Education ยป
Essential Oil Testing and Analysis
Who is Dr. Pappas?
Dr. Robert Pappas teaches essential oil chemistry classes at the Indiana University and is a leading authority in his field of GC/MS analysis and reporting the chemical breakdowns of essential oils, CO2s and absolutes. He also has a website dedicated to share analytical reference data for research and quality control education purposes. It is the largest online chemical reference database for essential oils in the world, and it’s free for anyone to use.
The Indiana University Fall 2013 Magazine featured an article about Dr. Pappas and noted that he is a “sought-after consultant for companies and individuals all over the world because the information he provides helps with quality assurance and with learning how an essential oil might be useful.”
After graduate school, in 1996 Pappas took a position with The Lebermuth Company and said: “I spent two years getting exposed to everything about the [essential oil] industry and what it takes to control quality.” Rob Brown, president of the Lebermuth Company says of Pappas: “Dr. Pappas is an expert in understanding, qualifying and managing the chemistry of plants that produce essential oil and other aromatic extraction.” Dr. Pappas started his own consulting business, analyzing oil samples and so on in 1998.
In the IU article, Sylla Sheppard-Hanger, the founder and director of the Atlantic Institute of Aromatherapy is quoted noting that Pappas is the “champion” of those who value high-quality essential oils.
Sheppard-Hanger continues, “He’s the go-to person for chemical analysis, and he’s always open to answering any questions about essential oils, whether you are actually on the industry side or a student.”
Brilliant Idea
I recently became aware of a website dedicated to sharing information about using essential oils. The site owner, Lea Harris (Learning About Essential Oils - LAEO), had a brilliant idea. She offered to raise funds from people to have a single essential oil GC/MS tested from a number of essential oil companies. She sent the samples to the lab in unlabeled bottles (other than the numerals to identify them). In Round #1 of testing she sent samples of Myrrh to Dr. Robert Pappas, who analyzed the oil samples and reported back that: “There were no problems with any of the samples, but I thought #3 was the best. All the samples were very good quality; I just liked #3 slightly better because of the chemistry. It’s just my opinion. Number 2 was the closest to #3. In fact, very close, so it’s really a hard choice.” (Heritage Essential Oils was not tested)
In Round #2, LAEO tested Tea Tree essential oil. The funds were raised, and for this round she sent the samples to Pyrenessences Analyses lab in France for testing. Per the information on her website, she felt to base this test on compliance with ISO guidelines. In order to understand the subsequent “results,” you’ll need to have some understanding about ISO guidelines. (Heritage Essential Oils was not tested)
Understanding the ISO Standard
AFNOR/ISO standards are only a baseline profile of a few of the constituents of a single essential oil. These standards are updated periodically as new data from distillations come available.
Relying solely on ISO standards to judge an essential oil can be problematic since there are only a few compounds listed and monitored out of hundreds of compounds present in the complete, natural essential oil. This "incomplete" assessment leaves room for an unethical company to adulterate the oil and still meet AFNOR/ISO standards. These adulterated oils may go undetected by a lab technician only trained to report the results of the test, whereas a master in the chemistry of essential oils evaluates the whole including organoleptic assessment where his expertise is invaluable and cannot be duplicated by a machine.
Dr. Pappas Comments About the ISO Standard
Dr. Pappas recently heard about Learning About EOs Tea Tree oil test results and posted his concerns about relying solely on ISO guidelines to judge the quality of an essential oil.
The entire article is linked below, but I’ll just post a portion of it here. There are six points in Pappas' article; this is a quote from point #3 (I put the key points in bold):
Dr. Robert Pappas writes: “The ISO standard has very broad ranges for some components, some so broad they leave the door open for very poor quality. In the case of tea tree for example, the acceptable range of 1,8-cineole in tea tree oil is between 0 and 15% !!! This is unacceptable on many levels. I have never seen a tea tree oil with 0% 1,8-cineole, and I would think it a physical impossibility, and yet a compound containing only the 7 other components in the appropriate ranges would pass the ISO profile. On the other extreme, no client that I know would EVER buy Australian Tea Tree oil that has 15% 1,8-cineole because that would be way too high to be acceptable for most clients who know anything about tea tree essential oil. In fact, most all of my clients who would be purchasing for therapeutic value typically want the 1,8-cineole at between 2-5%, which would adhere to the pharmaceutical standard. I would much rather have a tea tree oil that fell slightly out of ISO range on one or more of the ISO components and be under 5% cineole than one that was within all the ISO ranges and yet had 15% cineole. It’s a crazy number that is only allowed to be that wide, in my opinion, to allow for industrial adulteration with eucalyptus and/or Chinese tea tree oil which would increase the1,8-cineole level. The best evaluation of an oil has to not only include the overall chemical analysis of a wide range of components, but equally important is the organoleptic evaluation of an oil, which is something that a machine cannot give you. This is where the art meets the science.”
One company tested was Plant Therapy. Their Tea Tree oil was reported by Mr. Dantin with the French lab as “not in compliance” based on ISO guidelines, yet Dr. Pappas noted that “from the analysis alone, I would say that Plant Therapy had the overall best quality of all ten samples looked at.” To demonstrate his “strong” feelings “about this issue,” Pappas graciously offered to analyze and evaluate Plant Therapy’s sample at no cost to the owner of the company.
Update: Plant Therapy resubmitted a sample of Tea Tree from a new batch that is now listed as "In Compliance," but it is actually not compliant with the ranges in the report. Limonene is still out of range and the 1,8-cineole level of the new Tea Tree is too high [for therapeutic use], as it should be (according to Dr. Pappas above) 5% or less.
We hope this information, though somewhat thick to wade through, will help you understand that some companies may choose to follow the ISO standard while others may not. At HEO, we are seeking the best essential oil we can find for therapeutic purposes, so that is our goal and Dr. Pappas's EOU "standard" is what we strive for.
Producing the Best Essential Oil
(Quotes are from Medical Aromatherapy, pages 145-158, by Kurt Schnaubelt, who has a PhD in chemistry and is the founder and scientific director of the Pacific Institute of Aromatherapy in San Francisco)
“During all stages of producing a genuine and authentic oil, the final goal should be to produce the best possible essential oil.
“Essential oils are commonly analyzed by either gas chromatography (GC) or a combination of gas chromatography and mass spectroscopy (GC-MS). GC-MS are powerful methods for routine analysis, quality control and research. Because of the varying parameters such as different machines, columns, flow rates, temperature programs and so on, chromatograms can usually only be compared within one experimental setting. Usefulness of the chromatogram is, therefore, limited to those performing the analysis.
“Interpretation is, therefore, a question of the quality of the available libraries. In real life, this means that big research entities that specialize in fragrance research own very impressive libraries of the mass-spectra of fragrance materials. Such libraries represent great value, and such data tends to be proprietary. This also means that the computerized evaluation of a GC-MS from a lab that has not previously specialized in this type of analysis will probably not yield satisfying results. . . .These chromatograms represent no practical value to someone not involved in interpreting them.”
Schnaubelt goes on to say: “Essential oils may be impossible to standardize because they reflect the intrinsic variability of nature. . . .For this very reason, attempts to standardize essential oil to fit a certain set of ingredients seem counterproductive. Essential oils should be as rich and complex as they are when they come out of the still. Seasonal variations (or variations originating from different distillation processes) should be permitted because they are the legitimate expression of the regional geographic and climatic influences as well as the interaction of the grower with nature in crafting the oil.
“While many businesses continue to prosper by securing success in the mass-market, this strategy brings endless compromise and insures mediocrity. In the long run, success is not defined by this type of marketing but by the excellence of a product and a living craft.”
For a good analogy for why we are not looking for a rigid standard for naturally grown and processed essential oils, Schnaubelt offers: “The fine-wine industry, which also deals in expensive liquids of varying natural origin, shows how a reliable standard of authenticity can be created and how it can be challenged by the demands of industrialization. There are vintners who make their wine with as little wine-making as possible — letting the wine reflect the earth on which is grows and the sunlight that ripens the fruit. Then there are the big industrial reserve cabernets that are deliberately constructed to please the masses.”
In the case of essential oils, there are large corporations that rely on the ISO standard so that their products have very little variation. Manufacturers of toothpastes, gum, muscle salves and so on want to produce a product that is consistent, so rigidly adhering to a standard serves their purpose well.
“While analysis is absolutely critical in the field of holistic aromatherapy, the right approach is not to rely exclusively on technology and science but to integrate the human element."
LAEO Round #3
LAEO tested Peppermint from 13 companies using ISO standards again. HEO's Peppermint was one of ten companies found "not in compliance" with the ISO standard, and the lab also noted ethyl vanillin at a trace amount (seven hundredths of one percent). Being outside of ISO, as noted above, is not troubling when choosing essential oils for therapeutic quality, but it was puzzling and concerning that ethyl vanillin (a synthetic food additive) would be identified when several previous tests of HEO's Peppermint with a variety of labs and health care professionals do not identify this.
We forwarded the results of the test to Dr. Pappas who had run a previous test on the same Peppermint. After reviewing the results, he sent an email within the day to Mr. Dantin (with the French lab), LAEO and myself enumerating his concerns and questions about the test. Mr. Dantin nor LAEO responded, and LAEO made the decision to post the results without noting Dr. Pappa’s concerns.
We asked Dr. Pappas to run another test down to 0.01% (one hundredth of 1 percent, which is farther than the French lab's report), and again, he found no trace of ethyl vanillin.
Essential Oil University (EOU) uses the very latest GC/MS technology on two state-of-the art instruments. They also use the industry standard non-polar DB5 column for most applications. DB5 is the standard because it gives the best separation and best overall results for essential oils. Dr. Pappas noted that the French lab used the older, polar carbowax-type column (in this case HP Innowax). According to Dr. Pappas: "When this column is used it makes it impossible to really compare with the results of other reputable labs because the retention order of the components is drastically different than on the non-polar DB5 column. Perhaps non-uniformity with other labs is intentional, making comparison difficult and not subjecting oneself to scrutiny over potentially misidentified components, or perhaps its just inexperience. But there is no question that DB5 or similar non-polar is the column of choice for essential oil analysis. ”
Dr. Pappas also noted that “in addition to our own custom component library with thousands of components specific to essential oils and fragrances created by running pure authentic component samples, EOU also uses the latest commercial libraries for its component identifications, including the latest Wiley library with over 400,000 mass spectra. The [French] lab used an older NIST library with only 75,000 mass spectra for its source of identification of the components. Furthermore, most people in the industry realize the severe shortcomings of the government sponsored NIST library which has a considerable number of errors in it.”
Dr. Pappas concluded that “it's entirely possible that the ethyl vanillin peak, claimed to be present at only 0.07%, was actually a misidentification of another trace component of peppermint oil that perhaps the analyst did not consider.” He explained that ethyl vanillin has molecular weight of 166, and when it’s in pure form in reasonable concentration, it has the mass spectrum at 166, 137, 138, 109 and 81. The mass spectra of a naturally occurring trace peppermint oil component called iso-mint lactone, a little-known component of mint oil, contains the same main mass fragments at 166, 137, 138, 109 and 81. "This is the spectrum for the pure component with no interference from other co-eluting components. When in extreme dilution or when interference with other components in a complex mixture occurs (like in essential oils), this spectrum can look different in its relative peak intensities. Furthermore, the retention time of iso-mint lactone is almost exactly the same as ethyl vanillin!! It’s entirely possible that the other lab mistakenly identified iso-mint lactone as ethyl vanillin in such a dilute concentration. Even an experienced analyst could make this mistake. The analyst of the [French] lab identified mint lactone but did not list its cousin iso-mint lactone and most likely does not have this mass spectrum in his library, and even if it were there, confusion of the computer between two similar mass spectra happens all the time, especially when you are looking at components in such small concentration.”
Given that tests from other labs also concur, we feel confident that the test results from Dr. Pappas are accurate and reliable. Over the years, we've received many positive testimonies and comments about our Peppermint from both individual customers and health-care providers who have felt it was exceptional in both quality and effectiveness. We make every effort to ensure that we only offer top-quality oils, and we trust the expertise of Dr. Pappas to help us achieve our goal.
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Links
Get A Whiff of This! article by Indiana University
Essential Oil University [Pappas’ online database]
Round #1 Testing: Myrrh: Learning About EOs.com
Round #2 Testing: Tea Tree: Learning About EOs.com