Question

I have completed a column chromatography lab and need to write a discussion. We performed a TLC at the end to check our separation. Unfortunately, I did not do a good job separating ferrocene and acetyl ferrocene (with hexane, TBME, then acetone) and could not see any of the spots on the developed TLC. Why can't I see the spots at all? They disappeared.

How do I explain what the TLC experiment shows about the effectiveness of my separation?

Answer 1

Ferrocene (a nonpolar compound) moved with hexane (nonpolar eluent).

Therefore, all the ferrocene was eluted out by hexane from the column.

Acetylferrocene (a polar compound) moved with MTBE (methyl tert-butyl ether, a polar eluent).

Therefore, all the acetylferrocene was eluted out by MTBE from the column.

Finally, the acetone (highly polar solvent) had wiped away both the compounds from the column. That is the reason why you could not see any spot at all.