Ethyl Glucuronide in Alcoholic Beverages.

Aims: This study examines the biomarker ethyl glucuronide (EtG) in various alcoholic beverages.

Short summary: The biomarker EtG was consistently found to be a natural compound of wine, whereas it was not detected in any of the other tested alcoholic beverages, which included various distilled spirits, liqueurs and beer of different types and geographical origins.

Methods: Alcoholic beverages (n = 114) were analyzed by a validated liquid chromatography/tandem mass spectrometry assay. Beverages included samples from beer, wine, liqueurs and spirits from different manufacturers and geographical origins.

Results: EtG was not detected in any kind of distilled alcoholic beverages, regardless of the type of spirit (rum, gin, vodka, whiskey, fruit brandy, corn brandy, cordial) or liqueur (n = 52). EtG was also not detected in any of the analyzed samples of beer, which included pilsener, weissbier, lager beer and ale from different origins (n = 20). In contrast, EtG was detected in every of the analyzed samples of wine (n = 42) without exception. Highest amounts were found in red wine and ranged from 1425 to 3720 μg/l (n = 16). Significantly, lower concentrations of EtG were observed for white wine (347-1685 μg/l, n = 14) and sparkling wine (281-1447 μg/l, n = 10).

Conclusions: Wine is an external source of EtG. It has been shown that milligram amounts of the biomarker can be contained in a bottle of wine. This should be considered in biomarker testing, especially in EtG hair analysis, which is susceptible to external contamination.