A novel protocol for measuring Cannabinoids and other Cannabis compounds based on IROA
Speaking at the Analytical Cannabis Expo East Online 2020 back in October, Dr Chris Beecher, CSO of IROA Technologies, presented a novel protocol for measuring cannabinoids using IROA.
One of the difficulties of working with Cannabis is that so many of the cannabinoids have the same formula, and therefore, have the same mass. Furthermore, they may be structurally similar enough that they tend to cluster in most chromatographic systems. Since small changes in solvent composition, or column health may cause retention times to drift it is important that the identification of each peak be verified. ClusterFinder algorithms are used to find to ensure accurate identification and quantitation.
The IROA Workflow incorporates two (2) Cannabis standards: 1) a Long-Term Reference Standard (LTRS); and 2) a chemically-identical but isotopically-different Internal Standard (IS) that ensures enhanced quantitation. These IROA standards exhibit unique isotopic patterns which make the parent compounds, their adducts and fragments easy to identify and also serves to distinguish biological data from noise or false data.
The LTRS is analyzed to generate a “library” of daily RT, m/z, formula and fragmentation data so that the identification of every peak can be mapped to compounds in the analytical samples. The LTRS, as a long-term standard sample, is analyzed multiple times during every analytical run to determine instrument performance characteristics.
The amount of IS added to the experimental sample is the same amount as present in the LTRS so that the concentration of all compounds in the IS is mirrored in the LTRS. With a verifiably identified internal standard in every sample the natural abundance compounds in the experimental samples may be verifiably identified, quantified, ion-suppression corrected, and sample-to-sample normalized.