Page 1 of 1

Pressure fluctuate proplem ??

Posted: Mon Jun 27, 2011 10:38 pm
by Newchromatographer
Hi there ,

I am using this pumb

Image

when i start my analysis the pubm read ( 26 mPa ) then it rise up to ( 30 mPa ) then reduce to ( 29 then 32 then 27 mPa ) .

I usually degas my mobile phase and my samples are just water with analyte .

Does this will effect my peak area ??how can i solve the problem

my column ( 250 mm * 4.6 mm ) , flow rate = 1.2 ml/min

Re: Pressure fluctuate proplem ??

Posted: Tue Jun 28, 2011 6:09 am
by Markus Laeubli, Metrohm
- Purge the pump head to make sure that no air bubble is trapped.
- If this does not help a pump head maintenace might be helpful.

Your pump seems to have a piston backflush system. Make sure that the solution in there is exchanged frequently.

Re: Pressure fluctuate proplem ??

Posted: Wed Jun 29, 2011 12:20 pm
by DSP007
Hello. Air bubble is a probability problem. Also-small leaks. Look, there are no puddles.

But in general, jumps can be. Pump- one plunger. The plunger goes back and forth, and the balls old valve may not have time to practice.

Need a damper - a long thin tube of milliliter internal volumes .
What problem can be strong-noise baseline. For higher concentrations it is not critical