Question

What is the theory behind GC and IR analysis?

Answer 1

Gas Chromatography (GC): It is an analytical technique generally used to identification of compounds in a mixture.

In this technique also separation of mixture of compounds based on the interaction between stationary and mobile phases.

But compared to other chromatographic techniques is differs, as the separation is based on the difference in their boiling points.

The compounds which have high boiling points and more interactive towards statonary phase will ellute slower than the compounds which have lower boiling points and less interactive towards stationary phase in a mixture.

The compounds in a mixture must be thermally stable in order to use GC.

Infrared (IR) Spectroscopy:

It is nothing but a graph between frequency and wave length.

When the molecule absorbs specific frequency which is characteristic to its structure and thus bonds in molecule starts vibrating. These vibrations differs from bond to bond, so that allows to differentiate bonds present in a molecule.