Chromatography Forum

We have a vacuum degasser which has become contaminated. Apparently it occured when we were doing a normal phase separation in Agilent 1100 system.

We were using a solvent mixture containing heptane and toluene. The toluene is showing up on every run of our system in the diode array trace (not in the LC-MS electrospray trace).

We took it apart and could smell the toluene and see the characteristic UV spectrum of toluene.

Anyone have any ideas how to clean up the degasser?

Not OK to run toluene as solvent in this type of system?

Thanks

The hollow fibers are (I think) fluorocarbon polymer; I wouldn't be surprised if toluene gets adsorbed/absorbed to some extent. If it were my problem, I'd replace either the entire degasser (or at least the fibers), and then try to clean up the old one "off-line" (maybe with warm air?). That way you'd be up and running quickly while you sorted out the fix at your leisure.

You could try running neat IPA through the degasser at a low flow rate overnight and check the waste in the morning for toluene content.

thanks for the suggestions, will try your suggestions.

The pumping IPA trick is a good thing to try, I would be more inclined to try the same technique, but with hexane or iso-octane, they should be able to get rid of the toluene, and any residue left from them is UV transparent.

Hexane soak, hexane rinse, then thorough MeOH flush. That's what I'd try.

Hexane soak, hexane rinse, then thorough MeOH flush. That's what I'd try.

But methanol is not miscible with hexane.