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many kinds of adsorbents as eluting agents in the process of adsorption

Discuss many kinds of adsorbents as eluting agents in the process of adsorption?
A large variety of adsorbents as eluting agents can be used in column adsorption chromatography.only the more common adsorbents which only act as adsorbent are under consideration here.
Enlist some commonly used adsorbent in column chromatography?
Calcium carbonate
Calcium sulphate
calcium phosphate
Magnesium carbonate
Calcium oxide
Silicic acid (silica gel)
Char col
Magnesium oxide
Aluminium oxide
All of these are given above in increasing order of adsorption power from top to bottom.
General adsorption sequence of some commonly used functional groups
Acids and bases
Hydroxy ,amino,thio,and nitro group
Aldehydes  ketones and esters
Halogen compounds
Unsaturated hydrocarbons
Saturated hydrocarbons
All above discussed functional groups are enlisted in decreasing order from top to bottom.
What are two commonly used adsorbents in adsorption chromatography?
Alumina and silica gel are commonly used adsorbents in chromatography
Alumina is available in many types for common use.The formula of alumina depends upon procedure of drying and initial stage.in this different site are responsible for the process of adsorption.
Activation procedure of alumina
Alumina is activated by heating it in an oven at a temperature range of 2000C or at 3000C for three hours.
Benefit of above drying procedure
This drying procedure as a result gives us two kinds of activated alumina.
Infact, anhydrous alumina is a poor chromatographic adsorbent.
Grading of alumina
Alumina can also be graded it being
Acid,base,or neutral washed
Silica gel
Activation of silica gel
Silica gel is activated by heating it at 1600C for three hours.Not complete water is removed and and adsorption sites resembling to those in alumina ,Except silicon are also a part of structure of silica gel. Like alumina silica gel is also compatible with water and and most common organic solvents however silica gel will swell and the amount of swelling is determined by the type of solvent used.

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