A Chromatography column is a device used in chromatography for the separation of chemical compounds. It is in essence a tube filled with a solid substance (the stationary phase) through which the liquid sample (the mobile phase) passes. A chromatography column contains the stationary phase, allowing the mobile phase to pass through it. Chromatography columns of different types are used in both gas and liquid chromatography. The size of the chromatography column, the substance that makes up the stationary phase, and the temperature range you will be working with all need to be taken into consideration when choosing a chromatography column.