Chromatography Forum

Hello.

I have an Agilent 1100 series.

This morning when I replaced the solvents I use (Hexane and Methanol) and switched the instrument on with thecpurge valve open, a strange sound started to come from the quaternary pump or degasser. This sound still appears when the purge valve is closed.

The normal sound from the pump is a "click.......click.......click", but sometimes it gives a 5 seconds "GRRRRRR..." sound just after the clicks.

My pressure is stable as well as my baseline and I no errors appear.

Does anyone ever had a similar problem? What can I do to solve it?

Thank you.

Hello,

to test which part makes the noise turn of the degasser and let the system pump with purge valve opened.

When it disappeared it is your degasser.

Normally the degasser makes such a sound when he pumps down the vacuum.

Make sure all channels in the degasser are filled with solvents or methanol and are closed.

Be aware that pumping without degasser can cause gas-bubbles in your system.

Thank you for your response.

I doubled-checked methanol and hexane miscibility and they are not miscible.

Maybe the formation of two phases in the mixer promoted that noise?

I'm currently purging the system with ethanol (ethanol and hexane are miscible) and the noise apparently disappeared.

I'll make an update as soon as I have news.

Thank you

This does happen from time to time on the 1100 pumps. It might be the springs making the noise. I recall someone suggested squirting a small amount of water on them to get rid of the noise. I prefer to take the pump apart, replace all the seals and give it a good clean, and re-grease the pistons. It's a relatively straightforward procedure.

http://www.chem.agilent.com/cag/cabu/lc ... ernaryPump