Quantitative solid phase microextraction – Gas chromatography mass spectrometry analysis of five megastigmatrienone isomers in aged wine

Abstract

Megastigmatrienone is a key flavor compound in tobacco. It has also been detected in wine, where it may contribute to a tobacco/incense aroma, but its importance and concentration in wines had never previously been evaluated.A method was developed and validated for quantifying the five megastigmatrienone isomers in red and white wines.Megastigmatrienone isomers were extracted by headspace solid-phase microextraction (HS-SPME), with a 65μm film thickness polydimethylsiloxane–divinylbenzene (PDMS–DVB) fiber and analyzed using gas chromatography–mass spectrometry (GC/MS) in selected ion monitoring mode (SIM). Several parameters affecting the length of the adsorption process (i.e., adding salt, extraction time and extraction temperature) were tested. The optimum analytical conditions were established.The LOQ were between 0.06μgL−1 and 0.49μgL−1 for white wine and 0.11μgL−1 and 0.98μgL−1 for red wine, repeatability in both types of wine was less than 10% and recovery ranged from 96% for white wine to 94% for red wine. The five isomers of megastigmatrienone were quantified in red and white wines for the first time. Concentrations ranged from 2μgL−1 to 41μgL−1 in both red and white wines. Initial results revealed a link between wine aging and megastigmatrienone levels, indicating that megastigmatrienone may be a component in wine “bouquet”.