js1c00140_si_001.mp4 (2.99 MB)
Simulation of Cluster Dynamics of Proton-Bound Water Clusters in a High Kinetic Energy Ion-Mobility Spectrometer
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posted on 2021-08-03, 18:05 authored by Duygu Erdogdu, Walter Wißdorf, Maria Allers, Ansgar T. Kirk, Hendrik Kersten, Stefan Zimmermann, Thorsten BenterIons are separated
in ion mobility spectrometry (IMS) by their
characteristic motion through a gas-filled drift tube with a static
electric field present. Chemical dynamics, such as clustering and
declustering of chemically reactive systems, and physical parameters,
as, for example, the electric field strength or background gas temperature,
impact on the observed ion mobility. In high kinetic energy IMS (HiKE-IMS),
the reduced electric field strength is up to 120 Td in both the reaction
region and drift region of the instrument. The ion generation in a
corona discharge driven chemical ionization source leads generally
to formation of proton-bound water clusters. However, the reduced
electric field strength and therefore the effective ion temperature
has a significant influence on the chemical equilibria of this reaction
system. In order to characterize the effects occurring in IMS systems
in general, numerical simulations can support and potentially explain
experimental observations. The comparison of the simulation of a well
characterized chemical reaction system (i.e., the proton-bound water
cluster system) with experimental results allows us to validate the
numerical model applied in this work. Numerical simulations of the
proton-bound water cluster system were performed with the custom particle-based
ion dynamics simulation framework (IDSimF). The ion-transport calculation
in the model is based on a Verlet integration of the equations of
motion and uses a customized Barnes–Hut method to calculate
space charge interactions. The chemical kinetics is modeled stochastically
with a Monte Carlo method. The experimental and simulated drift spectra
are in good qualitative and quantitative agreement, and experimentally
observed individual transitions of cluster ions are clearly reproduced
and identified by the numerical model.
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Monte Carlo methodfield strengthchemical ionization sourcebackground gas temperaturecustom particle-based ion dynamics ...gas-filled drift tubeproton-bound water cluster systemProton-Bound Water Clusterschemical reaction systemHigh Kinetic Energy Ion-Mobility Sp...IMSspace charge interactionsion mobility spectrometryproton-bound water clustersmodel