title: Analysis of volatile phenols in alcoholic beverage by ethylene glycol-polydimethylsiloxane based stir bar sorptive extraction and gas chromatography-mass spectrometry.
abstract: 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 (1M, 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 R(2) in the range of 0.994-0.999 were obtained for volatile phenol concentration of 5-500μg/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 3μg/L. The method was further applied to analyze the concentrations of volatile phenols in beer, wine and other alcoholic beverage samples.
authors.affiliation: Oregon State University, Department of Food Science and Technology, 100 Wiegand Hall, Corvallis, OR 97331, United States.
authors.forename: Qin
authors.initials: Q
authors.lastname: Zhou
authors.affiliation: Oregon State University, Department of Food Science and Technology, 100 Wiegand Hall, Corvallis, OR 97331, United States.
authors.forename: Yanping
authors.initials: Y
authors.lastname: Qian
authors.affiliation: Oregon State University, Department of Food Science and Technology, 100 Wiegand Hall, Corvallis, OR 97331, United States. Electronic address: michael.qian@oregonstate.edu.
authors.forename: Michael C
authors.initials: MC
authors.lastname: Qian
mesh_terms: D000434:Alcoholic Beverages / Q000032:analysis*; D001515:Beer / Q000032:analysis; D004129:Dimethylpolysiloxanes / Q000737:chemistry*; D000431:Ethanol / Q000032:analysis; D019855:Ethylene Glycol / Q000737:chemistry*; D008401:Gas Chromatography-Mass Spectrometry; D006139:Guaiacol / Q000031:analogs & derivatives / Q000032:analysis; D006863:Hydrogen-Ion Concentration; D009994:Osmolar Concentration; D010636:Phenols / Q000032:analysis*; D014920:Wine / Q000032:analysis
chemical_list: D004129:Dimethylpolysiloxanes; D010636:Phenols; D000431:Ethanol; D006139:Guaiacol; C014245:4-vinylguaiacol; C042291:4-ethylphenol; C084991:4-ethylguaiacol; D019855:Ethylene Glycol; C030626:4-vinylphenol
keywords: Beer; EG/PDMS phase; SBSE-GC–MS; Volatile phenols; Wine