We have confirmed that some our proteins are binding to active sites on our SEC column used on our MS. We need this specific column material and pore size so we cannot switch to bioinert.
The column vendor recommended running 40 mM EDTA disodium hydrate through the column prior to use. I've used EDTA for scrubbing metals from an LC but never with a QTOF attached. I would obviously bypass the MS until the EDTA had flushed out completely but I'm concerned that it might contaminate the system with sodium and lead to increased Na+ adducts in our spectra.
I've seen some non disodium based solutions but it's hard to tell whether there is Na/K present and non are MS-grade.
Thanks for your help!