TLC and polarity

[jackflag]

Hi I'm doing a lab with TLC and I have a polar TLC plate and a polar specimen. I know that because of those two being polar, the migration of my sample will be reduced, but if I use a more polar solvent for my mobile phase, will this increase the migration or reduce it? How does the polarity of the mobile phase affects the migration?

Thank you.

 

[hypervalent_iodine]

Without meaning to sound facetious, how do you think it might change it? Do you think that a polar solvent might be able to interact with the silica as well and if so, how might that change the ability for a polar substrate to move up the plate? Would it be more impeded or less?

[jackflag]

I just think that the substrate would move up more with a more polar solvent than with one who is less polar because the interaction between the solvent and the substrate would be stronger and the substrate would want to move up with the solvent in the plate. I'm trying to see if the solvent (with different polarity) we use with a polar plate and a polar substrate affects the speed of the migration of the substrate. 

[hypervalent_iodine]

8 hours ago, jackflag said:

I just think that the substrate would move up more with a more polar solvent than with one who is less polar because the interaction between the solvent and the substrate would be stronger and the substrate would want to move up with the solvent in the plate. 

This is correct. 

[BabcockHall]

I would also consider the interaction between the solvent and the silica (the stationary phase).