An approach to the static-dynamic subcritical water extraction of laurel essential oil: comparison with conventional techniques

The coupling of a subcritical extractor with a three-way inlet valve and an on/off outlet valve was used for performing static-dynamic subcritical wat er extractions for the isolation of essential oils. The applicability of th e assembly was tested using laurel leaves as a model sample, but can be ext ended to other natural products. The compounds were removed from the aqueou s extract by a single extraction with 5 ml of hexane, individually separate d and detected by gas chromatography-flame ionisation detection and identif ied by electron ionization mass spectrometry. The proposed method was compa red with both conventional (hydrodistillation and dichloromethane manual ex traction) and recent (subcritical dichloromethane extraction) alternatives in terms of rapidity, efficiency, cleanliness, possibility of manipulating the composition of the oil and quality of the oil, revealing the proposed m ethod to be clearly advantageous. This fact, together with the good precisi on for the overall method [(RSD < 15% for n = 6) for each compound], make i t a good alternative to both conventional and recent counterparts.