Online membrane sample-entering device for ion mobility spectrometry

Abstract

The invention relates to an ion-mobility-spectrometry membrane sample-entering device. The membrane sample-entering device comprises a membrane device, a sample gathering cavity and two two-position three-way valves. The membrane device is provided with a heating device. A membrane cavity is divided by a membrane into an outer membrane cavity body and an inner membrane cavity body. The outer membrane cavity body is communicated with a sampling pump. The inner membrane cavity body and the sample gathering cavity generate negative pressure under the effect of an air sucking pump. During sample entering, a sample rapidly permeates through the membrane under the three effects of the concentration diffusion effect, the thermal motion diffusion effect and the pressure diffusion effect, so that the membrane permeating speed, the membrane permeating rate and the residual removing rate of the sample are greatly increased. The sample gathering cavity can be further used for gathering a trace quantity of samples. The membrane sample-entering device is mainly used for gas sample entering and can also be used for liquid sample entering. The two modes of discontinuous sample entering and continuous sample entering can be achieved.

Description

technical field [0001] The invention relates to the rapid collection and sampling technology of samples. Specifically, the ion mobility spectrometry membrane sampling device uses a semi-permeable membrane as a separation membrane. The device is mainly used in rapid gas sampling for ion mobility spectrometry, and can also be used for liquid sampling. Background technique [0002] Ion mobility spectrometry appeared as a new analytical technique as early as the 1970s. This technique itself has the characteristics of high sensitivity, fast analysis speed, relatively simple equipment, low cost and easy miniaturization, making it widely used in anti-terrorist security checks and drug inspections. , chemical warfare agent early warning detection and other aspects have a wide range of applications. [0003] At present, the sampling methods of ion mobility spectrometry include: direct suction method, membrane sampling, thermal desorption and laser desorption, etc. Among them, membr...

AI Technical Summary

Problems solved by technology

[0004] In the published U.S. patents US4311669, US4378499, and US5491337, the sample passes through the membrane, but the method of concentration difference diffusion is adopted, and the sample permeation efficiency can be improved without considering the pressure difference. Although the pressure difference is considered in the Chinese patent 200510028968.6 , there is sampling gas on one side of the membrane, and there is no carrier gas passing through the membrane on the other side. This kind of sampling efficiency is not high. At the same time, the sampling process is through the micro pump, which is easy to make the sample pollute the micro pump. cause residue

Images