Analysis of volatile phenols in alcoholic beverage by ethylene glycol-polydimethylsiloxane based stir bar sorptive extraction and gas chromatography–mass spectrometry

• An EG/PDMS-GC–MS method was developed to analyze volatile phenols in alcoholic beverages.
• Extraction parameters were optimized in alcoholic samples.
• The method was validated.
• The application of the method was demonstrated in wine, beer and hard apple cider.

An ethylene glycol (EG)/polydimethylsiloxane (PDMS) copolymer based stir bar sorptive extraction (SBSE)-GC–MS method was developed for the analysis of volatile phenols (4-ethylphenol, 4-vinylphenol, 4-ethylguaiacol, and 4-vinylguaiacol) in alcoholic beverages. The beverage samples were diluted with phosphate buffer (1 M, pH 7) and extracted with an EG/PDMS stir bar. Volatile phenols were thermally desorbed and analyzed by GC–MS. Parameters affecting extraction efficiency were studied including ionic strength, pH, extraction time, ethanol content and nonvolatile matrix. Good correlation coefficients with R2 in the range of 0.994–0.999 were obtained for volatile phenol concentration of 5–500 μg/L. Recovery for all phenols were from 95.7% to 104.4% in a beer matrix and 81.4% to 97.6% in a wine matrix. The method had a standard deviation less than 5.8% for all volatile phenols. The limit of quantification (LOQs) in beer samples was lower than 3 μg/L. The method was further applied to analyze the concentrations of volatile phenols in beer, wine and other alcoholic beverage samples.