Adulteration of Natural Perfume Ingredients

A supplier of ylang-ylang oil once tried to sell drums that contained only a small amount of the oil, the remainder of the drum contents being river water. This attempt at deceit was easily discovered, since QC samples are normally drawn from top, middle and bottom of drums, so one sample would be oil and the other two water. 

Lavender oils are relatively inexpensive essential oils, but their major components are available as even cheaper chemicals and so the possibility to cheat does exist. Like all natural products, the composition 

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Brazil, Paraguay Portugal, Yugoslavia Indonesia N. Korea, India China 

Indonesia, Comoros Islands, Reunion Bulgaria, Egypt, Australia China 

The most important component of the vanilla bean, as far as flavour is concerned, is vanillin. Synthetic vanillin costs only a few pounds per kilogramme but vanillin extracted from vanilla beans can cost 5000 or more per kg. Food labelling laws are very strict and the penalties for declaring a flavour to be natural when it is not, are very high. Not only can companies be fined for false declaration but also their directors are liable to imprisonment in certain countries, in particular, in the United States. It is therefore very important that a company buying vanilla should be able to verify for itself whether or not the goods for sale are of natural origin. 

One simple test is to measure the level of radioactivity from the sample. Synthetic vanillin is not radioactive. However, natural vanilla, like all natural products, is. This is, of course, because atmospheric carbon dioxide contains some radioactive 14C formed by exposure to cosmic radiation in the upper atmosphere. Plants then incorporate this into their photosynthetic pathway and produce metabolites, which exhibit a low level of radioactivity. Synthetic vanillin is prepared from coal tar, which is not radioactive since the 14C has long since decayed. However, unscrupulous dealers know this and can synthesise radiolabelled or hot vanillin and dose it into synthetic material so that the level of radioactivity matches that of a natural sample. Another method of checking for naturalness must therefore be found. When plant enzymes synthesise molecules, they, like all catalysts, are susceptible to isotope effects. The vanilla plant is no exception and examination of the distribution of hydrogen and carbon isotopes in the vanillin molecule reveals that the heavier deuterium and 13C isotopes accumulate at certain specific sites. A suitable NMR spectrometer can determine the isotopic distribution in a sample and the cost of using 2H, 13C and 14C labelled synthetic materials to replicate the NMR spectra and radioactivity of natural vanillin in a synthetic sample would not be financially attractive. Furthermore, the 2H and 13C labelling patterns in the vanilla bean are different from those of other natural shikimate sources and so the NMR technique can also distinguish between vanillin from vanilla and vanillin produced by 

As each opportunity for adulteration is blocked by analysts, the crooks will seek new methods and so the QC analyst must proactively think to keep ahead. 

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