Abdolmajid Bayandori Moghaddam, Ali Mohammadi and Somaye Mohammadi
The development of an electrochemical sensor for determination of mefenamic acid is the main purpose of this work. The determination was performed in pharmaceutical formulations, spiked urine and human plasma samples by multi-walled carbon nanotube-graphite/Ag (MWCNTs-G/Ag) electrode. Hence some voltammetric methods were investigated to determination of mefenamic acid. The dependence of peak currents and potentials on pH and voltammetric parameters was investigated for the optimization of electrochemical method. The porous structure of MWCNTs-graphite mixture improves the electroactive surface area. As a result, a remarkable increasing in the peak currents was observed. The prepared mixture displayed an electrocatalytic effect in anodic oxidation of mefenamic acid with a sensitivity augmentation. The best electrochemical response was obtained from square wave voltammetry with a sensitive peak at 0.68 V in pH 5. The prepared electrode showed good standard calibration curves during 3 days over a wide concentration range with RSD values ranging from 1.6-8%. The limits of quantification and detection were 50 and 16 ng/mL, respectively.