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 optimized methodology based on differential pulse voltammetry for diclofenac quantification, using electrochemically activated carbon paste electrodes and multi-walled nanotubes carbon paste electrodes. Under the optimized experimental conditions, diclofenac presented linear response over the range of 10-10 to 10-4 M for both electrodes. The lower detection limits found were 0.001 and 0.29 μM for the paste electrodes with and without nanotubes respectively. The effect of common interferences on diclofenac current response was investigated. Finally the proposed methodology was validated comparing the results obtained measuring the concentration of diclofenac in pharmaceutical samples with those obtained with the reference methodology.