Ion isolation method and system of ion trap mass spectrometer and medium

Abstract

The invention provides an ion isolation method and system of an ion trap mass spectrometer and a medium, and relates to the technical field of mass analysis, and the method comprises the following steps: an ion introduction step: opening an ion gate of an ion trap, placing a rear end cover of the mass spectrometer at a preset potential, and capturing ions; an ion trapping step: closing the ion gate, and stabilizing the trapped ions in the central region of the ion trap; an ion isolation step: obtaining any one or more of a parent ion mass-to-charge ratio m/z, an isolation mass number range and a parent ion isolation efficiency value according to the number of the DDS occupied by the positive voltage and/or the isolation time; an isolation cooling step: placing the ions at a preset value, and cooling the ions according to a preset isolation cooling time; and an ion emptying step: applying a preset duty ratio to the ion trap electrode to complete ion emptying. According to the invention, the hardware requirement is low, the equivalent quadrupole direct current can be generated in the ion trap by adjusting the duty ratio of the digital rectangular wave main radio frequency, and an extra high-precision and high-stability hardware direct current circuit is not needed.

Description

technical field [0001] The invention relates to the technical field of mass analysis, in particular to a mass spectrometry analysis method for ion isolation in a digital square wave mode, and to an ion isolation method, system and medium for an ion trap mass spectrometer. Background technique [0002] Introduction to Mass Spectrometry [0003] Mass spectrometry is a method of qualitative and quantitative analysis by measuring the mass-to-charge ratio of sample ions and the corresponding relative and absolute intensities between each mass-to-charge ratio. The process of mass spectrometry is: first, the sample to be tested is ionized, and the sample ionization device is called the ion source; the next is the ion transmission guide device, which extracts the ions from the ion source and focuses them into the mass analyzer; the mass analyzer Under the action of an electric field or a magnetic field, the ions are expelled in sequence according to the mass-to-charge ratio, and th...

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Problems solved by technology

[0008] 1. The storage capacity is large, and high-speed and large-capacity storage devices are required. General storage devices cannot meet its needs, so the requirements for the hardware of the instrument are high, which greatly increases the development cost of the entire instrument;

[0009] 2. The speed is slow, and the isolation is generally at the millisecond level. After storage, Fourier transform, and high-speed digital-to-analog digital-to-analog conversion, the time-consuming may exceed the millisecond level, and the isolation function cannot be realized;

[0010] 3. The isolation efficiency is low. If the selected phase is not suitable, the number of parent ion isolation will be reduced in the well, and the isolation efficiency will become smaller, which will affect the effect of the entire cascade.

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