Accurately measuring cannabinoid levels is a crucial element of a legitimate cannabis industry, and also one of the trickiest so far, with various cases of drastic inaccuracies and contaminations highlighting the lack of consistency and room for improvement. As the industry and market demands move beyond THC and CBD, toward more obscure cannabinoids, like delta-8-THC, the need for sophisticated and discerning measurement methodologies only increases.
Measuring delta-8-THC in particular comes with a specific problem – distinguishing it from its more popular isomer, delta-9-THC, or THC. And as we know, problem with THC levels come with serious legal implications.
A Certificate of Analysis (COA), which indicates that a product has gone through third-party testing, has so far been considered a major stamp of legitimacy. However, even it might not hold up when it comes to delta-8-THC.
She sent a batch of Delta-8-THC products with a “squeaky clean” COA for additional testing to ACS Laboratory, a DEA-licensed lab that’s pushing the envelope when it comes to measuring delta-8-THC in particular.
The original COA said the Delta8 solution contained less than 0.3% THC, but ACS’s new Delta8 analysis told a different story. The results of the test showed the solution contained illicit levels of THC. We had to retire the whole batch but luckily ACS caught the error before we went to production,” Stacey explains.
ACS uses Ultra High Performance Liquid Chromatography (HPLC) to measure delta-8-THC potency, because it enables testing samples at room temperature, without additional heat and its transformational effects on cannabinoids that can skew results.
Moreover, a study validated a high-performance liquid chromatography-tandem mass spectrometry method (HPLC-MS-MS) for 13 different cannabinoids, one of which was delta-8-THC.  The study involved 200 human subject oral fluid samples. Delta-8-THC was confirmed in 11 samples, with or without the presence of THC, which is a clear proof of this method’s efficacy in discerning between the two isomers.
Origo Labs uses couples HPLC with diode-array detector (DAD) to distinguish between the two.
Another study managed to develop “a simple, sensitive, selective, reproducible LC-MS method for the estimation of delta8-tetrahydrocannabinol (delta8-THC) and its metabolite, 11-nor-delta8-tetrahydrocannabinol-9-carboxylic acid (11-nor-delta8-THC-9-COOH), at low concentrations in small volumes of guinea pig plasma after topical drug application.” 
So far, HPLC, HPLC-MS-MS, HPLC-DAD, and LC-MS seem to be the most reliable and accurate methods for measuring delta-8-THC levels without putting this compound under the umbrella of THC and all its isomers.
- Lin et al, Quantitation of Δ8-THC, Δ9-THC, Cannabidiol and 10 Other Cannabinoids and Metabolites in Oral Fluid by HPLC–MS-MS, Journal of Analytical Toxicology, bkaa184, Impact Factor = 3.513, Valiveti et al, LC-MS method for the estimation of delta8-THC and 11-nor-delta8-THC-9-COOH in plasma, July 2005, Journal of Pharmaceutical and Biomedical Analysis38(1):112-8, Impact Factor = 3.209; Times Cited =12
Image Credits: flickr / Governor Tom Wolf