Simultaneous Distillation–Extraction of Essential Oils from Rosmarinus officinalis L.

The present study describes a procedure to isolate essential oils from Rosmarinus officinalis L. using simultaneous distillation–extraction (SDE). Rosmarinus officinalis L. can be used for medicinal purposes, as well in the cooking and cosmetics industries. SDE technique extraction combines a steam distillation combined with a continuous extraction using a solvent or a co-solvent mixture, providing faster extractions with low extraction solvent volumes. The effect of the solvent nature and the extraction time on the simultaneous distillation–extraction efficiency was evaluated. The best performance was achieved using pentane as a solvent for 1 h of extraction. The essential oils obtained by simultaneous distillation–extraction extracts were analyzed by gas chromatography with flame ionization detection (GC-FID). Extraction efficiencies ranged from 40 to 70% for the majority of the compounds tested, and the precision (measured by the relative standard deviation) varied between 6 and 35%. Among the compounds analyzed the most abundant in the Rosmarinus officinalis L. sample were 1,8-cineole, (-) –borneol, α-pinene, (S)-(-)- α–terpineol, (-)-bornyl acetate, linalool, and 2,2,6-trimethylcyclohexanone. The SDE method proved to be a suitable option for obtaining extracts free from cuticular waxes or chlorophylls.