[DavidW]

I have a question about high resolution MS, using CI in particular.  I have submitted a large number of compounds to our MS facility, and a few of them came back with problems.  I was told that they couldn't get the mass because their molecular weights happen to overlap with the MW of the reference compound they use.   They said I need to send them out for elemental analysis instead.   

My question is:  couldn't they have simply used a different reference compound?  I don't know too much about technical side of CI.

[movies]

You might have a problem if the overlapping signals come from the chemical the use to do the ionization.  They might not have the proper set up to use some other ionizing agent.  Why can't they do electrospray or FAB instead of CI?

[DavidW]

Ah... I see what you mean.  I thought the reference compound was just a standard to make sure it's getting the right mass.  They already tried electrospray but it's not working for type of compound I'm submitting.  Thanks.

[movies]

Yeah, "reference compound" makes me think the same thing.  Good luck finding something that works!