CHROMATOGRAPHY

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CHROMATOGRAPHY 

  • It is a method used for the separation, purification, and identification of a mixture of substances.
  • It is useful when components of a mixture have similar physical and chemical properties and hence cannot be separated by other methods.
  • Principle: It is based on the distribution of the components in a mixture between a stationary and a mobile phase.
  • The stationary phase may be a column of adsorbent, a paper, a thin layer of adsorbent through which the mobile phase moves on. The mobile phase may be a liquid or gas.
  • The principle of chromatographic separation is always adsorption (absorption of a constituent on the surface of the solid stationary phase) or partition (distribution of a constituent in between two liquid stationary phases).

THEORY OF CHROMATOGRAPHY

  • The separation takes place due to the differential migration of components which depends on the relative affinity towards the stationary and mobile phases. 
  • The component which is less strongly held by the stationary phase would tend to move faster in the mobile phase and vice versa.

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