Yeah, for each their own. Injection speed needs to be documented for a repeatable result. It also helps to have just one person run it. That can eliminate some day to day varyables.
4 Likes
Just got off the phone with Sage Analytics.
At ~$20k MSRP their product looks like a useful tool for some.
Pros: non-destructive testing of flower and concentrates in 9 seconds!
Cons: currently only programmed to distinguish THC(A) and CBD(A).
So you can’t look at edibles or tinctures & you’ll learn nothing about those mystery peaks in your distillate. Without the ability to see CBN, it also can’t be used in a mobile 3rd party lab model in Oregon, because OR requires CBN numbers.
The Orange Photonics LightLab is a transportable HPLC with a diode array for a detector. It uses a proprietary MeOH based solvent and disposable columns.
It can’t tell you anything about terpenes, but does cover more cannabinoids than the SAGE. at $13.5K it’s cheaper too. analysis times are on the order of 10 min.
it will do infused products if you extract up front. unlike the GC w/FID approach, it can tell acidic cannabinoids from their decarboxylated buddies.
2 Likes
Shimadzu’s Cannabis Analyser has a list price of $65k. Made in Canby OR.
It’s a full blown, turn-key HPLC system that comes with the right column and cannabinoids standards in addition to all the other bits and pieces you need.
might be overkill for some. It’s on my christmas list…although I tend to go with used or repurposed equipment whenever possible.
6 Likes
Oh god! The ebay mystery gcms! Ahhhh!
1 Like
GC-MS? nah, I’m still pondering using a UV/Vis spec.
I blame the Shimadzu sales-engineer (WTF is a “sales-engineer”?!?).
3 Likes
We have not purchased it yet, doing some shopping around, but the SRI GC/FID just has the most capability for the least amount of money. Especially on your consumables!
Sage analytics are off their cracker with the cost of those devices. And $50 for a sheet of 250 stickers? So much nope.
HP/Agilent… well, who wouldn’t want one. Oh yeah, people working a budget.
Orange, not bad but limited.
Shimadzu, very nice instrument. But weirdly more limited than the SRI. You might be able to change the columns but they don’t even mention terpenes or solvents.
SInce this is in houseHPLC is overkill, and I’m not sure how much it would take but I remember putting a fricken jug of methanol or some solvent on top of our instruments about 10 years ago. I just dont want to deal with that.
I just want to know the concentrations and my terps. Any safety check will be done at the licensed lab at the end of my run.
My 2c. Worth exactly what you paid.
6 Likes
They claim they can measure THCA, I had wondered about that.
1 Like
You can quantitate acidic cannabinoids on a GC with an FID. You just have to derivativize the carboxyl group. But as “decarboxylation” is how our bodies join amino-acids together, I can’t take the risk that the stoners I work with will manage to get it in their coffee. At least until I can lock them out of the QC lab.
2 Likes
derivative? Could you expand on this please. Are we talking mathematically or based on something else we derive the answer with some known?
And nobody comes in my lab without I say so. If they see my secrets i gag them with Parafilm and burn out their eyes with my bunsen burner! lol, just kidding. About the bunsen burner, but seriously NOBODY comes in my lab without me there. 
3 Likes
chemically modify so decarb doesn’t happen in the injector or 30meter tube leading to the eternal (internal?) flame.
poisonous: because if you can’t join amino-acids to make proteins, you’re dead.
I find coffee cups, beverages of all description, and occasionally a half smoked joint or cigar on the bench with the GC. constantly having to move flammables off the GC itself. as if it’s a great place to store packages.
3 Likes
Out comes the whip! Or perhaps we should use old gc columns…?
2 Likes
nice, thank you very much! Looks easy as pie. Looked up the MSTFA, doesn’t look to unhealthy. Mostly one exposure when you make your standard and then minor off gassing when using a septum.
You make me appreciate my private, little, windowless, airflow free box in the back of the building.
2 Likes
I derivitized chlorinated herbicide extracts for drinking water, waste water and other analytical tests. Those tests involved a diazomthane generator and had serious safety measures that needed to be implimented.
the DZM was for the gas flow, yes? I’ll stick with nice safe hydrogen… he said as he set out on the Hindenburg bound for America.
2 Likes
Derivitizations are useful for a lot of different analyses…I did sugars by GC (alfalfa sugars!?) for part of my PhD work and it worked great. There are lots of different approaches, depending on your targets and analytical setup (e.g.: there are derivatives for TLC and HPLC that put on groups that confer fluorescence. Methylations with diazomethane [explosive!?] are often used for fatty acids). What we’re discussing here is the creation of silyl ethers, built off hydroxyl groups. My sugar work way-back-when used HMDS (hexamethyldisilazane), and that reagent was effective for my problem. BUT, I’ve had mixed success forming cannabinoid derivatives. Mostly around reproducibility. Some thoughts:
-
I’ve used BSFTA+ 1% TMCS (N,O-bis(trimethylsilyl) trifluoroacetamide, with 1% trimethylchlorosilane as a catalyst); this is the most commonly reported silylating reagent in the cannabis literature. The TMCS might be omitted if pyridine (proton scavenger solvent) is added, but I haven’t tried this yet.
-
I believe (haven’t proved!) that your sample has to be quite dry before adding the derivatizing reagents. Blowing N2 over the sample, and gentle heating (e.g.: <40 C) works well.
-
Remember that ALL compounds in your sample that have hydroxyl groups will be dervatized along with THCA/CBDA, etc., which means their retention times will shift, and if using a mass spec, the spectra will be different, from the added groups.
-
Silating reagents (BSFTA, MSTFA, HMDS, all of them) are extremely reactive (read: corrosive! Personal experience…) to organic compounds, which include your skin, eyes, and lungs!! Nitrile gloves, wrap-around safety glasses, good ventilation are all mandatory!
I’m planning another campaign with this approach with my HP GC/MS (>20 yrs old): 6890 GC w/5972 MS + autosampler. Put together from eBay and donations, so it is possible to get there on the cheap. Finding the right version of MSD Chemstation software to drive the thing can be challenging.
Keep in mind that with this approach quite a number of targets can be measured by GC, including sugars, and with the right reagents, fatty acids and other compounds we’re interested in. Does take homework to get sample preparation, retention times, etc. worked out, but it allows broader coverage with your base instrument.
Here’s an Aldrich tech note on derivitization that’s pretty comprehensive:
4537.pdf (176.7 KB)
This also might help:
5.pdf (463.1 KB)
7 Likes
There is (almost) no way to edit the poll after the first vote has been cast.
Possible course of action is to hold multiple rounds of polls, or a pre-poll asking for input on options. Limit each poll using the ‘automatically close poll’ option to ~1 week. IMO If there was any kind of serious vote or election we would use a more sophisticated system.
Interesting note: The co-creator of this forum software (discourse) says about polls “I too thought polls would be more useful, but I find polls to be of very limited use on a discussion site. You want explanations and discussions and explorations… not context-free snap judgments that hew to a very narrow set of inflexible, predefined options. (For example, I find that the best “option” is often one that I hadn’t even thought of…)”
3 Likes
Hey guys, I know its a tangent but for a different kind of testing. Good for onsite genetic testing/dna amplification
PCR is a very useful technique. Not the first I’d bring in-house, but certainly on the list.
How exactly are you applying it to learn more about your cannabis?
are you using marker assisted selection? DNA based sexing?
Edit: as cute as that kit is, I wouldn’t bother with it even for DNA based sexing. I’d get a real machine used. A PTC-100 can be had for less than $400. I do like the LED based transilluminator. definitely beats EthBr & UV.
…and of course the low price leader: TLC, where $160 will get you up and running
I have no experience with this vendor. I have run TLC for state mandated testing in OR. Accuracy depends on the operator to a much larger degree than any of the other methods listed here imo. It can be very useful. I don’t currently have it in house.
4 Likes