I work for a legal extraction lab in Humboldt county and was wondering if anyone had any good ideas on how to perform a acetone RSO for local labs to test for pesticides and heavy metals. I just started at this facility and think I could better this Preparation process but need to make sure cross contamination does not occur. Thanks cheers.
why acetone?
what is your production solvent?
why would you use a different solvent for analytics?
Assuming ethanol is your production solvent, I would extract in ethanol
For one it won’t eat plastic, so you can extract in disposable tubes…
Using your production solvent should also give a more accurate picture of what’s gonna happen in your production process.
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U at arcata x?
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I think you’ve jumped to the wrong conclusion about OPs purpose is in performing this exercise - I dont think hes trying to model his production scenario at all. The way I read this is, OP wants to deliberately over extract everything and anything in the plant matrix for analysis (and possibly to determine what a theoretical 100% yield would look like if hes clever). Acetone is just a safe bet for this operation since its cheap, will extract fucking everything if you want it to, and can be quickly concentrated before analysis (lower BP, specific heat, and heat of vaporization than ethanol). Perhaps OP could elucidate further? I agree, if for whatever reason hes trying to model production then yea use the same solvent - but since that endeavor sound pointless (and I assume OP is a reasonable person) then I doubt thats what hes doing.
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if the object of the game is to figure out if the biomass will extract cleanly (test -ve for pesticides) in production the difference in solvents might be critical.
using disposables to avoid cross-contamination was ALSO a consideration. disposable plastic tubes will work with ethanol. not with Acetone.
which is why I asked clarifying questions.
Rubbish!! testing incoming biomass for pesticide/heavy metals is not pointless.
Seems like using a solvent that didn’t extract pesticides that your production solvent did would make it so…
I have no idea if there are such critters. Do you?
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I detect a pattern of misinterpreting what I’m saying beyond what I care to repair. I regret saying anything.
I understand the advantages of Acetone vs ethanol from chemical extraction standpoint.
I don’t understand the relative solubilities of ALL the pesticides one might run into as a tolling facility.
If you know that everything on CA’s list is extractable with Acetone (I certainly don’t), then you’re correct, acetone is at least as good as ethanol for a biomass prescreen, which is what the OP’s question reads as to me (although not eating cheap plastic tubes seems like a win for etoh to me…)
I have certainly run into pesticides that extract with Ethanol but don’t seem to come along for the ride with Butane. I’m simply generalizing that empirical data and asking the OP if that’s what they’re up to.
I’d love to understand what your point is. if indeed I’ve missed it.
or, we can await the OP’s response and leave the guessing for more important things like winning lottery numbers 
Edit: appreciate the DM @eyeworm. we are on the same page now…
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I have done a lot with acetone. Only use high grade acetone, and the extraction is very similar to etho.
Boiling point is lower, so it comes off faster.
Not much too it.
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inexpensive disposable extraction vessels:
https://www.google.com/search?q=falcon+tubes
which won’t work with Acetone…
bifenthrin, for example, is soluble in Acetone and only slightly so in methanol.
one might posit that it would also be less soluble in ethanol than acetone.
one could certainly argue that in this case extracting with Acetone would provide more information.
or one could argue that a clean micro extraction with ethanol would bode well for a production run on the same material.
We have experience with acetone. Here’s the thing, if you use a solvent that doesn’t represent how much your extraction solvent concentrates that particular pesticide, then if acetone under concentrates a pesticide there is the possibility that it will be an ND (the labs are permitted 30% error margin, and still get certified by Emerald Scientific). So when you go to extract it could end up showing up.
Another consideration, you typically pick up more material in an acetone extraction, so the pesticides that concentrate in acetone or your extraction solvent will appear diluted as compared to your actual extract.
I’m a fan of the extraction done with the extraction media, but we’ve never tried it. Theoretically, I’d use the exact same conditions as you’d use to run your material.
This part of the process is not my favorite. From time to time there are false positives and negatives. Cross contamination is always a worry.
Also, if you run hydrocarbon or CO2 this presents a challenge…who has a small extractor just for micros?
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OCO labs has your itty bitty CO2 covered.
I’ve still got my iitty bitty glass tube from my earliest R&D
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Good to know. Let me put you on the spot now, where do you fall on the micro debate?
- Original extraction conditions
- Super solvent (acetone, DCM, etc)
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I’ve let @drjackhughes put me on the spot…
now where do you fall on the micro debate?
- Original extraction solvent
- Super solvent
- huh?
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You want to do cryo acetone.
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Interesting. Explain.
It’s nearly the same as etho. Get it cold. Super cold. -78C. You can do 5 minute washes w/o the need to winterize.
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no I did apply to them though lol
Thank you for your input no answer is a bad one in my opinion. I really just enjoy hearing other opinions.
Basically I make A small RSO sample to send in to get tested for Heavy metals and pesticides. I understand that ethanol would possible be a better route but I like how acetone will strip the material at a faster rate. I was thinking possibly a small 2L roto but then I was thinking about cleaning that thing each time and got discouraged at that idea.
This thing looks really cool. I wonder what the yield is like and if this machine would strip the material of heavy metals and pesticides more than a larger CO2 system?