How do particle size and flow rate affect normal-phase flash column chromatography?

Media particle size and solvent flow rate play major roles in chromatographic separations including flash purification.  This is true in both reversed-phase chromatography (aka partition chromatography) as well as normal-phase chromatography.

The roles played are related to the overall compound mass-transfer kinetics and diffusion/dispersion as they migrate through the column.  Smaller particles reduce sample dilution by reducing interstitial volume, while flow rate impacts the ability of molecules to efficiently pass through the porous particles.

In this post, I will show how both particle size and flow rate impact flash chromatography.

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How to efficiently scale-up flash column chromatography

For synthesis and medicinal chemists, compounds are typically made only once en route to a final product. Once that compound shows activity toward a particular target, then the synthesis is scaled up meaning that purification too requires scaling. The same is true in natural product research where once a high-value compound is isolated at small scale, there is a need to isolate it at larger scale.

Both of these scenarios can be problematic to scale-up/ process chemists when other, non-chromatographic purification techniques are not successful. When this happens, either a different synthetic route or extraction process is needed or large scale chromatography is employed. In this post, I will explain how flash chromatography can be successfully scaled while minimizing time and solvent consumption. Continue reading How to efficiently scale-up flash column chromatography

Cannabis extract purification using orthogonal flash column chromatography

For some cannabis-based product developers reversed-phase chromatography has become the analytical tool of choice for determining the extract content profile as well as for purification of specific cannabinoid compounds. However, the extracts often contain many other compounds which reduce load capacity and purity of the product(s) of interest and then require even more extensive clean-up.

In this post I show the results of an orthogonal flash purification approach that first uses normal-phase flash column chromatography to clean up the crude cannabis extract followed by reversed-phase C18 flash chromatography of the isolated target compounds.  This orthogonal approach to purification increases the targeted product’s purity.

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