Purple compound found

I have noted that in even what seems like water clear isolate that inevitably upon feeezing the isolate it becomes clear a purple component is involved. I have posted a DCVC run demonstrating the removal of that purple compound as well.

This month at least I discovered just when it transfers from boiling flask to cold finger. It was a big find for me and almost went unnoticed.

This month I did not run the horizontal distillation to remove terps because I instead employed liquid to liquid extraction for this. This left enough trace terps and volitiles that when running my sublimator rig after as a first run it requires the cold finger to be removed and wiped clean of the terps several times. This normally proceeds until the vacuum pulls down to just a few microns after which the terps are depleted and the THC will begin to come out.

This month the cold finger had to be wiped clean three times to remove the trace terps left where normally I would only wipe it once after a horizontal run. So I was wiping with large kimwipes as the vacuum pulled slowly down towards zero. After the vacuum got to about 12 microns it seemed to “stick” there for a bit indicating gas evolving from something new instead of the steady pull down. I had seen this many times down there in vacuum on first run crude and have always wondered why.

The cold finger looked like just a trace had built up and normally below ten microns I just let it run and deal with the trace later. But this month being a bit different running LLE seperation and such I popped the cold finger one last time to wipe that trace film off.

I almost crumpled the kimwipe and tossed it but the light caught the kimwipe. There it was. Purple on the white kimwipe and I was ready to just let it run. Below twenty microns it had enough drips building I had already wiped it and noted the drips smelled very mellow, unlike say terpenes. I figured as usual they had depleted enough and was ready to just let whatever was left run with it until next pass. Now at least for me one more piece of the puzzle is in place. That purple stuff distills over after the terps but before the cannabinoid and it definitely stays liquid at ice water temps. No real odor.

One lab is just one lab and a repeat will be necessary to confirm but it appears as if I now know exactly where to find that stuff and remove it with a kimwipe. There is almost always some little tidbit of info that pops up running this stuff in a lab type setting. There is no possible way I would have detected that in a traditional distillation rig or been able to pinpoint the conditions to find and remove it. Lesson learned.


Sometimes you get a blue colored fraction while short path distilling canabinoids.

1 Like

Based on mantle temp then we could estimate that this compound has a boiling point of approximately 140C at 12-20 microns. This photo still shows terps collecting on the finger and a vacuum down to 100 microns. The cold finger is wiped clean as I said when enough gathered to drip as seen here. Very little actually was still present but it must be removed by hand for fractioning to occur.

I did not change the mantle temp during the terp removal portion and it continued down as is normal but then hit the 12 micron plateau and stayed there while only a fog really of vapor condensed on the cold finger.

What known compound that could reasonably be present in extract has a boiling point of about 140C at lets say about .015 mmHg (15 microns)? Assume purple color and not cannabinoid.

1 Like

I am not up to date on the whole story. This purple color only forms when freezing? Are you saying it is a separation coloration from when the ultra pure distillate is exposed to oxygen (is that more reddish than purple?)

Here is a DCVC run after a first distillation pass. The purple fraction is pretty easily removed. The order of those fractions collected is left to right bottom to top. The purple stuff proceeds the brown cannabinoid fraction by enough it is easy to spot in the column. This purple does not seem to show up in DCVC runs I do on crude that has not been molecularly evaporated or distilled. When those tubes in the picture are individually evaporated the purple fraction is just a trace and I will vape it but it is not something I would not put in a Xmas stocking lolz. It could be in crude and not been spotted because crude has a lot more color bands overlapping but I haven’t observed it there. If I leave it in I do not see it in even water clear looking stuff until I freeze it then it very subtly emerges.


Strange that freezing brings it out. Maybe it is precipitating from the THC when frozen? I definitely separate lots of purple fractions when running distillate through my flash system.