Sample introduction device for improving detection sensitivity of ion mobility spectrometry (IMS)

Abstract

The invention relates to a sample introduction device for improving detection sensitivity of ion mobility spectrometry (IMS) by improving the sample introduction efficiency of the IMS. The device comprises a sample introduction pad, a purging cavity inside the pad, a liner-containing thermal desorption chamber, an connector for the thermal desorption chamber and an ion mobility pipe, a heating rod, a temperature sensor and an external thermal insulation component. The IMS can be directly used for detection for gas phase, liquid phase or solid phase samples. The sample introduction efficiency of the sample is improved, and the sensitivity of the detected sample is improved. Compared with a traditional solenoid valve or a stepping motor sample injector, the sample introduction device has the advantages that the detection sensitivity of the IMS is greatly improved. Compared with a negative ion mode, the sensitivity for testing the TNT sample is 100 times higher, phthalic acid ester is tested in a positive ion mode, and the sensitivity for testing the dibutyl phthalate is 1000 times higher. With the designs of strict sealing structure, carrier gas preheating and the like, the detection repeatability of the tested sample is high, and qualitative and quantitative analysis test of the IMS is promoted.

Description

technical field [0001] The invention relates to a thermal desorption sampling device which improves the detection sensitivity of ion mobility spectrometry by improving the sampling efficiency of ion mobility spectrometry. chamber, thermal desorption chamber and ion transfer tube interface pipes and heating rods, temperature sensors and external insulation components. Ion mobility spectrometry can be directly used for the detection of gas phase, liquid phase or solid phase samples. Generally, liquid phase or solid phase samples can be quickly and efficiently converted into gas phase and introduced into the IMS system for detection. The thermal desorption method is a sample injection method that is widely used at present. The sample is directly introduced into the sealed thermal desorber, which can be vaporized instantly. By increasing the sampling rate of the sample, the sensitivity of the detection sample is improved; the strictly sealed design structure, carrier gas preheat...

AI Technical Summary

Problems solved by technology

A heating plate or heating tube is installed in front of the injection port to vaporize the sample. Usually, the volume of these injection devices is large, the sample analysis time is long, and the concentration of the sample is low. During the injection process, the sample is prone to local temperature unevenness. Losses due to instability of the sample flow, etc.

Difficult to use in quantitative detection, especially for high-boiling point substances or unstable substances, the sample is easy to recondense in a lower temperature area or continue to heat to cause overheating decomposition, causing changes in the structure of the substance or loss of components, resulting in cross-contamination and ultimately affecting the analysis results

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