Portugal Bilateral Agreement[CAPES/FCT 177/07]

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

FAPESP-Brazil[04/08550-0]

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

FAPESP-Brazil[05/04297-1]

Fundação para a Ciência e a Tecnologia de Portugal (FCT)

ICEMS-Coimbra, Research Unit 103 (FCT)

CAPES[2670/06-2]

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

CAPES[3183/07-6]

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Fundação para a Ciência e a Tecnologia de Portugal (FCT)

FCT[SFRH/BD/31483/2006]