Hello! I frequent the Future 4200 forums in search of answers that often come up in my work. I am a laboratory tech in an extraction lab associated with a dispensary. We do extraction with different solvents different ways and my responsibilities involve much of the vacuum distillation used to procure high concentration delta 9 distillate.
Some time ago we produced a less than satisfactory green shatter. In the effort not to let the material go to waste we made several attempts to clean it up, get rid of the funky color and associated smell. Try as we might, no effort to remove both the color and the smell was successful and the wack shatter was consigned to distillation to try and capture the cannabinoids away from whatever contaminant was producing such unappealing properties.
That distillation run was not only one of the highest purity distillations the company has achieved but also primarily delta 8 thc (99.2% total cannabinoids, 86.5% delta 8, 11.3% delta 9). Now the name of the game has been to reobtain and refine the SOP for consistency and in these trials a peculiar trend has arisen. When delta 8 was recovered during distillation the heads leading up to the 150+ vapor temp range always contained a strikingly blue fraction. When delta 8 was not present (or present only in a tiny concentration, say <8% total) the blue heads were notably absent. Some of the material used for positive runs was already old, darkened distillate itself (routinely tested above 92% d9 with terps already removed) so the likelihood of a blue terpene existing there in concentration is slim.
The key seems to be the presence of an acidic environment in the boiling flask during distillation. I have observed extensively others using bleaching earth, clays and Lewis acids for isomerizing both CBD and d9-THC into d8-THC however we have measured marked success using even a strong Bronsted-Lowry acid in low concentrations placed directly in the boiling flask during vacuum distillation.
What I am mostly interested in is the chemical processes that are occurring to produce these results.
The inclusion of a strong acid is clearly enough to alter the position of the double bond in the cannabinoid molecule but it is not behaving in a purely catalytic fashion. The resulting distillate and residue in the flask both respond negatively for the presence of acid when treated with a sodium bicarbonate solution. The ratio of d9 and d8 can vary, CBN and CBC come and go in varying amounts between tests. The residue in the boiling flask after distillation has a characteristic sulfurous odor that sulfuric acid lacks, suggesting the presence of detectable by-products.
I’ve heard mention of HHC being produced via the hydrogenation of the phenolic double bonds, and that HHC can sometimes produce a false positive as CBC by various testing agencies. Is it possible that the reaction of sulfuric acid with some cannabinoid or terpene is producing hydrogen gas and hydrogenating other molecules under high heat and vacuum?
If azulene or chamazulene are present due to an acidic reaction then what is the most likely reagent that is interacting with the acid to produce a bright blue fraction?
I have searched for others discussing the matter but most seem to be curious in how to prevent or dispose of these oddly colored heads. I seek to understand and better characterize just what is going on. Anybody with experience or insight into the matter would be greatly appreciated for coming forward.