Emma Brady

1st July 2016

Cannabis analysis using GC


Many studies have provided evidence which would suggest that cannabis could be used in the treatment of many diseases and cancers.

These studies have shown that cannabis can be effective in decreasing epilepsy symptoms, can reduce brain damage after a stroke and may have powerful anti-tumor properties. Despite this, since the 1960s, scientific research has been limited in many countries because medical marijuana research has been blocked, mainly due to anti-cannabis legislation in developed nations.

Mainstream acceptance of cannabis has increased steadily over the past decade in the US and in several states, criminal penalties have been eliminated for possession of small amounts of marijuana. As the medical and recreational uses for cannabinoids increase not just in the US but worldwide, the need for improved quality control and testing also increases.


In a recent c&en white paper written in partnership with Shimadzu titled: A closer look at Cannabis Testing it is stated that cannabis growers and dispensaries benefit tremendously from testing performed by independent laboratories. The testing carried out by the independent labs determine potencies, reduce the risk of contamination and help improve product quality.

A critical test associated with cannabis is cannabinoid potency. Most labs measure 3 major cannabinoids: Tetrahydrocannabino (THC), Cannabidiol (CBD) and cannabinol (CBN) and their different forms (carboxylated vs decarboxylated). Some labs use gas chromatography (GC) analysis in which the sample is vaporized under heat. GC-FID and GC-MS analysis are commonly used as the intense heat in the GC and any THAC present in the natural sample is converted to THC and labs report this value as ‘THC Total’. Some labs also use HPLC methods.

The analysis detection of pesticides in cannabis remains a challenge as there is an enormous amount of pesticide in the commercial marketplace. GC-MS is the preferred instrument of choice for such testing and while there are no guidelines for residual pesticide screening in cannabis, most labs test for the most common employed during the cultivation process. These are: organophosphates, carbamates, pyrethroids and avermectins.

Shimadzu’s cannabis testing solutions cover a broad range of applications, from potency testing to pesticide screening. They are equipped to supply the instruments, methods and experience necessary to get your lab up and running at full capacity.  MRX Labs in Portland, G.O.A.T labs in Vancouver and Trace Analytics in Washington all use Shimadzu equipment in their cannabis analysis. 

Testing of cannabis is still in its infancy.  As the need for better quality control continues and standardization is introduced, it is likely that lower limits of the various cannabis contaminants will be established and regulations will be introduced. Mass spectrometry will like play a greater role in quantitation as detection levels are lowered and confirmatory tests are required. With Shimadzu at the forefront of cannabis testing, PEAK are on hand to offer GC and LC-MS gas generation solutions that couple with Shimadzu instruments. These gas generator solutions offer an uninterrupted steady flow of gas at a consistent purity, eliminate the safety concerns surrounding cylinder gas and offer a fast payback, return on investment.  

Specifically designed and engineered for GC applications, the Precision series represents the cutting-edge of PEAK Scientific innovation in robust and dependable gas generator design. The Precision series combines convenience and reliability in a stackable and modular design and is the safe and practical GC gas solution for hydrogen and nitrogen in your lab.

With Shimadzu and PEAK instrumentation in cannabis testing facilities across the world, consumers can be confident of accurate results.

To find out about PEAK's GC generators    


View the Shimadzu/Trace Analysis video that specifically discussed cannabis testing.

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