What Is Chromatography And It's Types

Chromatography

Introduction

Chromatography is separation technique, used to separate components of a mixture using a stationary phase and mobile phase.

This technique was introduced by a Russian scientist TSWETT in 1906.by using separation of color component of leaf extract

Definition

As per IUPAC – Chromatography is a physical method of separation in which the component to be separated and distributed between two phases that one is a stationary phase and mobile phase moves in definite direction

Principle

 Chromatography mainly based on two categories

• Adsorption
• Partition

Adsorption 

 In this process analyse substance is absorbed in stationary phase.

adsorption image

Partition

1. Distribution of solute take place in 2 immiscible phases.
2. Distribution depends on partition coefficient.
3. Example- take oil and water add another substance the distribution of substance is depend on the partition coefficient of oil and water

partition coefficient
it is determined by the ability of solute to be partitioned be two immiscible liquids.

Formula

Kd=concentration of solute in solvent A/

 concentrationof solute in solvent B

Types of Chromatography

There is generally two types of chromatography ie. Gas chromatography and liquid chromatography.

On the basis equilibrium process the different type of chromatography as given below

• Adsorption chromatography
• Partition chromatography
• Ion exchange chromatography
• Molecular sieve chromatography

Adsorption chromatography
The adsorption of analyte on the surface of solid stationary phase. Liquid or gas is mobile phase.

Types

• Adsorption column chromatography

• Planar chromatography or Thin layer chromatography
• Modern Planar chromatography or High performance thin layer chromatography (HPTLC)
• Gas soiled chromatography

 

Partition chromatography

This involves the distribution of solute between two phases.

Generally Liquid or gas is mobile phase. And Liquid is stationary phase.

Types

• Partition chromatography
• Paper chromatography
• Thin layer chromatography
• Liquid chromatography
• Gas liquid chromatography

Ion exchange chromatography

Involves the exchange of ions between stationary phase which is ion exchange resin and Liquid is mobile phase.

Consider as column chromatography

Molecular sieve chromatography

Also called gel chromatography

Involve separation of analtye mixture on the basis of its molecule size

Other types of chromatography

• Flash chromatography
• Supercritical fluid chromatography
• Chiral chromatography
• Ion pair chromatography
• UPLC /MPLC

APPLICATION

Chromatography has wide range of application some major given below 

1. for the identification of pharmaceuticals substance and prepratio n 
2. test for homogenity ofsubstance 
3. determination of individual substances
4. it has got excellent application in pesticide analysis
5. applicable also for the analysis of glycoside and carbohydrate

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