Vacuum-assisted headspace SPME under sub-ambient temperature for the analysis of fish samples

Vacuum-assisted headspace solid-phase microextraction (Vac-HS-SPME) has been proposed as a valid technique to increase the performance of conventional HS-SPME in particular in terms of kinetics for the semi-volatiles compounds. Although the total amount extracted at the equilibrium does not change when reduced pressure conditions are applied, the overall result from an applicative viewpoint is an increase of extraction yield at shorter extraction time and milder extraction temperature compared to conventional applications, thanks to the improved kinetics. This is particularly beneficial for analysis of food volatiles for a more comprehensive evaluation of the aroma profile and when heating the sample can easily cause artefact formation. The advantages of using Vac-HS-SPME in food samples have been explored at sub-ambient temperature (i.e., refrigerated temperature) for the analysis of particularly perishable foods, such as raw fish. The use of reduced pressure conditions allowed to efficiently sampling at refrigerated temperature, obtaining results comparable to regular HS-SPME at room temperature.