Determination of Hydroquinone with a Carbon Nanotube/Polyurethane Resin Composite Electrode

A new composite electrode based on multi-walled carbon nanotubes and a polyurethane resin was evaluated using potassium ferricyanide and hydroquinone as probes. The device was used for the determination of hydroquinone in a cosmetic formulation. The effect of using multi-walled carbon nanotubes and graphite mixtures in various proportions was also investigated. Cyclic voltammetry and scanning electron micrography were used for characterization of electrode compositions. Hydroquinone was determined using a 60% (m/m) multi-walled carbon nanotubes/polyurethane resin electrode by differential pulse voltammetry with a linear dynamic range from 0.05 to 1.12 m mol L-1 and a limit of detection of 12 mu mol L-1. The analysis of commercial cosmetic formulation was performed by differential pulse voltammetry and high-performance liquid chromatography as a comparison method. The results for both procedures agreed at the 95% confidence level according to Student's t-test. The reported electrode was mechanically robust and provided reproducible results.