CN219144122U

CN219144122U - Ion mobility spectrometry device for detecting inorganic gas

Info

Publication number: CN219144122U
Application number: CN202223148086.1U
Authority: CN
Inventors: 李林; 刘巍; 朱颖杰; 陈志强
Original assignee: FOCUSED PHOTONICS (HANGZHOU) Inc; Zhejiang Shuangpu Technology Co ltd
Current assignee: FOCUSED PHOTONICS (HANGZHOU) Inc; Zhejiang Shuangpu Technology Co ltd
Priority date: 2022-11-28
Filing date: 2022-11-28
Publication date: 2023-06-06
Anticipated expiration: 2032-11-28

Abstract

The utility model provides an ion mobility spectrometry device for detecting inorganic gas, which comprises an ion mobility tube and a signal detection unit, wherein the ion mobility spectrometry device comprises a first ion mobility tube and a second ion mobility tube; the ion mobility spectrometry apparatus for detecting an inorganic gas further includes: the reaction vessel is provided with a first inlet and a first outlet, and the first outlet is communicated with a second inlet of the ion migration tube; a filler is arranged in the reaction container; the heating unit is used for heating the filling material in the reaction container, so that organic matters in the gas entering the reaction container from the second inlet react to generate inorganic matters. The utility model has the advantages of removing the interference of organic matters and the like.

Description

Ion mobility spectrometry device for detecting inorganic gas

Technical Field

The present utility model relates to ion mobility spectrometry, and more particularly, to an ion mobility spectrometry apparatus for detecting inorganic gases.

Background

Among the common toxic gases in industrial parks are a plurality of inorganic gases which commonly have acid and alkali properties, such as hydrogen sulfide, sulfuric acid mist, chlorine, hydrogen chloride, fluoride, hydrogen cyanide, ammonia and the like, and have important safety precaution function for realizing high-sensitivity detection, and common technologies include a sensor method, a spectroscopy method, an ion mobility spectrometry method and the like.

Ion mobility spectrometry (Ion Mobility Spectrometry, IMS) is a separation analysis technique with high sensitivity and high analysis speed. The device has the capability of detecting various inorganic gases simultaneously, has a high market share in explosive drug detection and toxic gas detection in the national security industry as the device has a simple structure and is easy to miniaturize, and has abundant application in various other fields such as food security, life science and the like. The IMS uses the difference of ion mobility of different compounds as a separation analysis method, but the difference of ion mobility of different compounds is smaller, and commercial IMS instruments have limited general resolution due to the limitation of conditions such as volume and the like, so that the IMS instruments are applied to field analysis, and particularly when the industrial field toxic gas detection is carried out, the following problems occur:

1. the complex matrix background containing more component compounds can interfere with the normal detection of the instrument spectrum peak, and can easily cause false positive false alarm or qualitative error and other phenomena.

2. Since the ionic molecular reaction of the IMS ionization mechanism is a competing reaction, the sensitivity of the instrument is also reduced when electron or proton affinity compounds are present simultaneously.

In order to solve the above technical problems, the prior art adopts the following two solutions:

1. applying a membrane sample injection method;

in the field of ion mobility spectrometry, pretreatment of samples by using a method of membrane sample introduction is common. The sample molecules are dissolved on the outer side surface of the membrane, and the sample molecules are driven to diffuse to the other side surface of the membrane due to the distribution difference of the concentration gradients on the two sides of the membrane, and then are desorbed from the surface in a mode of airflow blowing and eluting, and enter the IMS for detection. The IMS selectivity is improved by utilizing the different permeabilities of different samples through the membrane. For example, the utility model patent CN202010647793.1 of Shenzhen International research institute of Qinghua university, which is a membrane sample injection device and a sample injection method for gas detection, uses a membrane sample injection of a multi-gas chamber device, and sample gas selectively penetrates through a membrane to enter a detection gas chamber from the sample gas chamber, and improves sample injection efficiency and selectivity by controlling the pressure at the rear end of the membrane.

The membrane sample injection mode has the defect that only a small part of target compounds in the sample can penetrate the membrane and be detected by IMS, so that the detection sensitivity is reduced to a certain extent; when the sample concentration is changed, the response time of the signal intensity change is relatively longer, and when the sample concentration is larger, the memory effect on the membrane is more serious. The PDMS membrane used conventionally has a good filtering effect on H2O when the humidity in the sample is high, but cannot effectively separate the sample concerned in the mixed gas.

2. Adding a dopant;

the relatively wide application method in IMS also uses the additive doping agent, adds the compound with moderate electron or proton affinity as the Reactive Ion Peak (RIP) of the doping agent generating reagent in the ion mobility spectrometry system, thereby shielding the interfering substances with low affinity and improving the selectivity and the sensitivity of the IMS system. A number of patents for dopant applications are filed both at home and abroad, such as:

the use of MS or 2-HAP as a dopant in US503272 improves the separation of acid gases such as HF from the RIP peak of air. In U.S. Pat. No. 3,182 SO is used ₂ As a dopant; in US5234838 DMMP is used as a dopant to achieve separation of NH3 from air peaks in the positive mode. Patent WO2009018305A1 uses a unique way of adding dopants while improving selectivity and sensitivity. CN200910093179.9 combines a dopant with a sampling carrier, and samples are collected using the sampling carrier combined with the dopantThe sample is introduced into the instrument for analysis by sampling and sampling operations, along with the sample. Patent CN200910089161.1 describes a method for controlling the timing of dopant addition, which enables the dopant to play a role in the detection of explosives with low vapor pressure, and also enables explosives with high sensitivity without adding dopant to be analyzed with low dopant content, which gives consideration to the sensitivity of the instrument to different compounds.

The use of a dopant is a more effective method for improving selectivity, but the application of the dopant can only be selected according to the difference of electron or proton affinities of the compounds, and when the affinities of the tested compounds are greatly different, the selection of the dopant is difficult to be compatible, and the determination of a certain type of compound needs to be abandoned to be more effective. And the concentration of the dopant is not easy to control in the application process, and the dopant is used as a consumable material to be replaced by a user at random.

Disclosure of Invention

In order to solve the defects in the prior art, the utility model provides an ion mobility spectrometry device for detecting inorganic gas.

The utility model aims at realizing the following technical scheme:

an ion mobility spectrometry device for detecting inorganic gas, wherein the ion mobility spectrometry device for detecting inorganic gas comprises an ion mobility tube and a signal detection unit; the ion mobility spectrometry apparatus for detecting an inorganic gas further includes:

a reaction vessel having a first inlet and a first outlet, the first outlet communicating with a second inlet of the ion transfer tube; a filler is arranged in the reaction container;

and the heating unit is used for heating the filler in the reaction container so that organic matters in the gas entering the reaction container from the second inlet react to generate inorganic matters.

Compared with the prior art, the utility model has the following beneficial effects:

1. the pretreatment method is used for removing VOCs in the ambient air, so that the interference of high electron or proton affinity VOCs on inorganic gas in the process of measuring mixed gas by IMS is reduced, the selectivity of an ion mobility spectrometry instrument on inorganic gas detection is improved, the applicability of the instrument on an industrial site is particularly enhanced, and false positive false alarm of the whole machine is reduced;

2. the method reduces the types of compounds entering the IMS to be detected, reduces the interference of organic matters to the competition reaction of ion molecules, improves the sensitivity of an IMS instrument to the detection of inorganic gases in mixed gases, and reduces the probability of qualitative errors.

Drawings

The present disclosure will become more readily understood with reference to the accompanying drawings. As will be readily appreciated by those skilled in the art: the drawings are only for illustrating the technical scheme of the present utility model and are not intended to limit the scope of the present utility model. In the figure:

fig. 1 is a schematic structural view of an ion mobility spectrometry apparatus for detecting an inorganic gas according to an embodiment of the present utility model.

Detailed Description

Fig. 1 and the following description depict alternative embodiments of the utility model to teach those skilled in the art how to make and reproduce the utility model. For the purpose of explaining the technical solution of the present utility model, some conventional aspects have been simplified or omitted. Those skilled in the art will appreciate variations or alternatives derived from these embodiments that fall within the scope of the utility model. Those skilled in the art will appreciate that the features described below can be combined in various ways to form multiple variations of the utility model. Thus, the utility model is not limited to the following alternative embodiments, but only by the claims and their equivalents.

Example 1:

fig. 1 schematically shows a schematic structure of an ion mobility spectrometry apparatus for detecting an inorganic gas according to an embodiment of the present utility model, as shown in fig. 1, comprising:

an ion transfer tube 4 and a signal detection unit 6;

a reaction vessel 2 having a first inlet and a first outlet, the first outlet communicating with a second inlet 3 of the ion transfer tube 4; a filler is arranged in the reaction container 2;

and the heating unit is used for heating the filler in the reaction container 2, so that organic matters in the gas entering the reaction container 2 from the second inlet react to generate inorganic matters, and the influence of the organic matters on the measurement of the inorganic matters is eliminated.

In order to improve the detection accuracy, further, the ion mobility spectrometry apparatus for detecting an inorganic gas further includes:

the first purifying unit 8, the first pump 1 and the first pressure control unit 11, wherein the first purifying unit 8, the first pump 1, the first pressure control unit 11 and the third inlet 5 of the ion transfer tube 4 are communicated.

a second pressure control unit 9, a second pump 10 and a second purifying unit 12, wherein the second pressure control unit 9, the second pump 10, the second purifying unit 12 and the second outlet 7 of the ion transfer tube 4 are communicated.

Example 2:

application example of the ion mobility spectrometry apparatus for detecting inorganic gas according to embodiment 1 of the present utility model to air detection.

In this application example, as shown in fig. 1, the filler in the reaction vessel 2 is platinum-palladium alloy, and the heating unit is used for heating the filler in the reaction vessel, so that all hydrocarbons (alkane, alkene, alkyne, alcohol, aldehyde, ether, ester, etc.) in the air entering the reaction vessel 2 are subjected to catalytic oxidation and removal purification, and the VOCs generate CO ₂ And H ₂ O, the problem of interference of VOCs such as common benzene series and the like on inorganic gas detection is solved;

the first purifying unit 8, the first pump 1, the first pressure control unit 11 and the third inlet 5 of the ion transfer tube 4 are communicated; a second pressure control unit 9, a second pump 10, a second purification unit 12 and a second outlet 7 of the ion transfer tube 4 are communicated;

an ion transfer tube 4 and a signal detection unit 6;

the working mode of the ion mobility spectrometry device for detecting inorganic gas in the embodiment is as follows:

the mixed gas is controlled by the second pump 10 to enter in negative pressure mode, and the mixed gas is first passed through the reaction container 2 filled with catalyst to remove alkane and other VOCs in ambient air, and only inorganic gas such as H is retained ₂ S、NH ₃ And the like, the interface between the reaction vessel 2 and the ion transfer tube 4 can be directly connected, or can be connected by using a membrane sample injection mode, for example, a PDMS membrane is used, so that H is further reduced ₂ Interference of O to IMS;

inorganic gas enters the ion transfer tube 4 through the second inlet 3, the ion transfer tube 4 can use a single tube or a bipolar ion transfer tube, and the ion transfer tube can work in positive ion and negative ion modes simultaneously, such as H ₂ S、HCL、NH ₃ Detecting inorganic toxic gases;

the drift gas of the ion transfer tube 4 enters through the third inlet, the sample gas and the drift gas are discharged through the second outlet 7, the pressure inside the ion transfer tube 4 is regulated through the second pressure control unit 9 arranged at the rear, and the sample gas and the drift gas are filtered through the second purifying unit 12 and then discharged into the ambient air.

Claims

1. An ion mobility spectrometry device for detecting inorganic gas, wherein the ion mobility spectrometry device for detecting inorganic gas comprises an ion mobility tube and a signal detection unit; the ion mobility spectrometry device for detecting inorganic gas is characterized by further comprising:

2. The ion mobility spectrometry apparatus for detecting an inorganic gas according to claim 1, further comprising:

the ion transfer device comprises a first purifying unit, a first pump and a first pressure control unit, wherein the first purifying unit, the first pump, the first pressure control unit and a third inlet of the ion transfer tube are communicated.

3. The ion mobility spectrometry apparatus for detecting an inorganic gas according to claim 2, further comprising:

the second pressure control unit, the second pump and the second purifying unit are communicated with a second outlet of the ion migration tube.

4. The ion mobility spectrometry apparatus for detecting inorganic gases according to claim 2, wherein the filler is platinum palladium alloy.