Variation in pressure during injection
Posted: Tue Oct 23, 2007 12:44 am
Hi all,
During a simple isocratic analysis of tablet ( MeOH :Heptanosulfonic acid and buffer) I found this situation:
I have a pressure pulse after my injection, it falls 2 Bar. It’s the red line in the figure with axis on right side. And then during the elution of dead volume I have other pressure pulse. OK, a pressure pulse during injection is easy to understand, my valve turn and then the pressure of system (column) equalize with the sample in loop and then it falls a little. This is registered in real time.
But I can not find a meaning of a pressure pulse during the elution of dead volume. Why the elution of the sample solvent could create a pulse in my pressure?
Any ideas?
Thanks
Fabiano
During a simple isocratic analysis of tablet ( MeOH :Heptanosulfonic acid and buffer) I found this situation:
I have a pressure pulse after my injection, it falls 2 Bar. It’s the red line in the figure with axis on right side. And then during the elution of dead volume I have other pressure pulse. OK, a pressure pulse during injection is easy to understand, my valve turn and then the pressure of system (column) equalize with the sample in loop and then it falls a little. This is registered in real time.
But I can not find a meaning of a pressure pulse during the elution of dead volume. Why the elution of the sample solvent could create a pulse in my pressure?
Any ideas?
Thanks
Fabiano