Abstract
Mass spectrometry is often insufficient to distinguish between structural isomers, requiring confirmation using NMR spectroscopy. Here, a novel preparative technique based upon capillary multidimensional gas chromatography to isolate pure volatile components from complex samples is described. The method was developed through isolation of 1,4-dimethoxybenzene (5.2 mu g. 10 injections) from a peppermint essential oil. Then isomers of 1- and 2-methylnaphthalene were isolated from a complex crude oil in sufficient amounts (3.1 mu g, 38 injections and 5.0 mu g, 35 injections) for discrimination using H-1 NMR spectroscopy. This methodology is applicable to identify any volatile molecule in complex matrices requiring confirmation using NMR spectroscopy. (C) 2008 Elsevier B.V. All rights reserved.