Chromatography-
An Overview
Chromatography
is a separation process mainly used to segregate different components of any
given mixture. The various components are separated so that they can be taken
for further analysis. This is not possible if they are still part of the
mixture, so it can only be done only after separation. This is where the role
of chromatography becomes important. Chromatography is much in demand for
separating mixtures for two reasons.1) it gives best results in minimum time
possible and 2) it is very cost effective as components can be separated with
less expenditure.
Chromatography
can be divided into many categories, depending on the components, which need to
be separated. These include column chromatography, flash chromatography,
thin-layer chromatography, gas and liquid chromatography. All these forms of
chromatography use different chromatography adsorbents and chromatography
desiccants and have varied purposes.
How the Chromatography Process Functions
The
process of chromatography is very simple and works on the principle of
components of any given mixture separating at different levels, based on the relative
dissolving capacity of each solute. In chromatography, there are generally two
phases.The mobile or liquid phase and the solid or stationary phase. The
mobile phase consists of a moving liquid stream while the solid phase is
contiguous. While the mobile phase can either be a liquid or a gas, the
stationary phase is usually a solid or liquid. The solid phase makes use of
chromatography adsorbents like Silica Gel, Activated Alumina to absorb
different components of the mixture at different levels.
When the chromatography
process begins, then the mixture, which has to be separated is placed on top of
the column. Next, the liquid solvent is passed through the column. It moves
downwards with the help of gravity or externally applied pressure. As the mixture
moves downwards, its various components will be absorbed by the chromatography desiccants and will settle at different levels. When the mixture finally
reaches the bottom, that is when the separation is completed. The individual
components, also known as elutants, are taken as solvent drips from the column
end.
Chromatography
Adsorbents/Desiccants
As mentioned earlier, the
chromatography process required chromatography adsorbents and desiccants. These
chromatography, especially column chromatography adsorbents, are required to
absorb the components at different levels. Chromatography desiccants like
Silica Gel, Carbon and Activated Alumina have great absorption capacities and
therefore are the best choice.
When
the components move down in the vertical glass column, where the mixture is
being separated, they will be absorbed by the chromatography adsorbents based
on their acidity or alkaline nature. It is on the basis of this acidic/alkaline
nature of the components that the chromatography desiccants are selected. Only
that desiccant is chosen, which will work well with the components so that they
are successfully separated. Once they divided, these components will be taken
for further analysis.
Supplier of column chromatography
materials like Sorbead India always ensure that top-quality
chromatography adsorbents like Silica Gel are made available to companies. The
company is one of the most well-known adsorbents supplier for column chromatography in the country.