In this article, the sensitivity of two-dimensional gas chromatography coupled to two different detectors - a time-offl ight mass spectrometer (GCXGC–TOF-MS) and a fl ame ionization detector (GC?GC–FID) - was compared to the sensitivity of conventional one-dimensional gas chromatography (GC–TOF-MS and GC–FID) by determining method detection limits (MDLs) for a series of different compounds with different polarities.