shoulder peak

[moon704520]

I have been using the kromasil columns for a long time , I have been using the TEAP pH3.0 as the mobile phase,gradully i find that after a period of time shoulder peak will appear by using kromasil c-8 column ,yet this does not happend on the kromasil c-8,can anyone tell me
why is so ?

[tom jupille]

I have been using the kromasil columns for a long time , I have been using the TEAP pH3.0 as the mobile phase,gradully i find that after a period of time shoulder peak will appear by using kromasil c-8 column ,yet this does not happend on the kromasil c-8,can anyone tell me
why is so ?

As far as I know, kromasil c-8 should behave just like kromasil c-8.

If you really meant that the c-8 column is less stable than the c-18 column, then this is fairly typical. The shorter-chain bonded phase is more likely to be lost with low-pH cleavage of the silyl-ether linkage.