cannabis chromatography

Liquid Chromatography in Cannabis Testing

Cannabis is one of the most widely-consumed substances on the planet. The United Nations (UN) estimates that as many as 188 million people around the world use the drug in some capacity, accounting for over 3.8% of the global population. In the past, this figure might have been cause for concern, but the cannabis market has changed dramatically in recent decades. Global users now straddle illicit and legitimate markets that are regionally regulated; which makes for an extremely complex worldwide industry.

Liquid chromatography is central to a broad cross-section of cannabis testing applications. It has been used to help characterize the 100+ cannabinoids extracted from the cannabis plant, demonstrating radically different pharmacological mechanisms of action from one to the next. In this respect, liquid chromatography has been instrumental in disproving many of the unfounded claims often used in support of cannabis prohibition. It has even demonstrated the many medicinal benefits of the drug, although the opinions of global regulators are yet to align on this front.

Even in regions where cannabis prohibition has been repealed to some extent, illicit markets still exist. Liquid chromatography is used to help enforce local regulations, and to interrogate the state of illegal marketplaces from a basis of sound science.

Applications of Liquid Chromatography in Cannabis Testing

Liquid chromatography is implemented in numerous ways to help professionals on either side of the cannabis market’s gulf in legitimacy. Typical applications include, but are by no means limited to:

  • Agrochemical and pesticide screening
  • Cannabinoid profiling
  • Mycotoxins detection and characterization
  • Toxin and contaminant screening

Case Study: Cannabis Potency Testing

Cannabinoid analysis is central to all cannabis research and development (R&D) processes, providing insights into pharmacokinetics and biological mechanisms of action. The concentration of distinct cannabinoids is an indicator of potency, which has proven to be one of the primary flashpoints in the debate surrounding cannabis legalization.

Tetrahydrocannabinol (THC) is the chief psychoactive compound. It is responsible for the primary side-effects sought after by recreational users (analgesic effects, euphoria, mood alteration, etc.), but is also understood to exacerbate anxiety and psychotic disorders. By contrast, cannabidiol(CBD) is the main medicinal compound of the drug, forming the basis of numerous emerging treatments and interventions under consideration by medical regulators worldwide today. CBD is even believed to modulate the effects of THC when coexisting in the drug in the correct ratios. This complex relationship is merely one example of how the 100+ cannabinoids interact, and liquid chromatography is key to exploring these interplays to determine drug potency.

For example, the World Drug Report has shown a sharp increase in cannabis potency over the last decade. Products typically boast a high THC concentration and comparatively low CBD. This increases the risk that frequent cannabis users will develop severe mental health disorders like schizophrenia.

Trends in cannabis use vary from region to region, given strikingly different governmental and regulatory approaches to legislation. Prevalence in most regions typically remains stable from year to year but there have been widespread transformative changes to the American markets, where prohibition is gradually being repealed at the state level. Thirty-three states have legalized cannabis in a broad capacity, while Canada has completely legalized the drug for both medical and recreational purposes. As a result, the World Drug Report shows a significant increase in the number of people who used cannabis in North America within the past year. Past-year users of cannabis in Canada and the U.S. have respectively risen by 25% and 50% since 2015. Liquid chromatography can be used in these regions to ensure that safe products are released to consumers, with regards to potency and quality.

KNAUER: Liquid Chromatography Suppliers

KNAUER is one of Europe’s leading manufacturers and suppliers of liquid chromatography instrumentation for analytical and preparative applications. The methods used by cannabis testing facilities are similar to general liquid chromatography procedures, allowing the use of standard high-performance liquid chromatography (HPLC) columns and devices as opposed to specialist systems. We can provide a range of instruments suitable for the analysis of cannabinoids, whether you are performing quality assurance and control (QA/QC) or performing systemic research.

Contact a member of the KNAUER team today if you would like to learn more.

Liquid chromatography is used for many cannabis testing applications. It has been used to help characterize the 100+ cannabinoids extracted from the cannabis plant.

Using chromatography to purify cannabidiol for medical applications

We look at the importance of chromatographic purification in the production of medical-grade cannabidiol (CBD) for modern therapeutics.

Demand for CBD in medicinal research and treatment

The legalization of cannabis for both medicinal and recreational purposes is a hot industry topic in 2020, as pros and cons of its de-criminalization continue to be debated across the globe. The discovery of specific cannabinoids, such as CBD, that demonstrate promising characteristics for medical treatments, has resulted in an increasing demand for highly purified, safe cannabis-derivatives. This has prompted a need for robust analytical methods of purification that can provide reliable results for both manufacturers and consumers alike.

What is CBD?

CBD, the colloquial term for Cannabidiol, is one of at least 100 active compounds (cannabinoids) that can be found in hemp or marijuana cannabis plants. These chemical compounds join to the cannabinoid receptors of the body and brain, also known as the endocannabinoid system, to produce different effects.

CBD is a non-psychotropic cannabinoid, so it doesn’t create a “high” sensation. Instead, it demonstrates effective pain relief and anti-inflammatory properties, resulting in a growing interest in its potential medical applications. There is currently no evidence to suggest that there is any dependence potential of CBD and it is not associated with any major side effects.


A lot of focus is given to separating CBD from THC (or tetrahydrocannabinol), another cannabinoid derived from the plant. This is to remove the psychoactive effects of THC that have led to its status as a controlled substance in many countries worldwide. Both cannabinoids, although chemically similar, interact with the body’s endocannabinoid system in very different ways. THC binds with the CB1 (cannabinoid 1) receptors in the brain to produce a sense of euphoria, or a “high”. In contrast, CBD has a very low affinity to the CB1 receptors. This interaction with the body’s cannabinoid receptors affects the release of neurotransmitters. These chemicals play a part in pain, pleasure and memory amongst many other bodily functions. The indirect effect of CBD on the endocannabinoid system enhances the body’s natural levels of endocannabinoids through occupying select enzymes. The limit for THC content in cannabis-derived products is currently 0.2 % in the EU, 0.3 % in Canada and set at similar levels around the world, meaning that removal of THC from CBD is a requirement for commercialization.

Applications of CBD

The US FDA has, to date, approved one medical product containing CBD. Epidiolex, which contains a purified form of the drug substance CBD for the treatment of seizures associated with Lennox-Gastaut syndrome or Dravet syndrome in patients 2 years of age and older. This means that the FDA has concluded that this particular drug product is safe and effective for its intended use. The FDA has resources available that address their stance on cannabis products like CBD. You can view these resources here for more information.

CBD is also showing encouraging results in the treatment of:

Chronic Pain Relief

Neurological disorders such as Alzheimer’s disease

Extraction and purification of CBD through chromatography

Chromatography is proving the most effective method in the purification of cannabidiol as it acts as the cleaning stage once the CBD has been extracted. But achieving highly pure CBD for medicinal applications requires numerous pre-treatment stages to ensure the removal of impurities that could potentially foul the resins used in chromatography. This can include shredding the plant, drying, extraction, decarboxylation and distillation before the chromatography step can be performed. The removal of contaminants from cannabinoids is a prominent manufacturing challenge, but chromatography is becoming the leading purification method because of its quick and evident results.

CBD extraction

Extraction is usually the first step in the preparation of CBD. If the product contains both CBD and THC, then the extraction process becomes more complex. There are different methods of extraction available, but the three most common methods used are CO2, solvent and olive oil extraction. CO2 extraction is considered the most effective of these methods due to the production of consistent high quality concentrations of CBD. Although this demonstrates effective separation of cannabinoids, it is not enough to achieve the purity now required by manufacturers.

Reverse Phase Chromatography

Reverse phase chromatography is a widely utilized analytical method for purification because of its ability to separate compounds of varying hydrophobicities. This is effective in the separation of tetrahydrocannabinol from CBD, as THC has a greater hydrophobicity, allowing efficient removal of small amounts of THC from a CBD-dominant product. The larger the separation peaks identified in this method, the better the purification will be from a higher number of sample loads.

High Performance Liquid Chromatography (HPLC)

Liquid chromatography is considered an important method for determining concentrations of cannabinoids within the cannabis plant. High performance liquid chromatography (HPLC) is probably the most commonly used method for the separation (or remediation) of THC from CBD. It offers the ability to test for THCA, a compound normally untraceable in other methods. It is also a reliable choice for potency determination, allowing you to identify cannabinoids with similar structures in just one accurate analysis.

Chromatography resins for CBD purification

As we have seen, the pre-treatment of CBD before its purification is extremely important in order to provide cannabidiol-based treatments. Our range of Chromalite chromatographic resins offer an affordable and effective method to separate THC from CBD. The chemical and physical strength of these compounds means that traditional silica media can be damaged during chromatography, resulting in the need for expensive replacements. After vigorous testing of their mechanical stability, Chromalite resins show a much lower breakdown over time than equivalent competitor resins. As a result, they are stable for a long lifetime and will withstand tough conditions of use.

Our PCG600M and PCG600C resins have a smaller pore structure, creating wider peaks and a larger time gap between the peaks making the purification process much simpler. Alternatively, our PCG900M and PCG900C resins have a larger pore structure, giving sharper peaks and a smaller time gap. Our PCG1200M and PCG1200C resins are also being used in these applications.

Ready to enhance your CBD purification process? Order your Chromalite resin here.

Click the link below to view the full scientific poster.

the importance of chromatographic purification in the production of medical-grade cannabidiol (CBD) for modern therapeutics