Unravelling the composition of very complex samples by comprehensive gas chromatography coupled to time-of-flight mass spectrometry: Cigarette smoke

The potential and current limitations of comprehensive two-dimensional gas chromatography coupled to time-of-flight mass spectrometry (GC×GC–TOF-MS) for the analysis of very complex samples were studied with the separation of cigarette smoke as an example. Because of the large number of peaks in such a GC×GC chromatogram it was not possible to perform manual data processing. Instead, the GC–TOF-MS software was used to perform peak finding, deconvolution and library search in an automated fashion; this resulted in a peak table containing some 30 000 peaks. Mass spectral match factors were used to evaluate the library search results. The additional use of retention indices and information from second-dimension retention times can substantially improve the identification. The combined separation power of the GC×GC–TOF-MS system and the deconvolution algorithm provide a system with a most impressive separation power.