Quantification of the concentration of THC, CBD, CBG, THCA, CBDA, CBGA, THCTotal, CBDTotal and CBGTotal in HPLC
The cannabinoids produced by the plant are found in their acid form. When heat or UV lighting is applied these cannabinoides lose one molecule of CO2 and change into their neutral form. This process is called decarboxylation. Thus, when a cannabis sample is smoked or vaporised, a great portion of cannabinoids will be decarboxilated by the effect of the heat and will mutate into their neutral form. However, if the same sample is ingested, as no heat has been applied, the acidic cannabinoids will keep their original state.
The high performance liquid chromatography (HPLC) does not employ heat at any phase of the analysis and as a result, the samples are not decarboxylated. Therefore, when working with HPLC, if the cannabinoid content that any vegetable matter or extract has needs to be quantified, three different concentration results can be offered:
- % of Δ9-THC, CBD and CBG
- % of THCA, CBDA and CBGA
- % of THC Total, CBD Total and CBG Total
El THC Total, CBD Total and CBG Total are the maximum amounts that can be obtained from these cannabinoids if the sample is properly (or completely) decarboxilated.
THC Total percentage is the sum of the Δ9-THC percentage, plus the THCA percentage, multiplied by a conversion factor. Due to the fact that this factor is a number lower than 1, it is not surprising that the percentage of THC Total is less than the sum of Δ9-THC plus THCA, regardless of the conversion factor.
Knowing that the decarboxylation reaction is the transformation of THCA into THC through the loss of a carbon dioxide molecule (CO2), the conversion factor can be obtained in the following way:
When the THCA looses the CO2 molecule, it changes into THC, which is a smaller molecule, therefore, a less heavy molecule than THCA (THCA weighs 358 grams per mol, while THC weighs 314 grams per mol). Considering that loss, we will have 358/314=0.877 molecules of THC per molecule of THCA, thus, the correct way of calculating the percentage of THC Total in HPLC is:
% of THC Total = % of THC + (% of THCA x 0,877)
The same principle is applied for the calculation of the percentage of CBD Total and CBG Total. The formula for these cases is:
% of CBD Total = % of CBD + (% of CBDA x 0,877)
% of CBG Total = % of CBG + (% of CBGA x 0,878)
When samples are analysed by means of gas chromatography (GC), it is not necessary to apply this equation, because during the analysis they are exposed to very high temperatures. Thus, it is assumed that the decarboxilation reaction occurs entirely in the injector.
In the official method of “Regulation (EC) Nº 1177/2000 of 31st of May 2000” the injector is at 300ºC and the amount injected is very small. Therefore, it is understood that the decarboxilation reaction takes place in full.
The fact that the decarboxilation of any kind of cannabis is not usually perfect must be taken into account. This could happen because, either it has not been possible to convert all the acids to a neutral state, because other products have been formed from deterioration, or even due to the partial evaporation of the cannabinoides. Therefore, the amount of neutral cannabinoids that will be obtained if the decarboxilation is performed could be slightly lower than the THC Total, CBD Total or CBG Total values obtained, given that these values express the maximum amount obtained in the case of 100% decarboxilation.
In the light of the above, we can conclude that the HPLC analysis, without conducting a previous decarboxilation of the samples, is the most precise technique in order to know the cannabinoids content in cannabis, as the result values will be the real values of the sample.
For more information read: Cannabinoids Test
The cannabinoids produced by the plant are found in their acid form. When heat or UV lighting is applied these cannabinoides lose one molecule of CO2 and change into their neutral form. This process is called decarboxylation. Thus, when a cannabis sample is smoked or vaporised, a great portion of cannabinoids will be decarboxilated by the effect of the heat and will mutate
How to Calculate CBD Content? | 2020
Plant & Hemp
Apr 16, 2020 · 3 min read
When it comes to working out “How to Calculate CBD Content?”, we do the hard work so you don’t have to, meaning that any products you buy from us will have the CBD content clearly marked on the product, ad on our site before you check out.
However, what about CBD oil? How do you know how much CBD you are consuming if you are taking a small amount of a larger amount that is labelled for content, how do you know how much you’re taking?
We make sure t h at there’s both a percentage and a mg amount on our products to make that easier, but if you’re looking for the specific for every dose you take, there’s a pretty easy way to do it.
Calculating CBD Content
So, let’s get into the fun little details here. If you are using CBD oil, the dropper that comes with the oil will usually (unless otherwise stated) hold 1ml of CBD oil, for a single dose, people usually fill this to the top, or halfway, meaning that we’re dealing with either 1ml or 0.5ml of CBD oil, for the sake of ease here, we’re going to work with the 1ml, but for 0.5ml, just half it.
For a 1ml drop, you are dealing with an average of 20 drops, so we’re going to call it a round and steady 20 for the sake of ease.
Now, take the mg content of CBD contained in the oil you are using by the number of 1ml dropper fills in the bottle (so basically the ml amount, because each unit is one anyway).
Once you’ve got that, you can divide this by the number of drops in the bottle (20 per 1ml) which will then give you the exact (or as close as possible) amount of CBD in mg that appears in every single drop of CBD that exists in that bottle.
How to Calculate CBD Content, That’s a Lot of Work!
Yes, yes, it is, truth is, you don’t really have to do it, but if you really care about the exact amount of CBD you are taking, it’s the only way to do it, with oils at least.
Of course, there is a substantially easier way, and that’s to buy edibles such as gummies or chocolates, or capsules, where the CBD content is measured carefully into each unit for you, so the packaging will tell you how much you’re taking and you don’t have to deal with any of that silly maths above.
The Correct Dosage of CBD
If you’re going through all that work (or, you know, buying CBD chocolate bites instead) then the chances are you really care about the right CBD dosage, but how do you find the right dosage for you?
The answer to that is simple, and it’s something we come back to a lot, but it’s always worth repeating.
The only advisable way to find the correct CBD content for you and your body chemistry is to star with a low dose, the lowest possible really, and gradually build your way up until you find the level that feels right for you.
Regardless of the CBD product you’re using, this rule always stays the same, there’s no need to go hard straight away, it’s not about how much you can handle, it’s about how much works for you.
The best thing is, all signs point to the body not building up a tolerance to CBD products, so when you find that right dosage for you, you should be able to stick with it.
So, in conclusion, there is a way to calculate the exact CBD content in every drop of a CBD oil (it isn’t actually that complicated, it takes longer to write than it does to do) but if that feels like too much counting for you, you can just shoot us a message and we’ll do the calculations for you, we’re good people like that.
Of course, there are numerous products that don’t involve that maths necessity, and we have them all displayed proudly on our pages so you can choose whatever works for you.
When it comes to working out “How to Calculate CBD Content?”, we do the hard work so you don’t have to, meaning that any products you buy from us will have the CBD content clearly marked on the…