A spectroscopic technique (A-TEEM) classified cannabis chemotypes with 100% accuracy and quantified THC and CBD with precision comparable to standard chromatography methods — in under 45 seconds per sample.
Read this if you work in cannabis testing, regulation, or product quality control.
<45 secondsTime for A-TEEM to quantify cannabinoids with accuracy comparable to HPLC
What the researchers found
The A-TEEM technique, combining UV-visible and fluorescence spectroscopy with machine learning, classified 49 cannabis flower extracts into three chemotypes with 100% accuracy. It quantified total THC with LOQ of 0.061% and CBD with LOQ of 0.059% using GC-FID reference data, with cross-validation and prediction values >0.99. Using HPLC reference data, it achieved even lower LOQs for THC (0.026%). The method could separately quantify acid and neutral forms of cannabinoids and discriminate between legal and illegal chemotypes.
Why it matters
Cannabis testing is currently expensive and slow, requiring chromatographic equipment. A 45-second spectroscopic method could dramatically reduce costs and turnaround times for the cannabis industry and regulators.
The numbers in context
- 49 dry flower extracts from 84 accessions
- Chemotype classification: 100% accuracy
- THC LOQ: 0.061% (GC-FID) / 0.026% (HPLC)
- CBD LOQ: 0.059% (GC-FID) / 0.080% (HPLC)
- Cross-validation and prediction: >0.99
- Data acquisition: <45 seconds per measurement
- 12 cannabinoids quantified
How the study worked
Absorbance-transmittance excitation emission matrix (A-TEEM) spectroscopy with extreme gradient boost (XGB) discriminant analysis and regression. Validated against GC-FID and HPLC reference methods on 49 cannabis extracts.
Who was studied
49 cannabis flower extracts from diverse panel of 84 accessions
What this study cannot tell us
Tested on dried flower extracts only — may not work for other product forms. Requires solvent extraction (though simple). Model built on 49 samples; broader validation needed. Equipment cost for A-TEEM devices not discussed.
How to read the evidence
Analytical method development with rigorous validation against standard methods. Strong proof of concept for a specific application.
When this study was published
Published in 2023. Represents the cutting edge of rapid cannabinoid analysis technology.
The bigger picture
Rapid, inexpensive cannabinoid testing could democratize quality control in the cannabis industry, enable point-of-sale verification, and help enforcement distinguish legal hemp from illegal cannabis in seconds rather than days.
Questions still open
- Can A-TEEM work on cannabis edibles, concentrates, and other product forms?
- How does the instrument cost compare to HPLC systems?
- Could this be developed into a handheld field testing device?
Read the original research
Absorbance-Transmittance Excitation Emission Matrix Method for Quantification of Major Cannabinoids and Corresponding Acids: A Rapid Alternative to Chromatography for Rapid Chemotype Discrimination of Cannabis sativa Varieties.
Cannabis and cannabinoid research, 8(5), 911-922
Citation
Gilmore, Adam M; Elhendawy, Mostafa A; Radwan, Mohamed M; Kidder, Linda H; Wanas, Amira S; Godfrey, Murrell; Hildreth, Jana B; Robinson, A Edward; ElSohly, Mahmoud A. (2023). Absorbance-Transmittance Excitation Emission Matrix Method for Quantification of Major Cannabinoids and Corresponding Acids: A Rapid Alternative to Chromatography for Rapid Chemotype Discrimination of Cannabis sativa Varieties.. Cannabis and cannabinoid research, 8(5), 911-922. https://doi.org/10.1089/can.2021.0165