Labdog;
normal phase silica HPLC column.
Mobile phase cyclohexane modified with ethanol.
set the capacity factor for THC to be 3.0 running isocratic
at 1.5 ml/min by modifing the ethanol fraction. (guessing 10%)
as a start.
OK. you’re good to go. BTW…it is called normal phase mode.
Can you link to a normal phase separation of thc isomers? Also looked into the biphenyl phase and not coming up with anything particularly specific to isomers, the one app note I found that showed d8 VS d9 had about the same resolution as c18. Although the cbgs/cbds looked like a possibility better spread on biphenyl.
You know if we’re “going in blind” perhaps a chiral GC column would be a better starting point. Not messing around with mobile phase, better resolution, and available it seems for $800 or less.
I wish I had the money, space, and proper knowledge for this, but I am eager to see what you lot find.
@Photon_noir I agree with @Labdog that the presence of enantiomers is unlikely. ABN THCs / ABN CBD are conceivably worth looking for but I mentioned similar doubts. Not only do I not see a mechanism, but I don’t believe we’re seeing byproducts that you would expect either. From the discussion earlier, I would bet money on exo THC being the dominant byproduct, and @kcalabs mentioned something about looking into a couple different iso THCs.
ABN THCs and THC enantiomers are common when using various terpenoid building blocks but it’s already both easy and economically feasible with hemp so one would hope this isn’t something we’ll have to worry about.
Exactly, @stoopkid !
I’m not saying we will find enantiomers, diastereomers and the like, but in order to continue playing under CFR with FDA scrutiny (whom we are already seeing weigh in and trample things like D8, just because of our lack of their standards of quality assurance), we will be required to step up with QC/QA methods they approve! Unfortunately, it will not necessarily matter what products are being tested… be they biomass, resin concentrates, distillate, pure compounds or reaction products… all will be required to undergo more rigorous testing.
@Labdog @jakovsau5
And YES, @MagisterChemist , I completely agree that we should start with the much less expensive (and in many cases more precise) chiral GC methods!
My problem with using gc methods for potency is that according to Oregon regs we must measure acids in cannabis products. Not even sure if they are allowing derivitization. Not that you find acids in d8 conversions or that olcc even oversees d8 testing… But still I’d like to stick with lc for potency.
Also it is much easier for us to switch lc columns than gc… Damn it I hate handling gc columns.
the whole issue has been discussed elsewhere on 4200.
if you want to see a “chiral separation” of cannabinoids:
https://www.waters.com/webassets/cms/library/docs/720005812en.pdf
listen to what kcalabs is telling you.
or buy master chem a chiral column and let him “play”
with it.
Sure but we are talking about an exploratory study here… not designing a method to submit for state approval. First we need to know what we are looking for, whether it even exists, whether it has standards available… then we can discuss dialing in methods for the state.
Right, @MagisterChemist . The compliance testing may require LC, but if we can prove that the chiral isomers only show up in specific products (e.g. isomerization rxns and NOT biomass, disty), then we may not need to look for chiral acid forms, @Labdog !
I am listening bud, I have no problem listening to peoples opinions. But ultimately I’ll make the decision if this is an economical test for our lab to implement… kca can make that determination for their own lab.
And 1200$ for a new column which I don’t need to even really change MPs between VS c18… that is sounding decently economical to me. Although I’ll say it is kind of a pet project, and I definitely have not had anyone asking me for a test which might resolve even more byproducts in their d8 conversions. So I can agree on not much market demand.
I have seen that SFC paper and it is actually what made me want to try a chiral lc method with similar column chemistry (amylose1).
yes using a regular hplc set up with the amylose di phenyl carbamate modified silica with"alcohol modified hexane"- mobile phase should do it. i.e., separate racemic mixtures of cannabinoids.
Remember, you’re setting up to rapidly scan for a specific pairs of enantiomers…Tuning for specfic enantiomer interaction with stationary, bonded phase.
excepting some idosyncratic aspects of the material:
http://www.ct-k.com/layouts/default/image/files/CHIRALPAK_R_AD-H.pdf
Because the stationary phases are so easy to destroy…
used columns with sketchy history might not be a good buy.
regards