Study Set Content:
– from Greek words
“chroma” “graphein”
“chroma”
color
and “graphein” – to
write
Collective term for a set of laboratory techniques for the separation of mixures.
Chromatography
refers to the mixtures of substances to be separated dissolved in a liquid or a gas.
Mobile phase
a porous solid matrix through which the sample contained in the mobile phase
percolates.
Stationary Phase
Applications of Chromatography
1. Used for the separation of amino acids, proteins & carbohydrates.
2. In analysis of drugs, hormones, and vitamins
3. Helpful for the qualitative and quantitative analysis of complex mixtures.
4. Useful for the determination of molecular weight of proteins
a technique that involves placing a small dot or line of sample solution onto a strip of
chromatography paper.
Paper Chromatography
A chromatography technique that uses paper sheets or strips as the adsorbent being the
stationary phase through which a solution is made to pass.
Paper Chromatography
It is an inexpensive method of separating dissolved chemical substances by their different
() across the sheets of paper.
migration rates
It is a powerful analytical tool that uses very small quantities of material.
Paper Chromatography
Considered to be the simplest and most widely used of the chromatographic techniques
because of its applicability to isolation, identification, and quantitative determination of
organic and inorganic compounds.
Paper Chromatography
has become standard practice for the separation of complex mixtures of () and a long list of simple organic compounds.
() can also readily be separated on paper.
amino acids,
peptides, carbohydrates, steroids, purines, Inorganic ions
THEORY: of paper chromatography
Propelling Force –
Retarding force
– It tries to drag the substances in the direction of the flow of solvent.
Propelling Force
It
depends upon:
a. The rate of the solvent flow
b. The solubility of the substance in the solvent
c. The component with higher solubility will move rapidly along the filter paper than
the less soluble component.
The results are represented by Rf value which represents the movement or
migration of solute relative to the solvent front
Retarding force
Retardation Force +
Rf = the distance travelled by the solute/
distance travelled by the solvent front
Rf is a() quantity.
unit less
implies that the solute has not moved at all from the application
spot
A value of 0
