Determination of Clobetasol Propionate by Multi-walled Carbon Nanotube-modified Carbon Paste Electrode using Cyclic Voltammetry

We studied the electrochemical behaviour of Clobetasol Propionate (CP) on a multi-walled carbon nanotube-modified carbon paste electrode (MWCNTs-CPE) and developed a corresponding determination method. Sample solutions were scanned using cyclic voltammetry (CV) with a homemade MWCNTs-CPE as a working electrode in KH 2 PO 4 -Na 2 B 4 O 7 buffer solution (pH=4.90), and the peak potential and peak current of the cyclic voltammogram were recorded. CP showed a clear oxidation peak near 1.16 V, and the CP concentration exhibited an excellent linear relationship with peak current in the range of 1.0×10 -4 to 1.0x10 -6 mol/L, with a correlation coefficient of 0.999 and a detection limit of 3.45×10 -8 mol/L. The content of CP in a facial mask was determined by this method, the recovery rate was between 98.0% and 106.2% in the presence of interfering substances, and the relative standard deviation (RSD) ranges between 2.0% and 4.1% (n=5). The MWCNTs’CPE showed a good electrochemical response to CP and possessed high sensitivity. This method can be applied to the determination of CP in cosmetics and pharmaceuticals.