Thermal determination of the abundances of c and z type fragment ions generated by in-source decay of peptide ions in matrix-assisted laser desorption ionization

- MALDI spectrum of a peptide is thermally determined whether ISD of its molecular ion occurs via b-y or c-z mechanism.
- If hydrogen atoms participate in the c-z mechanism, they are generated by XH bond cleavage in the ground electronic state.
- A linear calibration curve is obtained for a peptide whose molecular ion dissociates mainly via c-z channels.