Conformational Dynamics in Ion Mobility Data

The spectral features in arrival time distributions (ATDs) recorded by ion mobility spectrometry (IMS) can often be interpretedin terms of the co-existence of different isomers. However, interconversion between co-existing species also participatesto shape the ATD. Overlooking interconversion may then lead to misinterpretation of experimental data. Unfortunately, onlyfew works have addressed this problem so far. We present an analytical model that allows simulating ATDs resulting frominterconverting species. This model is used to reproduce experimental data obtained on a bi-stable system, and to interpret discrepanciesbetween measurements on different types of instruments. We show that the proposed model can be further exploitedto extract kinetic and thermodynamic data from tandem-IMS measurements.