How much ion mobility would be necessary to replace the quadrupole?

 

Conflict of interest statement on this one - I'm both a compensated member of the Proteomics Advisory Board for Mobilion Systems and the first author of this preprint met weekly with me for 4 or 5 years while getting her PhD. I'm even more impressed by her work than by the quality of her education. ;)

Okay, but here is the real question and I know I've certainly wondered about this..... at what point would ion mobility and quadrupole isolation overlap? Or maybe this? Could you crank up your ion mobility resolution to a point you could widen your quadrupole and get equivalent data? Or if you had 1,000 resolving power ion mobility, would the quad just slow things down? 

Those are the questions tackled here. 

The short answers appear to be - absolutely, yes, and maybe. There is certainly a point where you can get enough ion mobility to get the same isolation you would get with a quadrupole alone. On the SLIM system the coisolation can be limited to about the coisolation of a quad running 5 Th windows. If you want the cleanest data you've ever seen, SLIM + 25 Th windows would get you there. And....yeah... in the world of wide window DIA or wide window DDA and now wide window PRM...these numbers are relevant.