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.