[hiohokaybye]

I just did a TLC lab that required us to test out all different ratios of hexane/ethanol and I ran into a question I couldn't answer...

A little background about the experiment: I used standard silica plate and the spinach extract contained ß-carotene (non-polar) and polar chlorophyll a/b. The different ratio of solvents were pre-made by the school.

I understand that with a non-polar solvent, the polar compound is unlikely to climb up - but the non-polar will still climb.
However, when I used pure hexane, the dot stayed on the origin line... and this was also the case with 9:1 hexane:ethanol. I don't have an answer to this question, if anyone could help me with this I'd greatly appreciate it!


Random note: 75:25 hex:ethanol showed three dots.

[spirochete]

It's not unheard of for organic molecules to stick to baseline in non polar solvent mixtures. This means that all your compounds in the crude mixture are fairly polar. It is a bit surprising that they stayed at baseline in ten percent ethanol, which is a very polar, and protic solvent. Hexanes is an extremely polar solvent however, so I'm not sure.

[hiohokaybye]

You meant that hexane is very non-polar right?

I eliminated that possibility that the extract was completely polar because in the hand out it showed that carotene was non polar... which means the plate should've at least showed one spot 

[spirochete]

You meant that hexane is very non-polar right?

I eliminated that possibility that the extract was completely polar because in the hand out it showed that carotene was non polar... which means the plate should've at least showed one spot 

Yes sorry I mis-typed. Hexane is very non-polar. Even more so than DCM, ether etc. which are more intermediate polarity solvents.