It’s a cost thing for alu plates. If I cut the aluminum ebay plates down to size myself it gets quite a bit cheaper than the silica plates I’ve seen
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Cannatest uses the hptlc plates.
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If you’re skilled you can also just get some gypsum bound silica and spread your own. That’s what we’re doing now and it works pretty well. Makes fucking up a lot cheaper lol
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I noted that sigma states “backing reusable” for their glass backed plates…
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Do you by chance have a version of this article from rollitup? The site is offline and experiencing difficulties.
I have been having the same experience as you. It’s next to impossible to find support for these kits other than a basic video. I bought a kit and extra supplies from Cannalytic Supply. It all seemed fairly straightforward and is, at least for plant material. However, I’m trying to analyze tinctures, oils, syrups and other forms of ingestion and I cannot find a formula or any information on how to determine mg/gm or mg/ml instead of %.
Cannalytic told me that they are going to team up with Alpha-CAT in a few months to produce an upgraded version and won’t have any videos or support for their current product until then.
When I read the plates everything looks in order as far as color size and intensity for the various compounds. I have a good idea of potency before I begin but the percentages are throwing me off. They match the known mg but in percentage. Instead of the 50mg I know it to be, the template says 50% which is 500mg and would make it a concentrate. Just trying to figure that out without much luck.
I’ve been trying to think of some key words to use in a search but have been striking out on that and hadn’t seen anything here that might help until I just ran across this thread and your bibliography.
If you find some good information please let me know. 
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I don’t have it saved unfortunately, maybe as a forum we should put up a bounty to archive all of the classic weed forums? I’ll throw some cash in
I haven’t moved any further with my efforts quite yet, and it doesn’t seem that anyone here plays with plates too much. If you go the icmag thread directly under that rollitup link it’s a more detailed thread from the same poster about the trial and error process of getting their TLC set up going
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I had a resource kicking around somewhere to use a flatbed scanner to quantify TLC spots. Basically, just spot the same amount of your sample and a standard (or known concentration material) diluted to approximately the same concentration as you expect. Then compare the areas of the developed spots and apply the ratio of the areas to the known concentration of the standard.
It is not very accurate but it’s better than nothing
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there are 1000mg in a gram. so 10% is 100mg/g
if you know the density of your “stuff”, getting from % to mg/ml is also trivial.
eg tincture in ethanol with density of 0.7892 g/mL
10% == 100mg/g => multiple by 0.7892g/ml (so your units cancel) and you’ve got 79.92mg/ml
if your results are actually off by a factor of ten, you’ve probably done the math wrong. tell us exactly what you’re doing.
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just realized that I archived that page with my wayback extension
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I’ve been using 3rd party labs for the last several years to confirm that the things I’m doing and teaching are viable and effective…or not. Things like decarb methods, processing/extracting methods, etc. Hobbyist type stuff and not the heavy duty things you guys do here but the same principles.
For an example sample, I wanted to determine, if possible, the THC potency of some powdered infused coconut oil I had made with tapioca starch, maltodextrin. I already had a good idea of dosage. I had used a gram of decarbed shatter in 10g of coconut oil and 8g of the starch, a 5:4 ratio for a total of 18g of infused powder. I used a standard 70%, 700mg, value for the shatter. A dose is 50mg so that’s 14 doses of 1.29g.
I ran this on a plate with three other samples…1 bud, 1 kief, 1 etoh tincture and the powder, a hot test for all. I used 2uL of extracted solution per lane followed up by the dye when it was time. I don’t know what those compounds are for sure but they seem to work.
My bud I knew to be 19% THC and that’s what that lane showed me along with the acids and even THCV. This was my first try and I was pleased. The kief again was well represented although I’m still trying to decide if I should run it as a concentrate or not since it was near that point at 32%. 40 is the concentration limit then math is needed. But everything was good there.
The tincture and the powder looked great and gave me a really great cannabinoid fingerprint and very intense points for the THC. Using those points in the template gives me the right numbers but not the correct unit. I’m not sure that TLC can quantify these values and only offer qualitative analysis and I can’t find out one way or the other. I know my lab used formulas for that but I never had the need to know. It’s seems challenging to try to get an approximate mg from a 2uL sample and extrapolate it to ml dose or a 10 gram piece of candy.
I’m pleased overall with the process and look forward to learning more and getting away from the kits but for now it’s a good learning tool. I’m looking for those formulas if they are available for TLC to approximate the dosage.
Here’s the plate and how I’ve calculated it. I’m just a half blind old man so I may be way off base. 
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Thanks so much. Rollitup seems to be having some major issues so I really appreciate you digging it up. It’s been really frustrating to try to find anything more than the simple stuff with the plant material. Or at least the stuff I can understand. 
Yeah, I scan my plates right away. The colors can fade before long. I can size the copies to exact size of the plate then be able to use those for analysis. I just read the Rollitup article and it seems to imply detail shouldn’t be expected which I pretty much realized already. And it is better than nothing.
Have a look at the HPLC from cannabis testing simplified.
Thanks!!
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Thanks again for posting that Rollitup thread. That was exactly what I needed along with some other links in there. That saves me from running around like a headless chicken, directionless, after investing all my spare change and then some for the kit and extra supplies. 
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I don’t believe you can say that spot confirms 19% THC and still have THCA showing up on the plate (which you do).
seems to me like you need to extend your decarb time.
What are you using as a carrier solvent and and what is your stain for illumination? Iodine chamber?
based on the picture, I’d say @PSam is developing with fast blue salts.
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Oh, I’m extremely confident in my decarb. That spot is raw plant material and should be chock full of THCa. Those first 2 lanes are raw plant/kief. The last 2 are my decarbed products, etoh tincture and coconut oil powder. Those decarbs are perfect. I’ve spent a lot of time and money on lab tests getting that figured out.
If those other lanes had shown a THCa streak like those raw ones then I would really be freaking out. 
You know, I’m not really sure. I think the dye is that blue one @cyclopath mentioned. I bought a kit and haven’t been able to find that info on their site. I have no clue about the solvent. I’m hoping to be able to learn what those are and then just restock on my own. Just the few brief interactions here have focused my insights already but I have a long way to go.
My “chamber” is an old shoebox I use for spraying. I’ll probably start dipping instead, though. 
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