TY - JOUR

T1 - Simulation of Cluster Dynamics of Proton-Bound Water Clusters in a High Kinetic Energy Ion-Mobility Spectrometer

AU - Erdogdu, Duygu

AU - Wißdorf, Walter

AU - Allers, Maria

AU - Kirk, Ansgar T.

AU - Kersten, Hendrik

AU - Zimmermann, Stefan

AU - Benter, Thorsten

N1 - Funding Information: This work is funded by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation), joint project BE 2124/8-1-ZI 1288/8-1.

PY - 2021/9/1

Y1 - 2021/9/1

N2 - Ions 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.

AB - Ions 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.

KW - cluster dissociation

KW - cluster formation

KW - corona discharge ionization

KW - HiKE-IMS

KW - hydrated hydronium ions

KW - Monte Carlo

KW - proton-bound water cluster

KW - secondary electrospray ionization

KW - selected ion flow tube

KW - simulation

UR - http://www.scopus.com/inward/record.url?scp=85113697885&partnerID=8YFLogxK

U2 - 10.1021/jasms.1c00140

DO - 10.1021/jasms.1c00140

M3 - Article

C2 - 34342982

AN - SCOPUS:85113697885

VL - 32

SP - 2436

EP - 2450

JO - Journal of the American Society for Mass Spectrometry

JF - Journal of the American Society for Mass Spectrometry

SN - 1044-0305

IS - 9

ER -