Paper Chromatography.

Hello everyone..

Today I am talking about PAPER CHROMATOGRAPHY..

So Paper...because we are using Whottman's filter papers here.

Chrome means color, graph essentially means separating. Hence the simple definition is separation of components in the mixture, which are later detected by a color developing reagent that is specific for a particular component.

I am still researching as to what ATO means, in case you find out before me, then please do inform :p

You can also use the technique for identification of the components in the mixture, by plotting the standard samples in the same paper. 

The sample mixture is applied to a piece of filter paper, the edge of the paper is immersed in a solvent, and the solvent moves up the paper by capillary action.Components of the mixture are carried along with the solvent up the paper to varying degrees, depending on the compound's preference to be adsorbed onto the paper versus being carried along with the solvent. 

The paper is composed of cellulose to which polar water molecules are adsorbed, while the solvent is less polar, usually consisting of a mixture of water and an organic liquid. The paper is called the stationary phase while the solvent is referred to as the mobile phase. 

Performing a chromatographic experiment is basically a three-step process: 

1) application of the sample, 

2) "developing" the chromatogram by allowing the mobile phase to move up the paper, and 

3) calculating Rf values and making conclusions.

Solvent systems and the color developing reagents differ on the basis of the samples that is being seperated.
For eg: In detection of amino acids, the most common solvent system used is - Butanol:acetic acid:water in proportions of 40:10:10.
Spraying reagent used is ninhydrin.

A modified technique is to add the color developing reagent in to the solvent system. this avoids the later need to dry, spray and incubate the paper.


In order to obtain a measure of the extent of movement of a component in a paper chromatography experiment, we can calculate an "Rf value" for each separated component in the developed chromatogram. An Rf value is a number that is defined as:

Rf - Distance traveled by component from application point.(A)
       ____________________________________________
       Distance traveled by solvent from application point (B)

Hope it helps you all.

Thank you.

Lots of love, don't forget to be amazing.

-Staph.