9701 · 37.2
Gas/liquid chromatography
Gas/Liquid Chromatography separates volatile compounds by passing them through a long, coated tube. How fast each compound travels depends on its boiling point and how much it interacts with the tube's liquid lining versus the moving gas.
Need to know
What you need to know
- **Mobile Phase:** An inert gas (e.g., $N_2$, He) that carries the sample.
- **Stationary Phase:** A non-volatile liquid on a solid support inside the column.
- **Principle:** Separation by partition based on relative volatility and solubility.
- **Requirement:** The sample must be volatile or be made volatile (derivatised).
Explanation
The Great Molecular Race
- Volatile sample in carrier gas (mobile phase). | Sim hint: Liquid stationary phase on column.
- Retention time identifies components. | Sim hint: Compare with standards.
- More volatile → shorter retention time. | Sim hint: Temperature affects separation.
- Area under peak ∝ amount. | Sim hint: Quantitative GLC.