This document summarizes adsorption chromatography, a method used to separate mixtures. It was developed by American scientist D.T. Day and later botanist M.S. Tswett used adsorption columns to investigate plant pigments. The principle is that components are separated based on how strongly they adsorb to the column material, with the most strongly adsorbed at the top and least at the bottom. Common adsorbents discussed include silica gel, alumina, fuller's earth, charcoal, and polystyrene beads. The column is prepared either through dry packing or wet packing of the adsorbent material. Adsorption chromatography is used to separate mixtures such as polycyclic aromatic

1. Prepared
by,
R

2. INTRODUCTION:
• Developed by American scientist,
D. T. Day.
• Later M. S. Tswett, botanist used
adsorption columns, for the
investigation of plant pigments.

3. PRINCIPLE:
 In this chromatography, seperation of
components of a mixture takes place by
the adsorption efficiency of the sample.
 The most strongly adsorbed component
forms the topmost band.
 the least adsorbed component forms
the lowermost band on the adsorbent
column.
 Degree of separation depends upon the
separation of surface area of
adsorbent.

4. The distribution co-efficient is given by
Amount of solute per unit of stationary
phase
K =-------------------------------------
Amount of solute per unit of mobile phase

6. TYPES OF ADSORBENTS:
There are number of adsorbents
commercially used. The most commonly
used adsorbents in adsorption
chromatography are
• Fullers earth
• Powdered charcoal
• Polystyrene beads
• Silica gel
• Alumina oxide

7. FULLERS EARTH:
• It consists of a mixture of minerals
obtained from certain clay deposits.
• It is widely used to decolorize the
food.
• Used in the removal of pigments from
wine sample.
• It is cheap.
• It sold under the name of Florisil.

8. POWDERED CHARCOAL:
 Powerful adsorbent
 Resource material are bone, coconut
 Finely divided charcoal is very difficult
to wet
 Preparing a column packed with
charcoal is very troublesome

9. POLYSTYRENE BEADS:
• It is modified as tiny beads
• It doesnot have any charged groups in
its surface.
• Function is only adsorption
• Useful in the separation of alkaloids,
steroids
• Commercial name is XAD resins

10. SILICA GEL:
 It is a popular adsorbent
 It is less stable than alumina
 It should handled properly to avoid
changes in the result
 It is available in the form of crushed
and powdered glass

11. ALUMINA:
 It is powerful adsorbent
 It is prepared as a precipitate of
aluminium hydroxide

12. PREPARATION OF THE COLUMN:
DRY PACKING
• The powdered sample is poured inside
the tube (both the sample and the
stationary column remain dry)
WET PACKING
• The bottom of the tube is closed
• The column is filled with solvent
• This method is known as wet packing

13. APPLICATIONS
Used for the separation of
• Polycyclic aromatic compounds
• Plasma cortisol
• Geometrical isomers