Hello!

I am trying to separate a fluorinated protein from a non fluorinated one. The proteins should be rather similar (apart from the F-) and their MMasses also similar.

I am using a fluoroflash column which should work perfectly but it actually doesn't.

I have tried different eluents. Water as eluent A and MeOH or ACN as B.
Slow and fast flow rates as well.
Isocratic, linear or gradient runs...

Very weird, if someone has used this column for similar separation type and has an idea about the subject, I would be grateful!

Best,

Evi