Anodic oxidation of phenoxyethanol in nonaqueous media

Abstract

The unknown electrochemical properties of phenoxyethanol (PE) - the most commonly used preservative in cosmetics were studied. The measurements were performed on platinum micro- and macroelectrodes by linear sweep (LSV), cyclic (CV) and differential pulse voltammetry (DPV) in mixed solvent acetic acid-acetonitrile (20%, v/v) containing NaClO4 as a supporting electrolyte. The anodic oxidation process has proved to be quasireversible, diffusion-controlled and proceeding with exchange of one electron giving the unstable cation radical as a primary product (EqCi mechanism). Very good reproducibility of the DPV curves and the wide linearity range up to 1 mmol L-1 indicate that the proposed medium can be successfully applied to develop the first voltammetric method of this preservative determination in pharmaceutical and cosmetic products.