Originally Posted by elmanito

HPLC means High Pressure Liquid Chromatography.You can use it to get rid of some constituents which you dont wanna have.

Namaste

I just gooled High Pressure Liquid Chromatography and what I got was High performance liquid chromatography...is that the beastie you're talking about?

muA

Originally Posted by medi-useA

I just gooled High Pressure Liquid Chromatography and what I got was High performance liquid chromatography...is that the beastie you're talking about?

Its the same!!!!

Namaste

[Sam_Skunkman]

Originally Posted by elmanito

For identification if your strain does containCBD you can better use the TLC-method



Namaste

TLC is pretty useless for determining the % of the Cannabinoids. It can be used to see if a plant has THC, CBD, CBG, CBN, etc. If you want the % use GC or MS/GC. A HPLC is only required if you want to know the ratio of acids, like THCA vs THC. A GC will give the total THCA + THC as the THCA is converted to THC by the heat of the GC analysis. HPLC's are not required for Cannabinoid analysis unless you need to know the acid % like THCA, CBDA, CBCA, etc. But that is not what you want as in a plant almost all Cannabinoids are acid during growth and for months after drying and storage at low temps.
A GC or GC/MS is what to use for Cannabinoid analysis.
I have both, and have used TLC in the past.
I use HPLC to isolate pure Cannabinoids, not for analysis, unless I need to know the acid %, which is never.
-SamS

Like i said before TLC is for identification not quantification, but for identification it is more accurate than GC and less expensive.(e.g. retention time of CBD & CBC)
To measure the quantity of the cannabinoids you can better use GC/MS than GC alone, unless you make the reference cannabinoid standards by your own every time you do a GC analyse.

Another method H-NMR can be used for quantitative analysis of Cannabinoids

https://www.jstage.jst.go.jp/article/cpb/52/6/718/_pdf

Namaste

[Sam_Skunkman]

I used a GC for thousands of analysis. I agree a MS/GC is better because once calibrated you don't need to use your analytical samples. But I did not have a MS/GC and I had zero problems. What is more important is two injection ports so you can have one column for the majority of the Cannabinoids and another just to separate CBD from CBC. As well an auto sample tray, mine holds 96 samples and can run un-supervised over night.
I don't believe a TLC is more accurate, specially in small amounts like .1-.001. And I have done hundreds of TLC tests.
As for H-NMR I know of no lab using this besides the folks that published the paper, maybe one or two others. What does a Nuclear Magnetic Resonance Spectroscopy set up cost? Sounds fast and easy if you happen to have a Nuclear Magnetic Resonance Spectroscopy set-up laying around, I don't.
-SamS

[veta]

Originally Posted by Sam_Skunkman

TLC is pretty useless for determining the % of the Cannabinoids. It can be used to see if a plant has THC, CBD, CBG, CBN, etc. If you want the % use GC or MS/GC. A HPLC is only required if you want to know the ratio of acids, like THCA vs THC. A GC will give the total THCA + THC as the THCA is converted to THC by the heat of the GC analysis. HPLC's are not required for Cannabinoid analysis unless you need to know the acid % like THCA, CBDA, CBCA, etc. But that is not what you want as in a plant almost all Cannabinoids are acid during growth and for months after drying and storage at low temps.
A GC or GC/MS is what to use for Cannabinoid analysis.
I have both, and have used TLC in the past.
I use HPLC to isolate pure Cannabinoids, not for analysis, unless I need to know the acid %, which is never.
-SamS

Sam, I don't agree with you 100% on this one. GC/MS and HPLC are equivalent methods for identification of components of a sample when they are present in greater than ppm quantities. For the major cannabinoids either will give you very accurate % composition. Each has strengths and weaknesses which can better suit for a given application. I have some great papers comparing the two methods for cannabis if you are interested.

GC/MS

GC/MS has a better lower detection limit, and is much better for identifying unknown molecules. But it is also VERY costly to operate and running plant extracts through them requiers a very tight maintenance cycle. Cost per sample is usually higher than a HPLC system. As you said, it has trouble detection heat liable molecules, such as the acid components in cannabis. It is an excellent research tool.

HPLC

Has about a order of a magnitude higher detection limit, and it is more difficult to identify unknown molecules. However, for plant extracts and raw plant material we are not trying to find molecules in the ppb range. So sensitivity is not an issue. Also cost per sample is very low. Operational costs are a fraction of a GC/MS system. Cleaning is no problem, so the overall through put on a HPLC system will be higher. As you said, HPLC is good for detecting a heat liable components. Also, you can inject a larger sample through a HPLC system, which to an extent makes sample prep easier (IE, less tech time, less dilutions), and you can collect fractions and recover components through it. The real problem is developing good separations methods for the sample you are trying to analysis.


It should be noted that to my knowledge no analytical lab uses GC/MS for high volume sample analysis where a suitable HPLC method is available. All of your supplements and vitamins are certified by HPLC these days. I see the two as complimentary methods, no one really being better than the other, just better suited for a given task.

as to the TLC test, that is nice if no other option is available, but I have seen the kit you are talking about and trying to sell it as a "semi-quantative" method is really misleading. TLC can be semi qunatiative, but given the reagents and equipment provided in that kit, getting reproducible results through it is very hard. Also, the people providing that kit are charging a whole lot of money for a what amounts to a experiment from a freshman biology lab. Its great that it is out there, because there are alot of people who don't have access to anything thing better. Hopefully that will change soon.

Drop me a line Sam, I would love to pick your brain. I am still reading through your 200+ pages of posts here, but so far you have some really impressive posts in there. We are forming a scientific advisory board, and I need to fill some seats if you are interested.

veta

[Sam_Skunkman]

For Cannabis HPLC is only required if you need to know the acid components like the THCA, or extracting pure Cannabinoids, but it is not needed for determining the Cannabinoid %'s. I have been to all the big labs doing Cannabinoid analytical work, they all use MS/GC, why? Because a HPLC is not needed, it gives info that is not needed for determining Cannabinoid %'s. They do have HPLC's but they don't use them much for this kind of work. As I said I have done ten's of thousands of GC analysis for Cannabinoids, a few labs have done more, but only a few, and they all use GC not HPLC for the vast majority of their analysis.
You say "you have some great papers comparing the two methods for cannabis if you are interested". Let me know the titles and I can see if I have them already, I know most of the authors personally for years.
As for the TLC I used it was not the kit you refer to, I made an in-house kit we tried to develop for use in the field, but we were never happy with it, so we quit with it, it did work, but I prefer GC results.
Have you done Cannabinoid analysis on any sort of regular basis or is your preference of HPLC just an intellectual one? I have used both GC and HPLC for more then 15 years. I don't use my HPLC's much except for my production HPLC that can isolate small amounts of a single Cannabinoids for standards. The first few years we used the HPLC a lot until we understood that the plant produces the Cannabinoids in their acid form, un-decarboxylated, and if kept refrigerated or frozen they are very stable if kept from Oxygen.
I had already sent you a visitor note but not a PM as I thought you can't get one yet. Look at your public profile and check your visitor messages.
No I am not interested in your offer of the scientific advisory board position, I am way to busy with my work and life, thanks for the offer.
Send me a list of the labs doing lots of Cannabinoid analysis using HPLC for lots of Cannabinoid analysis, I can tell you if they use HPLC or GC for the majority of their work. I have been to all the major players labs, and worked with many of them.

Have you seen Arno Hazekamp's power point review of the acid and neutral Cannabinoids and their retention times etc with GC, MS, HPLC, TLC? A good place to start if you want to do Cannabinoid analysis seriously. Ask him and he will sell you a copy.
-SamS

[veta]

I have read Hazekamp's work, its kind of hard to miss. I agree with you most of the research labs are using GC/MS for research purposes. It is the best fit for that application. I am interested in large scale open to the public commercial testing application.

MY post count is rising slowly, you can reach me at tortalk@gmail.com untill i can get pm's

veta

[Sam_Skunkman]

I did email you at gmail.
-SamS

[Sam_Skunkman]

Originally Posted by veta

I have read Hazekamp's work, its kind of hard to miss. I agree with you most of the research labs are using GC/MS for research purposes. It is the best fit for that application. I am interested in large scale open to the public commercial testing application.

MY post count is rising slowly, you can reach me at tortalk@gmail.com untill i can get pm's

veta

You have read the power point presentation?
Is it even legal to test Cannabis in the USA, for the public?
Have you ever done Cannabinoid analysis?

-SamS