2.5.1 Column Chromatography

Column chromatography remains the foundational technique for isolating individual phytoconstituents from a complex crude extract, most commonly performed...

Column chromatography remains the foundational technique for isolating individual phytoconstituents from a complex crude extract, most commonly performed using silica gel (typically 60–230 mesh, packed as a slurry at approximately ten times column height to diameter ratio) as the adsorptive stationary phase. The crude extract, dissolved in a minimum volume of solvent or pre-adsorbed onto dry silica, is loaded onto the column and eluted with a mobile phase of gradually increasing polarity, beginning with a non-polar solvent such as petroleum ether and progressing through intermediate-polarity solvents towards methanol; fractions are collected at defined volume intervals, monitored by thin-layer chromatography, and fractions showing an identical TLC profile are pooled and concentrated.