Impedimetric study of the electrocatalytic oxidation of alcohols by nickel-Schiff base metallopolymer: Potential application for forensic identification of alcoholic beverage contaminants by multivariate data analysis

The present paper presents a systematic electrochemical impedance study on the electrooxidation of methanol, ethanol, 1-propanol, ethylene glycol and glycerol by a sensor based on nickel-salen metallopolymer. As a second step, the application simulated the device in the identification of contamination in alcoholic beverages by principal component analysis (PCA). By studying electrochemical impedance, we verified that the reactivity of alcohols on the device is directly related to pKa values and polarity index. By multivariate analysis, it was possible to set up a system that differentiates the types of alcohol with impedimetric variables. The identification distance between the groups allowed the differentiation of mixed samples from the groups containing ethanolmethanol and ethanol-ethylene glycol.

Automated summary

This paper presents a systematic study on the electrochemical impedance of various alcohols using a sensor based on nickel-salen metallopolymer. The application of principal component analysis (PCA) was used for the identification of contaminants in alcoholic beverages. The reactivity of alcohols on the device was found to be directly related to pKa values and polarity index through electrochemical impedance analysis. A system that differentiates different types of alcohols based on impedimetric variables was successfully established using multivariate analysis.