Question

Why is a packed column instead of a capillary column, a good choise for analyzing percentage levels of components?

(Using Gas Chromatography/TCD)

Answer 1

Stainless steel, copper, glass or aluminum are the materials used to construct packed columns. They are 2-6 m in length with an internal diameters of approximately 2-4 nm. Capillary columns are made of fused silical and and are coated with a protective polymer coating.

Now interms of seperation efficiency and sample size although capillary column is a better choise but packed columns are less expensive. That's why packed column can be better choice to save the money. Generaly to nonpolar compound used to be seperated through stainless steel column whereas silica column is used to seperate polar compund. Gas chromatography is generaly used for compund with low molecular mass and generally low molecular mass indicates compunf with a very few unsaturation or made up of very few hetero atom. So all these indicates the better use of packed column over capilary column.