Supercritical CO2 is heavy like a liquid, with weird and useful properties

Take a look at the USP Acetone specification, it does not indicate definite ideal suitability for the task:

https://greenfield.com/wp-content/uploads/2018/11/Spec-Sheet...

This fungible specification has no specific limit for Diacetone Alcohol content, a common impurity and one which increases during storage.

Diacetone Alcohol is an industrial solvent with properties of its own, not nearly as low-boiling as Acetone. Clean Diacetone Alcohol will also show negligible Residue After Evaporation and Non-Volatile Residue under conditions of the tests, which report mostly solids content along with many higher-boiling liquid impurities but not components as moderately volatile as Diacetone Alcohol itself.

However Diacetone Alcohol can still be a significant component of the extract once the bulk Acetone has fully evaporated, depending on the conditions of the processing. Rotovap would help a lot and more than 135F would reduce residual solvent better from a viscous matrix.

The USP Purity minimum of 99.5 basically means that the water content plus any other chemical impurities such as Iso-Propyl Alcohol & Methanol (specified) and implying things like Diacetone Alcohol or Benzene, etc (but unspecified) must not add up to more than 0.5 percent.

You might even prefer to explicitly specify a maximum limit For some other target toxins, less than some low detectable amount if you were picky.

Some legitimate laboratories may not be able to detect the difference between Acetone which contains unlisted impurities and that where it is negligible.

Take a look at the associated weaselwords from legal:

https://greenfield.com/wp-content/uploads/2018/11/OVI-Residu...

Which references this as the closest applicable guideline, even though it was intended to apply to the residual solvent content of pharmaceutical products not solvents themselves:

https://www.uspnf.com/sites/default/files/usp_pdf/EN/USPNF/g...

Better than nothing but not as cautious as it could be. You may want fewer impurities than marginal drug companies anyway, you're allowed to do that. This particular supplier does look nicely better than marginal, which is good, with typicals looking well better than the limit.

Regardless with two lots of USP Acetone having apparently identically suitable certificates, one may result in its Diacetone Alcohol or other not-so-volatile components comprising a significant portion of the extract, while the other lot would not, under the same solvent-removal conditions which are excellent for the latter batch of Acetone having only the lighter impurities such as IPA & Methanol.

I would still want to test it myself first.

Source: pioneered laboratory techniques which some other testers and chemical plants eventually adopted years later, still state-of-the-art today, including this particular material. Certified billions of dollars worth of commodities like this, single-handedly more than some single petro-chemical companies can manufacture. Less than a year ago deployed a further advanced system with two backups for 100 percent uptime in a 24hr staffed operation, for when a big oil/chemical client has their ships come in, and it was Acetone. There is still no adequate publication within ASTM, been at it since dirt was rocks, and Acetone has been around even longer. Documentation not found elsewhere.

I don't want to be harsh, I admire and want to recognize the creative designer.

I enjoy guiding people through unfamiliar things which I have experimented with, it's good to see the diverse ways to grasp the same fundamental concept. Some students are quicker than some degreed engineers.

You seem like a person that could make an outstanding collaborator, building systems unique to the direction of the project.

I'm glad you put your website here, I'll pick up the phone and give your company a call, there's not a more promising, businesslike way.

I like instruments also, and have more than one.

Testing pays the bills, see the message for the acetone user.

When retired it might be good to build some robotic type stuff, maybe in a capitalist venture to overcome financial limitations.

Or looks like things would be fine without any equipment, helping companies negotiate the byzantine ASTM process alone instead, just been invited to join the emerging cannabis committee as an independent voting member.

That's only about testing, but extraction operators might best benefit from more supercritical ability on their side, you could surely consider this yourself now since it's very uncommon to have experience safely handling this type equipment, especially as a researcher on an experimental basis. Haven't done EOR in years and this time it could be CBD oil.

Anyway, presenting some findings on heavy petroleum oils to my traditional ASTM committee shortly, they want to get it into the book as soon as possible because it could save operators millions across the board.

Started to meet with some AI people just over a month ago too, inviting them to the lab to see firsthand (& smell) the kinds of crude oil they have been modeling about, some engineers for the first time.

Differential forms in thermo can be an eye opener

Easiest case of this: You have a tank of water and oil under supercritical conditions, and you pump high pressure oxygen gas into it. You get a "flame" around the intake, but unlike a regular flame (which is the boundary between fuel and the surrounding oxidizer) this is the boundary between the incoming oxidizer and the surrounding fuel.

The combustion products are the same as you would get in the absence of the supercritical water -- typically H2O and CO2 -- but they're all contained inside the supercritical water tank, which makes this very convenient for e.g. disposing of chemical weapons.