Comprehensive two-dimensional gas chromatography with time-of-flight mass spectrometric detection applied to the determination of pesticides in food extracts

The separation provided by conventional gas chromatography (1D-GC) can be significantly enhanced by using comprehensive two-dimensional GC (GC×GC) instead. Combination with mass spectrometric detection is desirable for unambiguous confirmation of target compounds and the provisional identification of unknowns. A GC×GC system using a cryogenic modulator was coupled to a time-of-flight mass spectrometric (TOF MS) detector. With the determination of pesticides in vegetable extracts as an example, it was demonstrated that GC×GC improves the separation dramatically. All 58 pesticides of interest could be identified using their full-scan mass spectra, which was not possible when using 1D-GC–TOF MS. In addition, the high scan speed of the TOF MS allowed the deconvolution of compounds partly co-eluting in GC×GC.