Ion-shutter-free ion mobility spectrometry using rapid pulse electron source

Abstract

The invention relates to the fields of an analysis instrument and detection, and discloses an ion-shutter-free ion mobility spectrometry using a rapid pulse electron source. The ion-shutter-free ion mobility spectrometry comprises an electron source, and a drifting tube, wherein the electron source consists of a filament, an extraction grid, an acceleration electrode, a silicon nitride film, a glass tube, electrodes and an acceleration voltage source and has a pulse working mode; the drifting tube consists of an ionized region and a drifting region; annular electrodes are arranged in the drifting tube; the starting end of the drifting tube is directly connected with the acceleration electrode of the electron source in a sealing manner; the central hole of the acceleration electrode is connected with the drifting tube, so that the ionized region is tightly attached to the silicon nitride film without being limited; the electron source generates periodical electron beams to perform ionization of to-be-tested gas; the ionized to-be-tested gas in each pulse cycle forms an ion pack; the different types of generated ions can directly enter the drifting region to be separated and to reach a Faraday detector to be detected in sequence; and options between the instrument sensitivity and resolution can be made by adjusting the output voltage of the acceleration voltage source.

Description

technical field [0001] The invention relates to the field of analytical instruments and detection, in particular to an ion mobility spectrometer with a simple and effective structure using a fast pulse electron source without an ion shutter. Background technique [0002] The ion mobility spectrometer is a fast and sensitive trace gas analysis instrument, and its measurement principle is based on the initial ionization process of the analyte to be measured. The working principle of ion mobility spectrometry is: after the sample is brought into the ionization reaction zone by the carrier gas, a series of ionization reactions and ion-molecule reactions occur between the carrier gas molecules and the sample molecules under the action of the ion source to form various product ions. Driven by an electric field, these ions enter the drift region through periodically opened ion shutters. In the process of continuous collision with the countercurrent neutral drift gas molecules, due...

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Problems solved by technology

[0004] Existing ion mobility spectrometers use a complex ion shutter mechanism to generate small ion packets of the gas molecules to be measured after ionization. After the gas to be measured is ionized, it enters the drift region through an ion shutter that is opened periodically. The structure is obviously complicated

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