Testing for Quality
The purity of an essential oil is its most important characteristic. We learned in the previous issues, that proper methods of growing, harvesting, and distilling are crucial to maintaining purity. Poor production practices and the development of synthetic essential oil variations suggest that it is impossible to accurately identify a pure essential oil without scientific analysis. Appropriate analysis of the constituents within an essential oil is one of the most challenging and detailed aspects of quality assurance.
Historically, Gas Chromatography was sufficient to identify individual components in an essential oil. However, as more sophisticated methods for developing synthetic essential oil products formed, further validation methods were needed. Over time, additional testing methods such as Mass Spectroscopy, Chiral Analysis, FTIR Scan, Carbon Isotope Analysis and others have been developed to more accurately identify each individual essential oil constituent.
VALIDATION OF QUALITY
doTERRA employs its testing methods for validation of quality at multiple production points. Directly after plant selection, harvesting, and distillation, each essential oil is reviewed for chemical composition. A second testing sequence is initiated when the oil is received at our production facility to ensure that what was distilled and tested is the same essential oil received. A third review of the chemistry is conducted in a three-phase procedure during the actual filling process. Each of these testing steps confirms that the essential oil has remained free of contaminants and unexpected alterations during production.
Organoleptic testing involves the use of the human senses— sight, smell, taste, and touch. To expert distillers, the senses are used as the first line of quality testing to provide immediate clues to the acceptability of a product. Oil that has an unusual smell, uneven consistency, or strange color instantly tells the distiller that something is wrong. Often times, this testing is used as a preliminary quality control step before any other tests are conducted.
Microbial testing involves analyzing a batch of essential oils for the presence of bio-hazardous microorganisms such as fungi, bacteria, viruses, and mold. The process involves drawing a sample and then adding that sample to a sterile growth medium in an enclosed dish or plate. The sample is incubated for a period of time and then observed for microbial growth. This test is performed on product entering the manufacturing facility and on finished products prior to distribution to ensure that the product has not been contaminated during the filling process.
Matter is made up of tiny chemical building blocks called elements. Although dozens of elements exist, each one is distinct due to the protons it contains. Sometimes, an element can exist in more than one stable form if it has more or less neutrons. When this occurs, the elements are called isotopes. The element carbon exists in two stable isotopes, carbon-12 (6 protons and 6 neutrons) and carbon-13 (6 protons and 7 neutrons). Because essential oils are organic compounds, they are composed primarily of carbon atoms and will have a certain ratio of carbon-12 to carbon-13 isotopes. This ratio varies based on location around the world.
Using a special type of Mass Spectroscopy, it is possible to determine which isotopes are present in an essential oil constituent and at what amounts. If sourced from the same location, every constituent in an essential oil should have the same ratio of isotopes. If a particular constituent has an isotopic profile different than that of the other constituents, then the quality control analyst will know that the oil contains an adulteration
Heavy Metal Testing
Heavy Metal testing shows the amount of heavy metal content in the essential oil. When properly distilled, essential oils should not contain heavy metals. ICP-MS testing uses a highenergy medium called Inductively Coupled Plasma (ICP) to ionize the sample. The sample is then run through a mass spectroscope, which separates the sample into its elemental parts and provides a reading about which elements are present and at what quantities.