Question

What would happen if 100% ethyl acetate was used as the mobile phase instead of 9-to-1 hexanes to ethyl acetate?

Answer 1

If we add 100% EtOAc instead of 9:1 hexane to EtOAc, polarity of mobile phase incerases as the dielectric constant of EtOAc is high than hexane and all the compounds with even low Rf value will come through the column. The most important interaction is that of the mobile phase with the stationary phase(silica) . If you increase the mobile phase’s polarity, that interaction will increase, decreasing the interaction of the solute with the stationary phase. Therefore, a higher ethyl acetate content in the mobile phase will increase Rf values and help to pass through the column very rapidly.