Thin Layer Chromatography
Gas Chromatography-Mass Spectrometry
Mohrig, pp. 178-187.)
is one of the most useful methods for the separation and purification
of both solids and liquids when carrying out small-scale experiments.
Column chromatography is another solid-liquid technique in which the two
phases are a solid (stationary phase) and a liquid (moving phase). The
theory of column chromatography is analogous to that of thin-layer chromatography.
The most common adsorbents - silica gel and alumina - are the same ones
used in TLC. The sample is dissolved in a small quantity of solvent (the
eluent) and applied to the top of the column. The eluent, instead of rising
by capillary action up a thin layer, flows down through the column filled
with the adsorbent. Just as in TLC, there is an equilibrium established
between the solute adsorbed on the silica gel or alumina and the eluting
solvent flowing down through the column.
In this experiment,
you will be using column chromatography to separate the two components
of a binary mixture. You will identify them from their melting points.
to detailed procedure for Lab III: Column Chromatography.