Which statement does not apply to gas-liquid chromatography?

Which statement does not apply to gas-liquid chromatography?

• A. Separation depends on volatility of the sample.
• B. Separation depends on the sample's solubility in the liquid layer of the stationary phase.
• C. Stationary phase is a liquid layer adsorbed on the column packing.
• D. Mobile phase is a liquid pumped through the column.

Answer: (D)

Gas-liquid chromatography uses a carrier gas as the mobile phase, pushing vaporized sample components through a column that is coated with a thin liquid stationary phase on a solid support. Separation relies on how each component distributes itself between the moving gas and the stationary liquid. Compounds with higher volatility tend to stay in the gas and move through the column faster, while less volatile compounds dissolve more in the liquid phase and elute later. The stationary phase being a liquid film on the packing is correct, providing the medium for partitioning. The mobile phase being a liquid pumped through the column is not true for this technique—the mobile phase is a gas. That’s why the statement about the mobile phase being a liquid does not fit gas-liquid chromatography.

Gas-liquid chromatography uses a carrier gas as the mobile phase, pushing vaporized sample components through a column that is coated with a thin liquid stationary phase on a solid support. Separation relies on how each component distributes itself between the moving gas and the stationary liquid. Compounds with higher volatility tend to stay in the gas and move through the column faster, while less volatile compounds dissolve more in the liquid phase and elute later. The stationary phase being a liquid film on the packing is correct, providing the medium for partitioning. The mobile phase being a liquid pumped through the column is not true for this technique—the mobile phase is a gas. That’s why the statement about the mobile phase being a liquid does not fit gas-liquid chromatography.