Bi-directional excitation and dissociation method based on digital ion trap

Abstract

The present invention belongs to the technical field of mass spectrometry, especially relates to a bi-directional excitation and dissociation method based on a digital ion trap. In a collision induceddissociation stage, digital square-wave excitation signals are loaded on two counter electrodes of an ion trap to allow an isolated parent ion to obtain energy and to be subjected to resonance excitation, and then to generate collision with the neutral molecules in the ion trap and dissociation to achieve resonance excitation and dissociation. The bi-directional excitation can improve the ion movement radius to allow the ion movement energy to be obviously higher than that of unidirectional excitation, in the same experiment condition, the method can obtain higher collision dissociation efficiency. Besides, in the same ion excitation and dissociation conditions, the bi-directional excitation and dissociation can obtain more low-mass number fragment ion peaks so as to reduce the low-mass cut-off effect of the ion trap spectrometry and obviously improve the cascade stage mass spectrometry performance of the ion trap spectrometry.

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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