CHROMATOGRAPHY Chromatography is a physico – chemical method used for the separation and identification of compounds in a mixture using stationary phase (filter paper, silica gel or alumina) and mobile phase (gas or solvents). The word chromatography was obtained from the Greek word which means “Colour writing” (Chroma – colour; Graphin – writing). The word chromatography was first introduced by Mikhail Tsweet in 1906. He used to separate the pigments from plants. Chromatography is having wide number of applications in both physical and biological sciences. Stationary Phase The stationary phase is one of the two phases forming a chromatographic system. It may be a solid, a gel or a liquid. If a liquid, it may be distributed on a solid. This solid may or may not contribute to the separation process. The liquid may also be chemically bonded to the solid. Mobile Phase A fluid which percolates through or along the stationary bed, in a definite direction. It may be a liquid ( Liquid C