Enhanced Oxidation of Simvastatin at a Multi-Walled Carbon Nanotubes-Dihexadecyl Hydrogen Phosphate Composite Modified Glassy Carbon Electrode and the Application in Determining Simvastatin in Pharmaceutical Dosage Forms

Abstract

A sensitive electrochemical method for the determination of simvastatin (SV) was established, based on the enhanced oxidation of SV at a multi-walled carbon nanotubes-dihexadecyl hydrogen phosphate composite modified glassy carbon electrode (MWNTs-DHP/GCE). The voltammetric studies showed that MWNTs instead of DHP or GCE could effectively catalyze the oxidation of SV. The dependence of oxidation current on SV concentration was explored under optimal conditions, which exhibited a good linear relationship in the range of 1.0×10−7–7.5×10−6 M. The detection limit of SV was also examined and a low value of 5.0×10−8 M was obtained for 5 min accumulation (σ=3). This electrode was applied to the detection of SV in drug forms and the results were in accordance with those obtained by UV spectroscopy.