Purity testing is a necessary step of the manufacture and sale of all essential oils. Given the complex composition of essential oils, it can be challenging to separate, isolate, and analyze their make up.
Gas Chromatography Mass Spectrometry analysis, or GC/MS analysis, is considered the gold standard for essential oil purity testing. Understanding GC/MS analysis is a great way to understand why purity testing is so important, why it requires an expert touch, and how you can get the essential oil purity testing you need.
Why do essential oils need to be purity tested?
The reason essential oils are called “essential” is because they are the pure, essentialized distillations of naturally occurring materials. If a manufacturer wants to call their oil an essential oil, they have to prove that it contains only the “essential” ingredients they claim it does and nothing else.
There’s a good reason for this distinction: Even trace impurities within an essential oil can have outsized effects on the oil’s therapeutic value, aroma, color, flavor, and the way it interacts with the skin or other ingredients when used in products. Not only will an impure essential oil lack the potency of a truly pure version, but its impurities could impair or alter the product’s intended use or even trigger allergic reactions or other harmful effects when used.
Purity tests of essential oils are designed to isolate all of the ingredients that comprise them and verify their purity. This allows testers to verify both that the essential oil contains only what it claims to and that the oil is not chemically compromised in any way that could affect its use. This makes purity testing a necessary step in the manufacture and sale of any essential oil product.
How is GC/MS used to test essential oil’s purity?
A GC/MS analysis allows testers to separate a sample of essential oil into its individual chemical components.
By exhaustively identifying, cataloging, and analyzing the individual chemical components comprising the sample of essential oil, testers can determine exactly what the essential oil is made of, how pure its ingredients are, and how it will behave when used as a product. Analysts can also compare the results of a GC/MS test of essential oil to industry standards of purity, either proving the product meets the appropriate criteria or determining exactly what impurities are present in it.
How does the GC/MS purity test work?
As the name implies, a gas chromatography-mass spectrometry test is two tests conducted one after the other, using a single machine that does both.
First, testers inject a sample of the essential oil into a port on the gas chromatograph. Inside this port, the sample is heated at a temperature high enough to volatilize the components of the sample into a gaseous vapor.
Next, testers introduce an inert gas called a “mobile phase” into the port. The mobile phase pushes the sample vapor through a column that contains a “stationary phase,” which is a microscopic layer of polymer. As the sample vapor passes through the stationary phase, different compounds within it separate as they travel through the stationary phase at different times based on their size and/or polarity. The speed at which each component makes its way through the gas chromatograph’s column is known as its “retention time.”
After separating in the column, the sample compounds flow down into the second part of the testing machine, known as the Mass Spectrometer, or MS. As compounds enter the MS, it bombards them with electrons. This bombardment further breaks down the sample compounds into positively charged ionic fragments.
As charged fragments, the sample compounds are attracted to an electromagnetic field in the MS. This field pulls the ions through an ion trap, which works as a filter and detector at once, counting the ions as they pass through.
Finally, the testing machine generates a “mass spectrum” based on the distribution of ions of different sizes. Each ion represented in the mass spectrum will have its own unique mass-to-charge ratio, fragmentation pattern, and retention time combination. Analysts compare this unique set of traits to a reference library in order to positively identify each of the ions they found and therefore, characterize the different components in the sample.
The GC/MS testing process is considered the gold standard method for determining essential oil purity. GC/MS is capable of identifying substances within an essential oil sample down to less than 1 part per million. Then, by simply comparing test results to GC/MS industry standards, analysts can prove the purity rating of the test sample.
How can I have my essential oils purity tested?
If you are an essential oil manufacturer and need to have your product purity tested, the experts at Innovatech are ready to help. Get in touch today.