TLC: Thin layer chromatography.

How do i achieve a standard plate for testing for cannabinoids?

Would i compare rf values with others results, or source isolated cannabinoid samples for comparative testing? Thanks in advance.

You need to be sure that your using the tech properly & have a few goes @ it & lean the chemistry skills & the critical control points in the mobile phase to get accurate results.

You have to look @ other tests & learn to read plates & compare values or pay for further analytical testing or ask somebody to read them for you.


No point in thinking about testing in a multi strain room as your samples will be under value due to not maxing it out & you need to beware of cross contamination.


To learn how to use the tech watch youtube for the basics on setting up the chambers & marking the plates & making a spotter. Watch real chemists. Learn the elutants needed & the reagents for the samples your taking & how to measure samples mark RF values & how to get the samples into a readable form.

you can get standards from Sigma, but they dont sell to people, only accredited labs etc, so maybe ask your local lab(s) if they can get it in for you

i use these guys. love this tech for the home grower.

https://www.cannalyticssupply.com/

i'm more interested in TLC for terps

https://pubs.acs.org/doi/pdfplus/10.1021/ac60229a035

stupid paywall!

Fuck yeah this thread

Go go chemistry

I’m an analytical chemist for my day job. I think you’ll find that tlc would be a very roughly quantitative and most qualitative exercise without the facilities of a lab, like accurate scale, pure reference standards, and honestly HPLC (high performance LC) or UPLC (Ultra-high performance LC).
If you were looking to screen for high cbd variants or get a rough idea of thc to cbd (I’d probably say max accuracy if probably 1:5 or 5:1) you could probably rely on TLC. But terps and pure thc would be almost impossible to quantitate without the aforementioned lab equipment

deltronZER0 said:

I’m an analytical chemist for my day job. I think you’ll find that tlc would be a very roughly quantitative and most qualitative exercise without the facilities of a lab, like accurate scale, pure reference standards, and honestly HPLC (high performance LC) or UPLC (Ultra-high performance LC).
If you were looking to screen for high cbd variants or get a rough idea of thc to cbd (I’d probably say max accuracy if probably 1:5 or 5:1) you could probably rely on TLC. But terps and pure thc would be almost impossible to quantitate without the aforementioned lab equipment

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Thanks for the reply. Could i sift for high thc chemotypes in veg, using the tlc?

Welp, I had started to write out a big reply but the page reloaded and nuked it
First of all, I was slightly wrong. I typically think of tlc and qualitative and NOT quantitative, but that’s also cuz I’m fussy. My job has me measuring 0.01% impurities in pharmaceuticals, so that’s where my head is at haha. I did some searching and there is a web app that would help you to get more quantitative results, see the video and linked app from here: https://www.chemistryworld.com/news...-in-thin-layer-chromatography/3010159.article

Your next hurdle is creating a calibration curve like they mention in the video. This is hard but not impossible. You want to create a few known points around what you expect. If you think most of your stuff would probably test around 20%, it would make sense to prepare solutions emulating what a solution would contain if you’d prepared a sample of 15%, 20% and 25% or even 10%, 20% and 30% if you expect some high or low outliers. Then when you run a plate of tlc, you’d do the low middle and high strength standards next to your sample. Then qtlc would be able to tell you; this sample is between the middle and high strength and appears to be about halfway, ergo 25% if you were using the 10/20/30% curve like I mentioned.
Preparing this curve requires: precise weighing, precise volume and pure known substances. Weighing would probably be best done with a small digital scale, but splurge and buy a new very accurate one. Volume is probably best controlled by a volumetric flask. Pure known substance can be hard; but assuming you’re doing this, you could probably make some quick and dirty iso hash, which would work okay.

So; how would you do that practically?
Let’s say that you could spare 2 grams of flower per plant. You’d take that flower, dry it till crispy (ideally no water weight), and extract it in a 10mL flask. For this example, that sample (if assumed 20%) would render 0.4g actual thc into your solution (2.00g*20%). To prepare your standards, work backwards from that to determine that to create a solution like that, you’d probably want to do 0.5g or so of quick and dirty isohash (since it’s probably close to 80% pure). Additionally, you’d want to do 0.25g for your 10% and 0.75g for your 30% solutions. Does that make sense?

BeAn v.2.0 said:

Thanks for the reply. Could i sift for high thc chemotypes in veg, using the tlc?

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There are cannabis labs in legal states taking samples for hemp testing through the mail now, google it.

They will give accurate cannabinoid and terpene info even if you sample isn't hemp, lol.

Kevin Jodrey has a video of how he sifts in veg using cannabinoid testing of veg plants, pretty sure he said he looked for ratios of THC to CBD and for high CBG numbers.

Any chance you could post the link to the Kevin jodrey vid? Sounds fascinating! Dude has great content

deltronZER0 said:

Any chance you could post the link to the Kevin jodrey vid? Sounds fascinating! Dude has great content

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I don't remember but it was from last year I think or 2018, might be in one of his Skunk Project vids or in the Regen conferences...

There is a couple from the future cannabis project that mention the predictive testing from phylos. Selecting breeder males and selection parts 1 to 4 i think are the titles off the top of my head.