Discharge gas assisted windowless radio frequency lamp mass spectrum ionization source

Abstract

The invention relates to a mass spectrometer, and particularly provides a discharge gas assisted windowless radio frequency lamp mass spectrum ionization source. The concrete structure comprises a windowless radio frequency lamp, an ionization source cavity, a baffle valve, a vacuum gauge and a vacuum pump. The ionization source cavity is internally provided with a sample molecule inlet tube, a sample ion repulsion electrode, a transmission electrode group and a Skimmer electrode which are arranged along the emergent direction of the windowless radio frequency lamp. Each electrode has a flat plate structure of which the middle is provided with a circular hole, and all the electrodes are coaxially arranged in a parallel and insulating way. According to the ionization source, the discharge gas is filled in the windowless radio frequency lamp to perform breakdown discharge with the low pressure charge transfer reaction acting as the mechanism so that charge transfer reaction occurs between the produced ultraviolet light and the sample molecules and the sample molecules can be ionized. The ionization efficiency of the substance which can be difficult to ionize by vacuum ultraviolet light ionization can be greatly enhanced by the novel ionization source technology so as to have wide application prospect in the field of environmental monitoring, food safety and medical diagnosis.

Description

technical field [0001] The invention relates to a mass spectrometer analysis instrument, in particular to a windowless radio frequency lamp mass spectrometer ionization source assisted by discharge gas. The ionization source uses the low-pressure charge transfer reaction as the mechanism, specifically, the sample molecules are ionized by the charge transfer reaction with the windowless radio frequency lamp to obtain ionization. The new ionization source technology greatly improves the ionization efficiency of substances that are difficult to ionize by vacuum ultraviolet photoionization. This technology has very broad application prospects in environmental analysis, medical diagnosis and other fields. Background technique [0002] The vacuum ultraviolet lamp ionization source has the advantages of small size, low power consumption, high sensitivity, long life, and simple spectrum. It is suitable for complex sample analysis, online monitoring of samples, process monitoring an...

AI Technical Summary

Problems solved by technology

[0003] However, there are certain limitations in the long-term use of vacuum ultraviolet lamps.

The ultraviolet light emitted by the vacuum ultraviolet lamp is emitted through the magnesium fluoride optical window. After a long period of experimentation, the sample molecules entering the ionization area will adhere to the optical window, which will affect the number of outgoing photons of the ultraviolet light and reduce the sensitivity.

At this time, if you want to restore the sensitivity, you must disassemble and clean the vacuum UV lamp regularly, and the vacuum system needs to be restarted to disassemble the vacuum UV lamp. The light window steps are cumbersome and time-consuming, which is not conducive to the stability of the long-term monitoring of the instrument

In addition, since krypton gas emits photon energy of 10.6eV, it can ionize substances with ionization energy less than 10.6eV, but it cannot ionize compounds with higher ionization energy, which also limits the ability to analyze complex samples.

Images