A chemical ionization-vacuum ultraviolet single photon ionization compound ionization source device based on air discharge

Abstract

The invention relates to a chemical ionization-vacuum ultraviolet single-photon ionization compound ionization source device based on air discharge, which includes a vacuum ultraviolet lamp, a discharge electrode and other electrodes of the ionization chamber cavity. There is a pair of discharge electrodes next to the vacuum ultraviolet lamp, and a certain DC voltage is applied to the vacuum ultraviolet lamp to cause discharge between the vacuum ultraviolet lamp and the discharge electrodes. In the ionization chamber cavity, a number of ion extraction electrodes and differential hole electrodes are arranged in parallel and at intervals below the discharge electrode. Through holes are opened along the axial direction of the electrodes. DC voltages are applied to the electrodes in sequence, and precision resistors with the same resistance are passed between the electrodes. connected. A sampling capillary is provided on the wall of the ionization chamber between the discharge electrode and the adjacent ion extraction electrode, and a vacuum pump suction port and a vacuum gauge interface are also provided. A certain DC voltage is applied to the vacuum ultraviolet lamp to light the vacuum ultraviolet lamp. The device is small in size, low in power consumption, simple in structure and easy to integrate.

Description

technical field [0001] The invention relates to a mass spectrometry instrument, specifically a chemical ionization-vacuum ultraviolet single photon ionization composite ionization source device based on air discharge, which can produce high concentration of NO by air discharge between a vacuum ultraviolet lamp and a discharge electrode + Reagent ions, combined with the single-photon ionization mode generated by the ultraviolet light emitted by the vacuum ultraviolet lamp, can realize the ionization analysis of a wide range of analytes, and can more accurately and effectively perform qualitative and identification of unknown samples according to the obtained characteristic spectra. Background technique [0002] Vacuum ultraviolet light can single-photon ionize organic molecules whose ionization energy is lower than its photon energy, mainly producing molecular ions with almost no fragment ions, suitable for rapid qualitative and quantitative analysis. Hou Keyong [Chinese Inve...

AI Technical Summary

Problems solved by technology

However, the lamp is large in size, high in cost, high in power consumption, complex in structure, and needs to consume a large amount of rare gas, so the cost is high

More importantly, the windowless structural design not only allows the ions and metastable neutral molecules generated by the discharge to enter the ionization region and undergo ion-molecule reactions with the sample, but also the sample gas in the ionization region will return to the discharge region. And cause the discharge spectrum line to be impure

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