Detecting system of ion migration spectrometer (IMS) using doping agent and detecting method thereof

Abstract

The invention discloses a detecting method of an ion migration spectrometer (IMS) using a doping agent. The ion migration spectrometer comprises a sample injection device, a migration pipe and a gas path system connected with the sample injection device and the migration pipe, wherein the gas path system comprises a pump, a filter device, a gas inlet and a gas outlet; and the gas inlet and the gas outlet are arranged on the migration pipe so as to provide clean gas used as migrating gas flow and sample carrying gas. The detecting method comprises the following steps: providing a sample collecting carrier for collecting samples; combining the doping agent and the sample collecting carrier; using the sample collecting carrier combined with the doping agent to collect samples; and guiding the sample collecting carrier after the samples are collected into the sample injection port of the ion migration spectrometer so as to implement detection of an ion migration spectrum. In the method, an independent gas path for the doping agent is not needed, so the implementation is simpler; and simultaneously, the quantity of the doping agent can be controlled and detected more easily and more accurately.

Description

technical field [0001] The present invention relates to ion mobility spectrometers (IMS) and detection methods and systems using dopants. Background technique [0002] Ion mobility (IMS) technology originated in the 1960s as a trace detection technology, and the early patents (US 3699333 and 4777363) described this technology in detail. The basic principle of the ion mobility spectrometer is to ionize the detected sample vapor or gasified solid particles to form ions, and then under the action of a weak electric field, the ions undergo directional migration in the transfer tube, and the detection at the end of the transfer tube The instrument measures the migration time of ions through the electric field, and then calculates the mobility of ions (that is, the migration speed of ions under the action of unit electric field strength) according to the migration time of ions. Since under certain conditions, the mobility of various material ions is specific and related to factor...

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Problems solved by technology

[0011] In the prior art, in addition to the gas source containing the dopant prepared by the semi-permeable membrane material, it is also necessary to control the temperature of the gas source device to provide a suitable concentration of dopant, so that the gas circuit structure and the detection system Device Design Gets Complicated

Moreover, since the dopant is continuously provided through a separate gas path, it is easy to cause the dopant dose to be too high due to the accumulation of the dopant in the system, or the dopant dose to be too low due to the consumption or agglomeration of the dopant It is difficult to quickly and accurately control the dopant dose, which affects the detection sensitivity of the instrument

In addition, the dopant is mostly corrosive, so the doping gas source device, gas circuit and related accessories need to use corrosion-resistant materials, which undoubtedly increases the manufacturing and maintenance costs of the detection system

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