Which support is traditionally used in paper chromatography?

• A. Whatman
• B. Plastic plates
• C. Silica gel
• D. Aluminum foil

Answer: (A)

In paper chromatography, the stationary phase is a porous, hydrophilic paper made from cellulose, and the traditional support is Whatman filter paper. Whatman became the standard because its uniform thickness and consistent pore structure give reproducible separations and reliable capillary flow, which is essential for the solvent front to travel consistently up the paper. The solvent moves by capillary action and interacts with analytes as they adsorb to and partition with the cellulose, enabling separation. Other options belong to different techniques: plastic plates are used in thin-layer chromatography with coated plates; silica gel is the typical stationary phase for TLC and other TLC-based methods; aluminum foil isn’t used as a chromatography support.