ABSTRACT
A method for analyzing phenol in an over-the-counter sore throat spray by cyclic voltammetry was developed. The method employed a glassy-carbon disk electrode (3 mm diameter) as the working electrode and 0.1 M HCl as the supporting electrolyte. The reference electrode was a silver-silver chloride electrode with 3 M NaCl. In the cyclic voltammetry procedure, the initial potential was +200 mV and the final potential was +1450 or +1500 mV. The cyclic voltammetric method was validated against a method based on reversed-phase high-performance liquid chromatography (HPLC). The phenol results for cyclic voltammetry at 50 mVs(-1) were in good agreement with the results obtained from HPLC. The results also agreed with the label claim (1.4% phenol). Good reproducibility and accuracy were obtained for the voltammetric method. Cyclic voltammetry was shown to be an accurate, reproducible, and rugged technique for the routine analysis of phenol in a sore throat spray.
