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Modelling some rod set imperfections of a quadrupole mass filter
Pavel V Bugrov1,2, Aleksey A Sysoev1, Nikolai V Konenkov1,2
1Laboratory of Applied Ion Physics and Mass Spectrometry, National Research Nuclear University MEPhI (Moscow Engineering Physics Institute), Moscow, Russia.
Journal of Mass Spectrometry : JMS
|November 22, 2023
Summary
This study models quadrupole mass filter (QMF) peak shapes, revealing how electrode displacement and diameter changes degrade performance. Simulations show shifts and dips in mass peaks due to these imperfections.
Area of Science:
- Analytical Chemistry
- Mass Spectrometry
- Physics
Background:
- Quadrupole mass filters (QMFs) are essential for mass analysis.
- Accurate modeling of QMF performance is crucial for reliable data.
- The mass peak shape is a key indicator of QMF performance.
Purpose of the Study:
- To investigate factors affecting the mass peak shape in round rod QMFs.
- To develop an analytical representation of ion motion under non-ideal conditions.
- To quantify the impact of electrode displacement and voltage asymmetry on peak shape.
Main Methods:
- Decomposition of the rod set electric field into multipole fields.
- Derivation of analytical equations for ion motion.
- Computational simulations to model the effects of imperfections.
Main Results:
- Electrode displacement causes mass peak shifts and apex dips.
- Changes in electrode diameter also affect peak shape.
- Supply voltage unbalance shifts the peak and alters the quadrupole offset potential.
Conclusions:
- Electrode geometry and stability are critical for maintaining QMF mass peak shape.
- Analytical modeling provides insights into performance degradation.
- Understanding these factors improves QMF design and operation for accurate mass measurements.
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