Question

The following are all commonly used solvents for TLC. What types are compounds are they good choices for separating?

Dichloromethane or toluene:

Hexane or petroleum ether:

Hexane or petroleum ether with varying proportions of toluene or ether:

Ethyl acetate, acetone, or methanol:

Answer 1

The solvents are used in TLC based on its polarity. The more polar the compound we need polar solvent to make it seperated and if its non-polar, less polar solvent is enough. Mostly the solvent system used will be a composition of polar and non-polar solvent such that the seperation is proper.

Dichloromethane, ethyl acetate, acetone methanol are polar solvents and petroleum ether, hexane, toluene are non- polar solvents. The increasing order of polarity is

Hexane/ petroleum ether < toluene < Dichloromethane < acetone< ethyl acetate < methanol