Ion trap analyzer and ion trap mass spectrometry analysis method

Abstract

An ion trap analyzer, an ion trap mass spectrometry analysis method, and an ion fragmentation method are provided. The ion trap analyzer includes an ion trapping space enclosed by multiple electrodes (), where a high-frequency voltage is applied on at least a part of the electrodes, so as to generate, within the trapping space, a trapping electric field dominated by a quadratic field. The apparatus is provided with an ion ejection outlet () in at least one direction away from the center of the trap; an alternating voltage signal used for resonant excitation of ion motions is overlaid on an electrode part that is on a side of the ion ejection outlet and closest to the ejection outlet, while no voltage signal that is identical in range and phase with the alternating voltage is applied on at least one remaining electrode part in said direction. With the method, or by further applying, to the remaining electrode part in said direction, a voltage signal that is inverted to the alternating voltage, the orientation of an alternating electric field induced by the excitation alternating voltage signal can be limited, thereby improving the resonance ejection efficiency of the ion trap, reducing, in ion motions, motion coupling between an ejection direction and a non-ejection direction, and improving the viability of selecting the ion trap as a mass analyzer.