**7.3 Column chromatography (CC)**

 Column chromatography works on the principle of ion exchange, molecular sieves, and adsorption phenomenon. CC is a most useful technique for separation of active constituents with larger concentration. Sometimes fractions require another step for concentration. Displacement chromatography is a newer method that contains elution of bioactive compounds that have great affinity for the adsorbent. Fractions of elute materials can be more concentrated than the original solution placed in column. The column was prepared using silica for column chromatography. The fraction was dissolved in smallest possible volume of solvent and it was mixed with 2 gms of silica for column chromatography. Wet column or dry column packing can be done. Packing of column plays an important role in good quality separation. The mixture was dried to obtain free flowing powder and it was added to column. Then, the column was eluted with solvent of various proportions. Every eluent was collected in properly cleaned test tube separately for further studies to be carried out.
