Pressure Difference

Question

Asslam o Alaikum (may peace and mercy be on all of you)

If I use isocratic elution on quarternay pump agilent 1260 infinity series, the pressure is different from that pressure when I use binary pump to elute same composition as i did in isocratic elution, the question is that why pressure is different while composition of the mobile phase is same?

jhagel · Accepted Answer

It should be the same- please check if you have a cross port leak of the MCGV...

You can do this by setting the flow to 100% the channel you want and pull out the bottle filters from the liquid of the other 3 channels...Do you see air being pulled up in the other 3 channels? If yes, then you have a cross port leak,

Also, if you take the adaptor into the active inlet valve from the isocratic pump and move it to the quaternary pump -so bypassing the MCGV (where you have 4 lines in and 1 out) how does the pressure look?

Agilent · Answer

we are replacing small spring inside valve, and many MCGV are recovered