What is a GC/MS Report?

Think of a GC/MS is like an essential oil report card. In the world of essential oils, GC/MS testing is the highest standard of analysis. The report verifies the authenticity, quality and purity of the essential oil as well as identifies its individual constituents. The constituents prove the oil’s therapeutic value. This is important because the potency of the constituent can have a dramatic effect on the oil’s effectiveness.

Testing for potency and safety 

GC/MS stands for Gas Chromatograph and Mass Spectrometry which are actually two analysis techniques. The report produced from the analysis separates an essential oil into its main constituents which show up in varying degrees through a linear graph and percentages. Those constituents are what give the essential oil its aromatic and therapeutic properties. It’s how we know Lavender can help you relax and Peppermint can support pain relief. 

Highly efficient, the test separates masses of volatile molecules over a relatively short period of time. To put it simply, the GC/MS test pulls the oil apart so we can view each naturally occurring component and assess its value. Additionally, the report shows if the oil contains any adulterants or additives. Identifying each component of the essential oil also allows us to verify its safety. If an essential oil did contain a contaminant, for example, it would no longer be safe for use. At our Aromawest, we examine these reports very closely because our oils must be 100% pure and undiluted before being added to our inventory. 

How does the GC/MS test work?

Like we discussed above, a GC/MS test is performed using two separate techniques: Gas Chromatography and Mass Spectrometry. To run a complete test, the essential oil is heated and vaporized in a gas chromatograph machine. The oil moves through a column assisted by a carrier gas (helium or hydrogen). Because the natural compounds of the oil move at different rates, the constituents can be distinguished by their molecular makeup. At the end of the machine, a detector measures each constituent which results in a chromatogram report. 

After the constituents are identified in the GC, it is put through a mass spectrometer. The machine breaks down molecules to be sorted and counted according to their mass. For a more detailed (and brainy) breakdown of the analysis by the Tisserand Institute, click here

Aromawest quality standards

At Aromawest, we don’t take ourselves too seriously but we are serious about our essential oils. That’s why we go to great lengths to ensure the purity and quality of our oils. On every single oil product page, you can find the main constituents of each specific oil. This provides a snapshot of the actual science behind the effectiveness of our oils. Basically, it gives you some easy background on why essential oils work. And always, if you have any questions about safety or purity, please reach out to us. We’d love to hear from you. 


Adams RP (2007). Identification of Essential Oil Components By Gas Chromatography/Mass Spectrometry. Allured Pub Corp. ISBN 978-1-932633-21-4.

Burfield, T. (2005). A Note on Gas Chromotography-Mass spectrometry (GC-MS). Schnaubelt K. (2012) Analysis vs Authenticity

McEwen CN, Kitson FG, Larsen BS (1996). Gas chromatography and mass spectrometry: a practical guide. Boston: Academic Press. ISBN 978-0-12-483385-2.