Home TLC Thin layer chromatography

[ganja din]

BTW,

You don't need all the materials I listed, like pipett, some jars, eppendorfs, etc. I made the list a bit bigger than the bare minimum. But, if you have the money my previous list can allow you to process more samples simultaneously and give you greater flexibility.

Here is what I think might be bare minimum:

Silica plates

Glass/pyrex jars a few sizes up to 1L.

Tweezers

Spatula (5mg)

Microscale

Many disposable capillary micropipett (3ul)

Filter paper or blotting paper or paper towel

5ml vials

50 ml test tube

Motor and pestal

 

[ganja din]

One last thought.

I will upload my digital mini-library on TLC, HPLC and GC; all on the topic of cannabis. Mostly TLC but the best manuals by the UN and NATO also have great directions for testing all kinds of drugs with TLC, GC, HPLC, etc. I can probably upload 5-10 full text journal article plus manuals from the DEA, UN and NATO.

I think people will learn a lot from them.

I will also post a how to for a DIY "fume hood", a must have for indoor solvent work!

Lastly, here is a great chemistry resource, a chemistry link-o-rama, people WILL learn a lot for this great (underground) chemistry page! Or they are already chemists:
http://www.erowid.org/archive/rhodium/chemistry/index.html

 

[NotaProfessor]

Rather than develop the plates with chemicals why not use silica that has the fluorescent indicator in it? Then all you need to characterize the spots is a UV light box. Less dicking around. Also, TLC thickness is notoriously inconsistent when you make the plates yourself. I'd use chromatography paper instead, much more reproducible results.

That Erowid link-o-rama needs a bit of caution when reading. For example, the THC total synthesis given is a real boner, a better one (less steps, most of the starting products unwatched) exists.

I'm very interested in viewing the articles in your digital mini-library, once they are made available.

 

[ganja din]

Hey

Using Rf vales is harder and a lot less accurate than scanning spot densities.

More expensive too. Ill try to upload the papers tomorrow.

Nobody making plates themselves. I noted that is the biggest cause of error, the plates. Chromatography paper is less accurate, can't get semi-quantitated results AFAIK. Not much dicking around, esp when the results are analytically valid as HPLC...



HTH

 

[ganja din]

Making or ordering standards:

As I mentioned before, one can use TLC (with effort) to make pure standards of THC (for example). That is great because it enables one to use true quantitated results with TLC on the cheap! See this thread:
www.chemicalforums.com/index.php?topic=10949.0

Although, if making ones own standard than using HPLC to create standards is generally much preferred. But HPLC are expensive. All I need to do is figure out what solvent to use to remove the silica, and maybe a second purification step, but its possible, tho not simple. Once one has their standard they need to test it to insure its purity, two tests are ideal.

 

[ganja din]

Use a fume hood or other ventilation for indoor work

It is important to use a fume hood or work in a well ventilated area when using n-butane or other volatile solvents and chemicals.

Uses:

• A fume hood would be used for the extraction apparatus to remove gas.
  
  
• Fume hood is used for toxic volatile solvents like torlene (sp?) which is common in TLC.
  
  
• A water aspirator would be used for boiling off the ethanol to remove gas (and lower pressure).

Its not hard to build a portable fume hood using plexiglass and a little math.

The fume hood will have to be large enough so the extraction apparatus can fit inside.

I will do a pictorial how to when I build one, but here's the dirty:

Build a three sided box, say 3'x2'x2' (LxWxH), although a truncated triangular footprint might provide better air velocity[1]. Attach a removable 'front' piece of plexiglass with an opening of around 2 feet (enough room to comfortably work). Build an upward sloping 'roof' (like a house's roof). At the center of the roof attach a squall cage fan or in-line fan which can provide a "face velocity" of 90-100 ft/min. If one can't reach a minimum of 80 ft/min than decrease or increase the size of the opening accordingly. Attach a 4" plastic drier hose to the fan and vent it outside.

That's it. Now when extracting with n-butane do so within the fume hood.

SEE:
"Design for a Miniature Portable Fume Hood"
By: R.A. Bailey & S.C. Wait, Jr. J. Chem. Educ. 76(2), 228-229 (1999)

http://www.erowid.org/archive/rhodium/chemistry/equipment/portable.fume.hood.html

 

[ganja din]

Hmmm,

Well after some thought and discussion with some chemist friends I am pretty convinced one can not use TLC to detect butane (bp is too low). I shortly considered using a large cooler kept cold for butane TLC, but that seems like a non-starter.

I am still hoping to find some method for testing at home, but it looks like GC is one of the few options. Thus, I will test my solvent-free extract to see if it's truly solvent free (at least totally free from butane). If my new method I'm working on turns out as well as it should I plan on writing a very detailed PDF paper on the 'how-to'. Then if one follows my methods to the letter they could be reasonably sure their extract is solvent free too.

 

[ganja din]

Wrong forum. Post deleted.

 

[ganja din]

As promised,

Here is a list of journal articles and manuals from my collection I included in the file "Testing.zip".* I encrypted the folder with the password (not incl. quotes): "TLCrocks"
http://www.filesavr.com/testing_1

TLC:

• "Analysis of Selected Pharmaceuticals by Quantitative TLC"
  
  
• "Separation and Identification of the Consitiuents of Hashish by TLC in Forensic Analysis"
  
  
• "Evaluation of quantitative TLC using Staining Reagents" --> paper about and review of "JustTLC"
  
  
• "Silica-Gel TLC Protocols"
  
  
• "TLC Test Protocol" --> GREAT manuel, excellent pics and explanations

GC:

• "Gas Chromatographic Determination of Tetrahydrocannabinol in Cannabis"

Multi tests - TLC, GC, HPLC:

• "The Analysis of Controlled Substances"
  
  
• "Identificiation and Determination fo Cannabinoids"
  
  
• "Simultaneous Seperation and Identification of Hashish Constituents by Coupled HPLC-MS"
  
  
• "Reccommended Methods for Testing Cannabis"* ---> Untied Nations manuel from 1987 (info still valid)
  
  
• "Detection of Cannabis in samples of different sources"* ---> The TLC method on page 6 is what I plan to use.* I might replace hexane.

 

[ganja din]

A note about using TLC to create a standard from silica stationary phase:

"Silica gel can be dissolved by solvents containing more than 10% MeOH."

See the following paper found in the folder "TLC" in the file "Testing.zip" I uploaded:

"Silica-Gel TLC Protocols"
Author(s): Unknown

 

[Amandla]

whats the meaning of ¨Cryptics¨ and ¨Acids¨ ? more shit and other things in weed or im wrong?
Im searching and i cant find nothing...maybe somebody can help me tnx

 

[dybert]

whats the meaning of ¨Cryptics¨ and ¨Acids¨ ? more shit and other things in weed or im wrong?
Im searching and i cant find nothing...maybe somebody can help me tnx

I am extremely versed in TLC testing of Cannabis.

Crytpics refer to cannabinoids we don't know the name of, or that haven't been properly identified yet.

Acids are the acidic forms of the cannabinoids. You will see a huge flame at the bottom of the plate that is comprised of all the acids.

In order to read the neutral forms, you need to heat the plate, and then run it. To read the acids, you can then read the difference in the hot and cold lane.

You seemed to have bumped an old thread, there are a few companies dedicated to this method of testing.

 

[Cannabliss420]

been interested in this route of home testing as well but have been hesitant. works on concentrates too right? what computer software/hardware is needed to quantify all the data from the TLC testing into an easy to read format on the computer? maybe dybert knows

 

[Mcgrh]

Hey bro,


You want the salt, fast blue bb salt, it shows all the neutral cannabinoids. You don't need a license.

Use silica. Dip the plate, do not spray.

Here is a quick into, this might have typos or slight omissions, I'm tired. If so ill fix it tomorrow:

1. Extract cannabinoids

2. Sample super critical solution with micropipett.

3. Spot plate with micropipett. Two applications per spot can be good. This is the stationary phase.

4. Put plate into 'developing chamber'. This is the mobile phase. In the chamber is the hexane:ether mix (4:1), a little in the bottom. Along one side of the chamber is the filter paper, it is wet with developing solvent (synonymous with mobile phase). The filter paper and solvent are to fill chamber with fumes to facilitate the mobile phase. The developing solution will run up the plate. Dragging invisible lines of cannabinoids with it. Once wet mark reaches top line of plate (0.5" from top of plate) its done. Pull out and allow plate to dry. This can be speed up with very light warm air from hair dryer, but allowing to dry in a vacuum desiccator is much, much more ideal and quicker too

5. Before applying the visualization reagent one should make the silica plate alkaline first, better results with cannabinoids. So mix up as below and quickly dip the plate into the alkaline solvent. Allow plate to dry as before.

6. After plate is dry dip in reagent (1% fast blue BB salt in water). Allow to dry as before.

7. After plate is dry dip in preservation solution. Same as the alkaline solution. Allow plate to dry as before.

8. Scan plate with flatbed scanner and upload to JustQuantify for free spot density scanning and assay. If you place a few different samples on one plate it makes comparisons easier and more accurate.


Done!


You also need (at least):

Chemicals:

Petroleum ether (extract solvent)

Hexane

Ether (mix with hexane as 4:1 hexane:ether as mobile phase)

Fast blue bb salt (visualization reagent - add 1% to water)

0.1M sodium hydroxide (Alkaline solvent and Preservation solvent)


Materials:

Glass jars 1L, 0.5 L, 0.25 L

filter paper

5mg spatula

Microscale

A few eppendorf (1.5 ml each)

Eppendorf holders

Capillary micropipett (3ul)

1ml pipett

Pasture Pipett

50 ml test tubes

5 ml vials

Motor and pestal

Test tube vibrator or ultrasonic vibrator (optional)



US sources of chemicals:

I get fast blue bb salt here:
http://www.sciencelab.com/page/S/PVAR/10413/SLF1114


Carolina chemicals:
(They sell many kinds of kits)
http://www.carolina.com/category/ph...try/chemicals.do?KickerID=int_t_hom_chemicals


Science Lab (same place I get reagent):
http://www.sciencelab.com/page/S/CTGY/10405


Here is a good ebay site:
http://stores.ebay.com/AVOGADROS-LAB-SUPPLY

Since this post is almost five years old, does anyone know if this is still the best deal/best place to procure these items? I've got one of those cannalytics test kits and the refills are pretty steep.

Furthermore, is this still the best and closest thing to measuring %THC vs. %CBD on a homemade scale as opposed to going to a professional full blown lab? MyDx is still a ways from being sold to the public (they're saying December).

Thanks in advance

 

[sadpanda]

Hello! Im sooo relieved to have found this thread. When i learned that all the main cannabis detection home kits just use TLC, and when i found out how easy TLC is, wow it was a relief!! My best friend has cancer and she's been amazed how well CBD oil has helped in all sorts of ways during her chemotherapy, but its not possible to get a high CBD clone here so they have to grow out seeds and test.

And if im not mistaken TLC seems the best option for a non-chemist home grower on a budget to get a rough estimate on whether their plant has no, low, medium or high CBD. I understand its limitations but that beautiful orange CBD spot seems better than anything else I could use - without it i'm blind. Although yes i think we'll also use the Beam's test with potassium hydroxide.

But then when it came to reading up about this special ingredient Fast Blue BB my heart sunk when I read this paper https://www.google.com/patents/US4771005

There are however problems with said diazonium salts with regard to their instability, since once formed, aromatic diazonium salts react with a host of different nucleophile. The Fast Blue BB Salt is attacked by the weakly nucleophile-H2 O and is decomposed to the corresponding phenol. In slightly basic solution, necessary for cannabis detection, this process is accelerated. With a life span of only days before decomposing, pre-packaged solutions of diazonium salts have not been commercialized, despite the proven superiority of such salts and the widespread demand thereof.
In recent years many attempts have been made to stabilize diazonium salts, so that they could be used in detection kits.

However that paper is from 1988.

So my question is how does Fast Blue BB come - just in a regular package? or refrigerated?

How long does it last once youve got it? does keeping it in the freezer allow long term storage??

In other words... HOW is everyone using it if it only lasts such a short time!? and what are those commercial cannabis kits like alpha cat and cannalytics etc using??

Everything else in the process and obtaining them seems no problem, its just this Fast Blue BB which has me stumped!!

 

[sadpanda]

i havent got any yet, there are quite a few labs in China that sell it though. From what i read Fast Corinth V works well as a "general purpose test for cannabinoids" but isnt as good as Fast Blue BB because it shows THC, CBD and CBN all as the same hue, whereas Fast Blue BB shows CBD as orange, THC as scarlet-red etc. (http://www.unodc.org/documents/scientific/ST-NAR-40-Ebook.pdf)

 

[sadpanda]

"A visualizing spray used early on, fast blue B, was replaced by many practitioners with fast blue 2B because the former is thought to be carcinogenic." page 56 http://www.google.com/search?tbo=p&tbm=bks&q=isbn:0080472893
im pretty sure Fast Blue 2B is just another name for Fast Blue BB

 

[G.O. Joe]

B and BB are more toxic than carcinogenic. The statement is based on scientists spraying this stuff in something on big plates all the time - and known issues with the B base o-dianisidine, traces of which may or may not be in the zinc tetrazo salt. Without a test it's speculative and hearsay.

The MSDS I read for BB said it's gray so that means it will be powder of some color. The container will probably say something about storage and may or may not have seen refrigeration at some point. The main thing is if there is gas released when the container is opened there is a problem. It's kept in the freezer, but cold moisture-sensitive substance containers are brought to room temperature before opening them. Solutions are used immediately.

 

[sadpanda]

thankyou very much Joe! this is the sort of information about Fast Blue which i've found virtually impossible to find. I wonder what the commercial cannabis test kits use? they all seem to come in a premixed solution, i dont think any come with Fast Blue powder

 

[G.O. Joe]

That same UNODC document says Daily preparation of the spray reagent may not be required when Fast Blue BB or Fast Blue RR are used (0.2 per cent w/v solution of Fast Blue BB or Fast Blue RR in methanol or methanol/water 1:1), so maybe the methanolic solution is more stable. No major chemical supplier sells it in solution ever, there's that.