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February 23, 2017 3 min read

Recently there was a lot of discussion about Certificate of Analysis (COA) and gas chromatography/mass spectronomy (GC/MS) analysis. It lead to questioning which is better - A "COA" or a GC/MS analysis for essential oils?

There is a huge difference between the two and they should not be mistaken as having equal value. Let me explain.

What is a “COA?”

A “COA” is an internal company document. Internal is a key word here.

The purpose of this internal document is to show perspective buyers that a product the company offers has passed internal quality control.

In regards to essential oils, it may contain a small amount of information about the essential oil it is created for. This information can but does not always include:

  • Small amount of information from a GC/MS analysis if available
  • Or listing of main components
  • Common and Latin/botanical name of the plant the essential oil is obtained from
  • Country of origin
  • Cultivation methods
  • Extraction method
  • Plant part
  • Specific gravity
  • Optical rotation
  • Refractive index
  • A statement from the company about the quality/purity based on their knowledge and standards regarding the specific essential oil.

It is important to really understand that this document is created by the company that is using it for their product. This is not a document that is made by an external source. It is entirely internal.

Many companies using this type of document use it to say that the essential oil listed in the document is pure and passes their set standards of quality control.

An example of a statement may read like this: “This Essential Oil is a 100% pure and natural product. It does not contain any artificial ingredients or adulteration of any kind to the best of XYZ Company knowledge. The analysis and statements herein constitute the most complete information available to XYZ Company. This product is guaranteed by XYZ Company to be of excellent quality.”

The reality is that this document does not actually verify purity. It doesn’t even verify quality. There is only one document that can verify purity. And as many of us know now, quality is subjective to a user’s bias…or in this case their nose’s bias.

What is a “GC/MS?”

A GC/MS analysis is a type of chemical analysis performed on essential oils that shows every chemical found within the tested substance. When this analysis is completed, the constituents found are then matched to the lab’s database containing industry standards for the essential oil it is performed on. Once this step is completed, the chemist or analyst is able to say that an essential oil is pure or adulterated.

When you look at an authentic GC/MS analysis there are a few things you will normally see. They may include:

  • Test date
  • Internal code the lab uses to identify the sample of essential oil
  • What the client requesting the analysis claims the sample is
  • Customer name
  • Analysis method used (GC/MS or GC/FID)
  • Who analyzed the data/essential oil
  • Graph showing constituent peaks
  • Complete listing of every single constituent found within the essential oil that the lab can identify
  • Percentage of each constituent found
  • Physical aspect of the essential oil (color)
  • Refractive index
  • Conclusion of the analyst (pure or adulterated)

Short version: This document verifies purity of an essential oil and is much more technical than a “COA.”

Which is better?

As mentioned before, a “COA” is a means to show prospective buyers that the product it is created for has passed all internal standards of quality and purity. Any company can create a “COA” using Microsoft word. However, a “COA” does not actually prove purity. Only a GC/MS or means of other analysis like a GC/FID can prove purity.

Depending on your level of comfortability with the ethical and business standards of an essential oil company, a “COA” may be meaningless to you. This is why many reputable companies share formatted GC/MS analysis now as well as offer to show you the original analysis.

If you have the GC/MS, you do not need a “COA.” If you want to verify purity you do need to see the GC/MS analysis with the conclusion of the analyst/chemist. Hopefully, this clears up a few things for you. If not, please ask me a question below!