A Bidirectional Excitation Dissociation Method Based on Digital Ion Trap

Abstract

The invention belongs to the technical field of mass spectrometry, in particular to a bidirectional excitation dissociation method based on a digital ion trap. In the stage of collision-induced dissociation, the present invention passes on two pairs of electrodes of the ion trap ( x direction and y direction) to load a digital square wave excitation signal, so that the isolated parent ions gain energy and are resonantly excited, and then collide with the neutral molecules in the ion trap and dissociate to achieve resonant excitation dissociation. The advantage of this method is that bidirectional excitation can increase the radius of motion of ions, making the kinetic energy of ions significantly higher than that of unidirectional excitation, and under the same experimental conditions, this method can obtain higher collision dissociation efficiency. In addition, under the same ion excitation and dissociation conditions, bidirectional excitation dissociation can obtain more low-mass fragment ion peaks, which reduces the low-mass cut-off effect of ion trap mass spectrometry and significantly improves the tandem mass spectrometry of ion trap mass spectrometry. Analyze performance.

Description

technical field [0001] The invention belongs to the technical field of mass spectrometry, and in particular relates to a bidirectional excitation dissociation method based on a digital ion trap. Background technique [0002] As a powerful analytical technique, mass spectrometry can achieve qualitative and quantitative analysis of compounds, and is widely used in pharmaceutical analysis, environmental monitoring, national security, forensic science, proteomics and other fields. As we all know, mass spectrometers can characterize and analyze the structure of compounds through tandem mass spectrometry (Tandem MS) analysis. The analysis process of tandem mass spectrometry is as follows: the first stage is isolation. For the ions in the sample to be analyzed, ions with a specific mass-to-charge ratio (m / z) are selected to isolate them, and the isolated ions become parent ions. (parent ion); the second stage is Collision Induced Dissociation (CID for short), the parent ion collid...

AI Technical Summary

Problems solved by technology

Although the technology of resonance excitation can obtain higher fragmentation efficiency, there are still disadvantages and deficiencies

The reason is that only an ion with a fixed mass-to-charge ratio will resonate, and the mass-to-charge ratio of the fragment ions obtained after the fragmentation of the ion will change, becoming larger or smaller. If the frequencies are different, resonance will not occur, that is, there will be no further dissociation, and the fragment information in the final tandem mass spectrogram is limited

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