Decontaminating HPLC?

[sechau1]

Can you please suggest me the solvent/buffer that I could use to decontaminate an old HPLC unit in my lab?

Thanks in advance.

[tom jupille]

That depends a lot on what it's contaminated with. The general rule is to flush the system with something that's a good solvent for whatever flavor of garbage may be in there. The major precautions:
- make sure than any solvent you change to and change from are fully miscible and soluble.
- a reasonable rule of thumb is that it takes at least 10x the system volume to get complete wash-out. When in doubt, err on the conservative side and use more!

If it's a stainless steel system, a reasonable last step is to passivate the system with dilute nitric acid. Check with the instrument manufacturer for compatibility before you do this. If they recommend something else, by all means follow that recommendation!

[sechau1]

Thanks Tom for the helpful suggestion.

This is a Waters 2695 separation module. It is an old machine and I do not know what has been run on it earlier. I guess I should call Waters to have their opinion on it.

Thanks again.

Sechau1

[tom jupille]

I guess I should call Waters to have their opinion on it.

That would be the best. Many, many years ago, I flushed a Waters M45 pump with dilute nitric acid, only to have the nitric acid come out discolored and the pressure transducer spring a leak. It turns out that the fittings on the transducer were silver-soldered in place.

I seriously doubt that would be true on any pump made in the last two decades, but it's better to be safe than sorry.