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 Chromatography) or a gas (Gas Chromatography) or a supercritical fluid (Supercritical-Fluid Chromatography).
- In Gas chromatography the expression Carrier Gas may be used for the mobile phase.
- In elution chromatography the expression Eluent is also used for the mobile phase.
Chromatogram
- A graphical or other presentation of detector response, concentration of analyte in the effluent or other quantity used as a measure of effluent concentration versus effluent volume or time. In planar chromatography "chromatogram" may refer to the paper or layer with the separated zones.
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