High concentration capacity sample preparation techniques to improve the informative potential of two-dimensional comprehensive gas chromatography–mass spectrometry: Application to sensomics

• High concentration capacity sample preparation for GC × GC–MS food profiling.
• High-throughput profiling and fingerprinting for sensomics.
• Sorption based sample preparation for successful definition of milk aroma blueprint.
• Fully-integrated system of multiple dimension analysis for sensomics.

This study reports and critically discusses the results of a systematic investigation on the effectiveness of different and complementary sampling approaches, based on either sorption and adsorption, treated as a further dimension of a two-dimensional comprehensive gas chromatography–mass spectrometry analytical platform for sensomics. The focus is on the potentials of a group of high concentration capacity (HCC) sample preparation (Solid Phase Microextraction, SPME, Stir Bar Sorptive Extraction, SBSE and Headspace Sorptive Extraction, HSSE) and Dynamic Headspace (D-HS) techniques investigated to provide information useful for fingerprinting and profiling studies of food aroma. Volatiles and semi-volatiles contributing to define whole and nonfat dry milk aroma have been successfully characterized thanks to the combination of effective and selective sampling by HCC and D-HS techniques, high separation and detection power of GC × GC–MS and suitable data elaboration (i.e., Comprehensive Template Matching Fingerprinting – CTMF). Out of the sample preparation techniques investigated, HSSE and SBSE have shown to be really effective for sensomics studies because of their high concentration factors, providing highly representative profiles as well as analyte recovery suitable for GC-Olfactometry even with high odor threshold (OT) markers or potent odorants in sub-trace amounts.