Analysis of Isotopic Labeling in Peptide Fragments by Tandem Mass Spectrometry
Figure 5
Comparison of the impact of different CID energies on fragmentation of 13C-labeled peptides.
NCE’s approaching 40 are necessary to completely fragment the precursor ion. Reduced energies resulted in asymmetric fragmentation, reflected by the isotopic distributions skewed towards higher m/z. A) indicates the applied NCE to the precursor ion distribution B) that results in a remaining ion distribution that is skewed at multiple energies (C–E).