A comparative study on the effect of vacuum on HS-SPME of olive oil volatiles

Solid-phase microextraction (SPME) is a simple, effective and selective technique for the analysis of volatiles and semi-volatiles compounds. However, frequently a long time is requested to reach the equilibrium condition to maximize the extraction efficiency, thus pre-equilibrium conditions are preferred as a compromise in term of throughput and sensitivity. Beside other strategy to improve the kinetic extraction, vacuum has been recently successfully proposed with the main advantages to speed up the extraction without increasing the temperature and thus preserving the sample profile.
In this work Vacuum-SPME has been investigated for the first time for the analysis of a fat matrix, namely olive oil, for the determination of its aroma profile. Gas chromatography coupled to a single quadrupole mass spectrometry was used for the final determination. A three variables (k= 3; temperature, extraction time and sample mass) inscribed rotatable central composite experimental design was used to optimize the sampling conditions. A series of compounds, covering the entire range of volatility and a wide chemical structure, were selected to compare atmospheric and under vacuum conditions.