Analytical HPLC for Cannabis Testing

As the legalisation of cannabis for both medical and recreational use continues to advance, researchers are relying on analytical HPLC to detect and characterise cannabinoids in various strains of the drug.

What are Cannabinoids?

The cannabis plant (Cannabis sativa) is a complex natural product known to produce at least 100 different compounds, many of which are present at extremely low concentrations. Many of the minor cannabinoids have shown some medicinal effects, so it is important to be able to separate and identify them. Quantitative analysis of trace constituents such as cannabinoids (THC, CBN, CBD), pesticides and mycotoxins in cannabis flowers and concentrates requires sample purification prior to instrumental analysis and is essential to ensure product safety, efficacy and quality.

Solutions for Purifying and Analysing Cannabis, Hemp and Cannabinoids

Liquid chromatography is central to cannabis testing applications. It has been used to characterise the more than 100 cannabinoids extracted from the cannabis plant.

Many market sectors use a combination of preparative and analytical HPLC for quality assurance and control (QA/QC) protocols to ensure a safe, high-quality product. These include cannabinoid profiling, potency testing by quantification of THC (presence/absence), determination of naturally occurring contaminants such as mycotoxins, and determination of man-made contaminants such as pesticides.

High-Performance Liquid Chromatography (HPLC) and Ultra Performance LC are ideal for potency testing because they can identify and measure structurally similar cannabinoids and their different forms (e.g. free form and corresponding acid forms of THC and CBD) in a single analysis.

Preparative chromatography is the method of choice when high-purity cannabinoids are to be produced from cannabis plants or raw extracts.

Analytical HPLC provides a quantitative basis for classifying cannabis according to chemotype. It is superior to many alternative techniques as it is not temperature-dependent, which guarantees that even cannabinoids at the lowest concentration are unlikely to undergo decarboxylation. This ensures that analytical HPLC are more representative of the actual crop as it gives insight into cannabinoid concentration in the native state.

Potency Determination with Liquid Chromatography Products from Waters

Liquid Chromatography Products: Alliance HPLC system and ACQUITY UPLC H-Class Plus in combination with CORTECS columns. A Waters application note for cannabinoid analysis can be downloaded here.

Key benefits:

• Dedicated and robust HPLC solution for cannabinoid profiling
• 16 cannabinoids completely separated by HPLC in only 26 minutes
• Rapid analysis of cannabinoids in less than 10 minutes using UPLC method
• Separation of structurally similar cannabinoids with UPC2

Testing Cannabis for Pesticides

Testing cannabis for pesticides is very important to ensure product safety and quality. The number of regulated pesticides that need to be monitored varies, as do the action limits, which range from 0.01 µg/g (10 ppb) to over 1 µg/g (1 ppm). The QuEChERS method has proven to be very effective for multi-residue analysis of pesticides and mycotoxins in a wide variety of food and agricultural products, including cannabis samples.

Pesticides and Mycotoxin Analysis Using QuEChERS Dispersive Solid Phase Extraction

Mass spectrometry (MS/MS) products: Xevo TQ-S micro and Xevo TQ-GC.

Key benefits:

• Simple extraction and dispersive SPE (dSPE) clean up procedure
• Simultaneous analysis of pesticides and mycotoxins
• Quantitative and confirmatory analysis using LC-MS/MS