Department of Chemistry, University of La Rioja, C/Madre de Dios 51, 26006 Logroño, La Rioja, Spain.
J Chromatogr A. 2010 Sep 24;1217(39):6013-21. doi: 10.1016/j.chroma.2010.07.021. Epub 2010 Jul 16.
A simple, accurate and sensitive method based on headspace solid-phase microextraction (HS-SPME) coupled to gas chromatography-tandem mass spectrometry (GC-MS/MS) was developed for the analysis of 4-ethylguaiacol, 4-ethylphenol, 4-vinylguaiacol and 4-vinylphenol in beer. The effect of the presence of CO2 in the sample on the extraction of analytes was examined. The influence on extraction efficiency of different fibre coatings, of salt addition and stirring was also evaluated. Divinylbenzene/carboxen/polydimethylsiloxane was selected as extraction fibre and was used to evaluate the influence of exposure time, extraction temperature and sample volume/total volume ratio (Vs/Vt) by means of a central composite design (CCD). The optimal conditions identified were 80 degrees C for extraction temperature, 55 min for extraction time and 6 mL of beer (Vs/Vt 0.30). Under optimal conditions, the proposed method showed satisfactory linearity (correlation coefficients between 0.993 and 0.999), precision (between 6.3% and 9.7%) and detection limits (lower than those previously reported for volatile phenols in beers). The method was applied successfully to the analysis of beer samples. To our knowledge, this is the first time that a HS-SPME based method has been developed to determine simultaneously these four volatile phenols in beers.
建立了一种基于顶空固相微萃取（HS-SPME）结合气相色谱-串联质谱（GC-MS/MS）的简单、准确、灵敏的方法，用于分析啤酒中的 4-乙基愈创木酚、4-乙基苯酚、4-乙烯基愈创木酚和 4-乙烯基苯酚。考察了样品中 CO2 对分析物萃取的影响。还评估了不同纤维涂层、加盐和搅拌对萃取效率的影响。选用二乙烯基苯/羧基/聚二甲基硅氧烷作为萃取纤维，通过中心组合设计（CCD）评估了暴露时间、萃取温度和样品体积/总体积比（Vs/Vt）的影响。确定的最佳条件为萃取温度 80°C，萃取时间 55 min，啤酒 6 mL（Vs/Vt 0.30）。在最佳条件下，该方法表现出令人满意的线性（相关系数在 0.993 到 0.999 之间）、精密度（6.3%到 9.7%之间）和检测限（低于先前报道的啤酒中挥发性酚的检测限）。该方法成功应用于啤酒样品的分析。据我们所知，这是首次建立基于 HS-SPME 的方法同时测定啤酒中的这四种挥发性酚。
