Novel corona discharge-based ion mobility spectrometry device

Abstract

The invention discloses a novel corona discharge-based ion mobility spectrometry device, which comprises a corona discharge ion source, an ion migration unit and an electric signal processing unit, wherein the corona discharge ion source comprises a discharge metal wire, a grounding electrode, a shielding layer, a gas and sample injection inlet I, a gas outlet I and a metal wire bracket; the ion migration unit comprises an ion migration member, an ion gate, a pulsed power supply, an annular metal electrode, a fixed-value resistor, a DC power supply, a gas outlet II and a gas inlet II; the electric signal processing unit comprises a faraday plate and a shielding metal plate; the faraday plate is arranged at the internal tail end surface of the ion migration member; the diameter of the faraday plate is greater than the inner diameter of the ion migration member; the shielding metal plate is arranged on the external tail end surface of the ion migration member; a certain gap is formed between the faraday plate and the shielding metal plate; and the diameter of the shielding metal plate is greater than the outer diameter of the ion migration member. The sensitivity of an ion mobility spectrometer can be improved.

Description

technical field [0001] The invention belongs to the technical field of detection, and in particular relates to a novel ion mobility spectrometer device based on corona discharge. Background technique [0002] Ion mobility spectrometer (IMS) is a trace gaseous chemical substance detection device, which is widely used in military, medical, biological, environmental and other fields. It mainly separates ions with different mobility in the electric field by ionizing gaseous substances, and then obtains the ion mobility spectrum of the sample gas ionization products. The main part of the ion mobility spectrometer is the transfer tube. The ionization source is one of the main components of the transfer tube, and its main function is to ionize the sample gas passed into the transfer tube. Most ion mobility spectrometers currently in use use Ni 63 source of radioactive ions. Ni 63 As a radioactive ion source, it has the advantages of stability and no energy consumption. Howeve...

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Problems solved by technology

But in fact, the corona needle tip is relatively easy to oxidize, and when it needs to be replaced, due to the limitation of processing technology and cost, it is difficult to ensure that the curvature of the needle tip used every time is exactly the same

On the other hand, the current of needle tip corona is very small. Although multiple needles can be used to increase the current, it involves the problem of their consistency.

In addition, the traditional needle electrode corona ion source has a large electromagnetic interference, and the grounded metal mesh shielding structure makes many charged ions absorbed by the metal mesh, which also leads to a large loss of ion flow

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