Another common adulteration is blending with less expensive, lower quality oils. Cinnamon bark, for example, is often mixed with cassia. Cassia is much cheaper, while sharing a similar composition to cinnamon (though inferior therapeutically), which tempts some to mix the cheap cassia oil with the expensive cinnamon bark to maximize profits. Testing with GC/MS and careful analysis will detect the blending of essential oils.
GC/MS along with proper analysis can pick up this type of adulteration due to the presence of constituents that don’t belong. For example, bergamottin and 5-geranyloxy-7-methoxycoumarin, which belong to the furocoumarin family, are not supposed to be present in orange oil. Bergamottin and 5-geranyloxy-7-methoxycoumarin are found in both lemon and lime essential oils and their presence in orange oil suggests interspecies adulteration(1).
As we covered in Part 1, Gas Chromatography (GC) is the process of distributing an essential oil’s volatile compounds into its individual constituents, then producing a graph showing the oil’s components. Mass spectrometry (MS) classifies each constituent along with its percentage of the entire oil’s chemical makeup. This process identifies any potential adulteration and contaminants, and in this case, identifying the oil’s complete chemical makeup -along with expert, unbiased analysis- is the key. In-house testing, while impressive sounding, can also be biased, especially when there is so much profit to be made from adulteration. The consumer’s best option is to look for companies who use reputable 3rd party testing and analysts, and who readily offer those findings to customers.
1). Hao Fan, Qingli Wu, James E. Simon, Shyi-Neng Lou, Chi-Tang Ho (2015) Authenticity analysis of citrus essential oils by HPLC-UV-MS on oxygenated heterocyclic components. Journal of Food and Drug Analysis Volume 23, Issue 1, Pages 30–39. DOI: http://dx.doi.org/10.1016/j.jfda.2014.05.008 Retrieved from http://www.jfda-online.com/article/S1021-9498(14)00149-5/fulltext