Question

Why is TLC limited to nonvolatile samples?

Answer 1

Nonvolatile refers to a substance that does not readily evaporate into a gas under existing conditions.

In Thin layer chromatography after spotting the solute (assuming that it didn't evaporate while spotting ), is run in the developing tank with the developing solvent , When a thin layer plate is removed from a developing tank, one needs to evaporate off the developing solvent, which is sometimes done by heating the plate or moving it thorugh a stream of air. Thsu any volatile components on the plate would be removed at the same time.

Further our assumption that the solute didn't evaporate during spotting may also not be true, according to the environment temperature of the lab.