Numerical Analysis and Quantification of Transfer Efficiency Coupled with Capillary and Quadrupole Ion Guide in an...

Area of Science:

• Analytical Chemistry
• Mass Spectrometry
• Computational Physics

Background:

• Ion trajectory simulation is crucial for understanding ion transfer in atmospheric pressure ionization mass spectrometry (API-MS).
• Existing methods face challenges due to complex gas dynamics and wide pressure variations, leading to inaccurate simulations and high computational expense.

Purpose of the Study:

• To develop a novel electrohydrodynamic simulation model for accurate and efficient ion trajectory characterization in API-MS.
• To incorporate dynamic pressure effects into ion trajectory simulations, addressing limitations of current models.

Main Methods:

• Development of the statistical diffusion-hard-sphere (SDHS) mixed collision model.
• Simulation of ion trajectories considering dynamic pressure variations for the first time.
• Comparison of SDHS model with conventional Monte Carlo collision models.

Main Results:

• The SDHS model significantly improves calculation accuracy and reduces computational cost by at least 12-fold compared to Monte Carlo methods.
• Identified electrode gaps and capillary-quadrupole ion guide distance as key factors for ion loss.
• Experimental results for caffeine, reserpine, and Ultramark 1621 showed good agreement with SDHS simulations, validating its applicability.

Conclusions:

• The SDHS model offers a more accurate and computationally efficient approach for simulating ion trajectories in API-MS.
• The findings provide insights into optimizing ion guide design to enhance API-MS sensitivity.
• SDHS is expected to be a valuable tool for improving the performance of mass spectrometry instruments.