Budget testing

Testing and Analytics
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Hello guys, im the new one^^
im a hobbynerd from germany, nearly 30.
for a long time i was just a quiet lurker, now it was the time for an account.
im a bit overwhelmed by the mass of info available here :smiley:
kudos to this great community

Searching for a lowcost method for quantifying CBD / THC, i stumbled upon this devices but all reviews were either “perfect” or “absolute crap”, hard to filter out here (list below).
What i believe to understand is that, theoretically, one could dissolve some plant matter or cbd-oil in a solvent like methanol, shine light through or on it, and measure the absorbed/reflected light to get a ±5% accurate spectrum of the content.
Some of the devices listed below use UV,NIR,MIR.

i have seen many spectrometers, with reflex cameras, smartphonecameras with ripped off uv-filters etc.
actually im trying to build one myself to play around. i have some old smartphones around and also bought the AS7265X Sensor.

could LIBS Laser Induced Breakdown Spectroscopy be a thing?
with a chinese tattoo removal machine? then fed into a suitable selfmade spectrometer?

Has anyone here tried to achieve something similar?
I saw the fraction monitoring thread, but did not wanted to interrupt it, hope this is ok :slight_smile:

BSS 3000 Portable Hemp Analyzer

https://bigsurscientific.com/

http://bigsurscientific.com/wp-content/uploads/2018/03/SmithEmeraldConferencePresentation2018.pdf

-works propably with an atr-crystal? and mid-Infrared ?

THC/CBD Analyzer v10 XXL Spectro

https://konnwork.de

-no info at all, despite that “spectro” version having an uv spectrometer added.
-seems like having an gas sensor doing the job.

-the normal, non uv method, needs heating up to ~50°C.
the sample cup has holes in the bottom, and for testing it is put on to a small pipe. could be air pressure.
by closing the case, he sticks that gas sensor right into the material.
is he pumping hot air through the sample and measures what using a gas sensor like the ones for arduino “mq-135”; “mq-2” etc ?
https://inv.cthd.icu/watch?v=WAx54NiYxt4

And then, there is that “calibration process” where he simply moves a bar with a touchpen
for every cannabinoid to the “correct” new value and saves it^^
https://inv.cthd.icu/watch?v=eJYSTM7ZHIg

MyDX Analyzer

https://www.mydxlife.com

https://www.mydxlife.com/wp-content/uploads/MyDx_WhitePaper-1.pdf

-Conducting Polymer Sensor Array
-“Built from a combination of patented technologies
originally developed by the Jet Propulsion
Laboratory and implemented by NASA, MyDx uses
electronic nose nanotechnology to ‘sniff out’
chemicals in nearly any solid, liquid, or gas form”

-i dont looked further into it yet, but here is more info:
https://enose.jpl.nasa.gov/

tCheck

https://tcheck.me/

Dropbox - tCheckGettingStartedGuide.pdf - Simplify your life

-sample is diluted in IPA, should be heated and given onto
sample shield, which is then analyzed with UV light?
-“tCheck uses Ultraviolet (UV) light that may be potentially harmful if exposure
”

kiss :kissing_heart:

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If you aren’t looking to acquire testing equipment, here’s the lowest budget option I can think of:

  • Buy TLC Plates
  • Get software to analyze your spots
  • dilute known amount of compound of interest (1mg/mL, for example)
  • scan plate, analyze potency as function of either color intensity, size, or combination of the 2. This might be where you need to derivatize a unique method or get creative with your new IP
  • Sell IP, invest in a used HPLC
    That should give you enough of an idea for how to do semi-quantitative potency analysis with about as much cost as a single test at a testing facility.

Source: Quantitative Thin-Layer Chromatographic Method for Determination of Amantadine Hydrochloride - PMC

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TLC is a great thing to learn. And fairly useful for known compounds like cannabinoids.

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I need to fill in the gaps and try it out myself, there’s not many clear SOPs out there

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Separation and Identification of Cannabis Components
by Different Planar Chromatography Techniques
(TLC, AMD, OPLC)
https://watermark.silverchair.com/42-3-130.pdf?token=AQECAHi208BE49Ooan9kkhW_Ercy7Dm3ZL_9Cf3qfKAc485ysgAAAtEwggLNBgkqhkiG9w0BBwagggK-MIICugIBADCCArMGCSqGSIb3DQEHATAeBglghkgBZQMEAS4wEQQMzXCAIbKSK4HKQICnAgEQgIIChNrxvcTVQbflnOObREtQ4FhhRiJrOYFqpkd4alN8yS0RlOpdYbfxjtG7FxbTRJd4lDVC-SkhecvKCcOD6elCez3VZo-hiltxmRSOPZoM04GLfUqzlWwxTJA0VoSrSo6JrYQ2Astq5a1mJE5jfFp0JAKnOLZqm1hIzvdpLoRpKki1z44EzedF-WpIpx8U7QXge4Ng8wdI_dJowaP7pCbBUw90gXyjDRmBt9wGS0cq-2XkKNvYYA7IV-SxNWa6CZfHUVaqrJCGNp5QYDsojCaq8RsvQ4aokX4fPzlfMGNhNw1C5yrREi2I8vtJgE80KdCTR1CW1PmJOjEtLVz7ZUSSEY0bvUTkeJ_BprJpOGry4-3xule5fvQlCyCvQ3UP6W2iANp5takJFoFwKGvJp-8KHphl7R2u3buxVXrZEZiMr2gdgDoHeCOQsSAf4gdvqeSUY03y0wi1Koxn0TVF1wyDUrVcMoyIT8DjYFuGo7SCB6uK3GjswEnxx6mT_MnXD4TRrJ8LCZ1nXhYqP9yi25kR6mZUxEdJQkgf34P0JjJNhYI4vOCpFoA7nNxE5_U7QftgHWq5fIP5N880GA6heoJzNba4jwHAV8MgbaEEEn71S_egCnDPAOav89XYn3ASmY42E5RkOWf2ahZBR5XszTe0oMvFHr5eAiCj2rmbyjqKY1Wusy4XRw6KxPA_knz2fczLJw29G2U074wTXYtZOD14j5r89w4R0NdllYerVYQB4VQ5YH8uLVO9PDJjYpUzw_dxMEpTlvsoPFpdEg9RJPghaJDiVlj8bjCtloSMkkmRPz9SZq_j9xvTVMSRh9eA7c9mr_NeG0MVcknkiYOjg75pfRLrDdZW

An improved thin-layer chromatographic method for the detection and identification of cannabinoids in cannabis

Thin layer chromatography in the analysis of
cannabis and its components and synthetic
cannabinoids

Lots of stuff out there, including ready made TLC kits for cannabinoids
consult the All Gnowing One

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Read a few papers to get the solvent systems and buy some ready made plates and spotters, a UV lamp is most useful and will save you the work and headache of preparing visualizing reagents, you can use a flat bottom jar for a chamber, then just learn a few things about TLC in general, like how to calculate Rf factor, how to mark your plates, (pencil), .

The work on how to run cannabinoids has already been done. Just repeat the methods that are relative to what you are looking to do. Look at photos of other cannabinoid plates and know what you are looking for when you do your own runs.

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Here is almost everything you need to know, explained by a child to give you the confidence to just start doing it. its cheap.

a little more in depth


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This might be the affordable way to go, if something could be developed.

@welld0ne Pretty much anything that uses light to read biomass directly is a gimmick that isn’t very accurate.

You are going to have to separate cannabinoids with chromatography (TLC, HPLC, GC) in order to quantify them.

Also, one of the most overlooked parts of quantification is sample prep. Your sample must be weighed accurately, dissolved in a precise amount of solvent, and then a precise amount of this solvent needs to be loaded into you TLC, HPLC, or GC. The most expensive part of this is usually the scale, but there are probably affordable ways to do it with scales that are not analytical grade.

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You mean something like this?
http://134.176.7.66/quanTLC/

Its open source and developped by Justus Liebig University in Germany. Written in R and Shell.

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I’ve run well over 20 HPLC tested samples, against a Tcheck. Each test was within 2 percentage points of the HPLC tests, and a majority were less than 1 point away
 $400ish dollar UV-VIS, sign me up.

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thanks for all your answers, highly appreciated!

i will definitely learn more about TLC to give it a try.

@strgg not exactly what i looked for, but still very useful for my future TLC experience, thanks!

@mj_martini thx for the linked stuff! but the session token for the 42-3-130.pdf has timed out, could you renew the link please?

@SoStupendous i understand. But as @vortal pointed out, the “accuracy loss” of 1-2% with his tcheck, would be perfectly enough for me for a quick overlook test.
dipse has a nice scale for 50 bucks which could fit pretty good for sample prep? DIPSE Juwelierwaage GM-20 im DIPSE Digitalwaagen Shop

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You can open it by plugging the title into Google and then Sci-Hub.se

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Just to clarify. T-check will report within 2% points of the total. The variance is infact 5-15%

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All you technically need is to measure the uv (~228 nm) absorbed by the solution and compare it to a reference solution, you could assume that is an estimation of total cannabinoids. But that is a lot of assumptions when you consider each cannabinoid has slightly different uv absorption (which could theoretically be accounted for if you’re reference solution matched your unknown material, ie cbd ref for hemp material)
 you would also be measuring uv absorbed by pigments and whatever else though so that would throw it off even more.

So it is technically feasible to use a cheap spectrophotometer and distillate to make a reference curve
 But again a lot of assumptions there and you would only be able to estimate total cannabinoids (or more like total uv absorbed)

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That’s really surprising to me. I tried a Purpl scientific against an HPLC and it was basically a random number generator.

Perhaps Tcheck works better because it does actual transmission? Is it that accurate for THC only or other calibrated standards?

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I’ve used it pretty much exclusively for thc. With the Tcheck you run your weighted sample diluted in propanol. The flower and concentrate report “total cannabinoids” but some of the other tests report THC and CBD. They have all been extremely accurate for a $300 device. Each test typically reports a different number, but they are all within an acceptable margin and I usually run a few tests off the sample i prep and average.

Just make sure you weigh properly and use the correct solvent temperature and I’m sure the Tcheck won’t dissapoint.

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SRI GC is about $11,000 and does a gold standard test for CBD and THC and also terps.
See this.

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With the tcheck, I don’t see anything in the instructions other than to “mix thoroughly” the solvent and sample.

Maybe that’s why the numbers vary even with the same sample. Could be nothing, could be something, but keeping the extraction consistent may help just as much as the temperature and sample weights.

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something to take into consideration, and I can find the paper if needed–

the closer you get to 200, the more background absorbance you’ll get with your solvent systems, especially acetone. I used 277nm for CBD to measure drug encapsulation efficiency in mimetic nanoparticles, and translated that to 280nm on an HPLC and flash chroma system once I got into the cannabis industry.

While we’re on this topic, does anyone know of any secondary absorption wavelengths that might be more specific for 1 cannabinoid? For example, I remember a paper that discussed a secondary peak for (D9) THC around 315nm. I’ve gotten familiar enough with a GCMS to appreciate how selective the fragmentation pattern is for identification of compounds, and I think it’d be really beneficial to the industry for someone to elucidate the absorbance/UV spectra of individual cannabinoids in a more selective manner. There’s no reason for testing facilities to do this, but imagine being able to validate the presence of D9 in hemp flower in the field at a unique wavelength, and knowing exactly when to harvest.

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You looking for this?

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