Capillary Column in Gas Chromatography

Liquidized stationary phases are used in capillary columns. Capillary column has a unique structure compared to the packed column. Capillary columns are also very tiny tube like structures which are highly coiled. The internal diameter of a capillary column is around 0.1-0.53 mm. 

The liquid stationary phase is coated as a thin film on the solid adsorbent which has been inserted into the coiled tube. This column type is longer than the packed column. Thus capillary columns may take more time to separate the test sample. On the other hand capillary columns do not need a large space in the GC system.