Fast analysis of important wine volatile compounds Development and validation of a new method based on gas chromatographic-flame ionisation detectionanalysis of dichloromethane microextracts

A method for the simultaneous determination of major (10-200 mg/l) and mino r (0.1-10 mg/l) volatile compounds from wine has been optimised and validat ed. A 3-ml volume of wine is diluted with water (7 ml), salted with 4.5 g o f ammonium sulfate and extracted with 0.2 ml of dichloromethane. The extrac t is injected in the split mode in a GC system, separated on a Carbowax 20M capillary column and detected by flame ionisation detection. Volatiles fro m wine are divided into four groups according to their behaviour in the ext raction, and a specific internal standard has been selected for each group. The method allows satisfactory determination of more than 30 volatile comp ounds of wine. Compounds analysed include acetaldehyde, diacetyl, acetoine (3-hydroxy butanone), fusel alcohols and their acetates. and fatty acids an d their ethyl esters. The linear dynamic range of the method covers the nor mal range of occurrence of analytes in wine and extends from at least one m agnitude order to more than two, with typical r(2) between 0.9938 and 0.999 8. Reproducibility ranges from 3.1 to 10% (as RSD) with 5.5% as the average . The analysis of spiked samples has shown that matrix effects do not signi ficantly affect method performance. (C) 2001 Elsevier Science B.V. All righ ts reserved.