Help for C8 column choice for peptide purification

[magicdice]

Hi everybody, I want to know which RP-C8 column is better, between YMC 10x250mm10um,120A and Spherisorb C8 10x250mm, 10um, 80A (both are from waters). Both columns are of silica, and I want to purify a amylin, a very hydrophobic peptide, like beta-amyloid. Any idea?

[tom jupille]

80 Angstroms is a bit on the small side for a peptide. Other things being equal, the 120 A would probably be a better bet.

That said, since you're getting a column from Waters either way, why don't you contact their tech support and ask *them* which they would recommend.

[unmgvar]

10u dp and 10mm ID means you are going for a purification step as well and not only separation.

do you have an analytical column?
did you develop a method on it?
if yes then simply go for an equivalent column to that one.

you should not try to use the 10mm 10u column in order to also create your method.
you will loose a lot more sample compare to a 4/4.6mm column.

and yes you are better of with a 120-300A column if you expect to have also very big Mw species as welll in your chromatogram