Pesticide Remediation Fail

Following Future’s pesticide remediation test on a kilo of oil and ran into a problem I couldn’t explain, was hoping someone might have some insight on what I did wrong.

Had to make a couple changes to the process (no reactor onsite), but nothing that should drastically effect the process.

Starting oil was 1kg T-Free Distillate; 88.44%CBD 90% total cannabanoid.

3 buckets were prepared, 20l of 3% saline solution (600g NaCl per 20l)
Here’s where I ran into the issue that I believe may have tripped me up. I got the first to to ph6 and ph4 without any issues.

PH8 is as high as I could go with the baking soda, and I stopped adding baking soda because I felt I was over saturating the solution and it wasn’t making a difference. Total baking soda added was less than 1/2 cup.

Now to the problem, first wash was in the PH8 solution, and went off just fine, separated nicely, however was leaving a film of baking soda on the glassware from the aqueous layer, but otherwise nothing looked amiss.

Washed everything up nicely and started the PH4 wash. Poured the oil in mixed is with the mixer for 5ish minutes, and let it settle for around 10min. When I cam back it appears (almost all) the CBD has crashed out of the oil and is sitting in a layer above the aqueous and below the heptane. Now I have 3 pretty distinct layers (Aqueous, CBD Isolate, Heptane Solution).

Only thing I can think of that I may have done wrong is too much baking soda giving the CBD nucleation points and causing the CBD to precipitate out. But I’m surprised to see that much crash out in such a short time at room temp.

Anyone have any ideas?

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Well this is pretty cool.

How cold are you doing the LLE?

Nice find first of all
But it seems that the cbd crashed in the aquatic solution ??? With ph4 ??
What ratio heptane to oleo you started with ??
@tweedledew @coppertop @Photon_noir @Future
What the. Heck ???
What’s the dry weight of the water crystelize cbd ???
Hey why did you asume your cbd was in that middle layer I imagine crystals dropping to the botom
What made you realize ?

Darn it it s TFree would have been awesome to see if the thc was in the aqua layer as well
I am still stunned let me contemplate :thinking:

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My first question would be are you sure it’s CBD that crashed out, and not crystallizing citric acid or baking soda? I’m finding it really hard to believe that the CBD would just spontaneously crash out of the heptane and sit there in a layer like that given the info you provided.

No darn isolate at hand does it float in salted water ?? Most likely it does
I like this at last something happening

Yeah if he tells me his exact sop I’ll see what happens. I have a few liters laying around.

Did you try adding more heptane?

Adding more heptane where ?
Trying to catch your drift :grin:

I’ll try to answer all the questions.

Oil was approx 40C when mixed into the PH washes. Washes themselves were room temp. Crystalite crashed out in 2nd wash, so presumably was down to room temp by then.

Was more so in the bottom heptane solution. But yes, it was first washed in the PH8 solution, then crashed out in the PH4. Ration was 2l heptane/1kg oil

I was too fed up with my fail to test it on our HPLC, it has the exact texture of CBD crystalite in heptane. :man_shrugging: I suppose it could be salt, but it wasn’t dissolving back into the water.

The only heptane that was used was the initial 2l into the 1kg of oil.

Thank you I am preparing my self som distillate to see if I can recreate this
Amazing even if it where salt wich i doubt
What did you use to acidify your saline solution ???

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I doubt it’s salt as well. It likes the heptane much more than the water. When the solids clog up my sep funnel it filters the water through it without dissolving.

I just don’t understand how it could possibly crystalize that quickly at room temp if it is CBD.

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Flash crystelization exist
But it seems that you have figured out a way to have heptane Dis like cannabinoids wich is weird
2:1 would mean a 25% cannabinoid ratio at wich crystelization at this speed is hardly seen NICE😁


Right here. If it is CBD that crashed out, it should go into heptane. If the heptane somehow became supersaturated (maybe some evaporated?) that could explain why some of it would crash out as the temperatures dropped

How come the beaker is at the 4000 ml
Fill line seems pretty filled with crystals
Yet you mention 1 liter starting point
Is the rest all saline /water ?

Exact steps taken.

Took three 7 gallon buckets.
Put 20l distilled water in each.
600g Plain Salt in each, mixed thoroughly will drill mixer. Let settle about 10 min and mixed again.
Measured PH in all buckets; all around 6; set one aside for neutral wash (Bucket #1).

Bucket #2: Added approx 1/2 tsp citric acid and mixed, measured ph around 5, added about another 1/2 and mixed measured PH around 4.5. Added a dash (1/4 tsp) of baking soda and brought it back to 4.

Bucket #3; added 1/2 tsp baking soda and mixed, measured ph of like 6.5. Added about a full tsp, tested again and it was around 7. 2 More tsp of baking soda and it measured just below 8. Added another tsp and it right at 8. Added another tsp and it brought it to 8.25ish. Added 3 more tsp and it still measured 8ph. So I gave up on getting to 9ph and settled for the 8 I had.

Heated 1kg oil up and thoroughly dissolved into 2l heptane.

Poured heptane solution into PH9 bucket. Mixed approx 5 min with drill mixer on high speed. Let settle for a little bit and mixed thoroughly again.

Separate heptane and aqueous solution 3l at a time in sep funnel. Aqueous layer was very saturated with baking soda, as water would evap would it would leave a layer of baking soda.

Took heptane solution and put it back in sep funnel to let it settle and do a better separation. FInished that up, and heptane solution looked a tad bit cloudy but not overly so.

Poured heptane solution into PH4 bucket, stirred with drill mixer approx 5 minutes and let settle. Came back less than 10 min to a solid layer of crystilate between the aqueous and heptane layers. Stood there looking at it for several minutes trying to figure WTF I had just done. The started trying to seperate it. The crystalite will clog up the funnel so I kind of just called it quits for the day.


That beaker was just an intermediate step to go from bucket to funnel, poured from the bucked into a 5l, then into the funnel. Not skilled enough to go from full 7gal bucket to small funnel 5 feet in the air. :slight_smile:


I will look over when I get home.

Bucket #2: Added approx 1/2 tsp citric acid and mixed, measured ph around 5, added about another 1/2 and mixed measured PH around 4.5. Added a dash (1/4 tsp) of baking soda and brought it back to 4.

That doesn’t make sense. Adding base should have made it more alkaline (higher pH), not more acidic (lower pH). Regardless, you created some sodium citrate buffer there.
The alkaline bucket is an oversaturated solution, so regardless of precipitation, there are probably solid crystals floating around in it.

It would be very interesting if the crystalline solid you see is CBD, of course, and I don’t think it is out of the question, considering the fairly high concentration of CBD distillate to its heptane solvent… 2 L of n-heptane is only 1,367.6g at room temperature, so accounting for some evaporation, you have maybe a 1:1.3 w/w ratio of solute to solvent or less if it was ventilated while warm.

The most important thing to do is to verify the identity of the precipitate. Then comes yield mass and purity.


I agree with Photon that there is surely a sodium citrate buffer in the mix. In regards to Future’s first comment, your low concentration of heptane is likely throwing the equilibrium point for your mixture out of spec.

The method you’re using is a very nice process, but it reminds me of enzyme de-gumming, which occasionally produces an emulsification layer that requires several rinses to ‘break’. In that scenario, we have byproduct reactions which are driving our equilibrium point out of spec.

Also, do you know the water quality of your water source? The photos look clean, but hardware stores carry a 13-panel test for less than $40.

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