Comparative study on volatile analysis of extra virgin olive oil by dynamic headspace and solid phase micro-extraction

The dynamic headspace thermal desorption (DHS-TD) apparatus using Tenax-TA and Carbotrap-300 traps, connected to a gas chromatography (GC)-ion trap-mass spectrometry (MS) equipment, as well as the solid phase micro-extraction (SPME) tool, with polydimethylsiloxane (PDMS) and polydimethylsiloxane-divinylbenzene (PDMS-DVB) fibers and connected to a GC-time of flight-MS equipment were implemented for the isolation and identification of virgin olive oil volatile compounds under various sampling conditions. Applying the DHS-TD Tenax-TA procedure separated a higher number of compounds compared to the SPME-PDMS-DVB, which on the other hand required shorter total times for the analysis. High ratio of gas flow rate/amount of oil gave better results for DHS-TD, while a high ratio of headspace/amount of oil worked better for SPME. PDMS exhibited a low sensitivity to olive oil polar volatile compounds while PDMS-DVB showed the overall best sensitivity for all classes of volatile compounds. Results indicate that SPME may find a wide application as an analytical technique for quick analysis of quality related volatile compounds of olive oil. The analyses performed on the GC-TOF-MS-system demonstrated high sensitivity and also high selectivity due to the high quality of mass spectra obtained. The SPME-GC/TOFMS technique appears to be faster and simpler than DHS-TD/GC/MS but the latter provides higher efficiency. (C) 2004 Elsevier Ltd. All rights reserved.