Test result from a recent distillation from dry trim yielded the following results…
Fail for 7 pesticides (Chlorpyrifos, 0.238, Bifenazate, 0.175, Malathion, 0.565, Myclobutinol, 0.486, Carbofuran, 0.056 and Fenhexamide, 0.13 Paclobutrazole, 0.184), plus traces of Permethrin, 0.108, Piperonylbutoxide, 0.374
Thanks to the great people on this forum we were able to eliminate all pesticide except chlorpyrifos. Starting with photon_noir’s de-gumming tek, we did a vigorous LLE (brine water, at pH’s 4, 9, 7 ) followed by the use of a combination of t-5/carbon stirred warm with a 2:1 hexane:distillate which was then filtered over chunk carbon (specifically for remediation of paclobutrazol), over 200-400 silica over MagisilPR in a chromatography column.
As my payment to this forum, the following is my tech for the remediation of chlorpyrifos which was completely unaffected by the above process (in fact the test results show higher levels…whatever).
By studying the Pesticide Properties Database (a phenomenal resource from The University of Hartfordshire) and doing my due diligence by scouring the web, I locked onto two things.
LLE with water was out of the question as it’s affinity for water is next to nothing.
However it does like both hexane and methanol, the problem being that they are miscible.
After a little experimentation, i did the following.
I dissolved the distillate in hexane and methanol; 4:1:1 Methanol:hexane:distillate in a sep funnel.
Here’s the fun part…I then added distilled water to the mix in an amount equivalent with the hexane, and shook vigorously.
As anticipated, the distillate and hexane created their own separate layer while the methanol and water (now 4:1, or so) settled out (hopefully containing our pesticide). I repeated the process and collected the distillate/hexane layer.
But wait! That’s not all…
The next piece of information that I gleaned from the PPDB was that chlorpyrifos was susceptible to degradation at both high temps (from 130c-160c depending or what you read) and alkalinity (above pH 8)
I increased the dilution to 2:1 with more hexane and added an equal amount of distilled water at pH 9.
I slowly heated over 2 hours with overhead stirring until I reached 160c which I allowed to stir for another half hour or so. I did want to go any longer or any hotter as I don’t know (and still don’t) what effect this process might have on my cannibinoids (which originally tested out at 92 %, 87% THC).
I just received test results back today and no pesticides were detected!
Here’s my question to all of you.
Which of the above procedures had the greatest effect, and/or is there a chance that I have adversely effected my original distillate (isomerization or ?) ?
I have not re-distilled or tested for cannabinoids at this writing.
Thanks again to everyone for this AWESOME resource! I would be happy to answer any questions.
