Optimization of a Differential Pulse Voltammetric Methodology for the Quantification of Diclofenac Using Paste Electrodes and Carbon Nanotubes

In this work we present the development of an optimizedmethodology based on differential pulse voltammetry fordiclofenac quantification, using electrochemically activated carbonpaste electrodes and multi-walled nanotubes carbon pasteelectrodes. Under the optimized experimental conditions,diclofenac presented linear response over the range of 10-10 to 10-4M for both electrodes. The lower detection limits found were 0.001and 0.29 ?M for the paste electrodes with and without nanotubesrespectively. The effect of common interferences on diclofenaccurrent response was investigated. Finally the proposedmethodology was validated comparing the results obtainedmeasuring the concentration of diclofenac in pharmaceuticalsamples with those obtained with the reference methodology.