I´ll give you some tips to solve your questions that you post about Thin-Layer Chromatography
and Developing Solvent Selection...
Here some handouts about Solvent Selection:
The secret to success in TLC often depends on choosing the developing solvent correctly. Optimizing a separation usually centres on the selection of the best developing solvent by adjusting solvent strength and selectivity to maximize separation. The Rf values are considered “optimum” between 0.2-0.6 (according to several authors). Normally you can get the best developing solvent using the classical technique “trial-and-error” or empirical approaches based on experience and intuition.
With polar adsorbents , non-polar solutes exhibit little affinity for the adsorbent surface and are not retained. In contrast, polar or polarizable (e.g. aromatic compounds) solutes are strong retained because of relatively strong dipole-dipole and dipole-induced dipole forces.
The solute elution on a polar adsorbent is, predictably, in the order of the POLARITY/POLARIZABILITY of the Solute Functional Groups, that is:
Alkanes <alkenes <aromatics,halides <ethers, polynuclear aromatics, nitriles, nitro compounds <esters <ketones <aldehydes <amines <alcohols, phenols <amides <carboxylic acids
You can see better this point on a drawing that I put on this link:http://tinypic.com/view/?pic=48fpjy0
If you have access to Journal of Chromatography A (Science Direct), please read this reference:
Snyder, J. Chromatogr. (1974) 92:223-230 (Talk about the "Chromatographic Polarity")