Optimization, evaluation, and use of advanced gas chromatography-mass spectrometry methods within the context of food analysis

The aim of the general research, described in this Ph.D. thesis, is the optimization, evaluation, and use of advanced gas chromatography-mass spectrometry methods within the context of food analysis. In such a respect, comprehensive two-dimensional gas chromatography coupled to various forms of mass spectrometry (GC×GC-MS) is one of the most powerful analytical tools available for the separation of complex food samples. Focus was herein dedicated to various optimization aspects of GC×GC-MS. Specifically, I was involved in a study focused on the off-line combination of normal phase high-performance liquid chromatography and GC×GC coupled with quadrupole mass spectrometry detection (QMS), for the detailed qualitative profiling of the entire volatile fraction of essential oils. A further study was related to the optimization aspects within the context of different modulator devices, namely cryogenic (CM) and flow (FM) modulators. In such a respect, the goal of the work was to generate similar chromatography profiles (related to a food-waste product, namely coconut bio-oil) using finely-tuned CM- and FM-GC×GC-MS experimental conditions, with emphasis directed to the challenge of defining an equivalent column set. Later, attention was devoted to various aspects of mass spectrometry, with emphasis directed to the use of “milder” electron ionization conditions in the GC×GC-QMS analysis of a variety of different molecular-mass compounds with various polarities contained in food products. In addition, I was involved in a study in the field of fast GC×GC-QMS, developing a method based on the use of micro-bore columns in both dimensions for the analysis of fragrance allergens. I also dedicated my activity on research focused on the evaluation of a novel form of consumable-free thermal modulation, namely solid-state modulation (SSM). Finally, I was involved in research focused on the analysis of pollutants released from food cooking emissions. The research work was carried out within the context of an internship at Helmholtz Zentrum Muenchen (Germany).