Chromatography Forum

Hello,
does anyone have any tips for me on how to avoid air bubbles in my injection syringe? I use water as mobile phase and water as rinsing medium of the autosampler, however, adding acetonitrile disturbed my measurements.
Kind regards

Degassing the water may help.

You may also rinse the syringe with acetonitrile first , then use water .This will clean the inside surface of syringe so reduce the possibility of bubble formation.

Thank you for your reply

Water is already degassed..

How often do you think I should rinse the syringe with ACN?

Logically , before starting a sequence ,but it also depends on the frequency of bubble formation.

Replacing the syringe with a new one, may also help.

Back in university we used to take the plunger out of the syringe, and push it gently on a flat surface with a little rubbing. Make sure the plunger is not tilted. The idea isto make the PTFE seal a little bit thicker. This usually helped for a while but sooner or later they must be replaced.
Good luck!
Jörg

Thank you both for the tips; I will try them next week!