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

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Hackerman

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I am planning to test for CBD in the strains I have coming up. I was looking into the different avenues available to us.

For me, sending out samples is out of the question. I'm too anal to wait for an answer. And, at $40 or more a test, it's not a great option.

Setting up a small lab for High Pressure Liquid Chromatography (HPLC) or Gas Chromatography would be fun and certainly would be a learning experience but it definitely wouldn't be cheap.

Thin Layer Chromatography (TLC) is probably the cheapest way to go but there seems to be quite a learning curve required to obtaining accuracy.

While I was looking for supplies for TLC I realized there are a number of home testing products for sale. Some use TLC and others use chemical dye test methods.

I have to wonder if there's any use in the drug test kits they sell for parents to test their kids for pot use.

Here are a few of the home kits you can buy....

http://corp.cbscientific.com/product/combo-kit-test4-cbd-medical-marijuana-kit-thc-percentage-kit/

http://www.cannalyticssupply.com/

http://www.thctestkits.com/

Has anyone tried any of these? Any comments?
 
Haven't tried them but might be willing to guinea pig in a week or 2.
 
I have been reading a little and this seems pretty straightforward. I'm going to post a couple links so I don't loose them.

Here is a very nice and simple explanation of the various types of chromatography. The read that's important to us is the first one, Introducing chromatography: Thin layer chromatography

http://www.chemguide.co.uk/analysis/chromatogrmenu.html#top

Buying the plates seems to be the most expensive part of this method of testing so I searched out ways that we can make our own plates. Pretty simple, really. This guy is about a ho-hum as they get but it's a nice video on how to make our own TLC plates.

https://www.youtube.com/watch?v=pNDQkM3jasA

I'll have more as I find it.

EDIT: Instructables.com is great source for many things.... http://www.instructables.com/id/Preparing-your-own-thin-layer-chromatography-plate/

A more detailed look...

https://chem.libretexts.org/Core/Analytical_Chemistry/Lab_Techniques/Thin_Layer_Chromatography
 
Pretty cool Hackerman. Doubt that we will see the price drop from $700 to $100. However as more and more states legalize cannabis and more and more people want to test that cannabis, I am guessing we will see more products like this and the price will drop. Great research.
 
So far, every one except Test4 uses the same TLC.

Only Test4 uses a dye system. I may buy one of the kits just to see what I get but I was reading the reviews and they are mostly all bad. I love this one......

ByLarryowen2on July 20, 2016
Verified Purchase
Everything tested over 20 percent even my lawn.
 
So far, every one except Test4 uses the same TLC.

Only Test4 uses a dye system. I may buy one of the kits just to see what I get but I was reading the reviews and they are mostly all bad. I love this one......

ByLarryowen2on July 20, 2016
Verified Purchase
Everything tested over 20 percent even my lawn.

Haha haha that's awesome!
 
Actually unless you are retesting a known sample, you really won't know how accurate it is. Can you guys get dispensary bud that has been tested by a certified lab to compare your results against?
 
That would be a problem for me. With no baseline, the best I can do is compare one to the other.

However, I definitely plan to test my lawn grass. LOL This would certainly invalidate the test altogether if it actually showed THC content.
 
Actually unless you are retesting a known sample, you really won't know how accurate it is. Can you guys get dispensary bud that has been tested by a certified lab to compare your results against?

I wish. No base line here either.
 
Even if your lawn tests 0%, I think that you need something to verify the accuracy of these. I'm thinking you either get a sample tested yourself by a certified lab or you have someone send you a fresh sample of dispensary bud with the test results.
 
There seems to be a number of DIY versions of the CB Scientific method. This method really only gives a 'high. medium. low' type of result. Anything more precise will require some type of chromatography.

Here are a couple of the home methods... These are all CBD only.

Test 1:
2% Lye to 100ml Rubbing alcohol (If solution too light then add 4g Lye to 100ml rubbing alcohol, if is too dark then 1g lye to 100ml or 200ml rubbing alcohol).
2g Lye to 100ml rubbing alcohol, 5ml of this added to .2g cannabis/.2g activated carbon.
Shake few seconds (if too light add 30-60 seconds of shaking) and wait 10 minutes for almost clear purple 1% or hard to see thru purple 15% or higher.

Test 2:
(5g Lye to 100 ml rubbing alcohol) 5 drops added to 10ml Rubbing alcohol, 5ml of this added to .2g cannabis/.2g activated carbon (If coloring too strong then add only 2-4 drops to 10ml solution)
Shake few seconds and wait 10 minutes for almost clear purple 1% or hard to see thru purple 15% or higher.

Test 3:
(5g Lye to 100 ml rubbing alcohol) 5 drops added to "white" test strip, 5ml rubbing alcohol added to .2g cannabis/.2g activated carbon and shaken few seconds (if too light add 30-60 seconds of shaking), test strip "dipped" into cannabis solution 1-2 seconds and let to air dry. White = 0% CBD, very very light purple=1% CBD, dark purple=15% or higher.


Notes:
Test should work for fan leaves even in veg, roaches, roach paper, buds, scrapings from pipe, etc etc.
Heating is not always required but may help (police field tests do not require heating of samples), prep Cannabis sample by folding up in aluminum foil and placing in pre heated oven of 302-325 degrees Fahrenheit (150-176 degrees Celsius) for 5 minutes.
Looking at coloring from top of vials may help in judging amount of fade.
Use different test tube for each sample.
The more crystal clear the test tube is the better (glass probally best), the plastic ones should be last resort (they give a murky white dull tint).

Alternatives:
Nail polish remover (ethyl acetate) could work as alternative of Rubbing alcohol, Nail polish remover costs around 1 dollar.
3-4 drops of the 2% Lye solution put on a test strip paper and dipped into the Rubbing alcohol/Cannabis/activated carbon solution.
Blotter paper MIGHT work as a test strip, or it may be possible to dip a piece of blotter paper into test 1 or 2 solution to get better fade, blotter paper is cheap in art sections of stores.


I am going to try some of the home methods. I'm also going to buy a couple of the home kits. One is actually TLC and should be every bit as accurate as any lab (given the ability of the operator) :)
 
Let's see if this works....

I found this at another site.. fairly similar to what chimera said, however this uses easily obtained materials and gives an idea of %. which would give mass instead of roach size.. anhoo

"This method gets tweeked here and there over time....currently working on tweeking it to pre test male plants.

--------------

Pheno seedz' CBD test method

------------

1.5 ml micro centrifuge vial (snap top)
0.08 gram lye
Tiny roach sized "pinch" of plant material.
1ml of 50% iso rubbing alcohol (although 70% can be used)
1 tiny Carbon pellet (sold at pet stores in fish dept)

--------------

Do the following in this exact order.

Add 0.08 grams of lye to vial, add plant material, add carbon pellet (on top of plant material to get better visability of color change), add rubbing alcohol as close to top of vial as possible (about 1ml). Close vial securely and shake for 60 seconds (making sure lye is not stuck to bottom..give few light taps if lye is stuck), wait 10 minutes and shake another 60 seconds, after 10 more minutes the color reaction should be ready.

Green = 0%
Yellow = 0-3%
Orange = 3-5%
Maroon with slight purple = 5-8%
Light purple = 8-12%

--------------

LYE safety should be researched and understood before trying the testing.

DO NOT add over 0.08 gram lye as the more you add then the hotter the chemical reaction will be and you can get burned, 0.08 is the most sensitive amount for percent testing (under 0.08 and you may not get any color reaction)....I burned my finger when I tried 1.5 gram of lye.

You should try to use dense samples over fluffy samples (fluffy samples do not react as good).

You should perform the test 3 times to each plant...using the highest percent as final result. Taking a pinch from different buds or different areas of a bud.

Wash hands often and make sure to wash work area after, cover work area in paper towels or paper in order to better clean up after.

Purple Nitrile gloves are better suited than latex gloves when dealing with lye.

As extra pre caution you can wrap toilet paper or something around the vial during the shaking process.

Drain cleaners can not be used instead of actual lye (drain cleaners add dye to the lye).

from my breedbazy thread posted by cbdseeker"

View Image

Images didn't come with the cut and paste. If you want to see the images, the thread is here at IC Mag..

https://www.mjp.com/ic/showthread.php?t=347984
 
Wow, how do you measure 0.08 gram of lye? That is really a small amount.

I think I may be a bit ignorant when it comes to testing and how it works. How can it work when the thing you are measuring does not have a definitive quantity? For instance why would a larger quantity not show more CBD than a smaller quantity?

Another caution on working with lye. It is a strong base and caustic--just as capable of burns as a strong acid--one of the reasons I NEVER used drain cleaners. And it can cause eruptions or dangerous gas if mixed with the wrong thing. Handle with care.
 
Actually, the proportions are not all that critical other than calibration. I could do it in a larger test tube and use different quantities for the tests. I have been reading about the chemical reasons why this works (and why the color test does not work on THC) and it's not that difficult to understand.

The lye basically heats. The carbon is a filter that draws from the mixture and what's left is the reaction of the CBD and the mixture. And, it's purple in color. The test takes advantage of that simple reaction. I read a bunch of different tests using different compounds other than lye and iso but it was always about the same result.... purple.

There is a thread at Jorge's forum with some very nice posts about how and why it works in the lab. I'll grab a link and post it here later.

This color thing is not a great test. The one you buy isn't all that bad because it's already been calibrated. Since I am doing my own from scratch, there will be the process of calibrating the mix and the resulting color to determine what colors are 'high, medium or low'. To do that, I would need some real tests to determine percentages. I don't really plan to take it that far.

However, I have 3 phenos here of that Med Tree Continuum and I could use this test to tell which pheno has more CBD. Not how much. But which of the 3 has the most. That test would be pretty accurate once the portions of lye and iso are established.

I bought the activated carbon, the Sodium Hydroxide and the vials on eBay just to try and to learn.... might be fun. Cost me about 20 bucks. Quite frankly, this is just more for fun that to really establish any accurate test results.

What I did buy that should actually work is the one called a 'Grow Buddy' from Montana Biotech. This is actually a very nice and affordable Thin Layer Chromatography kit. Given the user's ability, this should give as accurate a result as most labs. Unless someone is running HPLC or Gas or maybe near infrared spectroscopy, this is about as accurate as it gets.

It's a little more expensive but if I can learn to make my own silica plates (which doesn't look too hard) this might be very affordable in the long run.

The bad news on this process is that I imagine there is going to be a small learning curve. I have been reading a lot about TLC and there are definitely right ways and wrong ways to do it. If you want good results you have to do it the right way.

Still, it should be fun and almost certainly a learning experience.

HG, this is what I bought.... https://www.ebay.com/itm/Sodium-Hyd...var=484957997241&_trksid=p2057872.m2749.l2649

Is this any different than standard drain cleaner. I have used drain cleaner for years for all different things so I am pretty aware of the potential for injury. I have burned myself a couple times but you DO NOT want to get drain cleaner in your eyes. I have seen that happen. Safety glasses are an absolute must.

Also, keep in mind that most of these tests are stuff we pulled from 1930's and 1940's patents. This was about all they had in those days. Today, we have better methods and these old methods are seldom used in the lab. However, they are no less accurate now than they were then if conducted properly.
 

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