The Quadrupole Mass Analyzer and Ion Traps
Keywords:
quadrupole field, quadrupole mass analyzer, Mathieu equation, stability diagram, scan types, 3D quadrupole ion trap, tandem mass spectra, linear ion traps, radial scan, axial scanAbstract
In this review, we describe the fundamentals of ion separation and trapping with quadrupole analyzers used in mass spectrometry. Ion motion in quadrupole fields is characterized with simplified mathematics relying on stability diagrams to distinguish stable and unstable ion trajectories that are then used to separate ions of different mass and charge. Also described are scan types for the quadrupole mass filter and quadrupole traps with both 3D and linear geometry. References to review and original research papers are included.