Which is the basis of thin-layer chromatography?

a.) an electron beam excites atoms within the drug, which give off a characteristic x-ray spectrum.

b.) the drug gets carried through a stationary phase by a mobile phase and the retention time identifies the drug.

c.) the drug fragments have specific molecular weights that bind to the antibodies.

d.) the unknown amount of drug in a sample competes with a known amount of fluorescently labeled drug for binding to an antibody to that drug.

B.) The drug gets carried through a stationary phase by a mobile phase and the retention time identifies the drug.

Explanation:

Chromatography is used in purifying complex mixtures of organic compounds. It uses the adsorption tendencies of compounds to seperate and identify them.

Chromatography is made up of two phases in contact, the stationary phase or non-mobile phase and the mobile phase. The movement of the mobile phase over the stationary phase causes the separation of a mixture into its constituents.

The stationary phase is made up of silica-gel or alumina in a solvent (an adsorbent) and the mobile phase or carrier is the organic solvent which is the drug.