| 摘要 |
A method of time-of-flight mass spectrometry comprises acquiring mixed time-of-flight spectra containing signals of fragment ions from more than one parent ion species. The fragment ions are produced on the flight path 14 before the reflector 20 (e.g. post-source decay of metastable ions in MALDI or using a collision cell). A plurality of mixed spectra may be acquired with different instrument parameters (e.g. reflector voltages or accelerating voltages before the flight path). The mixed spectra can be compared to identify signals of fragment ions which originate from the same parent ion species. The time-of-flight of a fragment ion species in the mixed spectra can be used to calculate the mass-to-charge ratios of the fragment ion and associated parent ion. Alternatively, a single mixed time-of-flight spectrum may be acquired and the mass-to-charge ratios of the fragment ion and associated parent ion may be calculated by selected two signals in the isotopic pattern of the fragment ion and determining their times of flight. |
