Abstract
ABSTRACT
Rationale
The ion motion within a mass spectrometer is governed by the coupling of gas dynamics and electric fields. Therefore, a comprehensive understanding of ion transport from atmospheric pressure to the high‐vacuum mass analyzer is crucial.
Methods
In this work, a hybrid computational fluid dynamics–direct simulation Monte Carlo (CFD‐DSMC) strategy was employed to accurately resolve the cross‐scale flow fields spanning from the continuum to the rarefied regime in the mass spectrometer. Subsequently, a multiphysics model integrating gas dynamics, electric fields, and ion trajectories was developed to achieve high‐precision predictions of ion transport behavior.
Results
To validate the accuracy of the theoretical simulation, ion transmission efficiencies of acetone and toluene were experimentally measured using a homemade low‐pressure photoionization time‐of‐flight mass spectrometer (LPPI‐TOF‐MS). The experimental results demonstrated a strong correlation with the simulation predictions, achieving a maximum Pearson correlation coefficient (
r
) of 0.96 for toluene and 0.90 for acetone in the radio‐frequency‐only quadrupole (RFQ) region, confirming the model's reliability.
Conclusions
This study provides a robust theoretical tool for elucidating ion transport mechanisms and guiding the optimization of ion optics in mass spectrometers.