Silica Gel Column Chromatography
All chromatographic methods -with the exception of TLC- use columns for the separation process. Column chromatography has found its place in many laboratories for preparative purposes as well as for reaction control in organic syntheses. The importance of column chromatography is mainly due to following factors:
- Simple packing procedure
- Low operating pressure
- Low expense for instrumentation
Column chromatography is separated into two categories, depending on how the solvent flows down the column. If the solvent is allowed to flow down the column by gravity, or percolation, it is called gravity column chromatography. If the solvent is forced down the column by positive air pressure, it is called flash chromatography, a “state of the art” method currently used in organic chemistry research laboratories.