Analytical investigation of geranium oils from Pelargonium graveolenes

Pelargonium graveolens L'Hér (Geraniaceae family), also known as rose-scented geranium, is a highly valued aromatic plant native to South Africa. It is the main specie cultivated specifically for its essential oil. The oils also possess insect repellant, antifungal and antibacterial properties, making it useful in the medicinal and pharmaceutical fields. The goals of the proposed research were: i) to develop a gas chromatography-mass spectroscopy method that could be used to differentiate Pelargonium graveolens chemotypes of plant materials and commercial Geranium oil products; ii) to determine the enantiomeric ratios of Geranium oils using chiral GC/MS; iii) and to detect possible adulteration of commercial Geranium oils. A series of authenticated, fresh Pelargonium graveolens plant materials, commercial Geranium oils, and samples obtained from foreign collaborators were analyzed by GC/MS and chiral GC/MS. Fingerprinting analysis allowed the identification of possible markers for differentiating Pelargonium. graveolens chemotypes. The presence or absence of the relevant sesquiterpene, i.e. 10-epi-γ-eudesmol and 6,9-guaiadiene can be used to distinguish Egyptian and Bourbon/China cultivars.