Hello, I have a molecule soluble in chloroform. I've tried to learn its pureness with thin lead chromatography on silica gel. After several tries, I've discovered that my molecule is best eluted with 9:1 CHCl3:MeOH (for now). I am not satisfied with the elution, the molecule does not advance very well as progressed with a visible spot; it is a tailing spot. But I want it to be a single spot. I want to share my findings with you, and to expect your answers. I've found dielectric constants of the solvents I used, and here reads 4,8 for chloroform, and 33,6 for methanol. If we prepare a solution containing %90 chloroform by volume, what would the overall dielectric constant of the mixture? I did a simple calculation (4,8*9+33,6*1)/10=7,68. Is that a logical approach? Secondly, I tried to approximate all my different solvent mixtures to this value by appropriate mixing. But none of them worked, for one exception, methanol:toluene:chloroform. This is as nice as the initial one. I think that it is not about the final value; chloroform should be much to dissolve the compound, and the additional solvent is needed to drive the spot higher as pure chloroform does not drive it upwards. Sorry for long post, but I think you understood the event.