Due to the different stationary phases used, gas chromatography can be divided into two types: gas-solid chromatography, which uses a solid adsorbent as the stationary phase, and gas-liquid chromatography, which uses a carrier coated with a stationary liquid as the stationary phase.
Classification of Gas Chromatography (Nanjing Kejie)
- Classification by Chromatographic Separation Principle
Gas chromatography can also be categorized into adsorption chromatography and partition chromatography. In gas-solid chromatography, the stationary phase is an adsorbent, so gas-solid chromatography belongs to adsorption chromatography; gas-liquid chromatography, on the other hand, belongs to partition chromatography.
- Classification by Chromatographic Operation Mode
Gas chromatography falls under column chromatography. According to the difference in the thickness of the chromatographic column used, it can be divided into two types: general packed columns and capillary columns.
- A general packed columnis a glass or metal tube (with an inner diameter of 2–6 mm) filled with a stationary phase.
- Capillary columnscan be further divided into open tubular capillary columns and packed capillary columns:
- An open tubular capillary columnis made by coating a stationary liquid on the inner wall of a glass or metal capillary with an inner diameter of only 0.1–0.5 mm.
- A packed capillary columnis a relatively new development in recent years. It is prepared by first filling a thick-walled glass tube with certain porous solid particles, then heating and drawing the tube into a capillary. Its inner diameter is generally 0.25–0.5 mm.