cleaning

[gerapas]

when you try to clean up the inlet or outlet valves, the needle seat, parts of the pump etc and you do sonication, what is the better to use? H2O mQ, MeOH, Isopropanol, H2O with a little acid(glacial acetic)?
Is there any harm that can be made?

[tom jupille]

As a general rule, something that's a good solvent for whatever kind of junk is likely to have accumulated. Water with a bit of methanol would be a good choice for salt crystals, isopropanol might be a better choice for residual surfactant (e.g., ion-pair reagents).

[Markus Laeubli, Metrohm]

Be careful. Sonication may damage an intact check valve.