Separation of cannabinoids by Flash chromatography
Separation of cannabinoids by Flash chromatography
The compounds produced by the cannabis plant are famous for both recreational and medical purposes. The potency of the so-called cannabinoids in pharmaceutical applications, to ensure pain relief or to ease psychological burden, promoted the development of the cannabis industry. In many cases the challenge in this field is to purify the medically used substances from illegal psychoactive compounds. There are more than one hundred of cannabinoids identified, some of them having similar chemical structure. This feature complicates the separation of these compounds according to their chemical properties. Chromatography is the technique of choice for separation of multicomponents samples but when used at industrial scale, compromise has to be found between its separating power and the amount that can be purified. Larger capacity and loading are usually detrimental to the separation, i.e. they lower the resolution between the eluting substances. Flash-chromatography can be used to separate the most important components of cannabis extract despite its lower resolution. Depending on the criteria to isolate a given peak in the chromatogram, a high purity can be obtained without the need for baseline resolution. The material used for flash-chromatography also allows to increase the loading of sample to be purified, i.e. scale-up. Since scalling-up usually decreases the efficiency of separation, the process in chromatography is done by first optimizing the parameters for separation at a small-scale, before adaptation to the given size.
