The stationary phase in Gas Chromatography (GC) is the material inside the column that helps to separate the compounds in a mixture.
Simple explanation:
- The stationary phase can be a liquid coated on a solid support (in packed columns) or a thin film on the inner wall (in capillary columns).
- As the sample moves through the column with the carrier gas, each compound interacts differently with the stationary phase.
- Compounds that stick more strongly to the stationary phase move slowly.
- Compounds that stick less move faster.
- Because of these differences, the compounds separate and come out at different times (called retention times).
In short:
The stationary phase controls how long each compound stays in the column — it is the key part that separates the mixture based on each compound’s interaction and boiling point.