High-resolution MS on aggregates and what it can see — one year on

Picking up the opening post: that is the part I would want checked first.

What mass accuracy establishes: the measured mass is consistent with a specific composition. What it does not establish: purity, sequence order, stereochemistry, or the absence of an isobaric species. Every one of those requires something else.

It is the sort of thing that seems obvious in retrospect and was not at the time.

Electrospray ionisation produces multiply charged ions. For a 4 kDa peptide you expect mostly 2+, 3+, and 4+ charge states. Reading an electrospray spectrum means recognizing the envelope, not looking for one peak.

Two people can read the same figure differently here and both be reasonable.

Resolution and mass accuracy are different specifications. An instrument can resolve two species and still assign their masses imprecisely, and the reverse is also possible.

Not a conclusion. A place to stand while looking for one.

Thank you for the correction. I would rather find out here than later.

Reading back through, this was answered upthread and I missed it. My fault.

Two people in this thread mean different things by High-resolution and are disagreeing about the definition while believing they are disagreeing about the facts. Worth pausing to define it.

An observation about High-resolution that I cannot explain and am posting anyway, on the principle that unexplained observations are more useful public than private.