Thin-layer chromatography stationary phase is described as being on which medium?

Thin-layer chromatography stationary phase is described as being on which medium?

• A. Silica gel on glass
• B. A liquid on column packing
• C. A gas
• D. A metal plate

Answer: (A)

In thin-layer chromatography, the stationary phase is a solid adsorbent laid as a thin layer on a flat backing. The typical setup uses silica gel coated onto a glass plate, providing a polar surface that interacts with analytes as the mobile phase moves up the plate by capillary action. This solid, thin coating on a glass (or similar) backing is what enables separation based on differing affinities to the stationary phase. The other descriptions don’t fit TLC: a liquid as the stationary phase refers to other chromatography types where a liquid is immobilized as the phase; a gas isn’t used as the stationary phase in TLC; and a metal plate wouldn’t provide the controlled thin solid layer that silica gel on glass does.

In thin-layer chromatography, the stationary phase is a solid adsorbent laid as a thin layer on a flat backing. The typical setup uses silica gel coated onto a glass plate, providing a polar surface that interacts with analytes as the mobile phase moves up the plate by capillary action. This solid, thin coating on a glass (or similar) backing is what enables separation based on differing affinities to the stationary phase.

The other descriptions don’t fit TLC: a liquid as the stationary phase refers to other chromatography types where a liquid is immobilized as the phase; a gas isn’t used as the stationary phase in TLC; and a metal plate wouldn’t provide the controlled thin solid layer that silica gel on glass does.