Photochemical oxidation of alcohols: Simple derivatization strategy for their analysis by capillary electrophoresis

Abstract

The determination of ethanol is one of the most important parameters in the fermentation industry, influencing not only the production yield and the quality of the product, but also its commercial value. In addition to the traditional approach based on distillation/density, procedure that is considered laborious and time-consuming, methods based on chromatography are widely used. Alternatives using electrochemical, spectroscopic and colorimetric techniques have been also proposed for alcohol analysis. In general, these methods not only offer limited throughput, but also require harsh reaction conditions and/or complex instrumentation. Aiming to address these shortcomings, we propose a fast, simple and clean analytical approach for the determination of primary alcohols based on the photochemical oxidation under UV-LED irradiation in the presence of H₂O₂. The proposed method was successfully applied to the analysis of 12 different types of alcoholic beverages with an alcohol content ranging from 5% v/v (beer) to 53% v/v (whiskey).

Keywords: Alcoholic beverages; Capillary electrophoresis; Indirect detection; Photochemical derivatization.