Isotopic Ratio Mass Spectrometry Study for Differentiation Between Natural and Adulterated Essential Oils of Lemongrass (Cymbopogon flexuosus) and Palmarosa (Cymbopogon martinii)

Abstract

:Adulteration in aromatic oils with natural isolates and identical synthetic compounds is common practice in flavour and fragrance industry. Blending of synthetic materials is done in such a way that the chemical profile by gas chromatography of product (adulterated) oil remains nearly identical to original one. This practice makes complex issue for detection of adulterants in aromatic oil. In the present study, natural and adulterated essential oils of lemongrass (Cymbopogon flexuosus) and palmarosa (Cymbopogon martinii) were differentiated and identified on the basis of their carbon isotope composition (13C/12C) using isotopic-ratio mass spectrometry (IRMS) technique. This technique differentiates the natural oils (lemongrass and palmarosa oils) with adulterated oils by showing decrease in their carbon isotopic composition as blending of synthetic compounds viz. geraniol, citral, polyethylene glycol (PEG), dioctyl phthalate (DOP) and diethyl phthalate (DEP) of these adulterants with increasing order (5 % to 50 %).