The 411 on GC/MS For Essential Oils

Ethically speaking, would you sell a rock and try to pass it off as a diamond? Probably not, right? However, you might be surprised that this is what happens to essential oils, 90-95% of the time, as oil simply looks like oil. 

Unfortunately, blind adulteration is widespread to any ingredient that can not rely on physical attributes to determine its value. Other ingredients vulnerable to blind adulteration may include olive oil, honey, truffles, etc. In spite of, there are ways around adulteration through the use of advanced, data-driven technology. Still, it is rarely implemented. 

When determining the quality and value of an essential oil, there is unfortunately no set standard or universal grading system. This lack of a standardized system leaves essential oils prone to being adulterated with skin-irritating contaminants in the likes of alcohol or turpentine, synthetic fragrances, or diluted with bases oils beyond effectiveness.  

Without an industry standard, essential oils are left into two categories - marketing terms or scientific terms. Marketing terms appear as “therapeutic grade,” “third-party verified" whereas scientific terms appear as "GC/MS" or "GC/MS Technology". 

Adulteration is particularly rampant in essential oils as they are the most valuable plant-based ingredients. With the market value of rose otto essential oil at $200+ for 5ml, for example, adulteration is a lucrative business for many distributors. As an essential oil moves through multiple hands in the supply chain, many suppliers copiously alter oil with ethanol, turpentine, alcohol-based contaminants or cheaper, lower-grade oils to increase volume for profit then add synthetic compounds to mimic scent. 

Prior to GC/MS lab testing, physical quality control measurements included specific gravity, refractive index, optical rotation, and flash point. These tests measured density, direction of light, speed of light, and vapor ignition and were disclosed on a Certificate of Analysis. However, these limited tests are not a good indication of purity. 

Gas chromatography/mass spectrometry (GC/MS) is the gold standard in quantitative analytical lab testing, meaning it can identify exact percentages of volatile compounds. 

It is a two-part technological system. Gas chromatography separates compounds found in the essential oil, then mass spectrometry identifies these compounds. The separation process is utilized to identify, not to extract from, oil. Results are then generated onto a graph that a botanical chemist reads to decipher if an essential oil matches the oil’s authentic profile and if any adulterants, diluents, or contaminants are present. 

As a certified clinical aromatherapist, I then review the GC/MS report to determine which essential oil to formulate with based on compounds. This advanced technique is known as chemical component blending. For example, it could determine if we blend with lavender from Bulgaria or from South Africa as the plant’s environment impacts compound levels. Having the ability to dive deep into plant chemistry through GC/MS technology ensures our formulas are blended with the highest quality essential oil that has been harvested at its peak performance.

By pivoting our focus from deceptive marketing terms to science-based data, true transparency can be in the forefront. 


"The value of a diamond is based on The Four C's - cut, color, clarity, and carat. The value of an essential oil is based on the GC/MS lab report."

- Kirsten King, Founder + Clinical Aromatherapist