You won’t be able to recover the solvent with the blow down on ebay, it’s not a distalation apperatus. You need to rotovap it to reclaim the solvent.
Might sound like something super basic. But I have had luck with loading the flask with C-Bleach and adding about a teaspoon of citric acid. Very limited to no oxidation over time. 
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a speedvac would work well if your fractions were smaller
I have one of those! Actually two lol! Small rotors though… good for microtubes.
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Btw, for those who want a cheap alternative to a vac oven to seal jars, foodsaver make a jar lid sealer as an accessory. It works well.
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I would employ the k.i.s.s principal. (Keep it simple stupid) at first you’ll have something that works, you can tweak it down the road. Don’t let this put a stop to your analytics. When you need to do this on a large scale all your equipment could change. Don’t get hung up on the small things, think big picture. BTW I didn’t mean any offence by the k.i.s.s reference.
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What is the vial size your useing?
I may be able to fabracobble something on the cheap?
Totally!
@cyclopath The plant _does_make a cannabinoid protector! It is the naturally occurring carboxylic acid group! As long as it stays attached, it protects the cannabinoid from oxidation (e.g. THC converting to CBN or a quinoid). Cannabinoids themselves, and some terpenes, each have various types of antioxidant properties (aka Vitamin E activity), so they can be considered antioxidants in their decarboxylated states. Even while still in acid form, they absorb UV and emit visible light (aqua blue in the case of THC) through electron excitement and subsequent orbital relaxation, which is what causes fluorescence. This reduces the DNA damage particularly incurred by bombardment with the ionizing UVB and UVC wavelengths of light. This UV absorption also reduces free radicals (chemically and numerically) in the plant tissues, which are one of the main contributors to oxidation.
Antioxidants can be catalytic (i.e. self-regenerating) or just compounds that are easily oxidized under the given conditions. The former can be present in small quantities and remain effective, depending on the rate of incoming oxidizers and their reactions. The latter would be required in excess or at least stoichiometric equivalents to said incoming oxidizers.
All in all, for the purposes of this discussion, the problem is not merely oxidation, which in itself is relatively harmless to the bulk of the distillate’s goodies, as is made evident by the “red line”. The actual problem is oxidation of compounds to different colors. Luckily, cannabinoids are most likely to oxidize by additional bonds, which generally leaves similarly colorless compounds (e.g. CBN), moreso than by addition of oxygen atoms, which can result in a faint distribution of salmon-pink compounds (e.g. quinoids), often referred to as rosay or rose gold.
Therefore the real goal is to protect the cannabinoids from oxygen atoms, and to eliminate anything else in the distillate that will colorfully oxidize. The former can be accomplished by many means, including mixing in lipophylic antioxidants with stronger vitamin E activity than the cannabinoids (which must also oxidize colorlessly), mixing in compounds or process exit conditions that raise the activation energy of the cannabinoids’ colorful oxidation rxns, or even (dare I speak of such ephemeral solutions?) packaging under vacuum or with antioxidant boluses. The latter is accomplished by proper extraction and subsequent treatment of the resin and its cannabinoid distillate.
Useless as these comments may seem to some, it’s just the same old story restated to define the exact nature of the problem and its most obvious types of solutions. Because we learn more every day, sometimes remembering the goal is all it takes to attain it. 
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What do you think about adding the carboxil group back after distillation?
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sounds like magic.
might just be chemistry 
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Yes, adding carboxylic acid at a specifically sterically hindered location such as that in THCa, type A, is doable, but via a rather complex chemical synthesis.
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Wouldn’t that deactivate the THC once again, defeating the purpose of distillate for some and potentially shorten life of vape cartridges?
it would. so it is probably reasonable to ask why?
Can I? Should I?
even May I? comes into play in a regulated market…
How? seems the most interesting.
@cyclopath the compound appears to be polar and removed with a silica plug. CBN wouldn’t stick to the column in the conditions I use. We may have a peroxide of THC (double bond oxidized) or other oxidation of the 10 position as proposed in the literature. The end product is cannabinol, but the initial red isn’t CBN. A polymeric compound (dimer+) could also be responsible.
I swear by my PhD I will figure this little bastard out. If anyone has any MS or DAD data they’d like to share, I’ll share what I have.
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On what?
My bad…that no context thing😞. Cannabinoid quinones or other oxidation products.
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Oh! Some, but not really. Mostly just indirect evidence of things via MS-MS. The quantities are usually rather minute, so they end up convoluting with other peaks or insignificant against the background.
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