Separation, quantitation and isolation of cannabinoids from Cannabis sativa L. by overpressured layer chromatography.

Two overpressured layer chromatography (OPLC) methods have been developed for the separation of neutral and acidic cannabinoids. The first is an adaptation of Korte's well known method to the OPLC system, which improves its reproducibility. The second one is a new technique based on the phenomenon of chromatographic solvent demixing. The eluent itself is also divided into zones. In the alpha-zone the neutral cannabinoids and in the beta-zone the acidic ones are separated. As a result of the good and reproducible separation, there is a possibility to quantitate cannabinoids by densitometry. The on-line version of OPLC proved suitable for the isolation of hemp constituents.