A. Liquid-liquid chromatography

B. Gas-liquid chromatography

C. Gas-solid chromatography

D. Solid-solid chromatography

Correct Answer: D. Solid-solid chromatography

“Solid-solid chromatography” is not a recognized standard technique, as chromatography requires a mobile phase (gas or liquid) to carry components through the stationary phase for separation.

Option Analysis

A. Liquid-liquid chromatography
Valid technique where both stationary and mobile phases are liquids (stationary liquid coated on solid support). Separation occurs via partitioning based on solubility differences. Common in partition and HPLC methods.​

B. Gas-liquid chromatography
Standard gas chromatography (GC) variant using liquid stationary phase coated on solid support or capillary walls. Widely used for volatile compounds; separation via partitioning.​

C. Gas-solid chromatography
Recognized technique using solid stationary phase (silica, alumina) with gaseous mobile phase. Separation by adsorption; used for gases and small hydrocarbons despite peak tailing issues.​

D. Solid-solid chromatography (Correct – Not a stationary phase type)
No mobile phase exists, preventing component movement and separation. All chromatography requires fluid mobile phase flow over stationary phase. This term doesn’t exist in standard classifications.

Solid-solid chromatography is not a stationary phase type because chromatography requires mobile phase movement, absent in solid-solid systems—essential knowledge for GATE Life Sciences.

Valid Stationary Phase Types

Liquid-liquid, gas-liquid, and gas-solid all feature recognized stationary phases with mobile phase flow enabling separation through partitioning or adsorption.

Chromatography Classification

GATE Exam Relevance

Tests understanding of chromatography fundamentals across biochemistry and analytical techniques. Recognize only fluid mobile phases enable the separation process.​