Abstract
Essential oils extracted from plants are used in cosmetics, in many foods, and for their fragrance, flavoring, and preservative properties. The bulk is employed for the fragrance or flavor industries with only a small percentage for therapeutic purposes. Unscrupulous manufacturers of essential oils may resort to adulterating the oils with the intent to make the price competitive and to maximize the profit. Extraordinarily cheap essential oils and labels such as “for external use only,” “not for internal use,” and “dilute prior to topical application” should alert one to the possibility of adulteration. The methods available for authentication and adulterant detection include gas chromatography–mass spectrometry (GC–MS), determination of enantiomeric composition, supercritical fluid extraction GC–MS involving use of multidimensional GC to resolve enantiomers, enantioselective capillary gas chromatography, and online methods of isotope ratio mass spectrometry, enantioselective capillary gas chromatography, and isotope ratio mass spectrometry coupled online with capillary gas chromatography, near infrared spectroscopy, simple sequence repeat, random amplified polymorphic DNA method, and various other methods.