HPTLC for potency

The thread on Purpl Scientific’s near-IR instrument made search here for HPTLC, and I was surprised I didn’t find anything.

So, I figured I’d start a thread on it. The lead author Justin Fischedick is well know in the industry.

A Qualitative and Quantitative HPTLC Densitometry Method for the Analysis of Cannabinoids in Cannabis sativa L…pdf (198.2 KB)


The method validated in this study offers advantages over previously developed TLC methods for cannabis analysis because it utilises a simple decarboxylation procedure to convert THCA into ∆9-THC and requires only normal-phase HPTLC plates with an automated spotter and scanner. The method was shown to be comparable within a small degree of error (±0.5%) to results obtainable from a validated HPLC method. This chromatographic method can be utilised for qualitative fingerprinting of cannabis since good separation is achieved between the principle neutral cannabinoids (CBD, ∆9-THC, THCV, CBG and CBC), forensic analysis of cannabis, quality control of hemp and quality control of medical cannabis.

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I’ve seen a few papers from this guy and he does great work.

As a stoner though, his last name is too good to ignore.

Fishdicks :clap::clap::clap::fish::eggplant:


Fish dicks. Lol


LOL to be fair, I think it’s German?

Or, the digital version: Fisch-Edick? Lol.

TLC is the most powerful technique you can utilize before running off to use instrumentation.

I agree. And for simple TLC, JustTLC seems like a really useful application.

For some time now (years) I’ve been meaning to try HPTLC for potency following this paper. As compared to HPLC: good throughput, much lower startup costs, lower learning curve, and good accuracy. Seem like a win-win-win-win. At least for in-house analytics and quality control.

That is some expensive looking software that you can collect data for. The same data you input is probably what it will spit out.

Seriously. All you need is a ruler and references to collect data.


Not disagreeing. However, I suspect a lot of people find a lot of value in ease of use and simple digitization.

They do offer a free version of their quantification feature, its in the cloud and is called JustQuantify Free.

I’ve never used the Sweday products. Just thought they would add to the conversation.

Thank you for this information. I think i am a little more sold on the idea.

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OMG… how complicated can you possibly make it, when its so simple and cheap to do the test on a GC in 15 minutes for 15 cents.

I think you’re not looking at this from the perspective of breeders, growers and processors who can’t afford a good GC-FID or GC-MS or HLPC.

This work was done to provide an alternative to those instruments. There are many reasons those instruments won’t be a solution for many people. The interest in the Purple Scientific thread is a good example.

For those who can afford those kinds of instruments, know how to use them, or have access to people who do, I totally agree with your position.

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NIH-image NIH Image Home Page

Is free and can be used in a similar fashion for lane recognition & band quantification

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