The aim of flash column chromatography is to separate components from the mixture and purify it. Briefly, flash column chromatography allows samples to be separated through columns filled with gels.
Flash column chromatography has been widely used in organic chemistry since its inception. Although there are some guidelines translated inaccurately, some facts are still true.
Firstly, increasing the sample size will result in a lower resolution. The resolution of flash chromatography is medium-level compared with high-performance liquid chromatography. As a consequence, the increasing number of samples will aggravate the situation.
Secondly, the best velocity depends on the length and width of the flash column and the properties of the gel, which means how many plates are there available theoretically for the solution. The longer and narrower columns will provide more theoretical plates.
And thirdly, the resolution is also affected by the stationary phase. If the stationary phase or the gel arranged on the column is more homogeneous and has a smaller particle size, it provides better resolution.
Manipulating all these factors to optimize the purity or recovery of components can be quite complex because of their interaction. Therefore, it is necessary to calculate the settings used in flash column chromatography before starting any real experiments. The best settings of the flash column can be calculated with the data from TLC.