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pressure problem with HPLC
Posted: Mon Nov 20, 2006 12:07 pm
by kupikupi
hi.. i need help..
while i was injecting the standards, the peaks that came out were very messy.. when i checked the pressure, it was very low.. i tried to restart everything but nothing worked.. the pressure once increased but it decreased again..
anything wrong with my HPLC? anyone can help me? it's very urgent
thx..
Posted: Mon Nov 20, 2006 12:18 pm
by n-cute
hi,
you should make some diagnostics I think. e.g. leak test ("How to" should be in your manual). By the way use water as mobile phase and check wherever you can all the way it goes for leakage. thats all, what I can tell You know, I'm quite newbie.
Posted: Tue Nov 21, 2006 10:40 am
by danko
Hi kupikupi
Judging from the information you share with us, I’d say you have air in one or both pumps.
Prime your pump/s and suck a good portion of mobile phase using a syringe. Prospectively it might be a good idea to degas your mobile phase/s prior to use.
Best Regards
Posted: Tue Nov 21, 2006 5:19 pm
by Jamie
Kupikupi:
Happened to me several times and most of the time I run out of mobile phase and the pump sucked air.
Jaime
Pressure problem..
Posted: Wed Nov 22, 2006 1:11 am
by rolpe
Hi,
check following parameters:
How is your pressure, higher or lower than normal ?
If lower check for leaks. Tighten the fittings and check if purgevalve is properly closed.
Are there pressure changes ?
If there are high pressure changes >30 bar clean your check valves, especially if running ACN or buffers
If pressure difference between two pumps is about 10 bars change theinline filter.
Hope I can help you with this, otherwise download a troubleshooting guide (supelco etc). They are sometimes pretty helpful.
Best Regards
Rolpe
Posted: Thu Nov 23, 2006 2:01 pm
by unicorn
hi,
you should make some diagnostics I think. e.g. leak test ("How to" should be in your manual). By the way use water as mobile phase and check wherever you can all the way it goes for leakage. thats all, what I can tell You know, I'm quite newbie.
I agree with you, if system has bubbles the pressure will be change like a sine function corresponding to the pulsations of the pump.
It is better to check leakage at joints, valve.
Posted: Fri Nov 24, 2006 7:07 am
by diana
Yes, I would also check the valves and carry out a pressure test.
Good luck,
Diana