Gas alternate enrichment detection device and gas enrichment detection method

Abstract

The invention discloses a gas alternate enrichment detection device and a gas enrichment detection method.The device comprises a first three-way valve, a first U-shaped pipe, a first vacuum bottle, a first CO2 fire extinguisher, a second three-way valve, a third three-way valve, a second U-shaped pipe, a second heat preservation bottle, a second CO2 fire extinguisher, a fourth three-way valve and a time-of-flight mass spectrometer; the first U-shaped tube and the second U-shaped tube are respectively filled with enrichment fillers, the enrichment fillers are isolated and fixed by quartz wool, and a first electric heating wire is arranged on the outer wall surface of the first U-shaped tube; the first U-shaped tube is arranged in the first vacuum bottle, and a second electric heating wire is arranged on the outer wall surface of the second U-shaped tube; the second U-shaped pipe is arranged in the second vacuum bottle; according to the detection method, sample gas is alternately enriched in the first U-shaped tube and the second U-shaped tube and is detected in the time-of-flight mass spectrometer by switching the four three-way valves through the device. According to the method, alternate enrichment can be realized, non-intermittent detection is realized, and the method has the characteristics of high analysis speed and high sensitivity.

Description

Technical Field

[0001] This invention patent is mainly used for online analysis and detection of environmental gases. Specifically, it utilizes a three-way valve to switch between two enrichment devices, achieving an alternating enrichment operation, which is then detected by a time-of-flight mass spectrometer. This can greatly improve detection efficiency and shorten detection time. Background Technology

[0002] As the "blue breath" that nourishes life on Earth, subtle changes in the chemical composition of the atmosphere directly impact global ecological balance, climate change, and human public health. With the relentless march of industrialization and urbanization, the atmosphere is no longer merely a simple mixture of nitrogen, oxygen, and rare gases; it has evolved into a dynamic reaction vessel filled with tens of thousands of trace amounts of volatile organic compounds (VOCs), semi-volatile organic compounds (SVOCs), persistent free radicals, and metallic particulate matter. Accurately deciphering this atmospheric "chemical code" is not only a cutting-edge issue in environmental science but also a cornerstone for addressing pollution control, climate assessment, and public health challenges. In this grand and complex exploration, enrichment analysis, as a powerful bioinformatics concept, is transcending its traditional domain, bringing revolutionary perspectives and tools to atmospheric gas composition analysis. Its necessity stems from the profound contradiction between current analytical technology bottlenecks and the needs of scientific understanding.

[0003] When directly measuring a single key substance presents challenges, enrichment analysis offers an alternative approach. Many substances from the same source or involved in the same chemical reaction pathway often appear as a group. Even if the concentration signal of each individual substance within this group is weak and fails to reach a significant difference threshold, the overall trend of change exhibited by this functional ensemble can become clearly visible through statistical tests. Therefore, enrichment analysis can integrate the contributions of trace substances below the detection limit or with insignificant changes, revealing hidden information. Summary of the Invention

[0004] The purpose of this invention is to provide a gas alternating enrichment detection device and a gas enrichment detection method. Specifically, it utilizes a three-way valve to switch between two enrichment devices to achieve an alternating enrichment operation, which is then detected by a time-of-flight mass spectrometer.

[0005] To achieve the above objectives, the technical solution adopted in this invention application is as follows:

[0006] A gas alternating enrichment detection device, the device comprising a first three-way valve 1, a first U-tube 2, a first thermos flask 6, a first CO2 fire extinguisher 7, a second three-way valve 8, a third three-way valve 10, a second U-tube 11, a second thermos flask 15, a second CO2 fire extinguisher 16, a fourth three-way valve 17, and a time-of-flight mass spectrometer 9.

[0007] The C end of the first three-way valve 1 is connected to the sample gas to be tested. The normally open NO end of the first three-way valve 1 is connected to the first interface of the first three-way connector. The second interface of the first three-way connector is connected to the inlet of the first U-tube 2 through a pipeline. The third interface of the first three-way connector is connected to the normally open NO end of the third three-way valve 10 through a pipeline. The outlet of the first U-tube 2 is connected to the C end of the second three-way valve 8 through a pipeline. The normally open NO end of the second three-way valve 8 is the exhaust port and is open to the atmosphere. The NC end of the second three-way valve 8 is connected to the first interface of the third three-way connector. The second interface of the third three-way connector is connected to the inlet of the time-of-flight mass spectrometer 9 through a pipeline. The third interface of the third three-way connector is connected to the NC end of the fourth three-way valve 17.

[0008] The C end of the third three-way valve 10 is connected to the purging gas. The NC end of the third three-way valve 10 is connected to the first interface of the second three-way connector. The second interface of the second three-way connector is connected to the inlet of the second U-tube 11 through a pipeline. The third interface of the second three-way connector is connected to the NC end of the first three-way valve 1 through a pipeline. The outlet of the second U-tube 11 is connected to the C end of the fourth three-way valve 17. The NO normally open end of the fourth three-way valve 17 is the exhaust gas outlet connected to the atmosphere.

[0009] The first U-shaped tube 2 is filled with enriching filler 5, and the second U-shaped tube 11 is filled with enriching filler 14.

[0010] The enrichment packing 5 inside the first U-tube 2 is isolated and fixed by quartz wool 3, and the enrichment packing 14 inside the second U-tube 11 is isolated and fixed by quartz wool 12 to prevent the sample gas or purge gas from blowing away the enrichment material 5 or the enrichment packing 14.

[0011] The outer wall of the first U-shaped tube 2 is provided with a first electric heating wire 4; the first U-shaped tube 2 is placed in the first thermos 6, the outer wall of the second U-shaped tube 11 is provided with a second electric heating wire 13; the second U-shaped tube 11 is placed in the second thermos 15.

[0012] The first thermos flask 6 includes a hollow bottle-shaped body and a sealing cap. Two through holes are provided on the top of the sealing cap. The two ends of the first U-shaped tube 2 pass through the two through holes of the sealing cap respectively. A CO2 inlet is provided at the lower part of the body of the first thermos flask 6 near the bottom of the bottle. The CO2 inlet is connected to the first CO2 fire extinguisher 7.

[0013] The structure of the second thermos 15 is the same as that of the first thermos 6, including a hollow bottle-shaped body and a sealing cap. Two through holes are provided on the top of the sealing cap. The two ends of the second U-shaped tube 11 pass through the two through holes of the sealing cap respectively. A CO2 inlet is provided at the lower part of the bottle body of the second U-shaped tube 11 near the bottom of the bottle. The CO2 inlet is connected to the second CO2 fire extinguisher 16.

[0014] The first U-shaped tube 2 and the second U-shaped tube 11 are quartz glass tubes or stainless steel tubes. The first thermos bottle 6 and the second thermos bottle 15 both have heat preservation functions, and the inner liner of the thermos is made of stainless steel, ceramic or other materials.

[0015] The amount of enriched filler in the first U-tube 2 and the second U-tube 11 accounts for 1 / 2 to 2 / 3 of the volume of the U-tube; the enriched filler 5 and the enriched filler 14 are both Carbopack B and Carboxen-1000 with a weight ratio of 2-3:1-2.

[0016] The heating temperature of the first electric heating wire 4 and the second electric heating wire 14 is 150-200℃.

[0017] A method for enriching and detecting sample gas using the aforementioned alternating gas enrichment and detection device, wherein the enrichment and detection method involves alternating enrichment by a first U-tube 2 and a second U-tube 11, followed by detection by a time-of-flight mass spectrometer 9, the specific process being as follows:

[0018] The first U-tube 2 performs enrichment, while the second U-tube 11 performs purging or detection: Switching the third three-way valve 10 to the NC end allows the sample gas to enter the first U-tube 2 through the NO end of the first three-way valve 1. The first CO2 fire extinguisher 7 is activated, and the first U-tube 2 performs low-temperature enrichment of the sample gas. The enriched exhaust gas is directly discharged through the NO end of the second three-way valve 8 from the outlet of the first U-tube 2. Simultaneously, the purging gas enters the second U-tube 11 through the NC end of the third three-way valve 10. The heating wire 14 is activated to heat the second U-tube 11. By switching the fourth three-way valve 14, the purging gas exits the second U-tube 11 through the normally open NO end or the NC end of the fourth three-way valve 17, enabling the purging or enrichment of gas components in the second U-tube 11 for detection in the time-of-flight mass spectrometer 9.

[0019] The second U-tube 11 is used for enrichment, while the first U-tube 2 is used for purging or detection: the first three-way valve 1 is switched to the NC end, and the sample gas enters the second U-tube 11 through the NC end of the first three-way valve 1 and the second three-way connector. The second CO2 fire extinguisher 16 is turned on, and the second U-tube 11 performs low-temperature enrichment of the sample gas. The enriched tail gas is directly discharged through the NO end of the third three-way valve 10 through the outlet of the second U-tube 11. At the same time, the purging gas enters the first U-tube 2 through the NO end of the third three-way valve 10 and the first three-way connector. The heating wire 4 is turned on to heat the first U-tube 2. By switching the second three-way valve 8, the purging gas enters the first U-tube 2 through the NO normally open end or the NC end of the second three-way valve 8 through the outlet of the first U-tube 2, so that the purging or enriched gas components of the first U-tube 2 can be detected in the time-of-flight mass spectrometer 9.

[0020] By switching the first three-way valve 1, the second three-way valve 8, the third three-way valve 10, and the fourth three-way valve 17, the sample gas is alternately enriched in the first U-tube 2 and the second U-tube 11 and detected in the time-of-flight mass spectrometer 9.

[0021] The purging gas is an inert gas, including one or more of high-purity N2, argon, and helium.

[0022] The detection method disclosed in this invention application can achieve uninterrupted analysis and detection, and has the advantages of simple structure, high sensitivity and fast analysis speed. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of a gas alternating enrichment sampling device;

[0024] Among them, 1—first three-way valve, 2—first U-tube, 3—quartz wool, 4—first heating wire, 5—enriching filler, 6—first thermos bottle, 7—first CO2 fire extinguisher, 8—second three-way valve, 9—time-of-flight mass spectrometer (TOFMS), 10—third three-way valve, 11—second U-tube, 13—second heating wire, 15—second thermos bottle, 16—second CO2 fire extinguisher, 17—fourth three-way valve. Detailed Implementation

[0025] Example 1

[0026] This invention patent provides a gas alternating enrichment sampling device, such as... Figure 1 As shown, the device includes a first three-way valve 1, a first U-tube 2, a first thermos flask 6, a first CO2 fire extinguisher 7, a second three-way valve 8, a third three-way valve 10, a second U-tube 11, a second thermos flask 15, a second CO2 fire extinguisher 16, a fourth three-way valve 17, and a time-of-flight mass spectrometer 9.

[0027] The C end of the first three-way valve 1 is connected to the sample gas to be tested. The normally open NO end of the first three-way valve 1 is connected to the first interface of the first three-way connector. The second interface of the first three-way connector is connected to the inlet of the first U-tube 2 through a pipeline. The third interface of the first three-way connector is connected to the normally open NO end of the third three-way valve 10 through a pipeline. The outlet of the first U-tube 2 is connected to the C end of the second three-way valve 8 through a pipeline. The normally open NO end of the second three-way valve 8 is the exhaust port and is open to the atmosphere. The NC end of the second three-way valve 8 is connected to the first interface of the third three-way connector. The second interface of the third three-way connector is connected to the inlet of the time-of-flight mass spectrometer 9 through a pipeline. The third interface of the third three-way connector is connected to the NC end of the fourth three-way valve 17.

[0028] The C end of the third three-way valve 10 is connected to the purging gas. The NC end of the third three-way valve 10 is connected to the first interface of the second three-way connector. The second interface of the second three-way connector is connected to the inlet of the second U-tube 11 through a pipeline. The third interface of the second three-way connector is connected to the NC end of the first three-way valve 1 through a pipeline. The outlet of the second U-tube 11 is connected to the C end of the fourth three-way valve 17. The NO normally open end of the fourth three-way valve 17 is the exhaust gas outlet connected to the atmosphere.

[0029] The enrichment packing 5 inside the first U-tube 2 is isolated and fixed by quartz wool 3, and the enrichment packing 14 inside the second U-tube 11 is isolated and fixed by quartz wool 12 to prevent the sample gas or purge gas from blowing away the enrichment material 5 or the enrichment packing 14.

[0030] The outer wall of the first U-shaped tube 2 is provided with a first electric heating wire 4; the first U-shaped tube 2 is placed in the first thermos 6, the outer wall of the second U-shaped tube 11 is provided with a second electric heating wire 13; the second U-shaped tube 11 is placed in the second thermos 15.

[0031] The first thermos flask 6 includes a hollow bottle-shaped body and a sealing cap. Two through holes are provided on the top of the sealing cap. The two ends of the first U-shaped tube 2 pass through the two through holes of the sealing cap respectively. A CO2 inlet is provided at the lower part of the body of the first thermos flask 6 near the bottom of the bottle. The CO2 inlet is connected to the first CO2 fire extinguisher 7.

[0032] The structure of the second thermos 15 is the same as that of the first thermos 6, including a hollow bottle-shaped body and a sealing cap. Two through holes are provided on the top of the sealing cap. The two ends of the second U-shaped tube 11 pass through the two through holes of the sealing cap respectively. A CO2 inlet is provided at the lower part of the bottle body of the second U-shaped tube 11 near the bottom of the bottle. The CO2 inlet is connected to the second CO2 fire extinguisher 16.

[0033] The first U-shaped tube 2 and the second U-shaped tube 11 are stainless steel tubes with an outer diameter of 6mm, an inner diameter of 4mm, and a length of 150mm.

[0034] The enrichment material inside the first U-tube 2 and the second U-tube 11 is a mixture of graphitized carbon black adsorbent Carbopack B (particle size 60-80 mesh, specific surface area 100 m2 / g) and carbon molecular sieve adsorbent Carboxen-1000 (particle size 40-60 mesh, specific surface area 1200 m2 / g) in a weight ratio of 2:1. The filling amount of the enrichment filler accounts for 2 / 3 of the volume of the U-tube. The first electric heating wire 4 and the second electric heating wire 14 are respectively connected to external thermocouples to control their heating temperature at 150-260℃.

[0035] The inner liner of both the first thermos flask 6 and the second thermos flask 15 is made of stainless steel and has both heat preservation and cold preservation functions.

[0036] Example 2,

[0037] A method for enriching and detecting sample gas using the gas alternating enrichment and detection device described in Example 1, wherein the enrichment and detection method involves alternating enrichment using a first U-tube and a second U-tube, followed by detection using a time-of-flight mass spectrometer, the specific process being as follows:

[0038] The first U-tube performs enrichment, while the second U-tube performs purging: The third three-way valve is switched to the NC end, and the sample gas enters the first U-tube through the NO end of the first three-way valve. The first CO2 fire extinguisher is opened, and the first U-tube performs low-temperature enrichment of the sample gas. The enriched exhaust gas is directly discharged through the outlet of the first U-tube and the NO end of the second three-way valve. Simultaneously, the purging gas enters the second U-tube through the NC end of the third three-way valve. The heating wire is turned on to heat the second U-tube, and the purging gas is discharged as exhaust gas through the outlet of the second U-tube and the normally open NO end of the fourth three-way valve.

[0039] The second U-tube performs enrichment, while the first U-tube performs detection: the first three-way valve and the second three-way valve are switched to the NC end respectively. The sample gas enters the second U-tube through the NC end of the first three-way valve and the second three-way connector. The second CO2 fire extinguisher is turned on, and the second U-tube performs low-temperature enrichment of the sample gas. The enriched tail gas is discharged directly through the NO normally open end of the fourth three-way valve through the outlet of the second U-tube. At the same time, the time-of-flight mass spectrometer is started. The purge gas enters the first U-tube through the NO normally open end of the third three-way valve and the first three-way connector. The heating wire is turned on to heat the first U-tube. The purge gas passes through the outlet of the first U-tube and the NC end of the second three-way valve, carrying the enriched gas components to the time-of-flight mass spectrometer for detection, and the mass spectrum of the sample gas is obtained.

[0040] By switching the first three-way valve, the second three-way valve, the third three-way valve, and the fourth three-way valve, the sample gas is alternately enriched in the first U-tube and the second U-tube and then detected in the time-of-flight mass spectrometer.

Claims

1. A gas alternating enrichment detection device, characterized in that: The device includes a first three-way valve (1), a first U-tube (2), a first thermos bottle (6), a first CO2 fire extinguisher (7), a second three-way valve (8), a third three-way valve (10), a second U-tube (11), a second thermos bottle (15), a second CO2 fire extinguisher (16), a fourth three-way valve (17), and a time-of-flight mass spectrometer (9); The C end of the first three-way valve (1) is connected to the sample gas to be tested. The NO normally open end of the first three-way valve (1) is connected to the first interface of the first three-way connector. The second interface of the first three-way connector is connected to the inlet of the first U-tube (2) through a pipeline. The third interface of the first three-way connector is connected to the NO normally open end of the third three-way valve (10) through a pipeline. The outlet of the first U-tube (2) is connected to the C end of the second three-way valve (8) through a pipeline. The NO normally open end of the second three-way valve (8) is the exhaust port connected to the atmosphere. The NC end of the second three-way valve (8) is connected to the first interface of the third three-way connector. The second interface of the third three-way connector is connected to the inlet of the time-of-flight mass spectrometer (9) through a pipeline. The third interface of the third three-way connector is connected to the NC end of the fourth three-way valve (17). The C end of the third three-way valve (10) is connected to the purge gas, the NC end of the third three-way valve (10) is connected to the first interface of the second three-way connector, the second interface of the second three-way connector is connected to the inlet of the second U-tube (11) through a pipeline, the third interface of the second three-way connector is connected to the NC end of the first three-way valve (1) through a pipeline, the outlet of the second U-tube (11) is connected to the C end of the fourth three-way valve (17), and the NO normally open end of the fourth three-way valve (17) is the exhaust gas outlet connected to the atmosphere. The first U-shaped tube (2) is filled with enriched filler (5), and the second U-shaped tube (11) is filled with enriched filler (14).

2. The gas alternating enrichment detection device according to claim 1, characterized in that: The enrichment packing material (5) inside the first U-shaped tube (2) is isolated and fixed by quartz wool (3), and the enrichment packing material (14) inside the second U-shaped tube (11) is isolated and fixed by quartz wool (12) to prevent the sample gas or purge gas from blowing away the enrichment material (5) or the enrichment packing material (14).

3. The gas alternating enrichment detection device according to claim 1, characterized in that: The outer wall of the first U-shaped tube (2) is provided with a first electric heating wire (4); the first U-shaped tube (2) is placed in the first thermos bottle (6); the outer wall of the second U-shaped tube (11) is provided with a second electric heating wire (13); the second U-shaped tube (11) is placed in the second thermos bottle (15).

4. The gas alternating enrichment detection device according to claim 1, characterized in that: The first thermos flask (6) includes a hollow bottle-shaped body and a sealing cap. Two through holes are provided at the top of the sealing cap. The two ends of the first U-shaped tube (2) pass through the two through holes of the sealing cap respectively. A CO2 inlet is provided at the lower part of the body of the first thermos flask (6) near the bottom of the bottle. The CO2 inlet is connected to the first CO2 fire extinguisher (7). The second thermos bottle (15) has the same structure as the first thermos bottle (6), including a hollow bottle-shaped body and a sealing cap. Two through holes are provided on the top of the sealing cap. The two ends of the second U-shaped tube (11) pass through the two through holes of the sealing cap respectively. A CO2 inlet is provided near the bottom of the bottle body of the second U-shaped tube (11), and the CO2 inlet is connected to the second CO2 fire extinguisher (16).

5. The gas alternating enrichment detection device according to claim 1, characterized in that: The first U-shaped tube (2) and the second U-shaped tube (11) are quartz glass tubes or stainless steel tubes. The first thermos bottle (6) and the second thermos bottle (15) both have heat preservation functions. The inner liner of the thermos is made of stainless steel, ceramic or other materials.

6. The gas alternating enrichment detection device according to claim 1, characterized in that, The amount of enriched filler in the first U-tube (2) and the second U-tube (11) accounts for 1 / 2 to 2 / 3 of the volume of the U-tube; the enriched filler (5) and the enriched filler (14) are both Carbopack B and Carboxen-1000 with a weight ratio of 2-3:1-2.

7. The gas alternating enrichment sampling device according to claim 1, characterized in that, The heating temperature of the first electric heating wire (4) and the second electric heating wire (14) is 150-260℃.

8. A method for enriching and detecting sample gas using the gas alternating enrichment and detection device according to any one of claims 1-7, characterized in that, The enrichment and detection method involves alternating enrichment using the first U-tube (2) and the second U-tube (11) followed by detection within the time-of-flight mass spectrometer (9). The specific process is as follows: The first U-tube (2) is enriched, while the second U-tube (11) is purged or detected: the third three-way valve (10) is switched to the NC end, the sample gas enters the first U-tube (2) through the NO end of the first three-way valve (1), the first CO2 fire extinguisher (7) is opened, the first U-tube (2) enriches the sample gas at low temperature, and the enriched tail gas is directly discharged through the NO end of the second three-way valve (8) through the outlet of the first U-tube (2); at the same time, the purging gas enters the second U-tube (11) through the NC end of the third three-way valve (10), the heating wire (14) is turned on to heat the second U-tube (11), and the purging gas enters the second U-tube (11) through the NO normally open end or NC end of the fourth three-way valve (17) through the outlet of the second U-tube (11) to realize the purging or enrichment of gas components in the second U-tube 11 for detection in the time-of-flight mass spectrometer 9. During the purging test, the second U-tube (11) is enriched. The first three-way valve (1) is switched to the NC end. The sample gas enters the second U-tube (11) through the NC end of the first three-way valve (1) and the second three-way connector. The second CO2 fire extinguisher (16) is turned on. The second U-tube (11) enriches the sample gas at low temperature. The enriched tail gas is discharged directly through the NO end of the fourth three-way valve (17) through the outlet of the second U-tube (11). At the same time, the purging gas enters the first U-tube (2) through the NO end of the third three-way valve (10) and the first three-way connector. The heating wire (4) is turned on to heat the first U-tube (2). By switching the second three-way valve (8), the purging gas enters the first U-tube (2) through the NO normally open end or the NC end of the second three-way valve (8) through the outlet of the first U-tube (2). The purging or enriched gas components of the first U-tube (2) are detected in the time-of-flight mass spectrometer (9).

9. The method for enriching and detecting sample gas according to claim 7, characterized in that, By switching the first three-way valve (1), the second three-way valve (8), the third three-way valve (10) and the fourth three-way valve (17), the sample gas is alternately enriched in the first U-tube (2) and the second U-tube (11) and detected in the time-of-flight mass spectrometer (9).

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