Synthetic Markers of Linalyl Acetate: The Importance of Ethics, Integrity, and Scientific Method in Essential Oil Analysis
Aromatherapy is a continuously evolving field. Thanks to the more recent popularity of essential oils and other aromatic materials, new discoveries are constantly being made regarding the therapeutic benefits, safety, analysis, and adulteration of said materials.
There are several different reasons to perform an essential oil analysis, one of which is to look for adulteration. Adulteration can come in many different forms that, for the most part, have been discussed in depth by research papers over the years.1 Yet, due to unethical practices surrounding price, and because the demand for some oils is greater than the supply, there are those that are always looking for new ways in which to adulterate them. That leaves chemists who specialize in essential oil analysis, constantly looking for ways to identify these adulterations.
There are only a handful of labs in the world that are qualified to find essential oil adulterations. One of the ways they do so is through the use of gas-chromatography and mass spectrometry (GC/MS). With this they are able to identify many of these adulterations, some of which are revealed because of the presence of certain trace markers. However, they must be able to provide proper evidence, showing without a shadow of a doubt, that these markers are truly the result of adulteration.
This paper shows how one lab did not provide such evidence, and linalool oxide acetate cis and linalool oxide acetate trans (also referred to as (Z) and (E)-linalool oxide acetates), are not proven trace markers for the addition of synthetic linalyl acetate. In their quest to be considered the foremost authority in detecting the adulteration of essential oils, this lab did not follow proper procedure in regards to scientific method. This lab also demonstrates a lack of ethics and integrity that is required of reputable independent labs.
On June 18th, 2019, an article was published by ConsumersAdvocate.org reviewing some brands of essential oils by different criteria including GC/MS testing.2 It was shared on social media by Aromatic Plant Research Center (APRC), the lab who tested the samples of the different oils used in the Consumers Advocate article. In the article it was stated that some of the companies listed had oils which had failed the GC/MS testing performed by APRC.
From the beginning, the article left many unanswered questions about the testing procedure, and the lack of the actual GC/MS reports. After the article was updated to include said reports, it led to more questions as the reports stated that several of the oils had been adulterated, and were found to be so due to them containing certain synthetic markers.3 However, several of those identified are not recognized as synthetic markers in the scientific community.
While there were many different GC/MS reports, and other trace markers mentioned for other adulterants, concentration was placed on the reports for Lavender essential oil that specified, “Synthetic markers of Linalyl acetate were detected.” The focus of this paper was placed there because Lavender adulteration with synthetic linalyl acetate was one that this author already knew a little bit about, and what was being stated was not tracking with what is known within the scientific community.
It also was observed that other chemists were stating that Prabodh Satyal, Ph.D was wrong about linalool oxide acetate cis/trans (Z/E) being trace markers for synthetic linalyl acetate, yet they did not mention what the correct trace marker should have been. Something else noted was that APRC was the only one identifying linalool oxide acetate cis/trans in their reports.
In general, many people were left with unanswered questions, so in an attempt to try and gain more of an understanding of what was going on, this research paper unfolded.
In the beginning stages of research, general searches turned up three videos that included Prabodh Satyal, chemist and co-owner of APRC.4,5,6 Satyal used the Facebook video entitled “Prabodh Satyal, PhD with Aromatic Plant Research Center”, to promote a certain company (that shall be called Company X for the purposes of this paper).6 In this video, he makes false statements regarding his credentials as well as essential oils in general. They are as follows:
- He claimed to have a “Ph.D. in essential oil adulteration” from the University of Alabama in Huntsville, and that he was the only person in the world with one.
- Satyal claimed other companies distill their oils multiple times and that Company X does not. That he believes manipulation of the oil is bad, and that Company X does not do that.
- He stated that Company X is the only one who sells pure oils.
First, there is no such thing as a degree in essential oil adulteration.7 In addition to that, similar claims have also been made elsewhere including the APRC website which states, “he received his MS and Ph.D. in essential oil research.” However, his researchgate.net profile indicates that he has a M.S. in Chemistry and a Ph.D. in Biotechnology Science & Engineering.
Secondly, most essential oil companies, including Company X, have a few rectified or redistilled oils. This is not necessarily bad thing, and it is not always about fragrance as he said. Rectified oils have just had certain undesirable chemicals removed or reduced, some of which can be quite harsh. This reduction in turn causes the percentages of the remaining components to increase and that can have benefits also.8,9,10,11
When it comes to essential oils used in aromatherapy, it is important to note that there are only certain oils that are redistilled, and that is for very specific reasons. For example, if you ever get the chance, compare samples of unrectified and rectified Clove, Eucalyptus, and Peppermint essential oils. Have you ever noticed that many Peppermint essential oils smell sweet like peppermint candy rather than having the more herby smell you get when you crush the leaves of the plant between your fingers? That is because that oil itself has been redistilled. Also, Eucalyptus globulus essential oil is often rectified to remove certain aldehydes that can cause irritation and coughing in users.12 In turn, the process also increases the level of 1,8 cineole. Without that being done, we would not get the oil that many people are accustomed to, nor may we get the desired results.
Lastly, APRC’s own GC/MS reports that were included in the Consumers Advocate article, show that Company X is NOT the only one who sells pure oils. His statement is blatant bias that should not be coming from a true third party analysis company.
As far as the analysis of the oils in question and as to if they are adulterated or not, the following is what was found in research in regards to synthetic linalyl acetate…
Questions and Lack of Proper Evidence
The attempt was made by several people in Facebook posts to get Prabodh Satyal to answer basic questions to gain a better understanding of APRC’s process determining that the Lavender oils in question were adulterated. However, the questions either went unanswered, the response was vague, or he gave a response that did not answer the questions asked.4,13
The following were two of the main questions:
- There was the question as to what was the origin from which linalool oxide acetate cis/trans were supposed to be derived. Not getting a response, the following was located in the Consumers Advocate article as a quote by Aaron Sorensen, co-owner of APRC: “For example, linalyl acetate is one of the major components of lavender. A broker can turn linalool (which is readily available) into linalyl acetate through a simple chemical reaction and even if they get that process to be 99.9% effective in producing the desired linalyl acetate, there is still the .01% of other chemicals known as by-products that don’t naturally occur in the plant, and are hence termed synthetic markers.”2
- Satyal was also questioned by several of the chemists as to what his evidence was that linalool oxide acetate cis/trans were trace markers for the addition of synthetic linalyl acetate. He did cite several different papers, but there was no specific explanation about this particular mode of adulteration, and all of the papers were co-authored by him.14,15,16
Also, proper evidence was definitely not provided that would justify all the repercussions that come along with making the claims that the oils were adulterated.
PhytoChemia, one of the well respected analysis labs in North America, put out a Google document outlining flaws in APRC’s findings. That document addresses several of the synthetic markers, including the (Z) and (E)-linalool oxide acetates, with included references to show that most of them are naturally occuring in small amounts.17,18
As far as the paper on the antique Lavender oil that was referenced, it was understood that Satyal was inferring that since it did not show that those two chemical constituents were present, that it was definitive evidence that they do not occur naturally.
That is still not proper evidence.
Given what is known about analysis per PhytoChemia’s article (titled 100% identification?) referenced below, and Satyal’s own words in one of the videos, how can we be sure that they truly were not there without having access to the full analysis to look for them specifically? The point of that particular paper was not to prove or disprove the existence of those chemicals in Lavender essential oil, so there is just not enough information there to conclude that. Also, the above mentioned article and video explain why the linalool oxide acetate cis and trans may not have been listed in that paper, or on other GC/MS reports performed by others.6,19
Not to mention that there are many reasons (including a plant’s growing conditions, when it is harvested, etc.) that can and do cause chemical variations in the resulting essential oil.
For every adulteration chemists are able to uncover, there are people who are trying to find new, undetectable ways in which to adulterate essential oils. There are many ways known in which oils can be adulterated, but that does not mean that all of those methods can currently be detected. For instance, in regards to synthetic markers, while some have been found, others are yet to be identified or proven as known markers.
When it comes to Lavender essential oil being adulterated with the use of synthetic linalyl acetate, there are currently only two synthetic markers that have been recognized by proper evidence to be reliable. There is dihydrolinalyl acetate that has been well-known for years as the trace marker for linalyl acetate derived from petrochemicals, and plinyl acetate which is derived from natural alpha-pinene.1,20
As far as the scientific community is concerned, without solid evidence that something is factual, lack of said evidence IS evidence to the contrary. If there is no evidence, it is not fact, only hypothesis.21 However, if there is proper evidence, it needs to be published in a peer reviewed paper showing that it is replicable and can hold up to scrutiny. Once accepted, it should then be shared with enthusiasm as a new discovery to benefit the community as a whole.
Instead, we see an example of what should not happen. This is not how things work in the scientific community. There is a reason scientists use an accepted list of guidelines known as the scientific method when it comes to research.22 Someone cannot have a hypothesis that is used as fact to make decisions that effect other people’s reputations and livelihoods.
As it stands, there are only two chemical constituents that have been recognized by proper evidence to be reliable synthetic markers for linalyl acetate, and they are dihydrolinalyl acetate and plinyl acetate.
The constituents linalool oxide acetate cis and linalool oxide acetate trans identified as sythetic markers by APRC, are not recognized as trace markers for adulteration in the industry. The reasons for this are explained in the PhytoChemia document below as they are shown in other papers to be naturally occurring. Furthermore, they, or any others for that matter, should not be used by anyone to determine essential oil purity without proper evidence showing, beyond a shadow of a doubt, that they are correct.
APRC has been actively using findings, some of which are nothing more than hypotheses, in their analysis of essential oils. This has led to oils being deemed as adulterated that should not have been. This leaves one to wonder… How reliable are any of the analyses that have been performed by them?
**Edited 10/21/19- Since this article was initially published, Prabodh Satyal posted an article on one of his facebook pages titled “Synthetic Marker of Linalyl Acetate (Linalool oxide acetate cis & trans furanoid) in Lavender” that was also shared in the BTA: The Chemistry of Essential Oils Facebook group. There, a very informative discussion transpired between several chemists in the industry.23
Special thanks to everyone who read and gave input during the process of this article. Thank you all so much!
- Burfield, T. (2013). The Adulteration of Essential Oils – and the Consequences to Aromatherapy & Natural Perfumery Practice. [online] Available at: http://www.users.globalnet.co.uk/~nodice/new/magazine/october/october.htm [Accessed 8 Aug. 2019].
- Consumersadvocate.org. (2019). Best Essential Oil Brands Based on In-Depth Reviews. [online] Available at: https://www.consumersadvocate.org/essential-oils [Last Accessed 17 Jul. 2019].
- Consumersadvocate.org. (2019). Essential Oils GC-MS Test Results. [online] Available at: https://s3.amazonaws.com/s3.consumersadvocate.org/prd/docs/db/document/doc/930/071d08f3-9227-4ac1-850b-dc52021fcd12.pdf [Accessed 20 Jun. 2019].
- APRC Facebook.com. (2019). Linalool/Linalyl Acetate Synthesis and Detection. [online] Available at: https://www.facebook.com/AromaticPlantRC/videos/vb.678563765686487/377492013113581/?type=2&theater [Accessed 21 June. 2019].
- Natural Remedies Online Youtube.com. (2018). APRC Testing of doTerra Essential Oils Testimonial. [online] Available at: https://www.youtube.com/watch?v=OxoYgLZ4U_I [Accessed 22 Jun. 2019].
- Oil Shares Facebook.com. (2018). Prabodh Satyal, PhD with Aromatic Plant Research Center. [online] Available at: https://www.facebook.com/OilShares/videos/1616377561788741/?hc_location=ufi [Accessed 22 Jun. 2019].
- Uah.edu. (2019). University of Alabama in Huntsville Science Programs. [online] Available at: https://www.uah.edu/science [Accessed 8 Sept. 2019].
- Sheppard-Hanger, S. (1995). The Aromatherapy Practitioner Correspondence Course. Atlantic Institute of Aromatherapy.
- Tisserand, R. and Young, R. (2014). Essential Oil Safety: A Guide for Health Care Professionals, Second Edition. Churchill Livingstone.
- Tisserand, R. (2014). Is There Such a Thing as Re-distilled Peppermint Oil? [online] Available at: https://roberttisserand.com/2014/01/re-distilled-essential-oils/ [Accessed 6 Sept. 2019].
- Essential Oil University. (2016). The Difference Between a Rectified Oil and a Natural Isolate. [online] Available at: https://www.facebook.com/EssentialOilUniversity/posts/10154618269298083 [Accessed 6 Sept. 2019].
- Burfield, T. (2016). Natural Aromatic Materials: Odours & Origins, Second Edition. Atlantic Institute of Aromatherapy.
- BTA group Facebook.com. (2019). Discussion on APRC’s Test Results. [online] Available at: https://www.facebook.com/groups/BTAChemistry/permalink/2283143538439563/ [Last Accessed 6 Sept. 2019].
- Satyal, P. and Sorensen, A. (2016). Authentication of Lavender Essential Oil: Commercial Essential Oil Samples and Validity of Standard Specifications. International Journal of Professional Holistic Aromatherapy. 5 (3), p17–22. https://aromaticplant.org/assets/lavender-authentication.pdf
- Satyal, P. and Pappas, R. S. (2016). Adulteration Analysis in Essential Oils. International Journal of Professional Holistic Aromatherapy. 5 (2), p33–39.
- Satyal, Prabodh & S. Pappas, Robert. (2016). Antique Lavender Essential Oil From 1945, its Chemical Composition and Enantiomeric Distribution. Natural Volatiles and Essential Oils. 3. 20-25. https://www.researchgate.net/publication/308724220_Antique_lavender_essential_oil_from_1945_its_chemical_composition_and_enantiomeric_distribution
- PhytoChemia. (2019). Analysis of Synthetic Markers. [online] Available at: https://docs.google.com/document/d/1ZLyzn3PMMUR6gveVm9pU6xjdutb7Jic4q_8VAsf92eU/edit [Last Accessed 6 Sept. 2019].
- Mazza, G. (1987). Oxidations of Monoterpenes in Essential Oils. Essenze, Derivati Agrumari, 57(1), 5-18.
- St-Gelais, A. (2019). 100% Identification?. [online] Available at: https://phytochemia.com/en/2019/01/26/100-identification/ [Last Accessed 6 Sept. 2019].
- Pappas, R. Facebook.com. (2017). Scamazon! (video explaining adulteration and dihydrolinalyl acetate). [online] Available at: https://facebook.com/story.php?story_fbid=1827658567499849&id=1817997795132593&_rdr [Last Accessed 6 Sept. 2019].
- Merriam-webster.com. (2019). This is the Difference Between a Hypothesis and a Theory. [online] Available at: https://www.merriam-webster.com/words-at-play/difference-between-hypothesis-and-theory-usage [Last Accessed 6 Sept. 2019].
- Livescience.com. (2017). What Is Science?. [online] Available at: https://www.livescience.com/amp/20896-science-scientific-method.html [Last Accessed 6 Sept. 2019].
- BTA group Facebook.com. (2019). Discussion on an article written by Prabodh Satyal titled Synthetic Marker of Linalyl Acetate (Linalool oxide acetate cis & trans furanoid) in Lavender. [online] Available at: https://www.facebook.com/groups/BTAChemistry/permalink/2460721024015146/ [Last Accessed 21 Oct. 2019].
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