I’m conducting a measurement with HPLC, where the normal system pressure should be around 50 bar. However, I have around 100 bar instead, what drops down to 48 bar after the disconnection of the ELSD detector.
I presume there is an issue with the detector itself, but the ultrasonic cleaning of the nebulizer in methanol or rinsing the detector with eluent flow didn’t solved the issue. Actually, running the system with the ELSD attached results a small but continuous pressure increase. I also considered that the capillary tubing I use to connect the column to the detector might be clogged, but on that I didn’t see significant pressure increase.
Do you have any idea or suggestion, what could be the problem or what else should I check before changing the nebulizer?
Hello Attila, we also work with HPLCs-ELSD (preparative and analytic) in our institute. Have you tried to inject solvent directly through the isolated nebulizer tubing? (e.g with a syringe) if yes, how did the flow looked when it comes out of the capillary? (drops or continuous jet?)
I´ve had(and still have!) also some problems with ELSD detectors, what about your signal? Does it look diminished or unusual ?
Best regards,
André
Dear André,
I tried your recommendation and it worked. I injected first some air directly in the inlet of the nebulizer with a syringe. That seemingly unclogged the capillary, at least some remaining fluid left the nebulizer. Then I used the same method to rinse the capillary with methanol.
After this procedure, the pressure dropped to the normal value. I also ran some measurements the signal also looked like before.
Thanks for the idea!
Best regards,
Attila