Gas Chromatography for Cannabis Analysis

Written by Asia Mayfield

The cannabis industry desperately needs more rigorous testing requirements. A few states have introduced a host of serious regulations as recreational laws were born, but there’s no consensus across states.

Standardization is necessary for improvement. Cannabis consumers want testing laboratories to accurately identify pesticides and contaminants. Cannabis flower samples are still being failed for containing levels of toxic substances that are above permissible thresholds.

In addition to adulterants, modern consumers also want to know the terpene and cannabinoid content of their dispensary purchases.

Gas chromatography (GC) is often used by cannabis testing labs to delve into the intricacies of a sample strain. When performed correctly, the technician can use GC to learn about the sample’s potency, terpene profile, and if it’s contaminated with something foul.

Necessity drives innovation. GC used to be reserved for well-funded, experienced labs. Now, however, new instruments and methods are being created, making the technology more accessible to smaller operations.

Growers and industry leaders can now glean critical information about their strains before sending them to be tested by the state. Instruments exist that make it affordable for small operations to perform their own, in-house GC analyses.

Vacuum ultraviolet spectroscopy (VUV) is being developed as a new form of GC detector. Technicians who master the VUV detector can analyze almost every molecule of the sample, since multitudes of chemical compounds absorb light in the vacuum ultraviolet region (120-240 nm) of the electromagnetic spectrum captured by the detector.

“The qualification of cannabinoids and their metabolites is fast and simple with a GC–VUV system,” reads a study published by Separation Science Plus.

“This new method may be used for a rapid determination of these analytes in different types of matrices, and due to its short analysis time, may help facilitate routine analysis, without necessarily requiring a baseline separation of similar cannabinoids for their correct quantification.”

Many cannabis testing labs have been using flame ionization detectors (FID) on their GCs. Mass spectrometry is another popular detection method. Some researchers believe that VUV detectors will produce better results, but this hasn’t been conclusively demonstrated.

As medicinal and recreational cannabis laws become more common, consumers have become more educated about terpenes. They want to know how much THC is in the flowers they’re purchasing from the dispensary but they also want a detailed analysis of the terpene profile.

The birth of new technologies, like the VUV detector, will help growers and testing labs ensure better product safety.

About the author

Asia Mayfield

Asia Mayfield is a freelance writer who focuses on the cannabis industry. She can be reached at

Leave a Comment