(This thread existed already but I accidentally deleted it :facepalm: So here it is again )

Here is a database with the results for hundreds of substances tested with the reagents marquis, mecke, mandelin, ehrlich, hofmann/pdmab-ts, froehde, simons and liebermann.

You can purchase all these reagents here (or check here for other vendors). TLC kits can also be bought in this link.


Testing with TLC is easy! Test your substance next to any other substance that is of confirmed identity (if you don't have anything at home you can buy caffeine online or even just soak coffee beans in the provided testing liquid and use that). Then you measure the height of the spot of your known substance (for example caffeine or anything else you have), and then select your unknown substance (the one you suspect what it should be but need to confirm it's identity) from the dropdown list, and the calculator will tell you where your unknown substance should be on the plate.

EDIT: You need to be logged in to be able to download the attached excel file, or click here:

This file was uploaded on github by a friend, so now everybody can contribute and this calculator will keep growing

Thank you Endlessness, the spread sheet for TLC is "Spot On" (Sorry - couldn't resist).
By strange coincidence I do have some caffeine for the comparison base - one item less to worry about.

I will be making my own TLC plates and experimenting with different stationary phase materials, talc for a start, whiting (very fine chalk), calcined alumina, fine quartz flour at 600 grit. I'll mess about with the binder, a hard plaster including an acrylic polymer (SP201), as long as the acids from the reagents don't have a problem with the polymer. I am a lazy git and I can not for the life of me spend ages grinding up silica jel beads, I can visualize the darn things twanging against the walls as you try to herd them into the pestle and mortar to pound them into submission !!

The plaster (25 kilo - LOL!) and the 5 litre polymer I have was for casting chess pieces - another task in abeyance (posh word for procrastination). Cutting up the aluminium sheets into strips is going to be a pain but I might forgo that and buy in some glass microscope slides instead.

The spot height calculator on tlcconscious.me doesn't work in some browsers.

It seems like the actual calculator lives on https://chat.dmt-nexus.me/tlc_ratio.aspx anyway and that link works just fine for me and loads a bit faster.

I'm a bit puzzled.

In the XLS file there is no 3-MMC listed.

In the calculator pitubo linked, 3-MMC is listed, but the calculator does not work for 3-MMC.

I'm just wondering now. Does 4-MMC have the same value as 3-MMC? If not how different are they? (distinguishable by TLC?)

This is pretty awesome! I'm going to play with the spreadsheets later. Do you think it'd be useful to create a sheet with formulas where you could input the solvent and calculated Rf for an unknown, and it'd return a list of chemicals with values within some range of the unknown's Rf?

For sure that'd be interesting, another way to work with the data that could be useful when working with unknowns and trying to narrow down what they could be.

Cross-checking the TLC results with reagent results too and using something like this: https://app.testdrugs.info/

makes it even better.

Of course ultimately what one needs to be more sure is the actual reference standard to properly compare, and without that, any result should be considered tentative only, but having a reference standard isnt always possible, so such tools can be useful to have a better idea what substances/adulterants/impurities you are dealing with.

The two calculators seem to give different results, I wonder which one is more accurate. Is it possible to download the ratios used in the chat.dmt-nexus.me application?

Anyway, since I have found the format of the original calculator to be a little limiting / annoying, I have made a lookup table version of the same spreadsheet, with the same data. (Ie. you don't have to select the unknown compound from a list, you can just go to a lookup table and find it.)

ps. I'd like to ask for some clarification
- TLC depends on solubility in the solvent used, right? So what solvent do the numbers in the calculator assume?
- Also, it's relatively inexpensive to buy chromatography paper from laboratory suppliers, is that a viable route as opposed to making plates or buying kits?

awesome database.
i dont want to cause any effort but i noticed that mephedrone aka 4-mmc is missing.

Possibly - take a look at this recent thread. It could be even cheaper.

Sorry can you clarify which 2 calculators have different values?

As for the chromatographic paper, sure you can perform chromatography with paper but don´t expect the relative RF values that were posted here to be useful, since those are specific to the both the mobile (solvent) and the stationary (plate) phase. If you change any of those, you´ll get different forces that will attract the molecules differently and therefore they wont elute similarly. Also, TLC plates sold with kits have a fluorescent indicator that allows you to see the substances with UV light without needing a reagent first. This is very useful, and you won´t have this with chromatography paper

I think the kits are relatively cheap and very convenient, I highly recommend using those

The solvent used for the calculations is methanol and ammonia.. to make 100ml of the eluent mix you use 97.5ml methanol and 2.5ml 25% ammonia.

Thanks for doing the spreadsheet edit btw



If I have time at some point I´ll add it, thanks