Chromatography Forum

Hi,

We work on Agilent 1200 using solvents A- 100% MQ/0,1%FA; solvent B-100% ACN/0,1%FA, connected to the MS.
Two weeks ago the solvent B reservoir on the capillary pump got dried. After series of purging and washing, the baseline was not correct-the flow was fluctuating, spikes (0,03 bar difference).
The test injection showed an air injected on the spectrum. All connections and capillaries were checked and leaked were tighten, no leakage on the pump detected.
Then, the washing procedure was again implemented 95% ACN for around 4 hours:
-the solvent B is not being sucked-no change on the solvent level on the bottle; no solvent at waste capillaries,
-when purging both pumps for solvent A and B, the solvent is present at the waste tubing of both of them,
-degasser and cap. pump turned off and on-when turning on, the degasser pump works not ok- too loud and after several minutes gets back to normal

Would it be the pump from the cap pump not ok, a degasser should be purged or exchanged and the vacuum pump exchanged?

I highly appreciate any suggestion as I am new to the LC systems.

See if there is any specific "dry priming" procedure in the pump's manual and follow that. If it does not work, you may just need to replace check valve cartridges. Cleaning check valves has been discussed many times here.