Electrochemical Behavior of Verapamil at Graphite-Polyurethane Composite Electrodes: Determination of Release Profiles in Pharmaceutical Samples

A solid graphite-polyurethane composite electrode has been used to determine release profiles of verapamil, a calcium-channel blocker. The electro-oxidation process was characterized by cyclic voltammetry and electrochemical impedance spectroscopy and showed no adsorption of analyte or oxidation products, unlike at other carbon-based electrodes. Quantification gave linear ranges up to 40molL-1 with cyclic voltammetry and detection limits of 0.7molL-1 by differential pulse and square-wave voltammetry. Commercial product samples were successfully analyzed with results equal to those from spectrophotometry. Because no electrode surface renewal is needed, this electrode material has many advantages.

CAPES/FCT[177/07]

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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

CEMUC

CEMUC

CAPES[3183/07-6]

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)