A device and method for monitoring ozone-depleting substances and hydrofluorocarbons in the atmosphere.

Abstract

This invention relates to a device and method for monitoring ozone-depleting substances and hydrofluorocarbons in the atmosphere, belonging to the field of chromatography-mass spectrometry analysis technology. The solution mainly includes: a target analyte collection pipeline, including a collection module, used to collect target analytes from sample gas and remove interfering substances; a multi-stage analysis pipeline, including an analysis carrier gas inlet and a temporary storage column switching module; and a focusing analysis module, used for focusing and chromatographic separation of the target analytes before detection; the analysis carrier gas inlet is sequentially connected to the focusing analysis module through the collection module and the temporary storage column switching module, and the multi-stage analysis pipeline is used to transport the target analytes to be analyzed in batches to the focusing analysis module.

Description

Technical Field

[0001] This invention belongs to the field of chromatography-mass spectrometry analysis technology, specifically a device and method for monitoring ozone-depleting substances and hydrofluorocarbons in the atmosphere. Background Technology

[0002] Ozone (O3) is concentrated in the stratosphere, with the highest concentration at an altitude of 15 km to 30 km above the Earth's surface; this region is known as the ozone layer. It absorbs most of the ultraviolet radiation from sunlight, especially harmful UVB rays, thus protecting humans and other organisms from this harmful radiation. Scientists have discovered ozone-depleting substances in the air, primarily including ozone-depleting compounds (ODS) and fluorinated greenhouse gases. ODS comprise six major categories of halogenated hydrocarbons, such as chlorofluorocarbons (CFCs), hydrochlorofluorocarbons (HCFCs), halons, carbon tetrachloride (CCl4), methyl chloroform (CH3CCl3), and methyl bromide (CH3Br). Fluorine-containing greenhouse gases, abbreviated as F-gas, include four of the seven greenhouse gases listed in the Kyoto Protocol of the United Nations Framework Convention on Climate Change (UNFCCC): hydrofluorocarbons (HFCs), perfluorocarbons (PFCs), sulfur hexafluoride (SF6), and nitrogen trifluoride (NF3). Especially when dealing with multiple projects and multiple samples, problems such as low dosing efficiency, large dosing errors, and even incorrect dosing are common.

[0003] Currently, these ozone-depleting compounds are mainly produced industrially, used in refrigeration, cleaning, and foaming processes. To protect the human environment, the Montreal Protocol was signed in 1987, restricting the use and emissions of ozone-depleting substances and chlorofluorocarbons (CFCs) globally. This necessitates monitoring the concentrations of ozone-depleting substances and fluorinated greenhouse gases in the atmosphere mentioned in the Montreal Protocol. However, the concentrations of these substances in the atmosphere are at the ppt (parts per trillion) level, with some concentrations even less than 1 ppt. Therefore, the detection limits and accuracy requirements of monitoring systems are extremely high. Currently, such equipment covers relatively few components, making it difficult to accurately separate target substances from samples, resulting in significant deviations in detection results.

[0004] Patent CN113834884A discloses an online monitoring system for ozone-depleting substances. The technical solution employed is an "online sampling and pre-concentration system using a semiconductor refrigeration combined with a super-adsorbent cold trap, with an online low-temperature Nafion membrane dehydration device connected to the sample injection end. The sampling and pre-concentration system is sequentially connected to a gas chromatograph and a quadrupole mass spectrometer, respectively connected to the workstation computers of the pre-concentration system and the gas chromatograph and quadrupole mass spectrometer." However, this detection system only has a Nafion membrane dehydration device at the sample end, failing to remove moisture from the carrier gas end. Furthermore, it requires pressurizing the ambient air to complete continuous sample injection, and this system only covers the monitoring of 21 ozone-depleting substances. Patent CN116577446A discloses a method, device, and storage medium for detecting ozone-depleting substances in the air; this device requires pressurized sampling due to the use of Nafion tube dehydration technology at the front end, making the sampling structure more complex. Patent CN116465993A discloses a method for identifying and assessing the ecological and environmental damage caused by controlled ozone-depleting substances (ODS). However, this method is only applicable to the qualitative and quantitative analysis of ODS and hydrofluorocarbons in ambient air. Patent CN115494172A discloses a method and apparatus for measuring ODS and fluorinated greenhouse gases in the atmosphere. This method and apparatus can only analyze and measure high-concentration samples and lacks concentration capabilities; therefore, it cannot accurately analyze low-concentration samples qualitatively and quantitatively.

[0005] In summary, existing detection equipment struggles to accurately separate the target analyte from the sample, resulting in significant deviations in the detection results. Summary of the Invention

[0006] In view of the above analysis, in order to solve the above problems, a first aspect of the present invention provides a monitoring device for ozone-depleting substances and hydrofluorocarbons in the atmosphere, comprising:

[0007] The target object capture pipeline, including a capture module, is used to capture target objects in the sample gas and remove interfering substances through the capture module;

[0008] Multi-stage analytical pipeline, including analytical carrier gas inlet and temporary storage column switching module; and

[0009] The focusing analysis module is used for focusing and chromatographic separation of target analytes before detection.

[0010] The analytical carrier gas inlet is connected to the focusing analysis module in sequence through the trapping module and the temporary storage column switching module. The multi-stage analytical pipeline is used to transport the target objects to be analyzed in batches to the focusing analysis module.

[0011] The temporary storage column switching module has a first state and a second state. When it is in the first state, the collection module is connected to the focusing analysis module through the temporary storage column. When it is in the second state, the collection module is directly connected to the focusing analysis module without going through the temporary storage column. The temporary storage column has chromatographic separation capability.

[0012] The capture module has a first state and a second state. When it is in the first state, the analytical carrier gas inlet is connected to the temporary storage column switching module through the capture module. When it is in the second state, the analytical carrier gas inlet is directly connected to the temporary storage column switching module without going through the capture module.

[0013] In some embodiments, a dehydration module is further included, which is disposed on the target collection pipeline and is used to dehydrate the sample gas before the sample gas enters the collection module.

[0014] In some embodiments, the dehydration module includes a first dehydration module and a second dehydration module;

[0015] The target collection pipeline also includes an autosampler, a pump, and a first flow meter. The autosampler is used to connect to the Summa tank. The pump is located at one end near the outlet of the target collection pipeline. The autosampler is connected to the pump in sequence through the first dehydration module, the second dehydration module, the collection module, and the first flow meter.

[0016] The focusing analysis module includes a focusing module, a chromatographic separation module, and a detection unit connected in sequence. The focusing module is used to focus the target analyte and input the target analyte into the chromatographic separation module. The chromatographic separation module is used to perform chromatographic separation on the target analyte and then input it into the detection unit. The inlet of the focusing module is connected to the multi-stage analytical pipeline.

[0017] In some embodiments, a one-to-many selector valve, a first switching valve, and a second switching valve are also included;

[0018] The one-to-many selector valve has a fixed interface and a plurality of selectable interfaces, and the one-to-many selector valve is configured to connect one of the fixed interfaces to one of the selectable interfaces.

[0019] The autosampler is connected to the selection interface S7 of the one-to-many selection valve via the first dehydration module. The fixed interface is connected to the interface P1 of the first switching valve. The two ends of the second dehydration module are connected to the interfaces P2 and P8 of the first switching valve, respectively. The two ends of the trapping module are connected to the interfaces P3 and P6 of the first switching valve, respectively. The interface P7 of the first switching valve is connected to the pump via the first flow meter. The interface P5 of the first switching valve is connected to the desorption carrier gas inlet. The interface P4 of the first switching valve is connected to the interface P5 of the second switching valve. The two ends of the temporary storage column are connected to the interfaces P6 and P7 of the second switching valve, respectively. The interface P8 of the second switching valve is connected to the focusing module.

[0020] The first switching valve has an A state and a B state. When the first switching valve is in the A state, only its interfaces P1 and P8, P2 and P3, P4 and P5, and P6 and P7 are connected. When the first switching valve is in the B state, only its interfaces P1 and P2, P3 and P4, P5 and P6, and P7 and P8 are connected.

[0021] The second switching valve has an A state and a B state. When the second switching valve is in the A state, only its interfaces P6 and P7 and interfaces P5 and P8 are connected. When the second switching valve is in the B state, only its interfaces P5 and P6 and interfaces P7 and P8 are connected.

[0022] In some embodiments, a forward and reverse blowing pipeline is also included, which is connected to the target object collection pipeline and is used to introduce inert gas into the target object collection pipeline from two directions respectively, so that the collection module can collect the target object remaining in the target object collection pipeline.

[0023] The forward and reverse blowing pipeline has a first state and a second state. In the first state, the inert gas passes through the second dehydration module and the collection module in sequence. In the second state, the inert gas passes through the collection module and the second dehydration module in sequence.

[0024] In some embodiments, the forward and reverse blowing pipeline includes an inert gas inlet, a first three-way valve, and a second three-way valve;

[0025] One end of the first three-way valve is connected to one end of the second three-way valve. The other two ends of the first three-way valve are respectively connected to the inert gas inlet and the selection interface S5 of the one-to-many selector valve. The other two ends of the second three-way valve are respectively connected to the interface P7 of the first switching valve and the first flow meter.

[0026] The first three-way valve is configured to connect the inert gas inlet to the one-to-many selector valve or to connect the inert gas inlet to the second three-way valve;

[0027] The second three-way valve is configured to connect the first three-way valve to the first switching valve or to connect the first switching valve to the first flow meter.

[0028] This invention also provides a method for monitoring ozone-depleting substances and hydrofluorocarbons in the atmosphere, using the ozone-depleting substances and hydrofluorocarbons monitoring device described in any embodiment of the first aspect, and the method includes the following steps:

[0029] S1. Pass the sample gas into the collection pipeline and collect the target substance in the sample gas through the collection module;

[0030] S2. The temporary storage column switching module is switched to the first state, the collection module is switched to the first state, the collection module is set to the first given temperature to resolve the first part of the target analyte, and the carrier gas is introduced into the carrier gas inlet and flows into the collection module and the temporary storage column in sequence. The temperature of the temporary storage column is set to the second given temperature so that the first part of the target analyte is retained in the temporary storage column. The first part of the target analyte is separated by chromatography through the temporary storage column.

[0031] S3. The temporary storage column switching module is switched to the second state, the collection module is switched to the first state, the collection module is set to the third given temperature to resolve the second part of the target, the carrier gas is introduced into the carrier gas inlet and flows through the collection module to deliver the second part of the target to the focusing analysis module;

[0032] S4. The temporary storage column switching module switches to the first state, the collection module switches to the second state, and the carrier gas is introduced into the carrier gas inlet, flows through the temporary storage column, and delivers the first part of the target to the focusing analysis module.

[0033] The first given temperature is lower than the third given temperature.

[0034] A second aspect of the present invention provides a monitoring device for ozone-depleting substances and hydrofluorocarbons in the atmosphere, comprising:

[0035] The target object capture pipeline includes a capture module, which is used to capture the target object in the sample gas;

[0036] The focusing analysis module is used for focusing and chromatographic separation of target analytes before detection.

[0037] The analysis pipeline includes an analysis carrier gas inlet and a trapping module, wherein the trapping module is used to connect the analysis carrier gas inlet and the focusing analysis module at its two ends respectively;

[0038] A purification pipeline is provided to remove interfering substances from the target analyte in the trapping module. The purification pipeline includes a capillary column purification module for removing interfering substances from the target analyte. The purification pipeline has a first state and a second state. In the first state, the inert gas passes sequentially through the trapping module and the capillary column purification module. In the second state, the inert gas passes sequentially through the capillary column purification module and the trapping module.

[0039] In some embodiments, a dehydration module is further included, which is disposed on the target collection pipeline and is used to dehydrate the sample gas before the sample gas enters the collection module.

[0040] In some embodiments, the dehydration module includes a first dehydration module and a second dehydration module;

[0041] The target collection pipeline also includes an autosampler, a pump, and a first flow meter. The autosampler is used to connect to the Summa tank. The pump is located at one end near the outlet of the target collection pipeline. The autosampler is connected to the pump in sequence through the first dehydration module, the second dehydration module, the collection module, and the first flow meter.

[0042] The focusing analysis module includes a focusing module, a chromatographic separation module, and a detection unit connected in sequence. The focusing module is used to focus the target analyte and input the target analyte into the chromatographic separation module. The chromatographic separation module is used to perform chromatographic separation on the target analyte and then input it into the detection unit. The inlet of the focusing module is connected to the multi-stage analytical pipeline.

[0043] In some embodiments, a one-to-many selector valve, a first switching valve, and a second switching valve are also included;

[0044] The one-to-many selector valve has a fixed interface and a plurality of selectable interfaces, and the one-to-many selector valve is configured to connect one of the fixed interfaces to one of the selectable interfaces.

[0045] The autosampler is connected to the selection interface S7 of the one-to-many selector valve via the first dehydration module. The fixed interface is connected to the interface P1 of the first switching valve. The interface P2 of the first switching valve is connected to the interface P5 of the second switching valve. The two ends of the trapping module are connected to the interfaces P3 and P6 of the first switching valve, respectively. The interface P4 of the first switching valve is connected to the focusing module. The interface P5 of the first switching valve is connected to the desorption carrier gas inlet. The interface P7 of the first switching valve is connected to the pump via the first flow meter. The interface P8 of the first switching valve is connected to the interface P2 of the second switching valve. The two ends of the second dehydration module are connected to the interfaces P3 and P4 of the second switching valve, respectively. The two ends of the capillary column purification module are connected to the interfaces P6 and P1 of the second switching valve, respectively.

[0046] The first switching valve has an A state and a B state. When the first switching valve is in the A state, only its interfaces P1 and P8, P2 and P3, P4 and P5, and P6 and P7 are connected. When the first switching valve is in the B state, only its interfaces P1 and P2, P3 and P4, P5 and P6, and P7 and P8 are connected.

[0047] The second switching valve has an A state and a B state. When the second switching valve is in the A state, only its interfaces P1 and P6, P2 and P3, and P4 and P5 are connected. When the second switching valve is in the B state, only its interfaces P1 and P2, P4 and P5, and P5 and P6 are connected.

[0048] In some embodiments, the purification pipeline includes an inert gas inlet, a first three-way valve, and a second three-way valve;

[0049] One end of the first three-way valve is connected to one end of the second three-way valve. The other two ends of the first three-way valve are respectively connected to the inert gas inlet and the selection interface S5 of the one-to-many selector valve. The other two ends of the second three-way valve are respectively connected to the interface P7 of the first switching valve and the first flow meter.

[0050] The first three-way valve is configured to connect the inert gas inlet to the one-to-many selector valve or to connect the inert gas inlet to the second three-way valve;

[0051] The second three-way valve is configured to connect the first three-way valve to the first switching valve or to connect the first switching valve to the first flow meter.

[0052] This invention also provides a method for monitoring ozone-depleting substances and hydrofluorocarbons in the atmosphere, using the ozone-depleting substances and hydrofluorocarbons monitoring device described in any embodiment of the second aspect. The method includes the following steps:

[0053] S1. Pass the sample gas into the collection pipeline and collect the target substance in the sample gas through the collection module;

[0054] S2. The purification pipeline is switched to the first state. The temperature of the capillary column purification module is set to the fourth given temperature, and the temperature of the collection module is set to the fifth given temperature to decompose interfering substances and some target substances with boiling points below the fifth given temperature. Inert gas is introduced into the purification pipeline and flows into the collection module and the capillary column purification module in sequence, bringing the decomposed interfering substances and some target substances into the capillary column purification module. Chromatographic separation is performed through the capillary column purification module until the interfering substances are eliminated, and the introduction of inert gas is stopped.

[0055] S3. The purification pipeline is switched to the second state. The temperature of the capillary column purification module is set to the sixth given temperature to resolve the partial target analyte. The temperature of the collection module is set to the seventh given temperature. Inert gas is introduced into the purification pipeline to bring the partial target analyte back to the collection module, thus completing the recovery of the partial target analyte. The seventh given temperature is lower than the fifth given temperature.

[0056] S4. The capture module is switched to the analysis pipeline. The temperature of the capture module is set to the eighth given temperature. Carrier gas is introduced into the carrier gas inlet and flows through the capture module to deliver the target object to the focusing analysis module. Attached Figure Description

[0057] To more clearly illustrate the technical solutions in the embodiments of this specification or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the embodiments of this specification. For those skilled in the art, other drawings can be obtained based on these drawings.

[0058] Figure 1 This is a schematic diagram of the structure of the ozone-depleting substances and hydrofluorocarbons monitoring device in the atmosphere provided in Embodiment 1 of the present invention;

[0059] Figure 2 This is a schematic diagram of the structure of the ozone-depleting substances and hydrofluorocarbons monitoring device in the atmosphere provided in Embodiment 3 of the present invention;

[0060] Figure 3 These are the chromatograms of steps SC1 to SC8 in Embodiment 4 of the present invention;

[0061] Figure 4 The chromatograms are for steps SD1 to SD10 in Embodiment 4 of the present invention. Detailed Implementation

[0062] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0063] Example 1

[0064] This invention provides a monitoring device 100 for ozone-depleting substances and hydrofluorocarbons in the atmosphere, such as... Figure 1 As shown, it includes:

[0065] The system includes a target analyte collection line, a multi-stage analytical line, and a focusing analysis module. The target analyte collection line includes a collection module 203, which is used to capture the target analyte in the sample gas and remove interfering substances. The collection module 203 is used to remove other interfering substances such as carbon dioxide, oxygen, xenon, and argon from the gas. The multi-stage analytical line includes an analytical carrier gas inlet 304 and a temporary column switching module. The focusing analysis module is used to focus and chromatographically separate the target analyte before detection. The analytical carrier gas inlet 304 is, for example, an electronic pressure controller (EPC).

[0066] The carrier gas inlet is connected to the focusing analysis module via the collection module and the temporary storage column switching module. The multi-stage analysis pipeline is used to transport the target objects to be analyzed in batches to the focusing analysis module.

[0067] The temporary storage column switching module has a first state and a second state. In the first state, the collection module is connected to the focusing analysis module through the temporary storage column 301. In the second state, the collection module is directly connected to the focusing analysis module without going through the temporary storage column 301. The temporary storage column 301 has chromatographic separation capability. The temporary storage column is used to temporarily store the target analyte and deliver it to the focusing analysis module. The target analyte refers to the target gas.

[0068] The capture module has a first state and a second state. When it is in the first state, the analytical carrier gas inlet 304 is connected to the temporary storage column switching module through the capture module 203. When it is in the second state, the analytical carrier gas inlet is directly connected to the temporary storage column switching module without passing through the capture module 203.

[0069] In some embodiments, a dehydration module is further included, which is disposed on the target collection pipeline and is used to dehydrate the sample gas before the sample gas enters the collection module.

[0070] In some embodiments, the dehydration module includes a first dehydration module 201 and a second dehydration module 202. The first-stage dehydration module 201 and the second-stage dehydration module 202 are used to dehydrate the collected gas. By using the dehydration module 201, the second-stage dehydration module 202, and the trapping module 203 to dehydrate, enrich, and remove carbon dioxide from the sample gas, compared to a three-stage cold trap pre-concentrator, an additional dehydration cold trap is added, resulting in better water removal efficiency, higher recovery rate of target compounds, and better peak shape. Optionally, in some embodiments, the multi-stage analytical pipeline is equipped with a Nafion tube, which can further dehydrate the carrier gas and sample to ensure maximum removal of moisture interference while avoiding the need for a pressurization device for collecting ambient air, thereby making the peak time and peak shape more stable and the structure relatively simpler.

[0071] The target collection pipeline also includes an autosampler 101, a pump 109, and a first flow meter 105. The autosampler 101 is used to connect to the Summa tank. The pump 109 is located at one end near the outlet of the target collection pipeline. The autosampler 101 is connected to the pump 109 in sequence through the first dehydration module 201, the second dehydration module 202, the collection module 203, and the first flow meter 105. The autosampler 101 is used to collect sample gases from different Summa canisters as needed, wherein the Summa canisters are pre-filled with sample gases. The autosampler 101 provides two sampling methods: firstly, the Summa canisters can be directly connected to different sample positions provided by the pre-concentration valve, and the gas from the Summa canisters connected to these sample positions can be collected as needed; secondly, the autosampler 101 can be connected via a pre-concentration valve, allowing multiple Summa canisters to be connected simultaneously. The Summa canisters containing the gas are hung on the autosampler 101 as needed, and the gas is collected from the corresponding sample position of the autosampler. This improves monitoring and analysis efficiency and meets the need for continuous gas sampling from different Summa canisters. Optionally, the first flow meter 105 is, for example, a nitrogen sampling flow meter.

[0072] Optionally, the primary dehydration module 201 uses a polytetrafluoroethylene (PTFE) hollow tube, the secondary dehydration module 202 uses a PTFE hollow tube, and the collection module 203 is a stainless steel liner filled with a composite packing material of Tenax and carbon molecular sieve.

[0073] The focusing analysis module includes a focusing module 302, a chromatographic separation module, and a detection unit 501 connected in sequence. The focusing module 302 is used to focus the target analyte and input it into the chromatographic separation module. The chromatographic separation module includes a chromatographic column 401, a condenser, and a heat exchanger. The condenser and heat exchanger 403 are connected to the chromatographic column 401. One end of the chromatographic column 401 is connected to the detection unit, and the other end is connected to the focusing module 302 via an inert two-way valve. After chromatographic separation, the target analyte is input into the detection unit 501. The inlet of the focusing module 302 is connected to the multi-stage analytical pipeline. Specifically, the focusing analysis module is used to refocus the target analyte at low temperature through the focusing module 302, while simultaneously controlling the programmed temperature rise, so that the target analyte flows into the detection unit 501 one by one. It should be noted that the low temperature here refers to an environment of -15℃ to 15℃. The detection unit 501 includes an ion source and an ion multiplier. The ion source fragments the target molecule into ions. The ion fragments enter the ion multiplier to form a current signal. The ion multiplier is used to receive, amplify and form a chromatogram of the current signal, which facilitates qualitative and quantitative analysis.

[0074] Optionally, in some embodiments, the present invention further includes a signal acquisition and processing control unit, which is connected to other units and used to acquire, process, and control the temperature, pressure, analog signals, etc., of the other units. (It should be noted that reverse control refers to sending instructions to other units through the control unit to control them. These instructions can be automatic control based on the acquired data, or control instructions manually input by the operator. Through reverse control, the control unit can realize real-time monitoring and adjustment of the system to ensure the normal operation and stability of the system. For example, the temperature of various modules such as the capture module 203 can be controlled through reverse control.)

[0075] This invention achieves step-temperature analysis of target analytes through a combination of a collection module and a temporary storage column switching module. Step-temperature analysis involves cooling the collected gas, then reheating it to extract target analytes with different boiling points. Addressing the challenge of separating the target analytes, this invention employs a step-temperature analysis and temporary storage column design. The cooling method utilizes a cryogenic mode, and the heating method employs a hot nitrogen chamber mode for rapid temperature rise. Based on the differences in the boiling points of the target analytes, the analysis is divided into two stages, with each batch entering the chromatographic separation module in full volume to achieve higher separation and better peak shapes.

[0076] It should be understood that the two-stage analysis involves first analyzing the low-boiling-point target compound and temporarily storing it in the temporary storage column 301, then analyzing the high-boiling-point target compound and allowing it to enter the chromatographic separation module, and finally, the target compound in the temporary storage column 301 enters the chromatographic separation module. Since the temporary storage column 301 also uses a chromatographic separation column, it effectively pre-treats the low-boiling-point target compound. This allows the low-boiling-point target compound to pass through a longer column (combined with the temporary storage column and the chromatographic separation module column 401), which is beneficial for separating the difficult-to-remove interfering substances mixed in with the low-boiling-point target compound, thus resulting in a better overall separation effect.

[0077] In some embodiments, the present invention further includes a one-to-many selector valve 102, a first switching valve 103, and a second switching valve 104;

[0078] The one-to-many selector valve 102 has a fixed interface and multiple selector interfaces. The one-to-many selector valve 102 is configured to connect one of the fixed interfaces to one of the selector interfaces. Specifically, the one-to-many selector valve 102 is, for example, an eight-inlet, one-outlet selector valve. The multiple selector interfaces include, for example, flow paths S1 to S8, where S1 and S8 are blocked, S2 is an vent, S3 is a spare interface (which can also be used to directly connect to a Summa canister), S4 is an internal standard gas interface, S5 is a blank helium gas input interface, S6 is an environmental standard gas interface, and S7 is an interface for connecting to the target object collection pipeline.

[0079] The autosampler 101 is connected to the selection interface S7 of the one-to-many selection valve via the first dehydration module 201. The fixed interface S0 is connected to the interface P1 of the first switching valve. The two ends of the second dehydration module 202 are connected to the interfaces P2 and P8 of the first switching valve, respectively. The two ends of the trapping module 203 are connected to the interfaces P3 and P6 of the first switching valve, respectively. The interface P7 of the first switching valve is connected to the pump 109 via the first flow meter 105. The interface P5 of the first switching valve is connected to the desorption carrier gas inlet 304. The interface P4 of the first switching valve is connected to the interface P5 of the second switching valve. The two ends of the temporary storage column 301 are connected to the interfaces P6 and P7 of the second switching valve, respectively. The interface P8 of the second switching valve is connected to the focusing module. Optionally, in some embodiments, the nanofen tube is disposed between the interface P4 of the first switching valve and the interface P5 of the second switching valve.

[0080] The first switching valve 103 has an A state and a B state. When the first switching valve is in state A, only its ports P1 and P8, P2 and P3, P4 and P5, and P6 and P7 are connected. When the first switching valve is in state B, only its ports P1 and P2, P3 and P4, P5 and P6, and P7 and P8 are connected. Optionally, the first switching valve 103 is an eight-position switching valve.

[0081] The second switching valve 104 has states A and B. When the second switching valve is in state A, only its ports P6 and P7 and ports P5 and P8 are connected. When the second switching valve is in state B, only its ports P5 and P6 and ports P7 and P8 are connected. Optionally, the second switching valve 104 can be a four-position switching valve, a six-position switching valve, or an eight-position switching valve, such as... Figure 1 The embodiment shown employs an eight-position switching valve.

[0082] Optionally, such as Figure 1 As shown, regions H1 and H2 are constant-temperature zones, electrically heated and PID-controlled. T1–T5 are variable-temperature control zones. T1–T2 are cooled by semiconductor elements, electrically heated, and PID-controlled. T3 is cooled by Stirling elements, electrically heated, and PID-controlled. T4 is cooled by Stirling elements, electrically heated with nitrogen, and then heated with hot nitrogen. T5 is the variable-temperature control zone in the column oven. The temporary storage column 301 and the chromatographic separation module are located in the column oven, and the heat exchanger 403 is installed in the column oven. The variable-temperature control zone of T5 also includes a condenser 402. The compressor in condenser 402 drives the refrigerant to evaporate and cool in heat exchanger 403. Heating is provided by a heater in the column oven, and PID-controlled to -10 to 10 degrees Celsius as the initial chromatographic temperature.

[0083] In some embodiments, a forward and reverse blowing pipeline is also included, which is connected to the target object collection pipeline and is used to introduce inert gas into the target object collection pipeline from two directions respectively, so that the collection module 203 can collect the target object remaining in the target object collection pipeline.

[0084] The forward and reverse blowing pipeline has a first state and a second state. In the first state, the inert gas passes through the second dehydration module 202 and the collection module 203 in sequence. In the second state, the inert gas passes through the collection module 203 and the second dehydration module 202 in sequence.

[0085] In some embodiments, the forward and reverse blowing pipeline includes an inert gas inlet, a first three-way valve 107, and a second three-way valve 112;

[0086] One end of the first three-way valve 107 is connected to one end of the second three-way valve 112. The other two ends of the first three-way valve 107 are respectively connected to the inert gas inlet and the selection interface S5 of the one-to-many selector valve. The other two ends of the second three-way valve 112 are respectively connected to the interface P7 of the first switching valve and the first flow meter 105.

[0087] The first three-way valve 107 has a first state and a second state. In the first state, the inert gas inlet is connected to the one-to-many selector valve 102. In the second state, the inert gas inlet is connected to the second three-way valve 112.

[0088] The second three-way valve 112 has a first state and a second state. In the first state, the first three-way valve 107 is connected to the first switching valve 103. In the second state, the first switching valve 103 is connected to the first flow meter 105.

[0089] Optionally, the inert gas inlet is connected to the first three-way valve 107 via a second flow meter 108. Optionally, the inert gas inlet is used to introduce high-pressure helium, and the second flow meter 108 is a helium sampling flow meter.

[0090] Example 2

[0091] This invention also provides a method for monitoring ozone-depleting substances and hydrofluorocarbons in the atmosphere, using the ozone-depleting substances and hydrofluorocarbons monitoring device described in any of the embodiments of Embodiment 1. The method includes the following steps:

[0092] S1. Pass the sample gas into the collection pipeline and collect the target substance in the sample gas through the collection module;

[0093] S2. The temporary storage column switching module is switched to the first state, the collection module is switched to the first state, the collection module is set to the first given temperature to resolve the first part of the target analyte, and the carrier gas is introduced into the carrier gas inlet and flows into the collection module and the temporary storage column in sequence. The temperature of the temporary storage column is set to the second given temperature so that the first part of the target analyte is retained in the temporary storage column. The first part of the target analyte is separated by chromatography through the temporary storage column.

[0094] S3. The temporary storage column switching module is switched to the second state, the collection module is switched to the first state, the collection module is set to the third given temperature to resolve the second part of the target, the carrier gas is introduced into the carrier gas inlet and flows through the collection module to deliver the second part of the target to the focusing analysis module;

[0095] S4. The temporary storage column switching module switches to the first state, the collection module switches to the second state, and the carrier gas is introduced into the carrier gas inlet, flows through the temporary storage column, and delivers the first part of the target to the focusing analysis module.

[0096] The first given temperature is lower than the third given temperature.

[0097] In some embodiments, a method for monitoring ozone-depleting substances and hydrofluorocarbons in the atmosphere includes: using the ozone-depleting substances and hydrofluorocarbons monitoring device described in the first aspect embodiment, and further includes the following steps:

[0098] S1. System standby preparation, adjusting the temperature and gas pressure of each unit; this step is used to complete various pre-sampling preparations, including the temperature and gas pressure of each temperature control module.

[0099] S2, collect gas samples, pass the sample gas into the collection pipeline, and collect the target substances in the sample gas through the collection module;

[0100] Specifically, the autosampler 101 collects sample gas from the SUMMA canister, the one-to-many selector valve connects to the selector interface S7, and the first switching valve switches to state A, so that the sample gas flows out sequentially through the first dehydration module 201, the first switching valve 103, the second dehydration module 202, the collection module 203, the first flow meter 105 and the pump 109.

[0101] S3, Dehydration and Enrichment: First, the collected gas sample is dehydrated by the first dehydration module 201 and the second dehydration module 202 at a temperature of -45℃ to 25℃. Then, the dehydrated gas is adsorbed and enriched by the collection module 203 at a temperature of -100℃ to -30℃. Specifically, gas samples from different Sumatra containers are collected according to the set flow rate, volume, pre-concentrated sample position, or different sample positions of the autosampler 101, including diluted standard gas, internal standard gas, blank gas, and actual sample gas. The collected gas samples are then subjected to low-temperature bipolar dehydration and low-temperature adsorption enrichment. The temperature is maintained at -45℃ to 25℃ during the low-temperature bipolar dehydration treatment and at -45℃ to -2℃ during the low-temperature adsorption enrichment treatment.

[0102] S4. Dry blowing recovery and purification: The first three-way valve 107 is switched to the first state, and the one-to-many selector valve is connected to the selection interface S5. The system first uses high-purity helium gas at low temperature to purge the dehydration module and recover the target material remaining in the dehydration module to the collection module 203. Then, the first three-way valve 107 and the second three-way valve 112 are switched to the second state. High-purity helium gas is used to purge the collection module 203 in reverse to recover the target material that is difficult to concentrate and is about to leave the collection module 203, and then collect it in the collection module 203. Specifically, helium gas at low temperature (-5~10℃) is used to purge the dehydration tube in the forward direction to recover the target material to the adsorption tube in the collection module 203. At the same time, the adsorption tube is purified to remove interfering substances such as carbon dioxide. Then, the reverse purging is used to recover the target material that is difficult to concentrate and is about to leave the collection module 203, and then collect it in the collection module 203.

[0103] S5. In the first stage of analysis, the first switching valve is switched to state B, the second switching valve is switched to state B, and the collection module 203 is heated to a first given temperature to analyze the first part of the low-boiling-point target substance. The first given temperature is, for example, 0~50℃. Carrier gas is introduced into the analysis carrier gas inlet 304. The carrier gas carries the analyzed first part of the target substance through the collection module 203 into the temporary storage column 301. The temporary storage column 301 temporarily stores the first part of the target substance under the condition of controlling the temperature between -20℃ and 10℃. Specifically, the adsorption tube of the first stage collection module 203 is heated to 0~50℃ to analyze a part of the low-boiling-point target substance, which is carried into the temporary storage column 301 by the carrier gas.

[0104] S6. Second-stage analysis: The first switching valve switches to state B, and the second switching valve switches to state A. The temperature of the collection module 203 is controlled to rise to 180~280℃ to decompose the second part of the target substance with a high boiling point, which is then directly carried into the focusing module 302 by the carrier gas.

[0105] S7. First-stage injection: The focusing module 302 is rapidly heated to 120-200℃ using the hot nitrogen chamber for analysis, so that the second part of the target analyte from the focusing module 302 enters the chromatographic column 401 in its entirety.

[0106] S8. Second-stage injection: Switch the second switching valve 104 to B to pass the first part of the target analyte trapped in the temporary storage column 301 into the focusing module 302, and then inject it into the chromatographic column 401.

[0107] S9, low-temperature chromatographic separation and detection, involves performing chromatographic separation of all target substances in a chromatographic column 401 oven at an environment of -15 to 15℃, detecting the separated target substances, and analyzing the results.

[0108] In a preferred embodiment, during sample injection in system steps S7-S8, the primary dehydration module 201 and the secondary dehydration module 202 are simultaneously heated to 160-210°C, and the collection module 203 is heated to 180-250°C. Nitrogen gas is introduced to clean the dehydration module and the collection module 203 by controlling the flow rate of the first flow meter 105 to 80-160 mL / min.

[0109] In a preferred embodiment, the process of dehydrating the carrier gas end using a Nafent tube requires maintaining a certain nitrogen flow rate in the Nafent tube at all times, based on the dehydration principle of the Nafent tube itself. Nitrogen gas at a flow rate of 20-80 ml / min is introduced by setting a secondary nitrogen sampling flow meter to remove moisture from the carrier gas.

[0110] In some embodiments, a method for monitoring ozone-depleting substances and hydrofluorocarbons in the atmosphere includes:

[0111] SA1. System standby preparation, complete various pre-sampling preparations: H1, H2. Control the temperature to 140℃, the first dehydration module 201 and the second dehydration module 202 control the temperature to -30℃, the collection module 203 control the temperature to -60℃, the first switching valve 103 and the second switching valve 104 switch to state A, and the remaining components are in the default state.

[0112] SA2. Gas Sample Collection: Based on the set gas type, flow rate, and volume to be collected, switch the selector valve to the designated position to connect the interface, turn on the sampling pump 109, limit the collection flow rate with the nitrogen mass flow meter, and turn off the nitrogen mass flow meter after reaching the specified sampling volume; and sequentially switch between different sample channels and injector sample channels to perform adsorption and enrichment treatment on injector sample, injector ambient air, internal standard gas, blank nitrogen, etc.

[0113] SA3, Dry Blow Recovery: Heat the dehydration module to 5℃, set the multi-select valve to the selection interface S7, switch the autosampler 101 interface to interface 1, set the nitrogen mass flow meter to 4ml / min, purge the dehydration module with nitrogen for 2min, recover the target substance to the collection module 203, and at the same time purify the adsorption tube to remove interfering substances such as carbon dioxide.

[0114] SA4, Helium reverse dry blowing: Connect the one-to-many selector valve to the selector interface S5, set the helium mass flow meter to 20ml / min, and use helium reverse blowing to purge the collection module 203 for 30s to gather the dispersed target object into the collection module 203.

[0115] SA5, First-stage analysis to temporary storage column: Start the low-temperature column oven T5 for cooling. The compressor circulates the refrigerant in the heat exchanger 403 and condenser 402 to maintain the low-temperature column oven at -5℃. The focusing module 302 cools down to -30℃. The first switching valve 103 and the second switching valve 104 are switched to state B. At this time, the collection module 203 is connected to the temporary storage column 301 module. The collection module 203 is heated to 0℃ to analyze some of the target material, which is carried into the temporary storage column 301 by the carrier gas at 80kPa in a non-split mode.

[0116] SA6, Second-stage analysis to focusing module: First switching valve 103 to state B, second switching valve 104 to state A. At this time, the collection module 203 is connected to the focusing module 302. The collection module 203 is heated to 200°C to analyze the remaining target material, which is then carried into the focusing module 302 for storage by carrier gas 80kPa in a non-split mode.

[0117] SA7, one-stage full-volume injection: the focusing module 302 is rapidly heated to 200℃ for analysis, and the full volume is injected into the chromatographic column 401 under the silanization two-way connection to start chromatographic separation;

[0118] SA8, two-stage full-volume injection: the second switching valve 104 is switched back to state B, and the full volume is injected into column 401 under the silanization two-way connection to start chromatographic separation;

[0119] SA9, Hot Cleaning: Sample injection is performed simultaneously. Switch valve to state A. Temperatures of the dehydration module, dehydration module, and collection module 203 are raised to 200℃ and 250℃ respectively. Set the one-to-many selection valve to selection interface S7. Switch autosampler valve 101 to position 1 and sequentially open the solenoid valve and nitrogen mass flow meter to 100 ml / min, maintaining this for 8 minutes. Hot cleaning flow path system, hot cleaning dehydration module, dehydration module, and collection module 203.

[0120] SA10, Low-Temperature Chromatographic Separation and Detection: Chromatographic separation was performed using a T5 low-temperature column oven, maintaining -5℃ for 7 min, then increasing the temperature at 10℃ / min to 35℃ for 7 min; continuing at 10℃ / min to 120℃ for 10 min, then increasing the temperature at 5℃ / min to 182℃ for 0 min, and finally increasing the temperature at 48℃ / min to 230℃ for 2.3 min. An MS detector was used to detect the separated target analytes, and the results were analyzed and processed.

[0121] In some embodiments, a method for monitoring ozone-depleting substances and hydrofluorocarbons in the atmosphere includes:

[0122] SB1, System standby preparation, complete various pre-sampling preparations: H1, H2, control temperature to 140℃, dehydration module control temperature to -30℃, collection module 203 control temperature to -60℃, first switching valve 103 and second switching valve to state A, and other components in default state.

[0123] SB2. Gas Sample Collection: Based on the set gas type, flow rate, and volume to be collected, switch the one-to-many selector valve to the designated position to connect the interface, turn on the sampling pump, limit the collection flow rate with a nitrogen mass flow meter, and turn off the nitrogen mass flow meter after reaching the specified sampling volume; and sequentially switch between different sample channels and injector sample channels to perform adsorption and enrichment treatment on injector sample, injector ambient air, internal standard gas, blank nitrogen, etc.

[0124] SB3, Dry Blow Recovery: Heat the dehydration module to 5℃, set the multi-select valve to the selection interface S7, switch the autosampler interface to interface 1, set the nitrogen mass flow rate to 4ml / min, purge the dehydration module with nitrogen for 1.5min, recover the target substance to the collection module 203, and at the same time purify the adsorption tube to remove interfering substances such as carbon dioxide.

[0125] SB4, Helium reverse dry blowing: Set a one-to-many selector valve to the selector interface S5, the helium mass flow meter is 20ml / min, use helium to back purge the collection module 203 for 30s, and gather the dispersed target object into the collection module 203;

[0126] SB5, First-stage analysis to temporary storage column: Start the low-temperature column oven T5 for cooling. The compressor circulates the refrigerant in the heat exchanger 403 and condenser 402 to maintain the low-temperature column oven at -5℃. The focusing module 302 cools down to -30℃. The first switching valve 103 and the second switching valve 104 are switched to state B. At this time, the collection module 203 is connected to the temporary storage column 301 module. The collection module 203 is heated to 0℃ to analyze some of the target material, which is carried into the temporary storage column 301 module by the carrier gas at 80kPa in a non-split mode.

[0127] SB6, Second-stage analysis to focusing module 302: Eight-position switching valve 103 to state B, six-position switching valve 104 to state A. At this time, the collection module 203 is connected to the focusing module 302. The collection module 203 is heated to 200°C to analyze the remaining target material, which is then carried into the focusing module 302 for storage by carrier gas at 80 kPa in a non-splitting mode.

[0128] SB7, First-stage full-volume injection: Focusing module 302 is rapidly heated to 200℃ for analysis, and the full volume is injected into column 401 under the silanization two-way connection to start chromatographic separation. SB8, Second-stage full-volume injection: The second switching valve 104 is switched back to state B, and the full volume is injected into column 401 under the silanization two-way connection to start chromatographic separation.

[0129] SB9, Hot Cleaning: Sample injection is performed simultaneously. The first switching valve 103 is switched to state A. The temperatures of the first dehydration module 201, the second dehydration module 202, and the collection module 203 are controlled and raised to 200℃, 200℃, and 250℃ respectively. A one-to-many selection valve is set to the selection interface S7. The autosampler 101 valve is switched to position 1, and the solenoid valve and nitrogen mass flow meter are opened sequentially to 100 ml / min, maintained for 8 minutes. The hot cleaning flow path system hot cleans the first dehydration module 201, the second dehydration module 202, and the collection module 203.

[0130] SB10, Low-Temperature Chromatographic Separation and Detection: Chromatographic separation was performed using a T5 low-temperature column oven, maintaining -5℃ for 7 min, then increasing the temperature at 10℃ / min to 35℃ for 7 min; increasing the temperature at 10℃ / min to 120℃ for 10 min, then increasing the temperature at 5℃ / min to 182℃ for 0 min, and finally increasing the temperature at 48℃ / min to 230℃ for 2.3 min. An MS detector was used to detect the separated target analytes, and the results were analyzed and processed.

[0131] Example 3

[0132] Even after purification by the primary and secondary dehydration modules and the collection module, some difficult-to-remove interfering substances remain in the enriched target analytes. These interfering substances significantly hinder the quantitative detection of some low- and medium-boiling-point target analytes. To address this issue, Embodiment 1 of this invention employs a staged analysis approach. However, due to the difficulty in determining the boiling point boundary between the two stages in this staged analysis, the separation results of some target analytes overlap, resulting in some target analytes exhibiting two peaks of different sizes. To solve this problem, this embodiment provides a monitoring device for ozone-depleting substances and hydrofluorocarbons in the atmosphere, such as... Figure 2 As shown, it includes:

[0133] The target object capture pipeline includes a capture module 203, which is used to capture the target object in the sample gas;

[0134] The focusing analysis module is used for focusing and chromatographic separation of target analytes before detection.

[0135] The analysis pipeline includes an analysis carrier gas inlet 402 and a collection module, wherein the collection module is used to connect the two ends of the collection module 203 to the analysis carrier gas inlet 402 and the focusing analysis module, respectively.

[0136] A purification pipeline is provided to remove interfering substances from the target analyte in the trapping module. The purification pipeline includes a capillary column purification module 204, which is used to remove interfering substances from the target analyte. The purification pipeline has a first state and a second state. In the first state, the inert gas passes sequentially through the trapping module 203 and the capillary column purification module 204. In the second state, the inert gas passes sequentially through the capillary column purification module 204 and the trapping module 203.

[0137] In some embodiments, a dehydration module is further included, which is disposed on the target collection pipeline and is used to dehydrate the sample gas before the sample gas enters the collection module.

[0138] In some embodiments, the dehydration module includes a first dehydration module 201 and a second dehydration module 202;

[0139] The target collection pipeline also includes an autosampler 101, a pump 109, and a first flow meter 105. The autosampler 101 is used to connect to the Summa tank. The pump 109 is located at one end near the outlet of the target collection pipeline. The autosampler 101 is connected to the pump 109 in sequence through the first dehydration module 201, the second dehydration module 202, the collection module 203, and the first flow meter 105.

[0140] The focusing analysis module includes a focusing module 302, a chromatographic separation module, and a detection unit 405 connected in sequence. The focusing module 302 is used to focus the target analyte and input the target analyte into the chromatographic separation module. The chromatographic separation module is used to perform chromatographic separation on the target analyte and then input it into the detection unit. The inlet of the focusing module is connected to the multi-stage analytical pipeline.

[0141] The chromatographic separation module includes a chromatographic column 401, a condenser 404, and a heat exchanger 403. The condenser 404 and heat exchanger 403 are connected to the chromatographic column 401. One end of the chromatographic column 401 is connected to the detection unit, and the other end is connected to the focusing module 302 via an inert two-way valve. After chromatographic separation of the target analyte, the chromatographic separation module inputs the analyte into the detection unit 501. The inlet of the focusing module 302 is connected to the multi-stage analytical pipeline. Specifically, the focusing analysis module is used to refocus the target analyte at low temperature using the focusing module 302, while simultaneously controlling the programmed temperature rise, allowing the target analyte to flow into the detection unit 501 one by one. It should be noted that the low temperature here refers to an environment of -15℃ to 15℃. The detection unit 501 includes an ion source and an ion multiplier. The ion source fragments the target analyte molecules into ions; the ion fragments enter the ion multiplier to form a current signal, which is received, amplified, and used to form a chromatogram, facilitating qualitative and quantitative analysis.

[0142] In some embodiments, a multi-select valve 102, a first switching valve 103, and a second switching valve 104 are also included;

[0143] The one-to-many selector valve 102 has a fixed interface and a plurality of selector interfaces, and the one-to-many selector valve 102 is configured to enable one of the fixed interfaces to communicate with one of the selector interfaces.

[0144] The autosampler 101 is connected to the selection interface S7 of the one-to-many selector valve via the first dehydration module 201. The fixed interface is connected to the interface P1 of the first switching valve. The interface P2 of the first switching valve is connected to the interface P5 of the second switching valve. The two ends of the trapping module 203 are connected to the interfaces P3 and P6 of the first switching valve, respectively. The interface P4 of the first switching valve is connected to the focusing module. The interface P5 of the first switching valve is connected to the desorption carrier gas inlet. The interface P7 of the first switching valve is connected to the pump via the first flow meter. The interface P8 of the first switching valve is connected to the interface P2 of the second switching valve. The two ends of the second dehydration module 202 are connected to the interfaces P3 and P4 of the second switching valve, respectively. The two ends of the capillary column purification module 204 are connected to the interfaces P6 and P1 of the second switching valve, respectively.

[0145] The first switching valve 103 has an A state and a B state. When the first switching valve is in the A state, only its interfaces P1 and P8, P2 and P3, P4 and P5, and P6 and P7 are connected. When the first switching valve is in the B state, only its interfaces P1 and P2, P3 and P4, P5 and P6, and P7 and P8 are connected.

[0146] The second switching valve 104 has an A state and a B state. When the second switching valve is in the A state, only its ports P1 and P6, ports P2 and P3, and ports P4 and P5 are connected. When the second switching valve is in the B state, only its ports P1 and P2, ports P4 and P5, and ports P5 and P6 are connected.

[0147] Optionally, the one-to-many selector valve 102 can be an eight-in-one-out selector valve, the first switching valve 103 can be an eight-position switching valve, and the second switching valve 104 can be a six-position switching valve.

[0148] In some embodiments, the purification pipeline includes an inert gas inlet, a first three-way valve 110, and a second three-way valve 112; the first three-way valve 110 is, for example, a two-position three-way solenoid valve, and the second three-way valve 112 is, for example, a silanized three-way valve.

[0149] One end of the first three-way valve 110 is connected to one end of the second three-way valve 112. The other two ends of the first three-way valve 110 are respectively connected to the inert gas inlet and the selection interface S5 of the one-to-many selector valve. The other two ends of the second three-way valve 112 are respectively connected to the interface P7 of the first switching valve and the first flow meter.

[0150] The first three-way valve 110 is configured to connect the inert gas inlet to the one-to-many selector valve 102 or to connect the inert gas inlet to the second three-way valve 112;

[0151] The second three-way valve 112 is configured to connect the first three-way valve 110 to the first switching valve 103 or to connect the first switching valve 103 to the first flow meter 105.

[0152] In some embodiments, the system further includes a signal acquisition and processing control unit, including temperature and pressure sensors and PID control loops for each temperature control zone, as well as a high-temperature constant temperature zone and a variable temperature control zone; the high-temperature constant temperature zone is specifically defined as H1 to H3, wherein: a pair of multi-select valves 102, a first switching valve 103, a second switching valve 104, and a second three-way valve 112 are located in the H2 high-temperature constant temperature zone, positions S1-7 and both ends of the first-stage low-temperature empty tube dehydration module are located in the H1 high-temperature constant temperature zone, and the Nafion tube dehydration module is located in the H3 high-temperature constant temperature zone;

[0153] The temperature control zones are specifically T1 to T6, all employing PID temperature control with controllable temperature change rates. The first dehydration module 201 is located in the T1 temperature control zone, with a temperature range of -45℃ to 250℃. The second dehydration module 202 is located in the T2 temperature control zone, with a temperature range of -45℃ to 250℃. The collection module 203 is located in the T3 temperature control zone, with a temperature range of -160℃ to 300℃, cooled by a cryogenic compressor. The focusing module 302 is located in the T4 temperature control zone, with a temperature range of -160℃ to 200℃, cooled by a cryogenic compressor. The chromatographic column 401 is located in the T5 temperature control zone, with a temperature range of -5℃ to 300℃. The capillary column purification module 204 is located in the T6 temperature control zone, with a temperature range of 35℃ to 300℃.

[0154] In some embodiments, both the first dehydration module 201 and the second dehydration module 202 use polytetrafluoroethylene hollow tubes with an inner diameter of 2-4 mm and a length of 20-40 cm for cryogenic dehydration, thereby enabling sample collection under positive pressure, normal pressure, and negative pressure; the trapping module 203 is a silanized stainless steel tube with an inner diameter of 2-4 mm and a length of 20-40 cm, filled with a composite packing material of Tenax and carbon molecular sieve, which enriches the target analyte under ultra-low temperature conditions; the capillary column purification module 204 is a 30 m capillary column with a stationary phase coating, used to separate interfering substances and purify the target analyte.

[0155] In some embodiments, the focusing module 302 is a capillary chromatographic column with a stationary phase coating, having an outer diameter of 0.53 mm and a length of 20–40 cm. It is used to focus the target analyte into a very small volume for injection, ensuring sharp chromatographic peaks. The Nafion online dehydration module, which is 2–4 m long, continuously removes moisture from the carrier gas and desorption gas, ensuring that the chromatographic peaks do not drift.

[0156] This invention also provides a method for monitoring ozone-depleting substances and hydrofluorocarbons in the atmosphere, using the ozone-depleting substances and hydrofluorocarbons monitoring device described in any embodiment of the second aspect. The method includes the following steps:

[0157] S1. Pass the sample gas into the collection pipeline and collect the target substance in the sample gas through the collection module;

[0158] S2. The purification pipeline is switched to the first state. The temperature of the capillary column purification module is set to the fourth given temperature, and the temperature of the collection module is set to the fifth given temperature to decompose interfering substances and some target substances with boiling points below the fifth given temperature. Inert gas is introduced into the purification pipeline and flows into the collection module and the capillary column purification module in sequence, bringing the decomposed interfering substances and some target substances into the capillary column purification module. Chromatographic separation is performed through the capillary column purification module until the interfering substances are eliminated, and the introduction of inert gas is stopped.

[0159] S3. The purification pipeline is switched to the second state. The temperature of the capillary column purification module is set to the sixth given temperature to resolve the partial target analyte. The temperature of the collection module is set to the seventh given temperature. Inert gas is introduced into the purification pipeline to bring the partial target analyte back to the collection module, thus completing the recovery of the partial target analyte. The seventh given temperature is lower than the fifth given temperature.

[0160] S4. The capture module is switched to the analysis pipeline. The temperature of the capture module is set to the eighth given temperature. Carrier gas is introduced into the carrier gas inlet and flows through the capture module to deliver the target object to the focusing analysis module.

[0161] The capillary column purification module 204 in this embodiment of the invention can separate and purify impurities in the sample, including gases such as nitrogen, argon, krypton, and xenon, so that low-boiling-point substances such as NF3 and CF4, which are difficult to detect, can also be accurately analyzed qualitatively and quantitatively.

[0162] The first dehydration module 201, the second dehydration module 202, and the online Nafion tube dehydration module 303 of this invention can effectively remove a large amount of water from the sample and carrier gas, ensuring the stability of the retention time of each target component in the chromatogram formed by the detection unit, which is beneficial for accurate qualitative and quantitative analysis.

[0163] The trapping module 203 and focusing module 302 in this invention do not require any cooling medium to reduce the temperature to below -160°C by using a compressor. Therefore, they can be put into use as soon as possible without considering the site environment and the economic cost of the cooling medium.

[0164] The combined action of the refrigerator 404 and heat exchanger 403 in the low-temperature chromatography separation unit of the present invention controls the initial column temperature of the chromatography separation unit to be 35°C below room temperature. After injection, the column is refocused to optimize the peak shape, resulting in good separation and improved accuracy and reliability of the analysis.

[0165] In this invention, the Nafion online dehydration device 303 is located between the focusing module 302 and the eight-position switching valve. It cleverly uses the pressure provided by the EPC carrier gas pressure controller to achieve a third dehydration treatment of the carrier gas and the target material, minimizing the interference of moisture removal on the entire analysis.

[0166] The system of this invention has high sensitivity and low detection limit, and can effectively detect components with a concentration of some ppt (parts per billion) in ozone-depleting substances (ODS) and hydrofluorocarbons (HFCS).

[0167] Optionally, the sample gas in this invention is: a standard gas mixture of 40 ODS and controlled halocarbon gases with a concentration of 100 nmol·mol−1. Ultrapure helium: ≥99.9999%; high-purity nitrogen: ≥99.999%. Standard working gases: 5, 50, 500 pmol·mol−1 and 1 nmol·mol−1, prepared by stepwise dilution using a high-precision static dilutioner.

[0168] In some embodiments, a method for monitoring ozone-depleting substances and hydrofluorocarbons in the atmosphere includes:

[0169] SC1, System standby preparation: Adjust the temperature and gas pressure of each unit; raise the temperature of H1 and H2 areas to 120℃~160℃, raise the temperature of H3 to 40~60℃, adjust the flow rate of the auxiliary nitrogen mass flow meter to 30~60ml / min; lower the temperature of the primary dehydration module and the secondary dehydration module to 0℃~-40℃, lower the temperature of the collection module to -60~-80℃, the eight-position switching valve and the six-position switching valve are in state A, and the remaining components are in the default state.

[0170] SC2, Gas Sample Collection: Gas samples are collected from different Summa canisters through the sampling unit and transported to the concentration and purification unit; the mechanical pump is turned on, and the flow rate is set at 50~100ml / min using a nitrogen mass flow meter until the set volume is reached.

[0171] SC3, freeze dehydration, adsorption and capture: The primary and secondary dehydration modules remove moisture at temperatures of -45℃ to -10℃, while the capture module is set to a temperature of -60℃ to -80℃ to enrich the target analyte.

[0172] SC4, forward dry blowing recovery: heat the two dehydration modules to 2℃~20℃, set the nitrogen mass flow meter flow rate to 50ml / min~100ml / min, switch the eight-position selector valve to position 7, switch the autosampler selector valve to the nitrogen position, introduce nitrogen to purge the two dehydration modules for 10~45s, and recover the target material in the dehydration modules to the collection module;

[0173] SC5, capture and analyze, cryogenic capillary focusing: adjust the focusing module temperature to -120℃~-130℃, the capture module temperature to 180℃~220℃, switch the eight-position switching valve to state B, and bring the enriched target material into the focusing module for cryogenic focusing through the carrier gas.

[0174] SC6, full volume injection: control the temperature of the hot nitrogen chamber to 300℃, open the two-way solenoid valve, and use the high temperature nitrogen gas in the hot nitrogen chamber to rapidly heat the focusing module to 180~220℃, so that the target analyte in the focusing module enters the low temperature chromatographic column in the low temperature chromatography separation unit for secondary aggregation.

[0175] SC7, low-temperature chromatographic separation, uses a suitable temperature program and a certain pressure to perform chromatographic separation of the target analytes in the chromatographic column, and the analytes flow into the detector in batches to form a chromatographic mass spectrum for qualitative and quantitative analysis;

[0176] SC8, hot cleaning: the primary and secondary dehydration modules are heated to 180~220℃, the collection module is heated to 200~260℃, the flow rate is set to 80~100mL / min by controlling the nitrogen mass flow meter, the mechanical pump is turned on, and the cleaning is performed for 240s~480s.

[0177] Figure 3 In steps SC1 to SC8: the sampling unit collects 1000 ml of 1 nmol·mol−1 standard gas, which is concentrated and purified, and then focused into the low-temperature chromatographic separation and detection unit for processing to obtain a chromatographic mass spectrum. The spectrum contains 38 target peaks, which are numbered at the top of the peaks, and each number represents a target.

[0178] Table 1 shows the low, medium, and high linear relationships, detection limits, and background values ​​of some target compounds obtained from the analysis of a series of standard samples using the ozone-depleting substances and hydrofluorocarbons monitoring and analysis system in steps SC1-SC8. In this case, without reverse dry-blowing capillary column purification, the target compounds NF3 and CF4 could not be identified due to interference, and therefore could not be qualitatively or quantitatively analyzed.

[0179] Table 1

[0180]

[0181] In some embodiments, a method for monitoring ozone-depleting substances and hydrofluorocarbons in the atmosphere includes:

[0182] SD1, System standby preparation: Adjust the temperature and gas pressure of each unit; control the temperature of H1 and H2 to 120℃~160℃, control the temperature of H3 to 50℃, adjust the flow rate of the auxiliary nitrogen mass flow meter to 40~60ml / min; control the temperature of the primary dehydration module and the secondary dehydration module to 0℃~-40℃, control the temperature of the collection module to -135~-160℃, the eight-position switching valve and the six-position switching valve are in state A, and all other components are in default state;

[0183] SD2. Collect gas samples: According to the set gas to be collected, switch the eight-position selector valve to sample position 6, open the two-way solenoid valve, start the mechanical pump, and limit the collection flow rate to 50~100ml / min with the nitrogen mass flow meter to collect the set volume.

[0184] SD3, freeze dehydration, adsorption capture: The collected gas sample is dehydrated in a two-stage dehydration module at a temperature of -45℃ to 0℃, and then the dehydrated gas is enriched with the target substance in a capture module at a temperature of -160℃ to -135℃ after passing through a concentration and purification unit.

[0185] SD4, one-time forward dry purge recovery: heat the two dehydration modules to 5℃~10℃, adjust the flow rate of nitrogen mass flow meter to 50ml / min~100ml / min, switch the eight-position selector valve to position 7, switch the autosampler selector valve to the nitrogen position, introduce nitrogen to purge the dehydration modules for 10~30s, and recover the target material retained in the two dehydration modules into the collection module;

[0186] SD5, Helium reverse dry purge purification: Adjust the temperature of the collection module to -120~-100℃, raise the temperature of the capillary column purification module to 35℃~45℃, switch the six-position switching valve to state B, adjust the flow rate of the helium mass flow meter to 4ml / min~10ml / min, open the three-way solenoid valve to introduce helium from the silanized three-way purge collection module for 15s~60s;

[0187] SD6, secondary forward dry purge in situ collection, adjust the temperature of the capillary column purification module to 100℃~150℃, cool the collection module to -160℃~-135℃, adjust the flow rate of the helium mass flow meter to 4ml / min~10ml / min, close the three-way solenoid valve, switch the eight-position selector valve to position 5, and introduce helium to purge the capillary column purification module;

[0188] SD7, capture and analyze, cryogenic capillary focusing: adjust the focusing module temperature to -135℃~-160℃, the capture module temperature to 180℃~250℃, switch the eight-position switching valve to state B, and bring the captured target gas into the focusing module for cryogenic focusing through the carrier gas;

[0189] SD8, full volume injection, control the temperature of the hot nitrogen chamber to 300℃, open the two-way solenoid valve, use the high temperature nitrogen gas in the hot nitrogen chamber to rapidly heat the focusing module to 180~220℃, and introduce the target gas in the focusing module into the low temperature chromatographic column in the low temperature chromatographic analysis unit for secondary aggregation.

[0190] SD9, low-temperature chromatographic separation, uses appropriate carrier gas pressure and temperature program to perform chromatographic separation of target substances in the chromatographic column, and the substances flow into the detector in batches to form chromatographic mass spectra for qualitative and quantitative analysis;

[0191] SD10, hot cleaning, the primary and secondary dehydration modules are heated to 180~210℃, the collection module is heated to 180~250℃, the capillary column purification module is heated to 80℃~150℃, the flow rate is set to 80~160mL / min by controlling the nitrogen mass flow meter, the pump is turned on, and the cleaning is performed for 240s~480s.

[0192] Figure 4 In steps SD1 to SD10: the sampling unit collects 1000 ml of 1 nmol·mol−1 standard gas, which is then concentrated and purified. The gas is then focused into the low-temperature chromatographic separation and detection unit by ultra-low temperature capillary column to obtain a chromatographic mass spectrum. The spectrum contains 40 target peaks, which are numbered at the top of the peaks. Each number represents a target analyte.

[0193] Table 2 shows a comparison of the low, medium, and high correlation coefficients, detection limits, and background values ​​of the target analytes obtained from a series of standard samples analyzed by the ozone-depleting substances and hydrofluorocarbons monitoring and analysis system in steps SD1 to SD10. In steps SD1 to SD10, after reverse dry-blowing capillary column purification and two forward dry-blowing recoveries, NF3 and CF4 were captured and showed significant responses in the spectral path, allowing for qualitative and quantitative analysis.

[0194] Table 2

[0195]

[0196] In the description of this invention, it should be understood that the terms "coaxial," "bottom," "one end," "top," "middle," "other end," "upper," "side," "top," "inner," "front," "center," "both ends," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0197] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "setting," "connection," "fixing," "screw connection," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal connection of two components or the interaction between two components. Unless otherwise explicitly limited, those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0198] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A device for monitoring ozone-depleting substances and hydrofluorocarbons in the atmosphere, characterized in that, include: The target object capture pipeline, including a capture module, is used to capture target objects in the sample gas and remove interfering substances through the capture module; Multi-stage analytical pipeline, including analytical carrier gas inlet and temporary storage column switching module; and The focusing analysis module is used for focusing and chromatographic separation of target analytes before detection. The analytical carrier gas inlet is connected to the focusing analysis module in sequence through the trapping module and the temporary storage column switching module. The multi-stage analytical pipeline is used to transport the target objects to be analyzed in batches to the focusing analysis module. The temporary storage column switching module has a first state and a second state. When it is in the first state, the collection module is connected to the focusing analysis module through the temporary storage column. When it is in the second state, the collection module is directly connected to the focusing analysis module without going through the temporary storage column. The temporary storage column has chromatographic separation capability. The capture module has a first state and a second state. When it is in the first state, the analytical carrier gas inlet is connected to the temporary storage column switching module through the capture module. When it is in the second state, the analytical carrier gas inlet is directly connected to the temporary storage column switching module without going through the capture module.

2. The monitoring device for ozone-depleting substances and hydrofluorocarbons in the atmosphere according to claim 1, characterized in that: It also includes a dehydration module, which is located on the target gas collection pipeline and is used to dehydrate the sample gas before it enters the collection module.

3. The monitoring device for ozone-depleting substances and hydrofluorocarbons in the atmosphere according to claim 2, characterized in that: The dehydration module includes a first dehydration module and a second dehydration module; The target collection pipeline also includes an autosampler, a pump, and a first flow meter. The autosampler is used to connect to the Summa tank. The pump is located at one end near the outlet of the target collection pipeline. The autosampler is connected to the pump in sequence through the first dehydration module, the second dehydration module, the collection module, and the first flow meter. The focusing analysis module includes a focusing module, a chromatographic separation module, and a detection unit connected in sequence. The focusing module is used to focus the target analyte and input the target analyte into the chromatographic separation module. The chromatographic separation module is used to perform chromatographic separation on the target analyte and then input it into the detection unit. The inlet of the focusing module is connected to the multi-stage analytical pipeline.

4. The monitoring device for ozone-depleting substances and hydrofluorocarbons in the atmosphere according to claim 3, characterized in that: It also includes a one-to-many selector valve, a first switching valve, and a second switching valve; The one-to-many selector valve has a fixed interface and a plurality of selectable interfaces, and the one-to-many selector valve is configured to connect one of the fixed interfaces to one of the selectable interfaces. The autosampler is connected to the selection interface S7 of the one-to-many selection valve via the first dehydration module. The fixed interface is connected to the interface P1 of the first switching valve. The two ends of the second dehydration module are connected to the interfaces P2 and P8 of the first switching valve, respectively. The two ends of the trapping module are connected to the interfaces P3 and P6 of the first switching valve, respectively. The interface P7 of the first switching valve is connected to the pump via the first flow meter. The interface P5 of the first switching valve is connected to the desorption carrier gas inlet. The interface P4 of the first switching valve is connected to the interface P5 of the second switching valve. The two ends of the temporary storage column are connected to the interfaces P6 and P7 of the second switching valve, respectively. The interface P8 of the second switching valve is connected to the focusing module. The first switching valve has an A state and a B state. When the first switching valve is in the A state, only its interfaces P1 and P8, P2 and P3, P4 and P5, and P6 and P7 are connected. When the first switching valve is in the B state, only its interfaces P1 and P2, P3 and P4, P5 and P6, and P7 and P8 are connected. The second switching valve has an A state and a B state. When the second switching valve is in the A state, only its interfaces P6 and P7 and interfaces P5 and P8 are connected. When the second switching valve is in the B state, only its interfaces P5 and P6 and interfaces P7 and P8 are connected.

5. A monitoring device for ozone-depleting substances and hydrofluorocarbons in the atmosphere according to claim 4, characterized in that: It also includes forward and reverse blowing pipelines, which are connected to the target object collection pipeline and are used to introduce inert gas into the target object collection pipeline from two directions respectively, so that the collection module can collect the target object remaining in the target object collection pipeline; The forward and reverse blowing pipeline has a first state and a second state. In the first state, the inert gas passes through the second dehydration module and the collection module in sequence. In the second state, the inert gas passes through the collection module and the second dehydration module in sequence.

6. The monitoring device for ozone-depleting substances and hydrofluorocarbons in the atmosphere according to claim 5, characterized in that: The forward and reverse blowing pipeline includes an inert gas inlet, a first three-way valve, and a second three-way valve; One end of the first three-way valve is connected to one end of the second three-way valve. The other two ends of the first three-way valve are respectively connected to the inert gas inlet and the selection interface S5 of the one-to-many selector valve. The other two ends of the second three-way valve are respectively connected to the interface P7 of the first switching valve and the first flow meter. The first three-way valve is configured to connect the inert gas inlet to the one-to-many selector valve or to connect the Susonghu inert gas inlet to the second three-way valve; The second three-way valve is configured to connect the first three-way valve to the first switching valve or to connect the first switching valve to the first flow meter.

7. A method for monitoring ozone-depleting substances and hydrofluorocarbons in the atmosphere, characterized in that, The method using the ozone-depleting substances and hydrofluorocarbons monitoring device as described in any one of claims 1-6 includes the following steps: S1. Pass the sample gas into the collection pipeline and collect the target substance in the sample gas through the collection module; S2. The temporary storage column switching module is switched to the first state, the collection module is switched to the first state, the collection module is set to the first given temperature to resolve the first part of the target analyte, and the carrier gas is introduced into the carrier gas inlet and flows into the collection module and the temporary storage column in sequence. The temperature of the temporary storage column is set to the second given temperature so that the first part of the target analyte is retained in the temporary storage column. The first part of the target analyte is separated by chromatography through the temporary storage column. S3. The temporary storage column switching module is switched to the second state, the collection module is switched to the first state, the collection module is set to the third given temperature to resolve the second part of the target, the carrier gas is introduced into the carrier gas inlet and flows through the collection module to deliver the second part of the target to the focusing analysis module; S4. The temporary storage column switching module switches to the first state, the collection module switches to the second state, and the carrier gas is introduced into the carrier gas inlet, flows through the temporary storage column, and delivers the first part of the target to the focusing analysis module. The first given temperature is lower than the third given temperature.

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