Alternative GC-MS approaches in the analysis of substituted pyrazines and other volatile aromatic compounds formed during Maillard reaction in potato chips

Several methods have been developed for the analysis of substituted pyrazines and related substances in potato chips. Following separation/detection approaches (all employing head-space solid phase microextraction, HS-SPME, for volatiles sampling), have been critically assessed in our study: (i) gas chromatography-ion trap mass spectrometry (GC-ITMS), (ii) gas chromatography-time-of-flight mass spectrometry (GC-TOFMS); (iii) comprehensive two-dimensional gas chromatography-time-of-flight mass spectrometry (GC x GC-TOFMS). Although in none of the tested systems full chromatographic resolution of some isomeric pairs could be achieved, the use of GC x GC-TOFMS offered the best solution, mainly because of distinctly lower limits of quantification (LOQs) for all of 13 target alkylpyrazines. In addition to good performance characteristics, a non-target screening and tentative identification of altogether 46 N-containing heterocyclic compounds (pyrazines, pyrrols, pyridines, pyrrolidinones, and tetrahydropyridines) was also enabled.