Chromatography Forum

I have Deuterium labeled Fmoc-Amino acids, the D's are replaced with all H's in the amino acid. These are around ~95% pure. I'm trying to separate the non-labeled counter parts which are H labeled (~5%). I have seen few articles in late 80's separating labeled and non-labeled molecules. I'm trying to separate these molecules with less success.
If any body has suggestions that would be of great help.

Thank you