How to purify basic peptide

[proteinpeptide]

My peptide is very basic, if I use 0.1%TFA of H2O/ACN, I got very broad peak and coming up very early, do you guys have some suggestions to improve my purification? Thanks!

[Kostas Petritis]

You'll get more retention by using a higher perfluorinated homologue (i.e. HFBA or NFPA) and you'll get better peak shapes by using a well encapped silica stationary phase or even a polymeric one...

[Uwe Neue]

My suggestion is to use ammonia at pH ~ 10 with a packing stable at this pH, specifically XBridge C18

[danko]

Hi proteinpeptide,

If I understand you correctly, you’re aiming at purification of a peptide and not analysis for it.
I know, sometimes these two goals could be combined, but if you’re planning to use the peptide for further investigations etc. the TFA is a bad choice – it could be extremely difficult to get rid of TFA once it got in contact with the peptide/protein.
If I were you - for a first test/examination - I would look at Uwe’s suggestion. It shouldn’t take that much time to do a couple of experiments and evaluate the results.

If purification is the main goal I would consider HIC one of the possibilities.

Best Regards

[proteinpeptide]

Thank you guys