When should we use TIC peaks instead of EIC?

[sbashkyrtsev]

In this article they used GC–MS and compared TIC peak areas to get relative concentration of molecules.

Why didn't they create EIC for the specific masses and measure those peak areas? If molecules are fragmented you may need to sum up areas of all the fragments (if the software can't do this for you). But the alternative (TIC) is that you may incorporate some co-eluting molecules which will lead to incorrect conclusions.

So when should TIC peaks used?

[Steve Reimer]

I have used it when analyzing for gasoline components. It would be difficult to sum all the ions in a hydrocarbon mixture. In that case the MS detector is used in the same manner as an FID.

[sbashkyrtsev]

Got it, thanks!

If others have other use cases, please chime in.