Gas-liquid chromatography (GLC)
This is the method of choice for the
separation of volatile substances or the
volatile derivatives of certain nonvolatile substances. In GLC, the
stationary phase is an inert solid
material (diatomaceous earth or
powdered firebrick), impregnated with
a non-volatile liquid (silicon or
polyethylene glycol).
Gas chromatography is a method of choice used to separate a mixture of compounds that are volatile or can be made volatile. The components in
the sample are purified on the basis of partition between a gaseous mobile phase and a liquid stationary phase.
Commonly used gas is inert (nitrogen, helium or argon) and simply carries the molecules through the column, it is called a carrier gas. The column packed of a nonvolatile liquid coated on an inert solid support (Diatomaceous earth or powdered firebrick). The mixture of substances is injected into the column along with the mobile phase,which is an inert gas.
The partition of the volatile mixture is based on the separation of the components between
the mobile phase (gas) and stationary
phase (liquid), that is why it is known as gas liquid chromatography.
Separated compounds can be identified by a detector.
Basically this detector works on the principles of ionization or thermal conductivity.
Gas-liquid chromatography is reliable, sensitive and rapid. Sometimes it is used
for quantitative estimation of
biological materials such as drugs,
lipids and vitamins.
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