Natural and Synthetic Standards for Cannabinoid Identification and Potency Determination
The quantitative power of an analytical method is often measured by the quality and performance of the reference standard. This is true in many applications including the analysis of cannabinoid concentrations in cannabis extracts by means of HPLC, LC-MS, and other techniques.
Companies such as Cayman Chemical offer a wide range of certified reference standards for natural and synthetic cannabinoid compounds, suitable for applications ranging from research to forensic testing.
Compounds with Certified Reference Material (CRM) in the name are highly qualified materials manufactured and tested to meet ISO/IEC 17025 and ISO Guide 34 international guidelines for reference materials. These materials are tested using validated analytical methods on qualified instrumentation to ensure traceability to SI units of measure.
Cayman states their CRMs are tested for Homogeneity and Stability and are provided with a certificate stating the CRM property value(s) along with the combined uncertainty of the property value(s). They further state these materials are intended for quantitative applications where quantitative accuracy and uncertainty are critical.
In total, the Cayman website lists 36 phytocannabinoid products. The Phytocannabinol Mixture 1 product is a mixture of 10 common cannabinoids of interest, and is meant to provide high quality standards for HPLC-UV, GC-MS, LC-MS, and GC-FID analysis. The ≥98% pure mixture contains Δ9-THC, Δ8-THC, Tetrahydrocannabinolic Acid, Cannabinol, Cannabidiol, Cannabidiolic Acid, (±)-Cannabichromene, Cannabigerol, Cannabigerolic Acid, and Cannabidivarin.
Phytocannabinoid Mixture 10 is also listed offering a larger total amount of standard per sample. Individual cannabinoid standards are listed as well, including: Δ9-Tetrahydrocannabinol (THC), Cannabigerol (CBG), and Cannabidiol (CBD), among a multitude of others.
In addition to CRMs, exempt preparations are also available for use as internal standards in analytical instrumentation such as GC and LC-MS. As an example, the Δ9-THC-d9 product contains 9 deuterium atoms on the pentyl group of THC.
The resulting shift in molecular weight is ideal for mass spec quantitation, as the peaks of the internal standard and the analyte can be clearly resolved without impacting the structure and behavior of the core molecule. This compound is exempt from certified status and formulated to meet criteria established by the US DEA – as such DEA registration and licensure is not required for purchase. The same holds true for the other exempt internal standards listed.
The TOX/BOX product from Cayman Chemical is an all in one kit designed to allow identification and quantitation of THC and its main metabolites from biological samples (blood and urine) using LC-MS. The product can be used to detect THC down to 1-5 ng, levels that meet or exceed current statute limits. The kit contains an analytical standards plate (48-well) containing both labelled and unlabelled standards. Also included is an ISOLUTE SLE+ 48-well plate for aqueous sample extraction and sample collection and preparation plates for sample processing. The TOX/BOX is meant to streamline sample preparation and enable compound analysis using high quality QCs and calibrators.
As the cannabis industry matures, analytical testing labs with have a greater need for quality reference materials and internal standards for cannabinoid identification and potency testing. Tools like those detailed above from Cayman Chemical may find expanded use beyond forensics and research applications, and will help drive the quality control and GMP aspects of this new industry. It is good practice to know the resources available as one ventures into an emerging field such as cannabis processing and production.