Development and research of the quadrupole mass spectrometry simulation model with the entire ion optics system.

Quadrupole mass spectrometers are widely applied due to their compact structure, easy operation, and mature technology, which offer high economic and market competitiveness across various fields. A complete quadrupole mass spectrometer consists of components such as the ion source ionization chamber, ion optical system, and quadrupole mass analyzer. These components work together to enable qualitative and quantitative analysis. Researchers often adopt single-component simulation models rather than comprehensive ones due to the need for resource allocation and specific research goals. However, this approach has drawbacks which lead to inaccurate performance prediction in multi-component scenarios, especially in terms of the influence of fringe fields on ion trajectories. We have found that ignoring these interactions leads to an inability to accurately predict the overall system performance, especially regarding the influence of fringe fields on ion trajectories. This calls for a more sophisticated approach. To overcome these limitations and explore the optimal performance of quadrupole mass spectrometers, parameter optimization has become a crucial aspect. In this study, we developed a comprehensive quadrupole mass spectrometry simulation model integrating key components such as the electron impact ion source (EI source) ion optical system and the quadrupole mass analyzer. It covers the entire ion path, enabling the tracking of ion trajectories from the point of generation, and providing a thorough simulation of ion behavior and detailed analysis of component interactions. This capability addresses the limitations of traditional single-component simulation models, which often miss important ion dynamics behaviors. Based on this model, two distinct voltage optimization simulation experiments were conducted: staged optimization and global optimization. Staged optimization separately treats different parts while global optimization considers all components simultaneously. To address the challenges posed by numerous optimization parameters and high time costs, the orthogonal experimental design method was employed, which remarkably enhanced the efficiency of parameter optimization and reduced the experimental time and cost. The results showed that the ion transmission with the optimal voltage combination in the global optimization experiment increased by approximately 33% relative to the maximum ion transmission rate achieved in the staged optimization, indicating that global optimization can more comprehensively analyze the relationships between various voltage factors and significantly improve ion transmission efficiency. Additionally, an exploration was conducted regarding the impact of the newly introduced component (a pre-quadrupole) on the instrument's performance. The results of this study provide valuable data support for the optimized design of quadrupole mass spectrometers, highlighting the significance of both parameter and performance optimization in improving the overall capabilities of these instruments.