During this session we studied chromatography in general and the different chromatography methods used in laboratories, and industry today.

The principle: Separation of an individual component out of a mixture based on their relative affinities towards the stationary and mobile phases. The samples are subjected to flow by the mobile liquid onto or through the stable stationary phase. The different chromatography methods we reviewed are: paper chromatography, column chromatography, ion exchange chromatography, Gel permeation-molecular sieve chromatography, affinity chromatography, thin layer chromatography, gas chromatography, HPLC- high performance liquid chromatography. We learned to calculate the Rf factor (retardation or retention factor), which is the ratio of the distance traveled by the center of the spot to the distance traveled by the solvent front. This is the ID of this molecule in the conditions this chromatography was performed. We performed paper chromatography. The tested compound was chlorophyll extracted from parsley leaves a week earlier.