By Anonymous on Wednesday, February 11, 2004 - 11:42 am:
HPLC on the same product was worse than that of ten days ago. Peaks became asymmetric, tailing and broader. During these ten days, the column was stored in ACN/water mix. Any idea of what causes such a change?
By Anonymous on Thursday, February 12, 2004 - 11:58 am:
Are you using the same MP as 10 days ago? If so, make new and try again. The composition of the MP would have changed by now.
By Bernd Mischke on Tuesday, February 17, 2004 - 03:03 am:
Hi Anon,
if You have for Your peaks the same retention time the mobile phase is the same (!) but sometimes a HPLC column has a broken filling or a dead volume, the guard (pre-) column is also an object to control.
If nothing helps contact me.
By Frost on Wednesday, March 17, 2004 - 02:21 am:
I've experienced such a change by myself, and when I opened the column, I saw a crude hole on the surface. There were two causes for this: 1. These where my first self packed columns, so they had a rather bad quality.
I changed the solvents. The second solvent had a much higher viscosity. Given high pressure and relatively high flow rate (1 ml/min) the column was hit hardly by the new solvent.
I assume, this happens only with bad columns, so if you bought the column, you might not take point two into consideration.
Hope this helps you.