Ion mobility spectrometer cleaning device

Abstract

The utility model relates to the technical field of ion mobility spectrometers, and discloses an ion mobility spectrometer cleaning device which comprises a sample injector, an ion mobility spectrometer cleaning device, an ion mobility spectrometer cleaning device, an ion mobility spectrometer cleaning device, an ion mobility spectrometer cleaning device, an ion mobility spectrometer cleaning device, an ion mobility spectrometer cleaning device and an ion mobility spectrometer cleaning device, and the sample injector is internally provided with a polydimethylsiloxane membrane which divides the interior of the sample injector into a first area and a second area; the sample injector is provided with a sample inlet communicated with the first area, and a sample outlet, a first gas inlet and a first gas outlet which are communicated with the second area; the air inlet end of the air exhaust assembly communicates with the first air outlet, and the air outlet end of the air exhaust assembly communicates with the first air inlet. The air inlet end of the air exhaust assembly is communicated with the first air outlet, and the air outlet end of the air exhaust assembly is communicated with the first air inlet, so that stable flowing airflow can be formed in the second area. Through the air flow, on one hand, the sample can be promoted to be separated from the polydimethylsiloxane membrane, and on the other hand, the separated sample can leave the sample injector through the second air outlet, so that the possibility that the separated sample enters the ion mobility spectrometer through the sample outlet is reduced.

Description

TECHNICAL FIELD

[0001] The utility model relates to ion mobility spectrometer technical field, concretely relates to a kind of ion mobility spectrometer cleaning device. BACKGROUND

[0002] As a trace substance detection device, the main working process of ion mobility spectrometer is: the sample in the inlet module is heated, and the heated sample becomes gaseous sample molecules, and the gaseous sample molecules pass through the polydimethylsiloxane (PDMS) membrane into the internal gas path of the inlet module, and then follow the airflow into the ion mobility spectrometer to be ionized and detected. In order to restore the machine state to a good initial state, the internal substance of the instrument cannot be left over from the last detection, so the internal gas path of the ion mobility spectrometer needs to be cleaned.

[0003] However, since the PDMS membrane has strong adsorption, some substances from the last detection will remain on the PDMS membrane after the detection is completed. When cleaning the internal gas path of the ion mobility spectrometer, these residual substances will follow the airflow into the instrument, causing the extension of the cleaning and instrument downtime. SUMMARY

[0004] Therefore, the utility model provides an ion mobility spectrometer cleaning device to solve the problem of prolonged cleaning time of the internal gas path of the ion mobility spectrometer caused by the adsorption of the PDMS membrane to the sample.

[0005] The utility model provides an ion mobility spectrometer cleaning device, comprising:

[0006] The inlet module is provided with a sampling port in communication with the first area, and a sample outlet port, a first gas inlet and a first gas outlet in communication with the second area.

[0007] The gas extraction assembly has a gas inlet end in communication with the first gas outlet and a gas outlet end in communication with the first gas inlet.

[0008] Beneficial Effects: This invention connects the inlet of the gas extraction assembly to the first outlet and the outlet of the gas extraction assembly to the first inlet, enabling a stable airflow within the second region. This airflow promotes the detachment of sample molecules from the polydimethylsiloxane membrane, accelerating the cleaning rate of the membrane. Furthermore, it allows the detached sample molecules to exit the sample injector through the second outlet, reducing the likelihood of them entering the ion mobility spectrometer. This effectively shortens the time consumed in cleaning the internal gas path of the ion mobility spectrometer and reduces downtime caused by cleaning operations, thus meeting the requirements of continuous detection.

[0009] In one alternative embodiment, the cross-sectional area of ​​the first air outlet is larger than the cross-sectional area of ​​the sample outlet.

[0010] Beneficial effect: Reducing the cross-sectional area of ​​the sample outlet increases the air resistance as the gas flows out of the outlet. This reduces the gas flow rate leaving the injector through the outlet, ensuring that all gas carrying sample molecules in the second region exits the injector through the first outlet.

[0011] In one optional embodiment, the air extraction assembly includes a first air pump, the outlet of the first air pump being connected to the first air inlet via a first pipeline, and the air inlet of the first air pump being connected to the first air outlet via a second pipeline, the second pipeline being provided with a normally closed valve; when the ion mobility spectrometer cleaning device is in the cleaning state, the normally closed valve is opened and connects the air inlet of the first air pump and the first air outlet.

[0012] Beneficial Effects: For sample molecules in the sample injector to enter the ion mobility spectrometer for detection, a continuous and stable airflow is required to transfer the sample molecules located in the second region through the sample outlet to the ion mobility spectrometer. Therefore, this invention connects the first air inlet to the outlet of the first gas pump and the sample outlet to the inlet of the first gas pump, enabling airflow circulation between the second region and the ion mobility spectrometer, thus facilitating the smooth transfer of sample molecules between them. Furthermore, by installing a normally closed valve on the second pipeline, the connection between the second outlet and the first gas pump is blocked, ensuring that sample molecules can completely enter the ion mobility spectrometer through the sample outlet, thus laying the foundation for accurate subsequent detection. In addition, after the detection process is completed, the operator only needs to adjust the normally closed valve to the open state, that is, keep the first air inlet connected to the outlet of the first gas pump, to switch to the cleaning state. It is evident that this method is simple and quick, effectively saving time and labor costs.

[0013] In one optional embodiment, the sampler is further provided with a second air outlet connected to the first region; the gas extraction assembly further includes a second air pump, the air inlet of the second air pump being connected to the second air outlet; when the ion mobility spectrometer cleaning device is in the cleaning state, the second air pump is turned on.

[0014] Beneficial effects: Since the sample to be tested is heated and turns into gaseous sample molecules in the first region of the sample injector, after the ion mobility spectrometer completes the detection of the sample, not only will some sample molecules remain in the second region, but some sample molecules will also remain in the first region. Based on this, this invention connects the second gas outlet, which is connected to the first region, to the gas inlet of the second gas pump. The suction force generated by the second gas pump can be used to quickly remove the sample molecules remaining in the first region, preventing the residual sample molecules in the first region from continuing to permeate through the polydimethylsiloxane membrane into the second region and into the interior of the ion mobility spectrometer.

[0015] In one optional embodiment, the sampler further includes a second air outlet connected to the first region; the gas extraction assembly includes a first gas pump and a second gas pump, the outlet of the first gas pump is connected to the first air inlet, the inlet of the second gas pump is connected to both the first and second air outlets, and a normally closed valve is provided between the inlet of the second gas pump and the first air outlet; when the ion mobility spectrometer cleaning device is in the cleaning state, the second gas pump and the normally closed valve are open.

[0016] Beneficial effects: Compared to connecting the first air outlet to the first air pump, this invention connects the second air outlet to the air inlet of the second air pump. On one hand, this reduces the number of connecting parts to the first air pump, avoiding the problems of complex connections and inconvenient maintenance caused by too many connecting parts. On the other hand, it effectively reduces the working pressure of the first air pump, extending its service life. Furthermore, this connection method allows the second air pump to simultaneously clean sample molecules in both the first and second regions, preventing reduced cleaning efficiency due to first air pump malfunction.

[0017] In one alternative implementation, the flow rate of the second air pump is greater than the flow rate of the first air pump.

[0018] Beneficial effect: The larger airflow generated by the second gas pump means that the airflow in the second region is more likely to flow out of the sample injector through the first outlet, rather than flowing towards the sample outlet and entering the interior of the ion mobility spectrometer. This effectively reduces the possibility of sample molecules entering the ion mobility spectrometer, ensuring the cleanliness of the gas path inside the spectrometer.

[0019] In one optional embodiment, a migration tube is further included, wherein the migration tube has an ionization region and a drift region connected inside, the ionization region being connected to the sample outlet and the air inlet of the first air pump, and the drift region being connected to the air outlet of the first air pump.

[0020] Beneficial effects: After the ion mobility spectrometer completes the sample detection process, in addition to sample molecules remaining in the injector, some sample molecules will also remain in the detection area of ​​the ion mobility spectrometer, i.e., the migration tube. Therefore, to avoid the sample molecules remaining in the migration tube affecting the accuracy of subsequent detections, this invention connects the drift region to the outlet of the first gas pump and the ionization region to the inlet of the first gas pump. This allows the airflow generated by the first gas pump to carry away the sample molecules remaining in the migration tube, ensuring the cleanliness of the internal environment of the migration tube.

[0021] In one optional embodiment, a corona needle is provided inside the ionization region, and an air blowing pipe is provided between the air outlet of the first air pump and the corona needle; an air outlet pipe is provided between the air inlet of the first air pump and the corona needle.

[0022] Beneficial Effects: In addition to gaseous sample molecules, air also exists in the ionization region. When a corona needle is used to ionize sample molecules, the air also ionizes under the influence of the needle. Once ionized, air produces substances such as ozone and nitrogen oxides, which can interfere with the accuracy of detection. Therefore, this invention, by incorporating air blowing and exhaust pipes around the corona needle, can quickly expel these interfering substances from the ionization region, reducing their interference with subsequent detection processes and improving the accuracy and reliability of subsequent detections.

[0023] In one alternative embodiment, a third pipeline is further included, one end of which is connected to the air inlet of the first air pump, and the other end is connected to the outside atmosphere.

[0024] Beneficial effects: The third pipeline connects the inside of the ion mobility spectrometer to the outside atmosphere, ensuring that the internal pressure of the ion mobility spectrometer is always within a reasonable range and preventing excessive pressure difference between the inside of the ion mobility spectrometer and the outside atmosphere.

[0025] In one alternative embodiment, the exhaust end of the air extraction assembly is provided with a filter.

[0026] Beneficial effects: This filter can effectively absorb water vapor in the airflow and expel sample molecules from the second region, ensuring the cleanliness and dryness of the airflow discharged from the exhaust end of the extraction assembly. Attached Figure Description

[0027] To more clearly illustrate the specific embodiments of this utility model or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0028] Figure 1 This is a schematic diagram of the structure of an ion mobility spectrometer cleaning device according to an embodiment of the present invention;

[0029] Figure 2 This is a schematic diagram of another ion mobility spectrometer cleaning device according to an embodiment of the present invention.

[0030] Explanation of reference numerals in the attached figures:

[0031] 1. Sample injector; 101. Polydimethylsiloxane membrane; 102. First region; 103. Second region; 104. Sample inlet; 105. Sample outlet; 106. First air inlet; 107. First air outlet; 108. Second air outlet; 2. Vacuum assembly; 201. First air pump; 202. Second air pump; 3. First pipeline; 4. Second pipeline; 5. Normally closed valve; 6. Migration tube; 601. Ionization zone; 602. Drift zone; 7. Corona needle; 8. Air blowing pipeline; 9. Air outlet pipeline; 10. Third pipeline; 11. Filter element. Detailed Implementation

[0032] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0033] To address the problem of prolonged cleaning time of the internal gas path of an ion mobility spectrometer caused by sample adsorption on a PDMS membrane, this invention provides a cleaning device for an ion mobility spectrometer.

[0034] The following is combined Figures 1 to 2 The following describes embodiments of the present invention.

[0035] According to embodiments of the present invention, such as Figure 1 and Figure 2 As shown, an ion mobility spectrometer cleaning device is provided, including: a sampler 1 and a gas extraction assembly 2.

[0036] Specifically, the injector 1 has a polydimethylsiloxane membrane 101 inside, which divides the inside of the injector 1 into a first region 102 and a second region 103. The injector 1 has an inlet 104 connected to the first region 102 and an outlet 105 connected to the second region 103, a first air inlet 106 and a first air outlet 107. The air inlet end of the suction assembly 2 is connected to the first air outlet 107, and the air outlet end of the suction assembly 2 is connected to the first air inlet 106.

[0037] In this embodiment, the inlet of the gas extraction assembly 2 is connected to the first outlet 107, and the outlet of the gas extraction assembly 2 is connected to the first inlet 106, enabling a stable airflow to form within the second region 103. This airflow promotes the detachment of sample molecules from the polydimethylsiloxane membrane 101, accelerating the cleaning rate of the membrane. Furthermore, it allows the detached sample molecules to exit the sample injector 1 through the second outlet 108, reducing the likelihood of them entering the ion mobility spectrometer through the outlet 105. This effectively shortens the time consumed in cleaning the internal gas path of the ion mobility spectrometer and reduces downtime caused by cleaning operations, thus meeting the requirements of continuous detection operations.

[0038] According to one embodiment of the present invention, such as Figure 1 and Figure 2 As shown, the cross-sectional area of ​​the first outlet 107 is larger than that of the sample outlet 105. In this embodiment, reducing the cross-sectional area of ​​the sample outlet 105 increases the air resistance as the airflow exits the sample outlet 105. This reduces the airflow rate leaving the sample injector 1 through the sample outlet 105, ensuring that all airflow carrying sample molecules within the second region 103 exits the sample injector 1 through the first outlet 107.

[0039] According to one embodiment of the present invention, such as Figure 1 and Figure 2 As shown, the air extraction assembly 2 includes a first air pump 201. The outlet of the first air pump 201 is connected to the first air inlet 106 through the first pipeline 3. Therefore, the inlet of the first air pump 201 is connected to the first air outlet 107 through the second pipeline 4. The second pipeline 4 is equipped with a normally closed valve 5. When the ion mobility spectrometer cleaning device is in the cleaning state, the normally closed valve 5 is opened and connects the inlet of the first air pump 201 and the first air outlet 107.

[0040] For sample molecules in the sampler 1 to enter the ion mobility spectrometer for detection, a continuous and stable airflow is required to transfer the sample molecules located in the second region 103 through the sample outlet 105 to the ion mobility spectrometer. Therefore, in this embodiment, the first air inlet 106 is connected to the outlet of the first air pump 201, and the sample outlet 105 is connected to the air inlet of the first air pump 201. This allows an airflow circulation to be established between the second region 103 and the ion mobility spectrometer, thereby achieving smooth transfer of sample molecules between them. By setting a normally closed valve 5 on the second pipeline 4, the connection between the second air outlet 108 and the first air pump 201 can be blocked, ensuring that sample molecules can completely enter the ion mobility spectrometer through the sample outlet 105, thus laying the foundation for accurate subsequent detection. Furthermore, after the detection process is completed, the operator only needs to adjust the state of the normally closed valve 5 to the open state, that is, keep the first air inlet 106 connected to the outlet of the first air pump 201, to switch to the cleaning state. It is evident that this method is simple and quick, effectively saving time and manpower costs.

[0041] According to one embodiment of the present invention, such as Figure 1 and Figure 2 As shown, the sample injector 1 is also provided with a second air outlet 108 connected to the first region 102; the suction assembly 2 also includes a second air pump 202, the air inlet of the second air pump 202 being connected to the second air outlet 108; the ion mobility spectrometer cleaning device is in the cleaning state, and the second air pump 202 is turned on. Since the sample to be tested will be heated and turned into gaseous sample molecules in the first region 102 of the sample injector 1, after the ion mobility spectrometer completes the detection of the sample to be tested, not only will some sample molecules remain in the second region 103, but some sample molecules will also remain in the first region 102. Based on this, this embodiment connects the second air outlet 108 connected to the first region 102 to the air inlet of the second air pump 202, and can use the suction force generated by the second air pump 202 to quickly remove the sample molecules remaining in the first region 102, preventing the residual sample molecules in the first region 102 from continuing to permeate through the polydimethylsiloxane membrane 101 into the second region 103 and into the interior of the ion mobility spectrometer.

[0042] According to one embodiment of the present invention, such as Figure 2As shown, the sample injector 1 is also provided with a second air outlet 108 connected to the first region 102; the suction assembly 2 includes a first air pump 201 and a second air pump 202. The air outlet of the first air pump 201 is connected to the first air inlet 106, and the air inlet of the second air pump 202 is connected to the first air outlet 107 and the second air outlet 108. A normally closed valve 5 is provided between the air inlet of the second air pump 202 and the first air outlet 107. When the ion mobility spectrometer cleaning device is in the cleaning state, the second air pump 202 and the normally closed valve 5 are open. Compared with connecting the first air outlet 107 to the first air pump 201, this embodiment connects the second air outlet 108 to the air inlet of the second air pump 202. On the one hand, this reduces the number of connecting parts to the first air pump 201, avoiding the problem of complex connections and inconvenient maintenance due to too many connecting parts. On the other hand, it can effectively share the working pressure of the first air pump 201 and extend the service life of the first air pump 201. In addition, this connection method also enables the second air pump 202 to simultaneously clean sample molecules in the first region 102 and the second region 103, avoiding a decrease in cleaning efficiency due to a malfunction of the first air pump 201.

[0043] According to one embodiment of the present invention, such as Figure 2 As shown, the flow rate of the second gas pump 202 is greater than that of the first gas pump 201. The larger flow rate generated by the second gas pump 202 means that the airflow within the second region 103 is more likely to flow out of the sampler 1 along the first outlet 107, rather than flowing towards the sample outlet 105 and entering the ion mobility spectrometer. This effectively reduces the possibility of sample molecules entering the ion mobility spectrometer, ensuring the cleanliness of the gas path inside the ion mobility spectrometer.

[0044] According to one embodiment of the present invention, such as Figure 1 and Figure 2As shown, it also includes a migration tube 6, which has an ionization region 601 and a drift region 602 connected inside. The ionization region 601 is connected to the sample outlet 105 and the inlet of the first gas pump 201, and the drift region 602 is connected to the outlet of the first gas pump 201. After the ion mobility spectrometer completes the sample detection process, in addition to the sample molecules remaining in the sample injector 1, some sample molecules will also remain in the detection area of ​​the ion mobility spectrometer, i.e., the migration tube 6. Therefore, in order to avoid the sample molecules remaining in the migration tube 6 from affecting the accuracy of the next detection, this invention connects the drift region 602 to the outlet of the first gas pump 201 and the ionization region 601 to the inlet of the first gas pump 201. This allows the airflow generated by the first gas pump 201 to carry the sample molecules remaining in the migration tube 6 away from the migration tube 6, ensuring the cleanliness of the internal environment of the migration tube 6. Preferably, the connection between the drift region 602 and the outlet of the first air pump 201 is located at the end of the drift region 602 that is away from the ionization region 601.

[0045] According to one embodiment of the present invention, such as Figure 1 and Figure 2 As shown, an ionization region 601 contains a corona needle 7, and a blowing pipe 8 is provided between the outlet of the first air pump 201 and the corona needle 7; an outlet pipe 9 is provided between the inlet of the first air pump 201 and the corona needle 7. In addition to gaseous sample molecules, air also exists within the ionization region 601. When the sample molecules are ionized using the corona needle 7, the air also undergoes ionization under the influence of the corona needle 7. Once the air is ionized, substances such as ozone and nitrogen oxides are produced, which can interfere with the accuracy of the detection. Therefore, this embodiment, by providing a blowing pipe 8 and an outlet pipe 9 around the corona needle 7, can quickly expel these interfering substances from the ionization region 601, reducing their interference with subsequent detection processes and improving the accuracy and reliability of subsequent detections.

[0046] According to one embodiment of the present invention, such as Figure 1 and Figure 2 As shown, it also includes a third pipe 10, one end of which is connected to the air inlet of the first air pump 201, and the other end is connected to the outside atmosphere. The third pipe 10 connects the inside of the ion mobility spectrometer to the outside atmosphere, ensuring that the air pressure inside the ion mobility spectrometer is always within a reasonable range and preventing the pressure difference between the inside of the ion mobility spectrometer and the outside atmosphere from being too large.

[0047] Furthermore, to prevent impurities in the outside atmosphere from entering the ion mobility spectrometer along with the airflow, a filter nozzle can be installed on the third pipeline 10.

[0048] According to one embodiment of the present invention, such as Figure 1 and Figure 2As shown, the exhaust end of the extraction assembly 2 is equipped with a filter 11. Through this filter 11, water vapor in the airflow can be effectively absorbed and sample molecules in the second region 103 can be discharged, ensuring the cleanliness and dryness of the airflow discharged from the exhaust end of the extraction assembly 2.

[0049] Although embodiments of the present invention have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the present invention, and such modifications and variations all fall within the scope defined by the appended claims.

Claims

1. A cleaning device for an ion mobility spectrometer, characterized in that, include: The sample injector (1) has a polydimethylsiloxane membrane (101) inside, which divides the interior of the sample injector (1) into a first region (102) and a second region (103); the sample injector (1) has a sample inlet (104) communicating with the first region (102) and a sample outlet (105), a first air inlet (106) and a first air outlet (107) communicating with the second region (103); The air extraction assembly (2) has an air inlet end connected to the first air outlet (107) and an air outlet end connected to the first air inlet (106).

2. The ion mobility spectrometer cleaning device according to claim 1, characterized in that, The cross-sectional area of ​​the first air outlet (107) is larger than that of the sample outlet (105).

3. The ion mobility spectrometer cleaning device according to claim 1, characterized in that, The air extraction assembly (2) includes a first air pump (201). The outlet of the first air pump (201) is connected to the first air inlet (106) through a first pipeline (3). Therefore, the inlet of the first air pump (201) is connected to the first air outlet (107) through a second pipeline (4). A normally closed valve (5) is provided on the second pipeline (4). When the ion mobility spectrometer cleaning device is in the cleaning state, the normally closed valve (5) is opened and connects the inlet of the first air pump (201) and the first air outlet (107).

4. The ion mobility spectrometer cleaning apparatus according to claim 3, characterized in that, The sample injector (1) is also provided with a second air outlet (108) connected to the first region (102); the gas extraction assembly (2) also includes a second gas pump (202), the inlet end of the second gas pump (202) is connected to the second air outlet (108); when the ion mobility spectrometer cleaning device is in the cleaning state, the second gas pump (202) is turned on.

5. The ion mobility spectrometer cleaning device according to claim 1, characterized in that, The sample injector (1) is also provided with a second air outlet (108) connected to the first region (102); the gas extraction assembly (2) includes a first gas pump (201) and a second gas pump (202), the outlet of the first gas pump (201) is connected to the first air inlet (106), the inlet of the second gas pump (202) is connected to the first air outlet (107) and the second air outlet (108), and a normally closed valve (5) is provided between the inlet of the second gas pump (202) and the first air outlet (107); when the ion mobility spectrometer cleaning device is in the cleaning state, the second gas pump (202) and the normally closed valve (5) are opened.

6. The ion mobility spectrometer cleaning apparatus according to claim 5, characterized in that, The flow rate of the second air pump (202) is greater than that of the first air pump (201).

7. The ion mobility spectrometer cleaning apparatus according to any one of claims 3 to 6, characterized in that, It also includes a migration tube (6), which has an ionization region (601) and a drift region (602) connected inside. The ionization region (601) is connected to the sample outlet (105) and the air inlet of the first air pump (201), and the drift region (602) is connected to the air outlet of the first air pump (201).

8. The ion mobility spectrometer cleaning apparatus according to claim 7, characterized in that, The ionization region (601) is provided with a corona needle (7), and an air blowing pipe (8) is provided between the air outlet of the first air pump (201) and the corona needle (7); an air outlet pipe (9) is provided between the air inlet of the first air pump (201) and the corona needle (7).

9. The ion mobility spectrometer cleaning apparatus according to claim 7, characterized in that, It also includes a third pipeline (10), one end of which is connected to the air inlet of the first air pump (201), and the other end is connected to the outside atmosphere.

10. The ion mobility spectrometer cleaning apparatus according to any one of claims 1 to 6, characterized in that, The exhaust end of the air extraction assembly (2) is provided with a filter element (11).

Images