Capillary columns are generally 10 – 100m long tubes having an internal diameter ranging from 0.1 – 0.5mm made of flexible material such as fused silica. Common types of capillary columns are
Wall coated open tubular (WCOT) – Internal wall is coated with a very fine film of adsorbing liquid
Surface coated open tubular (SCOT) – Inner wall is lined with a layer of solid support on to which the liquid phase is absorbed.
The columns are flexible and wound into several turn coils supported on a SS cage inside the column oven.