Re: [Psidev-ms-dev] cvParam for mass analyzer in <scan>

[Darren K. <dke...@ya...>]

> I don't think this use case is all that common, though. Of course, if 
> precursor mass/charge correction were more common, then so would this
> use case.


Actually, this is more common than most people probably realize -- 
precursor m/z-intensity recalculation is done silently during RAW->mzXML 
conversion by ReAdW, which finds a local max in the parent scan near the 
value reported in the filter string (when it's not stored in the trailer 
data). I think this sort of processing should be made explicit in the 
data file, and when it is not done, we can at least facilitate this 
calculation.

But you're right that I'm absolutely biased ;) (For the rest of you on 
the list -- one of the tools I wrote for our lab, msprefix, does 
precursor recalculation for FT data sets).

On the other hand, it's not just for precursor recalculation. This would 
also facilitate other calculations that span scans, e.g. integrating a 
selected ion chromatogram over a certain time interval. Here again you 
can rely on the software layer to distinguish between the mass analyzer 
types, but I would argue that hybrid instruments are common enough to 
warrant making this calculation simpler.


Darren