Comment on the order of elution of the following solutes in (a) normal phase and (b) reversed phase liquid chromatography. Give reasons why.

Question

Solute X - non-polar
Solute Y- Polar, a dipole
Solute Z - Polar, more polar than solute Y

I understand that polarity is the reason of the difference in elution order, but can anyone help with how the order is determined and why? thanks

Answer 1

In the case of chromatography, like attracts like. So, the more polar compound will elute slower than the compounds not as polar because the plate is polar.

Highest Retention Time: X > Y > Z :Lowest Retention Time

In the case of reverse phase chromatography, it is reversed.