Chromatography Forum

LS,

We are currently analysing protein sample with HIC technique on one system. Peaks of interest are separated with a gradient ( linear). Peaks of degradants are eluting at ca 13 and 20 minutes while the main compound elutes at ca 40 minutes. This is our SST

We change towards another HPLC unit ( different brand) and the separation gets worse: degradants elutes at 18 to 20 minuts and are not fully separated and the main compound elutes at 35 minutes .

We have used the same solvents and freshly prepared solvents but up to now no succes.
Column test ( as described by the supplier) passes and check of gradient on the two pumps did not (yet) show any problem in the gradient proportional valves.

What could cause the problem ???

Regards

Philippe

LS,

Reaction to my own question. Problem solved

In the meantime I have received more information from the department where they perform these analysis.

The problem is caused by the column( batch). Previous batches do perform well whereas the new batch do not pass on the criterion for the resolution and retention time.
More attention towards teh SST wil begiven

Have a good day


Philippe