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J Chromatogr A

Title:		Optimisation of a simple and reliable method based on headspace solid-phase microextraction for the determination of volatile phenols in beer
Author(s):		Pizarro C; Perez-del-Notario N; Gonzalez-Saiz JM;
Address:		"Department of Chemistry, University of La Rioja, C/Madre de Dios 51, 26006 Logrono, La Rioja, Spain. consuelo.pizarro@unirioja.es"
Journal Title:		J Chromatogr A
Year:		2010
Volume:		20100716
Issue:		39
Page Number:		6013 - 6021
DOI:		10.1016/j.chroma.2010.07.021
ISSN/ISBN:		1873-3778 (Electronic) 0021-9673 (Linking)
Abstract:		"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"
Keywords:		Beer/*analysis Dimethylpolysiloxanes/chemistry Gas Chromatography-Mass Spectrometry/methods Least-Squares Analysis Phenols/*analysis Polyvinyls/chemistry Reproducibility of Results Sensitivity and Specificity Sodium Chloride/chemistry Solid Phase Microext;
Notes:		"MedlinePizarro, C Perez-del-Notario, N Gonzalez-Saiz, J M eng Research Support, Non-U.S. Gov't Netherlands 2010/08/24 J Chromatogr A. 2010 Sep 24; 1217(39):6013-21. doi: 10.1016/j.chroma.2010.07.021. Epub 2010 Jul 16"