Chromatographic fingerprint by combining headspace, SPME, and GC×GC (Steven Mascrez, MDCW 2023)

🎤 Presenter: Steven Mascrez, Giorgia Purcaro (University of Liège, Gembloux, Belgium)

Abstract

HS-SPME is an easy, solvent-free and selective technique for the analysis of semi- and volatile compounds. For the latter, long equilibration times are needed, which are typically shortened for routine applications. Therefore, a compromise between sensitivity and extraction time is necessary.

Two approaches have been recently proposed to improve extraction kinetics and thus the overall extraction yield: vacuum-assisted HS-SPME (Vac-SPME) and multi-cumulative trapping SPME (MC-SPME). Vac-HS-SPME showed a similar or an increment of extraction yield using a shorter time and milder temperature compared to conventional HS-SPME conditions [1]. Also MC-SPME has the potential to improve the overall sensitivity by using a cumulative shorter extraction time compared to a single long one [2]. In both cases, the extraction of semi-volatile has been significantly improved compared to the traditional approach allowing for a more comprehensive definition of the aroma profile.

In this work, we present the bursting combination of the two approaches, namely Vac-SPME and MC-SPME into Vac-MC-SPME, along with the enhanced separation capability provided by multidimensional comprehensive gas chromatography (GC×GC) and an advanced tile-based data handling. The synergic effect was shown by comparing the results with each of the two sampling techniques separately using targeted key compounds for the olive oil aroma definition. Moreover, the entire chromatographic fingerprint obtained in GC×GC was used to discriminate the different olive oil quality, comparing the performance of the three approaches, namely Vac-SPME, MC-SPME, and Vac-MC-SPME.