It sounds like you answered your own question.
you certainly seem to be asking the right questions. love this place!
pity it’s not carotene. if all you’ve got is “does adding this fraction back help” for finding your target, it’s going to be harder to find. follow the colored band is waaay easier.
if cannabinoids are made to protect the reproductive structures from UV based DNA damage**, it would behove the plant to make a “cannabinoid protectant” as well.
I’d wager such a critter would stick to THC fairly well (at least based on observations). Given the purities you’re seeing +/- this (proposed) anti-oxidant, it’s either much smaller than THC’s 314 Da or is not required in a 1:1 ratio. I don’t know that I would expect an anti-oxidant to be required in a 1:1 ratio.
Do you have access to a uv detector and a fraction collector? those would make your task more manageable and should be available for under $1k off ebay. I’m not sure if this unit would work, but it is approximately what I am referring to (only 20 years newer).
** Cannabinoids all absorb very well in the UV range, and UV stimulates cannabinoid production. DNA is very susceptible to DNA damage, especially at high altitudes where this shit grew up. So it’s a reasonable guess…
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Beaker is running an old UV spec, it has a flow through cuvette. such a beast would also solve the running blind problem.
I’m not sure how much he paid for it. not a fortune. He’s just doing this for fun/personal meds.
you’re right. no reason to expect an anti-oxidant to be required in much more than catalytic amounts. I’m high and was working from first principles. didn’t get as far as consulting [currently inaccessible] stored data on anti-oxidants.
hmmm, it’s either little, or there is f.all of it.
Attack strategy sounds appropriate. I’ll gladly share data once I have my hands on a WFE.
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I should also clarify that, fats & waxes, even if it might be AN answer (certainly not THE answer) to slowing down oxidation, it is certainly not an acceptable one:
- unwinterized distillate hasn’t been acceptable since 2013/2014 at least
- there are way too many examples of distillate with fats and waxes removed, that don’t have oxidation issues
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ideally you want a device that reads out from the eluate drip tube, stores & displays that data (chart recorder is old school) AND automagically dispenses into measured aliquots (fractions, in tubes/vials/mason jars… .). you can get by with out the automagic fraction collection (they’re usually shit anyway) if you’re not planning on doing it on a regular basis. or once you learn where your magic elutes.
I’m sure @Beaker will respond with a model number if we keep paging 
I would assume summit’s detector looked much like the $500 ebay unit linked above. perhaps without the fraction collector.
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I like the dcvc method, there is no chance of mixing your eluting bands. The uv detector can be used to Identify the fractions afterword.
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I use a gast piston oil-less pump. Same thing used for vaccum filtration. If you have a fitted funnel, sep funnel, and silica your ready to go.
I seen folks buildingcell sorters using $5 UV emitting diodes and cheap photo-detectors to detect their target.
ideally you want a diode array, with LED’s emitting at a variety of wavelengths.
A UV/Vis spec with a flow through cuvette would give you access to a lot more information. it would take up more room on your lab bench, but should come relatively cheap used.
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You absolutely can use an aspirator
you’d probably be better off with a chemist answering that.
this critter qualifies. https://www.ebay.com/itm/Shimadzu-SPD-10A-UV-Vis-Detector-w-New-bulb-and-New-Flow-cell
I searched for UV/Vis Spectrophotometer flow through. pulls up some other candidates. none qualify as cheap.
I imagine an old Gilson or Beckman UV detector would get you most of the way. I’m pretty sure that’s what I’ve seen paired with a fraction detector and a chart recorder on older HPLC’s
At a guess I’d say the gilson would be easier to interface with.
offer this guy $50 https://www.ebay.com/itm/Gilson-Model-111-LC-UV-Detector-/162985006966?hash=item25f2a9d776 or read the manual first, then offer him $50.
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more or less. although I’m guessing this is the controller. not the actual detector.
finding the manual would be required to be sure.
like the beckman unit, it appears to have a separate flow chamber.
there are three more pictures in the description. lots of wires in back. no hoses.
Edit: https://www.gelifesciences.co.jp/tech_support/manual/pdf/56103584af.pdf yep. separate optical cell.
I still think the Gilsons are going to be easier to talk to.
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My unit is a Hach DRU 4000 with a pour through module. It is 15+ years old.
The unit uses two bulbs. A tungsten bulb for VIS and Dueterium bulb for UV. The bulbs have a shelf life and it is taken up in warm up and runnning both. So turning on a bulb from cold puts about as much wear on the bulb as if you left it on for 8 hours or more. The unit is fairly slow at producing a spectrum scan but obviously you are wishing a single wavelength scan. The pour through module makes this pretty simple because you do not have to remove cuvettes.
I would not recommend a used Hach unit. The one I have works for the data but the old ones are notoriously finicky. There is a multitude of seperate circuit boards inside as was the design style back then . Power supply boards and the interconnects between boards are with plastic electrical clips on the wire ends that plug the boards together. I worked a career as a control systems design engineer and saw this over and over because I had to design with this kind of component. Over time those connections tend to oxidize and resistance builds. The problem with an oxidized connection is that it is not like either a broken wire or a short circuit and so a voltmeter is very tricky to use to track down problems. Voltages must be read across the connection which most electricians will not understand to do to track this stuff down.
All sorts of glitches creep with oxidized connections and components that will drive you nuts. Error codes will come and go and you have to know where to bang the cabinet and why to make some things boot up lolz. I am certain without an extensive electronics and motion control machine design knowledge a typical user would have returned the unit or trashed it immediately. It has value to me because I have only used it to take single measurements here and there and it is hobby. When I hit the lottery again, or at least if I make it through my disability review, I am looking at a new uv/vis unit.
The new models are surface mount circuitry and generally like all electronics are much more reliable. Plus a unit with a halogen bulb likely never needs the bulb replaced unlike standard tungsten and Dueterium bulbs. Old units like mine needed several minutes to warm the bulb up to temp. Halogen bulbs provide both UV and VIS light and need no warm up. If I sacrifice a small amount of resolution and select a model that scans the entire spectrum at the same time then every scan will have the entire spectrum stored in the same time it took me to scan just one wavelength on my old machine. This type of unit is called a photo detector array unit and they sacrifice a bit of resolution for the incredible option of full spectrum scanning instantaneously.
I don’t disagree with your concerns about such ancient technology. replacement bulbs are pretty expensive from what I recall. finding a manual & then chasing down replacement bulb options before jumping would not be a bad idea.
If you wanted to purchase new, you would be looking in the $5k range. for a fairly simple unit.
that looks like what Beaker is running. note the prices for bulbs.
The fun part is gonna be testing all those samples! I hope you got a lot of little flasks for your rotovap or one of these!
What about blow down evaporation? Use a length of copper tubing coiled inside a heating mantle. Have a bottle of nitrogen in a flow meter hooked to the coil, the other end should have a blunt needle or something to direct the hot gas into the top of the tube. If your fancy you can make a mantafold to do all your samples at once.
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Deleted by author
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Don’t fret, I have some solutions for you.
https://rover.ebay.com/rover/0/0/0?mpre=https%3A%2F%2Fwww.ebay.com%2Fulk%2Fitm%2F231557671697
https://rover.ebay.com/rover/0/0/0?mpre=https%3A%2F%2Fwww.ebay.com%2Fulk%2Fitm%2F282917514978
Measure your tubes and compair the diameter of your tube to the appropriate caliber/block size.
https://rover.ebay.com/rover/0/0/0?mpre=https%3A%2F%2Fwww.ebay.com%2Fulk%2Fitm%2F172122525528
https://rover.ebay.com/rover/0/0/0?mpre=https%3A%2F%2Fwww.ebay.com%2Fulk%2Fitm%2F162586913522
Combine these and
l think you’ll have a thing…
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Drill a hole in the alu block, use it to heat the block