Physiochemical Testing of Essential Oils- Part 1- Specific Gravity Test

When determining the quality and the physical properties of the essential oils several tests can be conducted. Once the results are obtained they are compared to different standards published by a variety of bodies such as IFRA, The International Fragrance Association or ISO, The International Organization for Standardization, and AFNOR, Association Francaise de Normalisation. AFNOR or ISO certification is one of the most reliable indicators of essential oil quality. Young Living is one of the few essential oil producers in North America that has made sure their oils meet AFNOR standards. Each batch coming into Young Living is tested by highly trained chemists at Independent European laboratories which utilize AFNOR standards. 



The testing

 Physical measures such as Specific Gravity and Optical Rotation can be carried out but it is not possible to absolutely detect fraud. Therefore, it might be needed to perform chemical analyses. Gas chromatography and mass spectrometer are two chemical methods, but they are linked to each other so I will treat them as one method.


Specific gravity is important in determining the quality and purity of an essential oil. There is more information available for Specific Gravity tests than any other test. Most of the essential oils have an specific gravity between 0.696 to 1.88 at 15 degrees Celsius. Specific Gravity may be explained as the ratio of the weight of a specific volume to the weight of an equal volume of water at a specific temperature. The specific gravity of water is 1. It is the norm to report the specific gravity for an essential oil at 15°C/15°C. It is important to have a standard temperature since warmer oils have lower specific gravity. When the essential oil has a lower specific gravity than water it will sink, and naturally when the specific gravity of the oil is higher it will float on water. The Specific Gravity test takes a lot of time, but it is possible to detect adulteration not noticed in an odor evaluation.


In the next post about testing I will share information about Gas Chromatography, GC, and Mass Spectrometer tests.

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Johanna is an aromatherapist and she is passionate about educating people about health, essential oils, real food, natural remedies, and nutrition so they make healthier choices in their lives. 
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