Short answer: minor-cannabinoid profiles can add discriminatory information beyond the usual THC-to-CBD ratio. They may help characterize and compare cannabis varieties, but they do not automatically identify the source of an unknown sample.
Cannabis is commonly divided into chemotypes using the relative amounts of THC and CBD. That approach is useful for broad classification, yet the plant contains many additional cannabinoids. Monti and colleagues asked whether these minor compounds could reveal chemical differences hidden by a two-analyte system.
The researchers studied inflorescences from 18 cannabis varieties grown under standardized conditions. That control reduced some environmental variation and made comparison of variety-related fingerprints more informative.
The team developed and validated a liquid-chromatography, high-resolution mass-spectrometry method. A targeted analysis measured 15 cannabinoids. An untargeted metabolomics workflow then searched more broadly for additional features, with in-silico assistance and manual review.
The untargeted process identified 19 additional compounds. Principal component analysis of the targeted and untargeted datasets produced subgroups extending beyond traditional THC/CBD classifications.
Principal component analysis reduces a large set of correlated chemical measurements into a smaller number of components that capture major patterns of variation. Samples that cluster together have similar measured profiles; separated clusters differ across the variables driving the model.
A cluster is not, by itself, a legal identity test. Results depend on the analytes, preprocessing, instrument performance, reference samples, and statistical model.
Cannabinoid profiles can be affected by genetics, plant age, environment, harvesting, storage, and processing. Growing the 18 varieties under common conditions helped the study focus on differences among varieties. A seized or retail sample, however, may have an unknown history and may not match those controlled conditions.
A minor-cannabinoid fingerprint may support:
It does not establish common origin unless the reference population, error rates, validation, and alternative sources are addressed. Similar profiles can occur in different materials, while material from one source can change during growth or processing.
Minor cannabinoids can substantially enrich cannabis characterization. The study demonstrates analytical discrimination among controlled varieties, not infallible attribution of every unknown sample. A defensible source opinion must connect the validated laboratory method, the comparison population, and the strength of the statistical association.
Source: Monti MC, et al. “Beyond Δ9-tetrahydrocannabinol and cannabidiol: chemical differentiation of cannabis varieties applying targeted and untargeted analysis.” PubMed PMID 35380230; doi:10.1007/s00216-022-04026-2.