Failing RSA

We have been trying to make our own terps in house with a CO2 machine. We sourced 5 pounds of lavender and did a terp run. After we sent it in for testing and it failed for ethanol, acetone and heptane. The ethanol could make a little sense if it was residual left over from our cleans runs but we don’t have any acetone in our lab. So I’m wondering if it could be because these solvents were present on the lavender that we bought? Or is this somehow a byproduct of the extraction? I’m also wondering if there is a way to remove the solvents with out oxidizing or damaging the terpenes?

Any input or advice would be greatly appreciated

What PPM did it test at?

I googled ‘compound in lavender’ and one of the first results was linalyl acetate.

If some organic chemistry whiz sees this, they might be able to identify a mechanism by which the acetate functional group turns into acetone. Otherwise the IR could be giving a false positive for carboxylic acid or something.

But it looks like the reason would be the highly reactive environment (is it highly reactive? I’m assuming here) of a high pressure supercritical fluid would be conducive to fractioning this compund into ethanol and/or acetone.

I always tag @Photon_noir in chemistry questions, sorry dude :sweat_smile:


@weave Supercritical CO2 is hot. Heat and pressure break down the sensitive molecules of flavor and aroma. This has been proven many times over with cannabis. Try cool liquid CO2 if you want to keep these things intact.

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@Photon_noir you are able to pull terps with a sub critical CO2 runs?

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Ethanol = 2068 ppm
Acetone = 7354 ppm
Heptane = 236 ppm

@TheGratefulPhil I noticed this too but wasn’t sure if they were at all related.

Correct, and ONLY with cool liquid CO2. The temperatures for supercritical usually thermally decompose the terpenes, which is why most CO2 cannabinoid extracts all taste the same kinda burnt flavor.
Some cannabinoids are naturally extracted by the terpenes acting as cosolvents, but this can be minimized by doing a short run (2 hours or less) and leaving the cannabinoids in their natural acid forms.
The final step is cool static vacuum distillation (iow, partially passive recovery) of the terpenes from the mixture with cannabinoids. It is best to keep them out of light and oxygen, if possible, and using a static vacuum, boiler temperatures below about 100°C, and a cold condenser (backed by a cold trap) to start which warms up as one gets to the heavier terpene fractions really helps to capture them.

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Is it possible the breakdown is happening in the Mass Spec?

I see @TheGratefulPhil suggests an IR misidentification. Do we know how it was tested?

do you have the chromatograms? (go talk to their head chemist :wink: )

Edit: nevermind. @Photon_noir seems to have confirmed the high likely hood of thermal degradation during (supercritical) extraction

…but I still maintain that your “ask a stranger” shouldn’t be :stuck_out_tongue: