Low-Temperature Partitioning: A Simple Screening Method for Determining Diethylene Glycol in Beer by Gas Chromatography

Abstract

Diethylene glycol is an extremely toxic substance to humans. Recently, cases of beer contamination in Brazil have raised awareness of the need for developing simple screening methods to evaluate this type of compound. This research developed a liquid-liquid extraction with low-temperature partitioning technique to determine diethylene glycol in beer via gas chromatography. Employing a flame-ionization detector simplifies the method, lowers its cost and therefore, it can be used as screening step to assess the possibility of contamination. A gas chromatograph coupled to a mass spectrometer would be used only for a confirmatory analysis. The optimized method was validated for the main figures of merit, and it proved to be adequate, with good values of recovery rate (94-106%), limit of detection (3.0 mg L-1), and quantification (10.0 mg L-1). Accuracy, in terms of repeatability and intermediate accuracy, showed variation coefficients lower than or equal to 20%. This method was applied to 28 samples of beers marketed in Brazil, and diethylene glycol was found above the limit of detection in three of them (10.7%). These results were confirmed by a gas chromatograph coupled to a mass spectrometer, which showed the reliability of the screening method for determining diethylene glycol in beer samples.

Ocorrência e toxicidade de glicois em cervejas

“…Segundo os autores, os glicois foram detectados em oito por cento das amostras analisadas, com teores variando de 15 a até acima de 5000 mg/L. Azevedo et al (2023) dosaram o teor de DEG em 28 amostras de cervejas brasileiras, dentre as quais apontaram apenas três amostras contaminadas. Em ambos os trabalhos, as amostras contaminadas foram identificadas como provenientes do acidente de contaminação ocorrido em 2020.…”