The global legal cannabis market is expected to reach $146.4 billion by the end of 2025. Growing adoption of cannabis in several medical fields such as cancer, mental disorders and chronic pain is expected to drive revenue growth in the near future. With this change in focus from recreational to medicinal, the legalization of cannabis is also driving the need to ensure quality control and standardized testing.
As with any other pharmaceutical drug, medicinal cannabis needs to undergo rigorous testing to ensure that it is both fit for human consumption and is delivered at the right potency to provide the medical outcomes that it is being taken for. Up to now, testing of cannabis has been sporadic and there is no universally agreed standard to which producers or testing labs must adhere to. Where regulations are in place responsibility for the testing is generally at a smaller number of approved independent testing laboratories.
Whilst such independent testing laboratories are vital for preventing potential conflicts of interest and the lack of credibility self-certification can bring for final product sign off, there should be more in-house testing going on throughout the supply chain to identify and eliminate problems earlier. Currently, cultivators, processors and retailers often have to wait weeks for results to come back from external labs, which means many companies are either not testing their product or are facing serious delays to their workflows. Testing is often not brought in-house because of a belief that it will be too expensive and complicated. This article looks at gas chromatography as a quality control testing method and how it is currently used in the market.
The need for cannabis analysis
One of the core issues with cannabis quality is the use of pesticides. In 2016, the Ministry of Environment and Health in the Netherlands reported that over 90 percent of cannabis plants had pesticides on them. Illegal producers of cannabis can supply cannabis unhindered with potentially harmful contaminants such as fungi or pesticide residues that are potentially threatening to health. It is evident that there is a need to develop appropriate analytical techniques for quality assurance and quality control laboratories for cannabis testing.
If ultimately categorized as a regulated pharmaceutical drug, cannabis would be rigorously tested to comply with stringent rules and regulations regarding quality (potency and purity) and safety of the product. However, as there is currently no centralized regulatory body that oversees this in Europe, the responsibility of quality assurance falls to the grower, manufacturer and processor. Regulation varies from territory to territory, for example, there are limits for pesticides in California, but these are different to those in Canada.
Gas chromatography (GC) is a widely used analytical tool for cannabis testing. Unlike other forms of chromatography, gas chromatography enables potency testing, terpenes profiling, pesticide screening and residual solvents analysis, all of which are carried out to protect the consumer market. Typically, the primary cannabinoids of interest for potency testing are: tetrahydrocannabinol (THC), cannabidiol (CBD) and cannabinol (CBN). A key goal in cannabis analysis is positive identification and quantification of the THC/CBD ratio. This is specifically significant for medicinal cannabis where CBD is often the primary component of interest and products with high levels of CBD and low levels of THC are sought after. Furthermore, it is perceived that acidic cannabinoids cannot be analyzed using GC. However, this is not true and by adding derivatization to the sample preparation it is possible to successfully analyze both acidic and neutral cannabinoids by GC.
Analytical instrumentation, such as GC, has long been perceived to require extensive experience in the laboratory, with training in chromatography or a deep understanding of analytical chemistry. However, with the increased need for quality control and quality assurance in the buoyant cannabis industry, GC technology is now more accessible to smaller companies and adapted for users with minimal GC experience. Newer instrumentation is more compact, cost-effective and ultimately, easier to use. While these instruments are no replacement for an accredited laboratory, they can give growers and processors an accurate result of cannabinoid percentages.
It is evident that the global cannabis production industry requires significant change and challenges must be overcome around analytical testing in order to provide consistently high-quality products. GC (and other chromatographic techniques) can alleviate this challenge, as it can be used for the rapid determination of THC and CBD concentrations in cannabis in order to characterize plant materials for medicinal and recreational cannabis applications. With the rapidly changing laws and regulations within the industry, this ability is going to be vital in order to provide a consistent, tested product to customers in the highly competitive marketplace.