BHO Chromium Heavy Metal Remediation

Hey guys, I have a client that recently did a butane extraction run on some flower material and made some bho extracts. They sent it in for testing and it failed for Chromium heavy metal testing. The flower did have small amounts of aresnic, cadmium, and chromium. They did run their extraction with Carbon Chemistry T-5 but from my knowledge T-5 only remediates lead, arsenic, cadmium, and mercury and not chromium. Arsenic and Cadmium did not show up on the heavy metal testing of course. My question I have for you guys is that is it possible to remediate Chromium at all without turning the final product into distillate? Is there any type of other media or process they can use to remediate this out? Thanks in advance!

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Some members here have advocated using a centrifuge to spin out the heavy metals or passing through a magnetic column in solvent.

@Photon_noir might be able to provide some valuable insight.

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You may need to dilute the extracts down into a compatible solvent but it would be worth trying filtration through metal chelating media.

For Chromium I would suggest a media with a polyamine or amidoxime functional group. These are usually good at chelating chromium ions either hexavalent or trivalent.

Unfortunately most of these kind of metal remediation media’s are designed for wastewater treatment or ion exchange in an aqueous solution, so there may not be a ton of information on compatibility or efficacy with solvents.

I’ve done some distillate bound material diluted in ethanol filtered through these types of media for other heavy metal removal, but it didn’t provide any better results than my normal filtration process + distillation so I don’t really employ these materials. Having said that, it may be an option for you to experiment with, I just don’t know the impact of diluting your extracts into a different solvent to filter then recovering that solvent and trying to get back your extract in a proper form.

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Hit up @Waxplug1 . I believe bentonite clay will help with heavy metals but he may have something else in mind.

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They used carbon chemistry T-5 which is bentonite clay. It remediated the Arsenic and Cadmium out which originally showed up in the flower sample but didn’t remediate the Chromium which came back at 1.5ppm.

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If you try to get in touch with Purolite - they sell a lot of different types of metal remediation resins, you can probably get them to send you a small sample of a couple resins at no cost to you. They might even have some specific solutions for Chromium remediation they recommend (again most likely for wastewater treatment but it’s worth seeing if it works in this scenario). Then you can potentially just take a small amount of your concentrate (you already know the starting metal content), dilute it down in ethanol, filter through the media, recover ethanol and then resubmit the extract for post filtration metal testing.

This should limit the costs to you while potentially getting some useful R&D data.

** I have no association or business interests with Purolite and merely suggest them as they are the company I have used to trial some different heavy metal remediation resins to varying degrees of success **.

Unfortunately I have no chromium specific chelating resins or I would send you some to try out, most of these larger companies will be happy to send small samples in hopes it will get them some business. Worth a shot.

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DJ and I have been discussing this via email since his web inquiry to CC, @PharmExOregon ! Thanks for the heads up!

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Halloysite clay is very good at absorbing heavy metals but you have to be carefull during filtration as it contains nanostructures that can get to your product. And you don’t need a lot of it as it has a surface area of 117 m2/g.

Recently an improved adsorption of aqueous hexavalent chromium by kaolin minerals including halloysite was reported. The minerals were previously interlayer grafted with triethanolamine and afterwards reacted with iodomethane.

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Oooh, @borysses! Halloysite micro/nanotubes used to be my JAM… or at least my bread & butter! :grin:
I has me a few patents from that work, in fact! :laughing:

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I used it as a filler for capsules. 30% of the capsule mass were cannabinoids that were undetectable on GC/MS :slight_smile:

One of the biggest deposits of it in the world is 30min drive from my lab. It’s kinda funny I can get hold of nanomaterial in any quantity just by using a bucket and a shovel :smiley:

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See DM inquiry, @borysses ! That’s fascinating about the GC results. How was the capsule prepared for the analysis?

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So the loaded clay looked like this:

I’ve used crude for CBC, CBD and CBG and the “hummus” one was actually loaded with d9 disty. The lab was told that the samples are adsorbent clay and I wanted to check the amount of cannabinoids locked there.

I also gave them samples of solutions where I’d boild the loaded clay in methanol, ethanol and isopropanol. Straight, acidic and basic. 1h, 6h, 12h and 24h.

All clay results came with LODs for everything same with 1, 6 and 12h solutions. 24h solutions would show LODs, LOQs and couple of detection on a level of 0,01 to 0.02%.

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Seems like that would require a mighty fast fuge…borrowed from the uranium enrichment sector?!?

Or chelated/flocculated/precipitated first?

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the fun part about this post is that the chromium is coming from the shitty metal most extractors are made from

cuz china = gud enuf

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I’m using ETS so I highly doubt the chromium is coming from my columns but thanks though.

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So you’re hypothesizing the magic dirt?

Shiny!

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Whats the benefit of the shiny steel?

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You can stare at yourself while you extract

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There is none. In the Pharma industry everything product contact is electro-polished due to potential contamination. A 20-25rA food-grade finish is still a granular finish and absolutely adequate for our uses.

China usually electro-polishes their stainless to hide material and fab quality. Not always, but its easy to hide when electro-polished.

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Who do you call to inspect the quality of steel?