Rosemary essential oil by hydrodistillation: SPME-GC-MS characterization

Rosemary (Salvia rosmarinus) is an aromatic herb with a multitude of uses. It is both a seasoning in various dishes, and a natural remedy for several diseases mainly due to its anti-inflammatory and anti-oxidative effects. Plus, it is also used in cosmetic industry and for improving agriculture practices and helping the environment, since it may be a natural antimicrobial. It is worth noting that this plant is also grown and commercialized in Uzbekistan, thus, if added value is given to rosemary’s products, it has potential for improving living conditions and helping in the economy of local farmers and entrepreneurs. In this work, we discuss a technique for obtaining rosemary essential oil, rich in terpenes, by vacuum assisted hydrodistillation. This is a solventless environmentally friendly and safe technique that allows the obtention of an added value rosemary product where terpenes, compounds responsible for most of rosemary’s properties, are the most abundant. Two samples of locally acquired rosemary were sourced, essential oil was extracted, and characterization was then performed by Solid Phase Micro Extraction (SPME) and Gas Chromatography – Mass Spectrometry (GC-MS). As a comparison, a direct injection of a dilution of one of the essential oil samples was also performed. It was concluded that samples of essential oil obtained from both sources were entirely composed of terpenes or terpene derivatives. Besides, SPME was a superior method when compared to direct injection, since a larger number of volatiles was able to be identified.