use of sorbent-based vacuum extraction for determination of volatile phenols in beer

A novel method based on vacuum-assisted sorbent extraction (vase) used with gas chromatography-mass spectrometry (gc-ms) for isolation of volatile phenols was described. the method is based on extraction of analytes into sorbent traps (sorbent pen) filled with tenax in a vacuum system—vials with traps from which air was evaluated. the method was applied for extraction of volatile phenols from aqueous matrix and smoked beer was used as a food example. methyl-, dimethyl-, and trimethylphenols, along with 4-ethylphenol, 4-methylguaiacol, 4-ethylguaiacol, 4-propylguaiacol, and eugenol, were used in method development. optimal extraction parameters were elaborated. for the analysis of volatile phenols in beer matrix, the method was characterized with satisfactory linearity (r2 ≥ 0.99) in a range of 0.005–0.5 mg/l. limits of detection (lods) for analyzed compounds ranged from 0.0006 to 0.018 mg/l and repeatability for majority of compounds was < 5% for a single trap extraction. the detected volatile phenols in beer samples ranged from 0.003 to 0.672 mg/l.