Chromatography Forum

We are a small university and just purchased a Thermo/dionex Aquion with AS22 column and a suppressor. We use carbonate buffer. Pretty basic.
I was looking for general procedures we can use between use. We use it for upper level classes and some research. And sometimes for long term shut down, like when covid closed us down! I have notes from the service engineer and from their documentation but wanted to ask the pros for tips. It is working well at this point.

1) When it won't be used for a few days. We lower the flow to 0.05ml/min from 0.3. Do you leave the suppressor on or off? I can't find this. Other tips?

2) long term storage. Like if it isn't being used for a few months. Tips?

3) Column cleaning or regeneration etc? I'm sure we will need to try that sometime.

4) anything else to add to our SOP.

Thanks!
Jarral

There is already a post about stand-by, so it's probably best to further discuss it there. But to give an answer:
1) The suppressor should not be turned off, if eluent is flowing through it (source: Dionex Suppressor Manuals); we do pretty much the same, although you need to check that the pressure does not fall below 1000 psi, so that the degasser works properly.
2) If you don't use the system for a long time shut it down; a guide is given at the unitylabservice "knowledge database" (see link below)
3) Ideally, you flush everything out of your column in/after the run, so you get no carry-over etc.; I can't help here, as we use a different eluent. With KOH you can go up to 50mM for sure..
4) Log stuff like baseline, backpressure and signalvalues of your calibrators to avoid surprises

unitylabservices database (excellent, once you found what you need):
https://kb.unitylabservices.com/?c=1314 ... rc:article