Chromatography Forum

I am using a Shimadzu HPLC, and I seem to have an issue with air bubbles being in the tubing. We have a low-pressure gradient unit (LPGU; located in the LC-20ADXr) which, after degassing, the solvent channels run through before continuing to run throughout the instrument. When purging the instrument, we found that only one solvent channel, only after passing through the LPGU, is forming air bubbles. These air bubbles are not present from the solvent bottle to the degassing unit, or from the degassing unit to the LPGU. When purging other solvent channels, none form air bubbles. We tried manually purging as well as replacing the filter in the solvent bottle, any other thoughts?

Hi.

My diagnostic is the degasser is defective. Try to connect the "bubble" line on another degasser line.
If the bubbles remain, check for a leak on the lpgu connector.
The last step is to replace the lpgu.
Lpgu is servicable if you are familiar with maintenance. But not easy.

Regards

Pierre

Hi.

My diagnostic is the degasser is defective. Try to connect the "bubble" line on another degasser line.
If the bubbles remain, check for a leak on the lpgu connector.
The last step is to replace the lpgu.
Lpgu is servicable if you are familiar with maintenance. But not easy.

Regards

Pierre

Thank you so much! We're thinking it's an issue with the LPGU, we'll probably get it serviced.

Hi.

My diagnostic is the degasser is defective. Try to connect the "bubble" line on another degasser line.
If the bubbles remain, check for a leak on the lpgu connector.
The last step is to replace the lpgu.
Lpgu is servicable if you are familiar with maintenance. But not easy.

Regards

Pierre

Thank you so much! We're thinking it's an issue with the LPGU, we'll probably get it serviced.