Headspace solid-phase microextraction for direct determination of volatile phenols in cider

Department of Chemistry, University of La Rioja, Logroño, La Rioja, Spain.
Journal of Separation Science (Impact Factor: 2.74). 11/2009; 32(21):3746-54. DOI: 10.1002/jssc.200900347
Source: PubMed


A headspace solid-phase microextraction coupled to gas chromatography-tandem mass spectrometry (GC-MS/MS) method was optimised and validated for the determination of 4-ethylguaiacol, 4-ethylphenol, 4-vinylguaiacol and 4-vinylphenol, involved in the presence of Brett character, in ciders. The influence of different parameters on extraction efficiency (fibre coating, salt addition, exposure time, extraction temperature and sample volume/total volume ratio) was evaluated. Divinylbenzene/carboxen/PDMS was selected as extraction fibre and the other optimised parameters were as follows: 10 mL of cider, temperature 70 degrees C, extraction time 60 min and addition of 0.4 g/mL of NaCl. The proposed method showed satisfactory linearity. The detection limits obtained were 0.01 microg/L for 4-ethylguaiacol, 0.02 microg/L for 4-ethylphenol, 0.08 microg/L for 4-vinylguaiacol and 0.03 microg/L for 4-vinylphenol. These detection limits were lower than those obtained in previous studies on the determination of volatile phenols in other alcoholic beverages. Good recoveries of over 95% were observed for all compounds, and the repeatability obtained was considered acceptable, ranging between 4 and 10%. To demonstrate the feasibility of the procedure, the method was applied to the analysis of commercial ciders. To our knowledge, this is the first time that the headspace solid-phase microextraction procedure has been optimised to determine specifically the Brett character responsible compounds in cider.

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    • "Unlike Brettanomyces/Dekkera sp., other wine associated yeasts such as S. cerevisiae, Pichia sp., Torulaspora sp., and Zygosaccharomyces sp. can produce vinylphenols but not ethylphenols under normal oenological conditions [15]. Analysis of volatile phenols in alcoholic beverages is an active research area [16] [17] [18] [19] [20] [21] [22] [23]. High performance liquid chromatography (HPLC) is a frequently used analytical technique [18] [19] [22] [24]. "
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