Related Experiment Video
Updated: May 31, 2026

Thermochemical Studies of Ni(II) and Zn(II) Ternary Complexes Using Ion Mobility-Mass Spectrometry
Published on: June 8, 2022
Effective temperature of ions in traveling wave ion mobility spectrometry
Denis Morsa1, Valérie Gabelica, Edwin De Pauw
1Physical Chemistry and Mass Spectrometry Laboratory, Department of Chemistry, University of Liège, Liège, Belgium.
Abstract:
Traveling wave ion mobility spectrometers (TW IMS) operate at significantly higher fields than drift tube ion mobility spectrometers. Here we measured the fragmentation of the fragile p-methoxybenzylpyridinium ion inside the TW ion mobility cell of the first-generation SYNAPT HDMS spectrometer. The ion's vibrational internal energy was quantified by a vibrational effective temperature T(eff,vib), which is the mean temperature of the ions inside the cell that would result in the same fragmentation yield as observed experimentally. Significant fragmentation of the probe ion inside the TW IMS cell was detected, indicating that field heating of the ions takes place in TW IMS. For typical small molecule IMS conditions, T(eff,vib) = 555 ± 2 K. The variations of the effective temperature were studied as a function of the IMS parameters, and we found that T(eff,vib) decreases when the wave height decreases, when the pressure increases, or when the wave speed increases. The energy transfer efficiency of argon is higher than for He, N(2), or CO(2). With T(eff,vib) being directly related to the ion speed inside the TW IMS, our results also provide new insight on the ion movement in TW IMS. We also discuss the influence of field heating of ions for calibration and structural studies in TW IMS.
Related Concept Videos
Atomic Spectroscopy: Effects of Temperature
At thermal equilibrium, the relative populations of excited and ground state atoms can be estimated using the Maxwell–Boltzmann distribution. For example, an increase in temperature from...
Transport Number
Electrospray Ionization (ESI) Mass Spectrometry
ESI utilizes electrical energy to transfer ions from the liquid phase of the sample into the...
Phase Transitions: Melting and Freezing
Mass Spectrum: Interpretation
Ion-Exchange Chromatography

