In Home and DIY Testing your Cannabis for THC and CBD Potency

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Belle Chemical is pretty dependable. I bought their NaOH and I liked it. Here is their Potassium Hydroxide. I bought a pound because it's so cheap and I knew I would be doing a lot of testing. And, for 10 bux... what the heck. LOL

https://www.amazon.com/dp/B075DJCR79/?tag=skimlinks_replacement-20

I also bought this one and it works well..

https://www.amazon.com/dp/B00TPI5WO2/?tag=skimlinks_replacement-20

Here is an Amazon link to the vanillin for THC testing, if you're going to test for that also.....

I bought this one...

https://www.amazon.com/dp/B00IAZHW0I/?tag=skimlinks_replacement-20

I didn't see any other lab grade vanillin on Amazon. If you search, add the word reagent to your search and it will return mostly lab grade.

Also, keep in mind that the vanillin is still a caustic base and can cause burns. It smells so delicious when you open the bottle. It's tempting to take a whif. Don't. And, as I was told by one of the chemists working on this.... "No, Hack, it's not safe so don't snort lines of it or you'll die". LMAO

Same with the KOH. It's no more dangerous than drain cleaner but... you would be careful not to splash drain cleaner in your eyes, too. So, gloves and goggles, please.

The denatured alcohol is available at any hardware store. Don't get anything GREEN,. The contents should read Ethanol and Methanol. Maybe some other 'proprietary' blend. But, still, Ethanol and Methanol.

Let me know if you have question on the alcohol.

Do you have some little coke vials? They make nice for mixing and....... I know we ain't a using 'em for coke no more. LMAO

Last week at our Wednesday gig, some of the older guys were doing coke. I was just shaking my head. I was wondering if I was going to get to see someone go into cardiac arrest while I was on break. LOL There is an age when it's time to quit. LMAO
 
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Thank you Hackerman, i don't have those little jars all i have are the cobolt blue ones, and it sounds like color is important. Do they need lids? do you shake it? would juice glasses work?
Old guys doing that is pretty scary I bet.
I have gloves and my led glasses should work, oh i do have goggles too. awesome.
 
I would mix the reagents (vanillin and alcohol) and the (Potasium Hydroxide and alcohol) in bottle or jars because you can store this and use it over and over. Amber jars or bottles are great for this.

As far as the extraction and testing, you can do that in shot glasses. Instead of shaking it, just stir it.

There are detailed instructions at mjp. I will cut and paste them here.

When you get around to doing it, I'll walk you through it.
 
Here are the instructions as he wrote them. I would print them out and have them at my side when I do the testing.....

Before I get into how the tests are made I’d like to let you know that some of the chemicals used can be very dangerous if not handled properly, so proper safety precautions are needed so as to not get hurt.

Things you will need to protect yourself:

1# Chemical resistant gloves

2# safety glasses

3# have a place nearby to wash in case of a spill or if any chemicals get into eyes. Something as simple as a large bucket of water nearby you can flush eyes or skin off quickly before running to a sink.

4# all of the chemicals used in this experiment can be washed off or neutralized with water just in case you need to in a emergence.

5# do not use anything metal when performing this experiment! A violent reaction will happen!!! No metal tools or containers can be used, only plastic, glass, rubber can be used….

6# if you don’t really know what these chemicals are don’t try and mix any of them other than the ones I say. Lye is very alkaline and hydrochloric acid is very acidic, mixing them would not be good.

7# Use caution when storing these chemicals. Keep them away from people that don’t know how to use them, it goes without saying it, but I’ll say it anyway. Keep them away from children and pets!

8# do these experiments only in a well ventilated room.

Bottom line is, think first and don’t be stupid!



Ok now that that’s out of the way, on to the fun part! I’ll start off with how you make the extract out of the bud you will be testing.

Things you’ll need:

1# A scale. I think we all have one of these lying around. One that can weigh very small amounts like tenths of a gram or one hundredths of a gram.

2# small plastic or glass jars to mix in

3# 1 or 2ml dropper

4# 100% alcohol/ethanol or as close as you can get. 90% rubbing alcohol will not work it has to be higher than that. 95% or higher. You can buy denatured alcohol at the hardware store.

5# An oven. I like to use a cheap toaster oven so as to not make my kitchen oven smell like ****. But do what you want.



The first thing you’re going to do is take about 1 gram of dry bud to be tested and place it in a piece of aluminum foil and fold it over and then fold all the edges closed.

Place the bud and aluminum foil in the oven for 30 minutes on 220f/110c to decarboxylate the sample..... let cool....
(this is to convert THCA and CBDA into THC and CBD)

Take your crispy bud out of the oven and weigh out ½ gram or .5000 on the scale in a small jar or shot glass. Now get your dropper out and put 5 grams of alcohol in the glass with the bud and mix well. Let that sit for at least one half hour then suck the liquid out and put that in another jar or glass without getting any bud material in the glass. That is your extract you will be testing.



The first test will be the Duquenois reagent test. This is for testing THC.

There are many ways to perform this test; this is just my modified version of this test. The original test called for chloroform to be used to stabilize the mixture and separate the organic layer. But chloroform is some nasty ****. This is the stuff the Nazi’s used to kill countless people. It’s very gaseous and is a silent killer when working with it. I also don’t like buying it for obvious reasons. It can be made with bleach and acetone easily if you know what you’re doing.

Things you’ll need:

1# Glass test tubes or shot glass

2# a dropper

3# hydrochloric acid 37% or higher

4# vanillin which is a synthetic vanilla

5# 100% ethenol

6# amber glass bottles with dropper built in if you want to store the reagent for later use.



We will be making the reagent first.

Weigh out 5 grams of vanillin and dissolve that in 100ml of alcohol then put in amber bottle. That is your reagent.

Get a test tube and place three drops of your cannabis extract in the test tube followed by ten drops of reagent. Mix well. Now carefully put 10 drops of hydrochloric acid in the same test tube with your reagent and extract. Mix well and wait for color change. This may take up to thirty minutes to get to its full color.

You should see a deep blue or royal purple to black color for a high THC strain and light blue or purple for a low THC strain. Little to no color change or off color means very little to no THC.

This test is best used when comparing two strains side by side or two phenotypes of the same variety so you can see the difference in color to know which one has more THC. (darker=more THC), (lighter=less THC).

I have found that One turned purple and one turned blue which can make it difficult to compare them so I just looked at how dark the colors were. In cases like this it’s best to have a known variety that you can compare to, but most of time you will get purple as your main color.






The beam test: This test is for CBD.

Things you’ll need:

1# Glass test tubes

2# a dropper

3# 100% alcohol

4# potassium hydroxide (AKA) Lye

Dissolve 5% lye into ethanol which is five grams of lye to 100ml alcohol. Mix well.

Grab a clean test tube and put three drops of extract into the test tube followed by 10 drops your dissolved lye, mix well. You should see a pink to purple color in the presence of CBD. It may take up to thirty minutes to see any color change. Pink is low CBD and purple is higher CBD.
 
Those little glass vials are about 25 cents each everywhere.

And, these little plastic vials make nice for the tiny 13 drop samples we test. You can use something larger like a juice glass but you'll probably have to take bigger samples and use more of everything so it doesn't get lost in the size of the glass.

These are nice and cheap. About a nickel each. They are called 1.5ml centrifuge vials if you want to search Amazon or your favorite shopping site....

https://www.ebay.com/itm/1-5ml-Micr...706973?hash=item1e8e2373dd:g:GyMAAOSwOA1aDbjP

Test tubes also work and can be bought at your local science shop or online.
 
Just FYI. I tested this on edibles today and it works like a charm. I had some coconut oil that I made from some Cinderella99. Moderate/High in THC and low in CBD.

The tests on the oil reflected just that.

A tiny speck of oil and the reagent.... bingo.

Pic 1. Oil
Pic 2. Results

Nice to have something to test edibles with.

View attachment oil-3.jpg

View attachment oil-4.jpg
 
Well, this is totally cool. I finally got around to playing with the thin layer chromatography.

This takes a lot more effort but the results are (supposedly) way more accurate than the easy home tests above.

However, I did the home tests on the same samples after doing these TLC tests and the results were just as clear. Plus, these tests cost a couple bucks each while the home tests above cost only a few pennies each.

After sampling and developing the plates, you take a picture of them and upload them to an online quantification tool and it does the quantification for you. After that, you can figure the percentage of each cannabinoid on the plate. Pretty awesome.

View attachment buddy-1.jpg

View attachment buddy-test-JustTLC-1.jpg

View attachment buddy-test-JustTLC-2.jpg
 
Looks impressive Hack, but I don’t know what it means...
 
Think of an ink blot.

If you take a green sharpie and put a dot on a napkin or piece of absorbent paper and let the paper wick up water from one end to the other, the green spot would bleed, right?

OK, simple enough.

What you may never have noticed is that while the green ink spot is bleeding it is also separating the yellow and blue. And, not in even amounts. It may be a yellow blot with a dark blue border. That's how much yellow and blue it took to make the green color.

That is paper chromatography.

This is done on silica plates but the same principle applies.

A tiny drop of the sample is placed at the bottom of the plate. The plate sits in chloroform and wicks up across the sample to the top of the plate, along the way, separating each cannabinoid (THC, CBD, CBN and CBG).

Then, you spray dye on it to show the blots and... bingo.

The large blots at the top of the plate are THC. The next blots down are (I think) CBD. Might be CBG. I need to go back and review more.

Anyway, you can use software to "map" the sizes of the blots, thus determining the percentages of each cannabinoid from each sample.

This method (when compared to HPLC) is supposed to be accurate to about 0.5% which is pretty darn accurate.

Personally, I am going to stick with the simple method using the lye and alcohol. That test really tells me everything I want to know and it is soooo quick and easy. I test all my edibles and rosin that way. Basicallly, it very clearly and accurately shows, NONE, A LITTLE BIT and A LOT of either CBD and/or THC.

Quit frankly, for me, that more than good enough.

I made butter yesterday and before tossing the scrap, I ran a quick test on it and it showed way high in THC still, so I rinsed it again real good and got a ton more butter. Glad I checked before tossing. LOL

This TLC was great fun and it was good to learn something new but it won't be my regular method of testing potency.

It will be good for knowing CBD from CBG from CBN. Those all show up as purple on the other tests. Only the chromatography will separate those cannabinoids out separately.
 
To further explain a little. The first picture is of the 2 plates. Each plate has 5 sample (dots) at the bottom.

The chloroform wicks from bottom to top and drags the sample, separating it on the way up.

The one sample on the left side of the one plate went off the edge and it was messing up the test so I cut the picture to show only 4 samples so the software would more easily recognize and map all the blots.

So, what you are seeing in the results are 2 separate tests of 4 samples each.

Lane 1 is Afghan Kush, lane 2 Med Tree Continuum, lane 3 Cinderella99 and lane 4 is Lemon OG.

Sounds like a lot but it's really pretty simple.
 
Here's a little rig I made up for doing the Duquenois and Beam tests. This is all that's needed. Whenever I want to run CBD or THC tests on a sample, I can just grab this rack and it has everything I need right there.

View attachment myrigforhometests.jpg
 
Just FYI, there's been some conversation at ICM about this and it seems pretty clear that you can test at about 3 weeks from seed and the plant will display an accurate ratio of cannabinoids that you can expect at maturity.

Quantity will be less, of course, but the ratio will remain consistent.

Pretty neat.

Next comes DNA sexing.
 
Still relevant no matter how much time has intervened, though as determining THC potency is something every grower should use, just as @Hackerman has laid out... Kudos for this.
 
What up Bro?
Hey,,i got an old fashion way of testing your Weed,,,send it to me and i will smoke it and get back with your info. :smoke1:

Heh heh heh. Love this stuff love tech info - would defo be messing with this stuff if I wasn't an old gadgee.
Nowadays I'm happy with WeedHoppers approach to testing 😊😊😊
 
Because of the popularity of medical CBD, I've read that devices have emerged to quickly and inexpensively measure % cannabidiol, tetrahydrocannabinol, and other cannabinoids at home. Prices range from $80 to $120,000. Techniques range from simple visual detection to high-performance liquid chromatography. Basically, the instruments focus on measuring THC and CBD. I honestly haven't tried these instruments, but I wouldn't trust the cheap models. Maybe on specialized sites, you can find professional information.
 

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