Cannabis Testing and Analysis

Cannabis Testing and Analysis: A Growing Industry

The recent decriminalization of cannabis in many states and countries has left scientists and government agencies scrambling to set up testing processes and regulations. One of the biggest concerns of a cannabis testing lab is safety. Cannabis has several known contaminants, including pesticides, heavy metals, residual solvents, and mycotoxins. In addition, it is often necessary to confirm strain and test for the presence of cannabinoids and terpenes to determine potency and effect.

Common Test Procedures

Common test procedures and corresponding equipment needs for cannabis testing are discussed below:

• Sample preparation: Sample preparation for cannabis testing depends on the condition of the sample prior to testing and the downstream application. Labs may test cannabis products in the form of dried flower, cannabis extracts and concentrates, and edibles, each of which will necessitate a slightly different sample preparation routine.
• Cannabinoid analysis: Cannabinoids include THC, CBD, and CBN; common methods of analysis for these compounds include HPLC and GC.
• Terpene analysis: Terpenes, known for their fragrance-conferring properties, also provide some of cannabis’s medicinal properties. Common methods of analysis include GC/MS, gas chromatography/flame ionization detection (GC/FID), and HPLC.
• Strain analysis: PCR is the most common technique used for strain analysis.
• Heavy metal detection: Heavy metals, including cadmium, mercury, lead, copper, tungsten, and arsenic, can be present in cannabis products. Mass spectrometry is an important tool for testing heavy metals in cannabis, as are techniques such as ICP/MS, ICP/OES, and AAS. Liquid chromatography is less commonly used, but is an effective method for arsenic testing.
• Pesticide testing: Pesticides used by growers can cause toxic effects if consumed. Techniques such as HPLC, GC/MS, and LC/MS are commonly used for pesticide analysis. The QuEChERS method is often employed for sample preparation prior to LC/MS/MS.
• Residual solvents: Solvents used to extract cannabis can include acetone, ethanol, butane, benzene, and propane, and these can remain in the final product. Headspace analysis coupled with GC is a common way to test for residual solvents. Other methods used include GC/FID and GC/MS.
• Microorganisms and mycotoxins: Cannabis can become contaminated with microorganisms such as mold, mildew, bacteria, and yeast as well as fungal toxins such as mycotoxins and aflatoxins. A dissecting microscope provides a quick visual assessment of mold and mildew, but more advanced methods are needed for a thorough examination. PCR is often used to detect distinct bacterial strains and toxins as well as traditional microbiology techniques such as petri film analysis.

What Are Key Considerations for Cannabis Testing and Analysis?

The factors that most influence the setup of a cannabis testing lab are the types of testing that will be performed and the volume of testing that will be done. It is also essential to know and adhere to the regulations in place for the particular region where the testing is being conducted. In the U.S., guidelines are currently dictated by state and can thus vary significantly.