by
Hollow » Thu Mar 09, 2023 9:15 pm
Arne wrote:
I was unsure if the image hosting service was right.
the picture hosting should work well. Use the provided BBCode from the ibb-page instead of only pasting the URL in [img]-tags
You can edit your initial post and replace the neat URLs with the BBCodes.
(for me, the pics from CPG are just the small images and not showing the whole pictures.
On your problem I don't have a clue neither but I will share my thoughts for troubleshooting.
First, please give more info about the system and method. Few of us have a crystal ball on the desk...
Some questions:
- is the mobile phase premixed and 100% of one line is used? (I guess so)
- is it a PDA or a Tuneable Wavelength detector?
-- if PDA or DualChannel: are the steps also seen in (all) other wavelengths?
-- > maybe the use of a reference wavelenght could then help
-- > or it would direct the problem to the detector itself, I guess.
- what about fluctuations in the electric current/voltage, that may in-/decrease the brightness of the lamp? Or a cooling fan or something like that? Maybe some air-conditioning or heatings of your whole building?
-- > can you put the detector on an stabilised power supply, e.g. on an UPS should filter fluctuations?
-- > can you run and record a prolonged run e.g. 3-4 hours to get an idea of the real frequency of the issue, not interupted by multiple injections that always autozero the detector?
- is there any battery on the mainboard of your detector/hplc, that need to be replaced?
- Or maybe some other capacitors on the mainboard are gone, which normally would filter these low frequency cycles
- are the bumps also seen with pure solvent?
As told, just guesses. Not sure how probable they are.