Mobile phase with Sodium Chloride

[Josh85]

I have to run a supplied method with 6mM NaCl in m.p. on Agilent 1200RRLC but the manual says to avoid NaCl because it is corrosive. What is the NaCl for - it is not a bio-molecule analysis? Has anyone any experience of running NaCl on a non-inert pump (i.e. stainless steel flowpath)? How high is it safe to go with the concentration?

[danko]

I've run 0.3 M NaCl in one of the eluents (the strong one in IEx) for several years with no significant problems to observe. As long as pH isn't acidic it's save.
What does it do in you're eluent? I'm not sure. There might be a rationale for that, but it might be also a misconception.
NaCl is a very potent eluting salt in IEx chromatography. Also in low concentrations it's a viable chaotropic agent.

Best Regards

P.S. Whatever the reason, it's a good routine to wash the system for salt containing mobile phase, following use of that type of eluents. Especially if the system is not to be used for several days, weeks etc.

[Phycal]

NaCl is corrosive because 316SS can become pitted by it. That said, washing the system everyday to remove the salt is important for longevity of the system.

[Josh85]

Thanks for comments.