pH balancing THC distillate (quick oxidation/color issues)

Hash and Stuff Pre/Post-Processing
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I’m having a helluva time with rapid surface (often noticeable within 24h) oxidation that turns the surface dark on distillate that has been through pH’d saline washes and/or magsil column for pesticide remediation. This is on 2nd pass distillate that normally has no color problems whatsoever, and stays remarkably color stable for a month+ before noticeable oxidation discoloration.

At first I was told by @photon_noir that this was simply “gum oxidation”, and that degumming will fix it. I degummed, and still seem to be getting it. I degummed using columbo’s DGUM and SOP, and used only a separatory funnel with multiple water washes, and did not further filter the solution or winterize it afterwards (it was already winterized).

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If it isn’t gums oxidizing, it’s the cannabinoids or cannabinoid-like byproducts of the distillation. That’s generally the rose color people see in very pure almost colorless stuff, and yes, it is purple if exposed to basic pH at some point during processing. I believe this pink color is the formation of quinoids, which are oxidized cannabinoids that actually have extra oxygen atoms attached to them at various sites on the molecules.

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For shits and giggles…here’s some reading y’all may be interested in:

US Patent - US9637706 May 2, 2017 “Refinement of Oils Using Green Tea Extract Antioxidants”

Looks like they suggest using the extract to reduce oxidation of oil products.

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Places like Vitamin Shoppe sell the liquid form online. I don’t know if there is a purity threshold or anything but it looks like a $15 bottle won’t set you back much.

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Some bits from the patent if you haven’t scanned over it:

The antioxidant composition used in the disclosed methods comprises one or more antioxidant components, at least one of which is a green tea extract. Though not required, one or more additional antioxidant components can also be present along with the green tea extract. In one specific example, the antioxidant composition comprises a green tea extract, rosemary extract, tocopherols, and other antioxidants.

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After the oil and antioxidant composition, which again contains a green tea extract and optional other antioxidant components, are combined to form a mixture, the oil is then deodorized. An alternative method involves adding the antioxidant composition containing a green tea extract during deodorization, or just after when the temperature of the oil is beginning to cool and has a temperature of about 90° C. or above.

Steam or nitrogen deodorization are the preferred process for deodorization (see e.g., Bailey “Steam Deodorization of Edible Fats and Oils,” Ind Eng Chem 33(3)404-408, 1941). Deodorization can also be achieved by molecular distillation, wiped film distillation, supercritical fluid extraction, or any other suitable method in the art can be used for Deodorization reduces or removes volatile compounds from oil that may impart odors to the oil.

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Not wishing to be bound by theory, adding citric acid after deodorization promotes the synergistic effect of the pre-deodorization antioxidant composition (i.e., the green tea extract and optionally rosemary extract and tocopherols) by chelating metals such as Fe and Cu, which induce auto-oxidation during storage. Thus, citric acid can prolong the oxidative stability of the oils and allow the oils to be stored for long terms. On the other hand, citrate esters should be avoided because they can make the oil cloudy.

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The oils obtained by the disclosed methods have enhanced sensory and oxidative stabilities. The stability of these product compositions can be determined by measuring, for example, the peroxide value of the compositions. Peroxide value (PV) refers to the concentration of peroxide compounds in the oil measured in meq/kg. Peroxide compounds are produced during oxidation of the oil; thus, an increased peroxide value after a period of time, as compared to initial peroxide values at the initial time, indicates that oxidation has occurred. The peroxide value of the product oils can be minimized by reducing the formation of peroxides or by removing/decomposing the peroxides present in the oil. Thus, the oils prepared according to the methods described herein have minimized peroxide values due to the use of the antioxidants as described herein. Any method for measuring the peroxide values of an oil as known in the art can be used in the methods described herein, such as, for example, AOCS Cd 8-53, which is incorporated by reference herein in its entirety.

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The disclosed products can also contain low levels of oxidized fatty acids and/or aldehydes. For example, many oils containing unsaturated fatty acids can oxidize and break down, resulting in the production of volatile aldehydes like hexanal and a non-volatile portion of the oxidized fatty acid, which remains part of the composition. The products disclosed herein can have reduced levels of such oxidized fatty acids and/or aldehydes, as compared to other marine oils.

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Alternative Methods

In one aspect, the disclosed methods can also involve a bleaching step. The bleaching step can occur before the oil is combined with the antioxidant composition or after the oil and antioxidant composition are combined, yet before deodorization. Thus, in one embodiment, the disclose method comprises the step of combining a bleached oil and antioxidant composition as disclosed herein before deodorization. In an alternative embodiment, the disclosed method comprises the step of combining an oil and antioxidant composition as disclosed herein, bleaching the oil, and then deodorization.

In still a further embodiment, the oil can be contacted with a tocopherol, bleached, combined with the antioxidant composition comprising a green tea extract, and deodorized.

Bleaching oil can be performed by contacting the oil with an adsorbent to provide a mixture, heating the mixture to from about 100 to about 210° C(Adjust temps for use with cannabinoids)., and removing the adsorbent from the mixture, to provide the bleached oil. Suitable adsorbent can be silica, clay, carbon, or a mixture thereof.

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I’ve done some (unsuccessful) experiments with tocopherol (vitamin E) for it’s antioxidant properties. However it wasn’t with degummed material… Side note, it made the distillate taste/smell like anise

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P Anisidase(sp) test is the odorant content metric. I’m hoping greent tea extract is a superior version of using tocopherol. You would also want to distill the material after adding the antioxidant according to this patent.

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The stuff I added is a potential fix for oxidation issues if a simple pH adjustment doesnt do it for you. You aren’t the only one experiencing this.

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Definitely not the only one.

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Delta 9 THC is unstable and has a shelf life when not held under vacuum OR shielded in some fashion from atmosphere. I have left waxes in the product on purpose but otherwise ran my unit to produce slightly opaque clean pale yellow product. This substantially halts the degredation and I believe the mechanics are the waxes provide a barrier against atmosphere.

Here is a photo of the run I did but left the waxes in it. It retained this appearance for weeks as I dabbed with only a slight perceptible darkening over several weeks. My avatar photo shows what this same process produces but without waxes left in. The wax content dab has a slight off taste but not harsh and potencies between the two dabs feel about the same when vaped.

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We are not the only ones who struggle with this. I dug pretty deep these last several years as I developed my own Tek. The manufacturers of Dronabil believe the red compound that forms from THC to be an oxidative degeneration into cannabinol. This is what their tests say it is. To protect it they put it into sesame oil and even have traces of isopropyl alcohol listed as inert (protective) contents in each pill.

I discarded traditional distillation techniques and now can run most batches at 130C as measured at the heat mantle. The thermal breakdown products during the run are a bare minimum. Pressures to carry this out are ¾ of one micron. I use a variety of chromatography techniques as well. When my med does get red after being left out then I just dump it into the cryogenic sublimator (which has almost no hold up) and run it again. The deep red traces of compound will be left behind and once again potency is water clear and very pale yellow.

Yet left out within just hours really it begins to take on a noticeable red hue. In my process it is unlikely that the Ph or any such factor is causing this. The manufacturers of Dronabil call the red byproduct cannabinol and they believe it happens from oxidation. Their pills are designed to mitigate this. Even then it is considered a “success” to have just a 90 day shelf life. (Of course medicinal standards are very high for shelf life.)

Here is a copy and paste of results in the synopsis of a government published study:
from the national library of medicine;
“RESULTS:
The appearance of the dronabinol capsules remained unaltered during frozen, cold, or room-temperature storage. Regardless of storage condition, the percentage of the initial Δ9-THC content remaining was greater than 97% for all evaluated samples at all time points over the three-month study. These experimental data indicate that the product packaging and the sesame oil used to formulate dronabinol capsules efficiently protect Δ9-THC from oxidative degradation to cannabinol; this suggests that pharmacies can store dronabinol capsules in nonrefrigerated automated dispensing systems, with a capsule expiration date of 90 days after removal from the refrigerator.”

Full link: Stability of dronabinol capsules when stored frozen, refrigerated, or at room temperature - PubMed

I am convinced the red I see develop in my med after even third run purity to be oxidative degeneration into cannabinol and do not believe my process impacts this except that it produces high enough purity that natural oxidative barriers are removed (like waxes). Trying to halt this in THC by adjusting refinement parameters is unlikely to work to stop this. It is oxidation and the oxygen must be prevented from intimate contact.

On a personal note, my favorite vaping is when the THC has aged for one day or so to just begin to take on a red hue. I get chuckles and grin a lot when vaping just slightly pink but otherwise pure compound, but when it degrades further it simply loses too much potency. A slight red hue imparts a delicious flavor to me as well although subtle but my point is that the medicine at absolute purity (which is sub orbital high lolz) becomes more enjoyable with just some slight aging into pink. I always see signs of purple in a first run after it sits in the freezer overnight that produces clear but it fades to red and subsequent runs this purple trace does not manifest. It was easily removed via DCVC chromatography and it is a mystery to me what this purple compound is. However removing it had no effect on the aging to red that I could detect.

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You could store the material under nitrogen atmosphere which would keep the oxygen out and prevent oxidation. Just pump/purge with nitrogen gas 3-5x.

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Any thoughts on the green tea extract patent I posted? The trouble seems to be finding an antioxidant that does not ruin flavor.

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Is it possible that the problem is you’re getting better?

If we take Beaker’s post on Drobinol at face value, the higher purity your extract is, the more susceptible to oxidative damage it is.

you’ve now pulled that last 3% protective waxes out, and your reward is pinks and purples and oxidation.

I’ve got no clue, but it is one way of putting the pieces presented here together.

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If you scroll up I posted the patent number. If you type it into Google you can read it and most of what you’re looking for is in there.

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It is pretty normal to see a red/purplish layer at the top of a jar of high purity distillate after several days or a week or so. I don’t think there is much to do to prevent this other than reduce exposure to oxygen. It would need to be vacuum purged while still a liquid and then backfilled with nitrogen and repeated several times would be my guess.

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For the record, over 80% distillate is still relatively high purity. So yeah, if you have a lot of THC it’s going to oxidize. However, I did find an old cartridge with some “high purity” (~93% THC, 97% total cannbinoids) thc, no terpenes added in my car that had been sitting there for almost a month, and the product was made 4-5 months ago. It still just looks yellow evenly throughout. Maybe a slightly darker or more golden yellow than originally. Maybe it oxidized and just mixed evenly? I have no idea.

Have you actually put your product into cartridges undiluted? It might have a better visual shelf life in that form than you are expecting. Test it out.

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@Beaker thinks its “fats and waxes” that are acting as the anti-oxidant. and has a protocol for leaving them in there. not sure how to adapt from his sublimator to a WFE.

carotene probably isn’t a bad bet either. given that it’s colored, you should at least be able to follow it in your eluate.

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