Spectroscopic determination of methanol content in alcoholic drinks

Abstract

The aim of this paper is to introduce an innovative method for measuring the concentration of methanol in alcoholic beverages. The novel approach consists in using Raman spectroscopic data for methanol content detection. Raman spectroscopy is a powerful method for material identification giving information about the structure of examined sample. This analytical method enables rapid, noncontact and non-destructive analysis that can be performed through the glass. The method for quantitative determination of methanol in alcoholic beverages has been developed on the basis of diverse Raman spectra for methanol and ethanol, their mathematical processing and using PLS regression method for the calibration and prediction model of methanol. Development of this new method is related to the massive methanol poisonings which occurred in the Czech Republic in September 2012. A large amount of harmful toxic alcoholic drinks containing methanol in quantities many times over legal limit was illegally distributed. This event led up to serious problems with poisoned people and the losses in lives. However, it can be assumed the problems may occur in the future since about a third of the defective alcohol has not been traced. The detection limit of the method lies below the permitted and safe amount of methanol in the beverages regulated by the European Parliament and the Council.