150 g of
fresh plant material was heated using a fixed power of 150 W without adding any solvent or
water. Essential oil and aromatic water was simply separated by decantation. The essential oil
was collected, dried under anhydrous sodium sulphate and stored at 4°C until subsequent analysis.
2.3 Hydro-distillation apparatus and procedure
One kilogram of fresh rosemary was submitted to hydrodistillation using Clevenger