Interesting read questioning the legitimacy of testing cannabis

TonightYou said:
http://gizmodo.com/why-legal-weed-isnt-much-safer-than-a-dime-bag-1665789200/all

Something I've been well aware of and something anyone who's spent any time in a scientific lab, these issues do arise.
Click to expand...

I've still yet to settle the question of how they arrive at canabinoid percentages in these tests?

I always thought that THC % was expressed as a percentage of total canabinoids present. Others says that its a percentage of the total sample weight (of the bud).

Thoughts?
 
st0wandgrow said:
I've still yet to settle the question of how they arrive at canabinoid percentages in these tests?

I always thought that THC % was expressed as a percentage of total canabinoids present. Others says that its a percentage of the total sample weight (of the bud).

Thoughts?
Click to expand...

I recall that conversation. I believe it's the total sample. I should hit up a friend over at a lab and get a better answer.

Eta: hence why none of the numbers add up to 100%

Eta2: when I used one in a lab, it was of the the total sample
 
TonightYou said:
I recall that conversation. I believe it's the total sample. I should hit up a friend over at a lab and get a better answer.

Eta: hence why none of the numbers add up to 100%

Eta2: when I used one in a lab, it was of the the total sample
Click to expand...


So when a test comes back at 25% THC, you're saying that 25% of the *total* bud sample weight is comprised of THC?? That seems like a lot to me. If that's the case, then you'd be better off bringing in a sample that's as dry as a popcorn fart, no? Any water weight in the sample would lower the number
 
st0wandgrow said:
I've still yet to settle the question of how they arrive at canabinoid percentages in these tests?

I always thought that THC % was expressed as a percentage of total canabinoids present. Others says that its a percentage of the total sample weight (of the bud).

Thoughts?
Click to expand...

TonightYou said:
I recall that conversation. I believe it's the total sample. I should hit up a friend over at a lab and get a better answer.

Eta: hence why none of the numbers add up to 100%

Eta2: when I used one in a lab, it was of the the total sample
Click to expand...





Just a guess, but neither of you cats have toked up in a while, am I right? :eyesmoke:
 
Amos Otis said:
Just a guess, but neither of you cats have toked up in a while, am I right? :eyesmoke:
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It's been about 10 hours, just got in the door and shall be doing so momentarily. The plan was to be high all day, but had to do some work for a client and that took away from my primary agenda.

st0wandgrow said:
So when a test comes back at 25% THC, you're saying that 25% of the *total* bud sample weight is comprised of THC?? That seems like a lot to me. If that's the case, then you'd be better off bringing in a sample that's as dry as a popcorn fart, no? Any water weight in the sample would lower the number
Click to expand...

Even though I know the labs ask for a gram, not all that gram will be used in the test. In fact only a little bit will be mixed into a solution and put into the machine.

Water can be excluded by its easily identifiable markers on the spectrum.
 
just a passing thought but if you
weigh a bud,
ISO the bud and strain.
dry and weigh the waste
weigh the dried ISO
do some math and wouldn't you have a decent rough estimate of your thc content? i don't know much about testing for cbd

(pressed Post Reply nervously)
 
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ficklejester said:
Gawker Media are nut jobs, not objective journalists. But they made an overall good point. I'm sure the '% by weight' comment was an error since they went on to say 'relative %' which is the standard, % of one cannabinoid to total cannabinoids. I dont like how they talked about pesticides- all commercial farmers including organic use some sort of pesticides.
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So you're saying what I thought.....thc is measured as a percentage of total cannabinoids, not total bud/sample weight?
 
Milovan said:
No matter what compounds your testing for to me
it's all a sham.
You can take 5 samples of the same bud to 5 different test labs
and you will get 5 different results.
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Agreed to a point. But those 5 tests should be similar to one another within a normal distribution.

Part of testing should be to always calibrate the machine, always keep it clean as to not contaminate samples, and to run multiple samples for an average.


I suppose one way of knowing the percentage by weight can be done via blasting (not that I'm a fan of BHO for a few reasons), and or traditional hash making (beating the plant on screens or even ice water hash). Would need to have dried the product and weigh prior and then weigh the collected amounts afterwards. Of course their will be some plant mater but there will also be lost trichomes and other cannabinoids lost as well.
 
ficklejester said:
Gawker Media are nut jobs, not objective journalists. But they made an overall good point. I'm sure the '% by weight' comment was an error since they went on to say 'relative %' which is the standard, % of one cannabinoid to total cannabinoids. I dont like how they talked about pesticides- all commercial farmers including organic use some sort of pesticides.
Click to expand...

I personally like gawker media. Not always the most professional by any means nor do I necessarily agree with some of their authors, but they do aggregate an awful lot of material from all over the place I wouldn't necessarily find elsewhere. Kinda like Vice, but they actually do real reporting (still take issue with some of their material).

Nonetheless I don't think all growers use pesticides. I have when I needed to, but haven't in well over a year.
 
The quantacann uses 1 gram ground up and its scanned with a laser to tell you how much THC and CBD are in it. I don't know how they do it in the labs.
 
ficklejester said:
I meant commercial produce farmers, stuff in whole foods and similar, I should have elaborated, we all come into contact with pesticides every day. Cannabis growers and private/coop farmers are the only true organic farmers.
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Oh that we are in agreement of, least we also forget stuff used to make vegetables and fruit not ripen quickly.

ficklejester said:
But yeah testing really is bullshit because growers can't control it. Not down to micro/milligrams.
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That's kinda my thinking. I've wanted to get some of my girls tested but a few concerns come to mind. How accurate and how qualified are these people? Every time I flower the same plant, it isn't necessarily going to be the same.

For instance, one of my patients wasnt too hot on my summer run of Goji. And in all honesty, it was a shit run.

Ran her right this go round and when he only wanted White Lotus #2 at first, he saw the goji and said "that's from the same fucking plant?"

Me: " Yep, she didn't have to deal with 100 degree temperatures and neglect"

Him: "well damn, good job on her, glad I didn't get all White Lotus"

Testing really is just for that one part of one plant. It isn't a constant either as it depends on age, as well as treatment.
 
Plus is testing going to change my mind on keeping a plant if I like it? Does it become some numbers game? Who cares what the numbers are if the plant does what you want it to do. Besides I've smoked some high tested strain only to enjoy another much more that tested in the teens. The relationships between cannabinoids, terpinoids and other shit I'm forgetting is really not understood all that well.

Eta: added "not" last line
 
If the test results can not be duplicated then the process is not scientific...

No cannabis testing is scientific... I've seen a large nug broken down into two samples that was tested one week and tested the following week with radically different results.
 
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