With the de-criminalization of recreational cannabis in several states, a need for higher purity products has become a necessity. Current technology uses extraction with supercritical fluids or other non-supercritical solvents to remove the products of interest from other endogenous species such as lipids, terpenes, chlorophylls and pesticides.
These techniques help clean up raw extracts and isolate cannabinoids with higher-purity, but not to the levels desired by many producers, so there is a developing need for a secondary purification step. For some producers, reversed-phase chromatography has become the analytical tool of choice for determining the extract profile and for purification as well. However, the extracts still contain many other compounds which reduce load capacity and recovered purity of the product(s) of interest.
Flash chromatography can be used to further purify previously extracted cannabis raw materials. However, taking an orthogonal approach with flash purification starting with normal-phase to remove potential co-eluting impurities followed by reversed-phase purification of collected normal-phase fractions dramatically improves separation efficiency, loading capacity, and compound purity.