[supermonkey]

for a 60% Hexane and 40% Ethyl Acetate mixture for TLC would the mixture be nonpolar because it is made up of 60% hexane? When calculating the Rf value the one with the greatest Rf value would be the least polar because the solvent mixture is nonpolar?

[MissPhosgene]

It's pretty non-polar. You are right about the Rf values.

[Doc Oc]

For what it's worth, I consider 40% EtOAc to be pretty polar and only run columns of very sticky molecules in that type of system (ie; amino acids).  I tend to start on the lower end of the spectrum, 20% or more often 10% EtOAc and then move up in polarity if the spots aren't behaving well.

[OC pro]

Agree with J-Bone: quite polar mixture. One can substitute ethyl acetate with tert butyl methyl ether or diethyl ether in case of very non-polar substances.

@Supermonkey: Try to avoid using hexane. It is quite neurotoxic. You can substitute with heptane or petroleum ether (still contains ~1% hexane). 

[collin_det]

J-bone; Is it possible to run aminoacids on this system? Is it normal phase? I have always been afraid for them to stick to the column, so I always use reverse phase or ion exchange for amino acids? Otherwise I always purify them, before they get to the amino acid and then recrystalize when getting there.

[MissPhosgene]

I think MeOH/DCM mixtures are polar, but I guess it's all relative to what a person uses.

[ardbeg]

yeah i have to use acetone/methanol for some of the s#*$ i make.

[Doc Oc]

I guess polar is a very relative term here, that could be confusing.  In terms of the typical hexane/EtOAc system that is most commonly used in TLC, I personally consider anything above 20% EtOAc to be polar.  At 40% EtOAc just about everything will start to run, except for maybe a free amine (but even some of those might start to drift off the baseline).  10-20% runs my nonpolars about 1/4-1/2 up the plate and keeps the polars stuck at the baseline.  For certain amino acids I have resorted to either DCM/MeOH or CH₃Cl/MeOH and I do consider that to be much more polar than hexane/EtOAc.

Collin_det, I have run some amino acids in that system, but it really depends on the compounds that you are trying to separate.  As I stated above, other times I've resorted to DCM/MeOH.

[discodermolide]

J-bone; Is it possible to run aminoacids on this system? Is it normal phase? I have always been afraid for them to stick to the column, so I always use reverse phase or ion exchange for amino acids? Otherwise I always purify them, before they get to the amino acid and then recrystalize when getting there.

You will not be able to run amino acids in this solvent system.