2.2 Classical extraction techniques
The essential oil was obtained by a Clevenger type hydrodistiller made at the Faculty of Sciences, Zaragoza, Spain. Hydrodistillation was performed for 4 h using 30 g of plant material.
Organic solvent extraction was performed with 0.18 L hexane (99.0% Panreac) in a Soxhlet apparatus with an extraction vessel of 0.15 L during four hours. 10 g of plant material were put into a cellulose cartridge. To obtain the concrete, hexane was evaporated with a rotary evaporator (Buchi model R-210).
The extraction conditions (temperature, time and ratio mass of plant material/mass of solvent) used in both techniques were optimized to approach the highest overall yield of extraction.