Question

In this lab, what would happen if your initial solvent level is above the baseline (i.e. the line where you spotted your samples on the TLC plate)?

a. The mobile phase will not move up the stationary phase
b. The solvent will polarize the non-polar compounds
c. The spotted compounds will move up the stationary phase quickly
d. The solvent will dissolve the spotted compounds

Answer 1

If the initial solvent level is above the baseline in TLC, the spotted compounds will dissolve, leading to potential failure of the chromatographic separation.

Step-by-step explanation:

If the initial solvent level in a thin-layer chromatography (TLC) experiment is above the baseline where the samples are spotted, then d. The solvent will dissolve the spotted compounds.

When the solvent front begins above the baseline, the solute does not have the chance to adhere to the stationary phase before it starts to migrate, which means the compounds may dissolve into the solvent without proper separation, leading to an inaccurate or failed chromatographic analysis.

It is crucial to start with the solvent level below the baseline to ensure that the compounds are appropriately adsorbed onto the stationary phase and can separate effectively as the mobile phase moves up the plate.