HPLC Solvent Front
Posted: Wed Oct 13, 2004 7:00 am
Hi,
I'm seeing quite different UV chromatogram for my runs these days. I'm not sure if someone had run dry the column or it is due to other factors,
1) The UV trace used to dips from the baseline (solvent effect) and regains to the baseline after 1-2 minutes. However now, it takes about 20 minutes for it to regain to the baseline level.
2) I'm suppose to see compounds eluting around 25minutes, however there is a huge peak at the end of the run (100%B to 100% A interface). My gradient is 0-50%B from 0-40minutes, solvents are A: 0.1% formic acid, B 80% MeCN with 0.1% Formic acid.
Would very much appreciate if anyone could advice what could be the problem? If it is really due to a dried column, how do you regenerate it (I am using a 75um ID * 15cm PepMap column for LC/MS)
Thanks!!!
CHing Seng
I'm seeing quite different UV chromatogram for my runs these days. I'm not sure if someone had run dry the column or it is due to other factors,
1) The UV trace used to dips from the baseline (solvent effect) and regains to the baseline after 1-2 minutes. However now, it takes about 20 minutes for it to regain to the baseline level.
2) I'm suppose to see compounds eluting around 25minutes, however there is a huge peak at the end of the run (100%B to 100% A interface). My gradient is 0-50%B from 0-40minutes, solvents are A: 0.1% formic acid, B 80% MeCN with 0.1% Formic acid.
Would very much appreciate if anyone could advice what could be the problem? If it is really due to a dried column, how do you regenerate it (I am using a 75um ID * 15cm PepMap column for LC/MS)
Thanks!!!
CHing Seng