Multidimensional gas chromatography platforms for the analysis of flavours and odorants

Multidimensional gas chromatography (MDGC) involving multiple GC separation stages has in recent decades been significantly extended beyond the classical heart-cut (H/C) MDGC method, where a single or few zones of eluate from a first column are sampled into a second column. While this target method is still of use for such examples as enantioselective analysis of a small number of compounds, a method which applies a two-column separation mode in an untargeted or profiling manner has become of substantial interest to general essential oil/flavour/fragrance analysis. This effectively describes a comprehensive two-dimensional GC (GC × GC) technique, in which greater peak capacity, improved component detectability and limits of detection, separation from underlying interferences, and likelihood of measurement of a single compound mass spectrum in GC × GC–mass spectrometry (MS) is now achieved when a well-designed GC × GC method is implemented. This chapter introduces the rationale for developing MDGC methods, and outlines a variety of MDGC approaches incorporating two or more capillary GC columns. Detection with a number of different MS techniques is considered. Olfactometry in conjunction with MDGC is described, and approaches to enantioselective analysis are described. Application to essential oils, flavours and fragrances are presented.