Two Common forms of Chromatography Used in Cannabis Testing

Written by Derek Johnson

In the cannabis industry, testing requirements necessitate a tool that can reliably breakdown, identify and analyze the chemical compounds found within a cannabis sample submitted for testing. Chromatography is such a tool.

Chromatography is also used to purify cannabis samples for research purposes and for the preparation of high-quality products.

What Is Chromatography Exactly?

Chromatography is a powerful laboratory technique that is employed to breakdown a sample into its individual parts for analysis or preparation purposes. It is widely used in all manner of fields, including food, drugs and criminology.

There are various types of chromatography, each with its own strong points. All of them can be and are used in the cannabis industry. Two of the most common are gas and high-performance liquid chromatography.


Gas chromatography (GC) is used for a variety of purposes, including the testing of a sample’s potency, screening for pesticides and other undesirable substances, as well as terpene analysis.

When testing for the cannabis industry first took off, laboratories primarily used gas chromatography. However, this form of chromatography was found to have a negative effect on acidic cannabinoids and their decarboxylation due to the need to use heat on testing samples. Additional steps must be taken when using gas chromatography for cannabinoid analysis in order to prevent this undesirable effect, which adds both time and costs.

Due to this, liquid chromatography (LC) is preferred over gas when testing for potency and analyzing cannabinoids and terpenes. That said, GC is still a preferred method for the detection of pesticides and other potentially harmful substances, such as solvents used in processing extracts.


Liquid chromatography has become the preferred method for the analysis of cannabis samples for their potency and for the determining of a sample’s cannabinoid and terpene profile. Over half of cannabis testing labs utilize LC. It can also be used to detect the presence of pesticides, fungi and other toxins. It is cost-effective and requires zero heating of samples, making it an effective alternative to the negative effects of gas chromatography.

Although GC and LC are the most common forms of chromatography, other methodologies are starting to become more prevalent. They include thin-layer chromatography, centrifugal, supercritical fluid chromatography, and reversed-phase column chromatography.

Photo courtesy of Polina Tankilevich at Pexels

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Derek Johnson

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