It may not be a hot topic in the media or a catchy marketing term, but chromatography plays an important role in the creation and testing of CBD products. This laboratory technique was not born of the CBD industry, in fact, it was first developed in the 1900s. It has, however, become a staple across the cannabis industry thanks to it's highly valuable multi-purpose uses.
Join us as we take a layman's look at chromatography, what it is, how it works, and how it's used across the hemp CBD industry.
Chromatography is a technique used to separate a mixture. In the case of the CBD industry, this mixture is a hemp extract. The extract is dissolved in a fluid which is called the mobile phase. This phase is passed through a media called the stationary phase. The components of a cannabis extract like terpenes, cannabinoids, and other plant materials travel at different speeds through the media, causing them to separate.
The way it works is that the various compounds of the extract have varying strengths of interaction with the media through various physical properties. This means that the individual compounds travel either faster or slower in relation to the other compounds. This can be used to separate the compounds or to capture specific compounds. There are a wide range of chromatography techniques around, but a select few have risen to popularity in working with cannabis.
Chromatography allows for a variety of analytical and preparatory ends to be met. In our case, this means either to test the purity and potency of an extract or to remove or isolate specific parts of that extract. This powerful tool plays an important role in the hemp CBD industry which we will cover more below.
Chromatography can be used in one of two ways: analytical or preparative. The two are not mutually exclusive, meaning that only one or the other can be performed at a time, not both simultaneously. Specific to the cannabis industry, the analytical method allows for lab testing of a sample to verify it's potency and purity. The preparative method allows for isolation, fractioning, or removal of specific compounds within an extract.
It is estimated that half the cannabis market uses high-performance liquid chromatography (HLPC) to test samples for cannabinoid potency. There are other methods like thin layer chromatography (TLC), gas chromatography (GC), centrifugal partition chromatography (CPC), and supercritical fluid chromatography (SFC) that are also used, but HLPC is by far the most popular.
This testing method is preferred as it does not require heating and provides an accurate analysis of the compounds within a sample. The returned results give a detailed look at the cannabinoid profile. These results are then included in reports which are presented to the end consumer for verification. Here at Big Sky Botanicals, we utilize HPLC in the testing of our products. You can see some example reports on our lab report page.
As we mentioned, the second way to use chromatography is in a preparatory fashion. In the case of cannabis, this is most commonly done in one of two ways: either isolating individual compounds from the extract or removing specific compounds - most often THC.
In our introduction to chromatography at the beginning of this article, we outlined that an extract is passed through a medium. In the case of liquid chromatography, this stationary medium is silica or silicon dioxide. The different compounds in the extract have different degrees of attraction, or stickiness, to the silica, and will pass through it at different rates.
Using this principle, it is then possible to separate and isolate the individual compounds in the mixture. See the example below which shows how over time THC and CBD might separate, allowing them to be collected separately. This example would show how CBD could be collected via chromatography to make CBD isolate.
The most relevant chromatography process for us here at Big Sky is the removal of THC via liquid chromatography. Using a similar design like the column chromatography above, the column is packed with an absorbent that acts as a binding agent with THC. As the mixture passes through the column, the THC is captured and the full remaining extract passes through the column.
The result is a broad-spectrum extract that retains all major and minor cannabinoids and terpenes with one exception - THC. This chromatography process is preferred to the alternative, fractional distillation, which requires heating of the extract to boil off and distill out the portions of the extract before adding them back together.
Here at Big Sky Botanicals, we are proud that our broad-spectrum, THC-free product line is created and tested using chromatography. Find more information about how our products are made, and be sure to visit our shop and give them a try yourself.