Determination of the chemical composition of alcoholic beverages by gas chromatography‐mass spectrometry

Abstract

A gas chromatography-mass spectrometry method was developed to determine the chemical composition of alcoholic beverages. Extraction was performed with 280 μl of butyl acetate added to 1.7 ml of the sample and placed into 2 ml gas chromatograph auto-injector vial. One microliter from the upper organic layer was analyzed. Natural constituents (i.e., phenylethyl alcohol, 4-hydroxybenzoate) found in beers and wines were profiled. Age markers for wines aged in contact with oak wood were studied. Artificial flavors and preservatives were identified in low quality and fruit wines (i.e., methyl anthranilate, triacetin). Esters of phthalic acids and squalene were identified as main polluters. Beers were contaminated to a lesser extent, while wines contained slightly higher concentrations, and distillated had higher concentrations of contaminants. The concentration of contaminants was related to the degree of alcohol and the quality of the beverages. No contamination was found in alcoholic beverages stored in polyethylene terephthalate containers. Practical applications The present study corresponds to a broad characterization of alcoholic beverages based on an optimized gas chromatography-mass spectrometry micro-extraction method to identify natural volatile and semi-volatile constituents as well as other substances such as artificial flavors, preservatives, and contaminants. The study has the potential to inform at the level of food safety, alcohol authenticity, and food toxicology.