Calculating the fragmentation process in quadrupole ion traps

Neugebauer T, Drewello T (2022)

Publication Type: Journal article

Publication year: 2022


Book Volume: 480

Article Number: 116890

DOI: 10.1016/j.ijms.2022.116890


The present theoretical study calculates the consequences of an ion dissociating in a quadrupole field, describing both 3D and linear ion traps. The dissociation induces a change in q-stability parameter, resulting in fragment ions abruptly changing their trajectories. This includes a change in oscillation amplitude and mean-square velocity, i.e., effective collisional temperature. While the first one can lead to ions being lost to the electrodes, the latter one can be used to determine how likely fragment ions are to be further excited. During the collisional focusing process, ions can endure internal heating, just like during the injection process. The difference here is that fragment ions start this process with already elevated internal energies. The process is calculated by making use of the well-known phase-space ellipses. It is shown that fragment ions of lower m/z in average decrease their oscillation amplitude and are thus better trapped. Only very light ions close to the LMCO have a high chance of being lost. However, lighter fragment ions in average start with higher mean-square velocities than the precursor was assumed to need to have to induce dissociation, suggesting further collisional heating. Despite the harsh collisional environment m/z ratios close to the LMCO in average have to endure, a small percentage of these ions drastically decrease their oscillation amplitude, not requiring any collisional focusing. Fragment ions of higher m/z in average increase their oscillation amplitudes, however, their low velocities make further internal heating unlikely. The used calculations have been uploaded to Github:

Authors with CRIS profile

How to cite


Neugebauer, T., & Drewello, T. (2022). Calculating the fragmentation process in quadrupole ion traps. International Journal of Mass Spectrometry, 480.


Neugebauer, Thomas, and Thomas Drewello. "Calculating the fragmentation process in quadrupole ion traps." International Journal of Mass Spectrometry 480 (2022).

BibTeX: Download