A sample enrichment trap device that can be integrated with a gas chromatograph and a gas chromatograph detection system

Abstract

The application provides a sample enrichment trapping device which can be integrated with a gas chromatograph and a gas chromatograph detection system, and the device comprises: a device body, an enrichment pipeline for sample flow communication is formed between a sample inlet and a sample outlet of the device body; a mounting bracket for mounting the device on the gas chromatograph; an enrichment trap for adsorbing target components in the sample; a temperature control module for sending the current temperature of the enrichment trap to a control host of the gas chromatograph and receiving control instructions of the control host to adjust the temperature of the enrichment trap; and a multi-way switching valve for enabling the enrichment pipeline to be connected to any one of a sampling line, an enrichment line and a desorption line of the gas chromatograph under the control of the control host. The scheme can greatly reduce the dead volume of the system detection line, and the communication with the gas chromatograph device is integrated, so that the test result is more sensitive, accurate and stable, the whole process is controlled by software, and the instrument operation is convenient and intelligent.

Description

Technical Field

[0001] This invention relates to the field of gas chromatography detection technology, and more particularly to a sample enrichment trap device and a gas chromatography detection system that can be integrated with a gas chromatograph. Background Technology

[0002] Currently, the analytical needs of gas chromatography are gradually shifting towards trace analysis, and the requirements for instrument detection limits are becoming increasingly stringent. Mainstream gas chromatographs are limited by their principles and materials, making it impossible to meet increasingly demanding detection targets. At the same time, the development of new detectors is slow, and it is difficult to produce commercially available trace analysis detectors in the short term.

[0003] Currently, most analytical platforms choose to enrich analytes during the pretreatment process to meet the current trace detection needs. This method requires a high level of experience from the laboratory technicians, and troubleshooting is difficult when problems arise. Some pretreatment manufacturers have introduced pretreatment devices similar to enrichment tanks for sample enrichment detection, but these devices are often too large, approaching the size of a gas chromatograph. Not only is the dead volume large, affecting the analytical results, but sample residues can also interfere with subsequent sample analysis. Furthermore, because they are independent devices, various communication and connection problems often arise when used with a gas chromatograph, affecting test results and efficiency. Summary of the Invention

[0004] The purpose of this invention is to provide a sample enrichment trap device and a gas chromatography detection system that can be integrated with a gas chromatograph, solving the problems of excessive dead volume and difficulty in cleaning the previous sample interference in current mainstream pretreatment devices, as well as solving the communication connection problem between current mainstream pretreatment devices and gas chromatographs, making the test results more accurate and stable, and the instrument control more convenient and intelligent.

[0005] The technical solution provided by this invention is as follows: In a first aspect, this application provides a sample enrichment trap device that can be integrated with a gas chromatograph, comprising: The device body is provided with a refrigerant inlet, a refrigerant outlet, a sample inlet, and a sample outlet, and an enrichment pipeline for sample flow is formed between the sample inlet and the sample outlet. Mounting bracket, adapted to a gas chromatograph, for mounting the device body onto the gas chromatograph; An enrichment trap, disposed within the device body, is used to adsorb target components from the sample; A temperature control module is connected to the control host of the gas chromatograph and is used to send the current temperature of the enrichment trap to the control host and to receive control commands from the control host to adjust the temperature of the enrichment trap. A multi-way switching valve, connected to the control host, is used to connect the enrichment pipeline to any one of the sampling line, enrichment line, and desorption line of the gas chromatograph under the control of the control host.

[0006] In some embodiments, the sample enrichment trap device provided in this application, in a first state, the multi-way switching valve, under the control of the control host, connects the enrichment pipeline to the sampling line of the gas chromatograph. The sample flows in from the first inlet of the gas chromatograph under the push of the carrier gas, flows through the enrichment pipeline through the inert pipeline, and finally flows out from the first outlet of the gas chromatograph. In the second state, under the control of the control host, the multi-way switching valve connects the enrichment pipeline to the enrichment circuit of the gas chromatograph. The sample flows in from the second inlet of the gas chromatograph under the push of the carrier gas, flows through the inert pipeline through the circulation pipeline containing the enrichment pipeline, and finally flows out from the second outlet of the gas chromatograph. In the third state, under the control of the control host, the multi-way switching valve connects the enrichment pipeline to the desorption line of the gas chromatograph. After the target component in the sample adsorbed by the enrichment trap in the second state is desorbed from the enrichment trap, it flows from the enrichment pipeline through the inert pipeline into the injection end of the chromatographic column of the gas chromatograph under the push of the carrier gas.

[0007] In some embodiments, in the second state, the temperature control module receives a control command from the control host to maintain the enrichment trap at a first preset temperature, so that the target component in the sample is adsorbed by the enrichment trap. In the third state, the temperature control module receives a control command from the control host to maintain the enrichment trap at a second preset temperature, thereby desorbing the target component in the sample adsorbed by the enrichment trap from the enrichment trap.

[0008] In some embodiments, the enrichment trap is helical and configured to have adjustable adsorption material.

[0009] In some embodiments, the temperature control module includes: A temperature sensor, connected to the control host, is used to detect the current temperature of the enrichment trap and send the current temperature to the control host; The trap heating assembly is connected to the control host and is used to receive control commands from the control host and heat the enrichment trap to the target temperature.

[0010] In some embodiments, the trap heating assembly is a hollow cylinder, and the enrichment trap is disposed inside the cavity of the trap heating assembly.

[0011] In some embodiments, the sample enrichment trap device provided in this application further includes: The pressure / flow monitoring module is connected to the control host of the gas chromatograph and is used to send the current pressure / flow of the enrichment pipeline to the control host.

[0012] Secondly, this application provides a gas chromatography detection system, including a gas chromatograph and the sample enrichment trap device described in the first aspect, wherein the sample enrichment trap device is fixed on the gas chromatograph by a mounting bracket.

[0013] In some embodiments, the gas chromatography detection system provided in this application, during the sampling stage, controls the multi-way switching valve of the gas chromatograph to switch the flow direction, so that the enrichment pipeline of the sample enrichment trap device is connected to the sampling line of the gas chromatograph, and controls the carrier gas to flow in the sampling line, so that under the impetus of the carrier gas, the sample can flow in from the first inlet of the gas chromatograph and flow through the inert pipeline through the enrichment pipeline, and the target component in the sample is adsorbed in the enrichment pipeline, while other components flow out from the first outlet of the gas chromatograph. During the enrichment stage, the control host receives the current temperature of the enrichment trap from the temperature control module on the sample enrichment trap device, and maintains the enrichment trap at a first preset temperature through the temperature control module. At the same time, the control host controls the multi-way switching valve to switch the flow direction, connecting the enrichment pipeline of the sample enrichment trap device to the enrichment line of the gas chromatograph, and controls the carrier gas to flow in the enrichment line, so that the sample can flow in from the second inlet of the gas chromatograph under the push of the carrier gas, and flow through the inert pipeline through the circulation pipeline containing the enrichment pipeline, and the target component in the sample is enriched in the enrichment pipeline, while other components flow out from the second outlet of the gas chromatograph. During the desorption stage, the control unit maintains the enrichment trap at a second preset temperature through the temperature control module, causing the target component in the sample adsorbed by the enrichment trap to desorb from the enrichment trap. At the same time, the control unit controls the multi-way switching valve to switch the flow direction, connecting the enrichment pipeline of the sample enrichment trap device to the desorption line of the gas chromatograph, and controls the carrier gas to flow in the desorption line, so that under the impetus of the carrier gas, the sample can flow from the enrichment pipeline through the inert pipeline into the injection end of the chromatographic column of the gas chromatograph.

[0014] In some embodiments, the control host is also used to receive the current pressure / flow rate of the enrichment line collected by the pressure / flow monitoring module on the sample enrichment trap device, and to control the flow rate of the carrier gas in the sampling line, the enrichment line, or the desorption line.

[0015] The sample enrichment trap device and gas chromatography detection system provided by this invention, which can be integrated with a gas chromatograph, are more versatile than traditional independent concentration devices. The sample pre-concentration trap and gas chromatograph are integrated into one design, resulting in a smaller dead volume, reduced space occupation, and lower maintenance costs. Furthermore, different analytical flow paths can be switched according to the detection requirements of different concentration ranges to achieve trace detection or routine concentration analysis. Attached Figure Description

[0016] The preferred embodiments will now be described in a clear and easy-to-understand manner, with reference to the accompanying drawings, to further explain the above-mentioned characteristics, technical features, advantages, and implementation methods of this solution.

[0017] Figure 1 This is a schematic diagram of the overall structure of a sample enrichment trap device according to an embodiment of the present invention; Figure 2 This is a schematic diagram of the sample enrichment trap device according to an embodiment of the present invention; Figure 3 This is a schematic diagram of an enrichment trap structure according to an embodiment of the present invention; Figure 4 This is a schematic diagram of a system sampling circuit according to an embodiment of the present invention; Figure 5 This is a schematic diagram of the system enrichment sample circuit according to an embodiment of the present invention; Figure 6 This is a schematic diagram of the system desorption circuit according to an embodiment of the present invention.

[0018] The following numbers are used in the figure: 10-device body; 11-refrigerant inlet; 12-refrigerant outlet; 13-sample inlet; 14-sample outlet; 15-low temperature nozzle; 20-mounting bracket; 30-enrichment trap; 40-trap body heating assembly. Detailed Implementation

[0019] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the specific implementation methods of the present invention will be described below with reference to the accompanying drawings. Obviously, the drawings described below are merely some embodiments of the present invention. For those skilled in the art, other drawings and other implementation methods can be obtained based on these drawings without any creative effort.

[0020] To keep the drawings concise, only the parts relevant to the invention are shown schematically in each figure, and they do not represent the actual structure of the product. Furthermore, for ease of understanding, in some figures, only one of components with the same structure or function is shown schematically, or only one is labeled. In this document, "one" can mean not only "only one" but also "more than one".

[0021] Currently, the analytical needs of gas chromatography are gradually shifting towards trace analysis, and the requirements for instrument detection limits are becoming increasingly stringent. Mainstream gas chromatographs are limited by their principles and materials, making it impossible to meet increasingly demanding detection targets. At the same time, the development of new detectors is slow, and it is difficult to produce commercially available trace analysis detectors in the short term.

[0022] Currently, most analytical platforms choose to enrich analytes during the pretreatment process to meet the current trace detection needs. This method requires a high level of experience from the laboratory technicians, and troubleshooting is difficult when problems arise. Some pretreatment manufacturers have introduced pretreatment devices similar to enrichment tanks for sample enrichment and detection. However, these devices are often too large, approaching the size of a gas chromatograph. Not only is the dead volume large, affecting the analytical results, but sample residues can also interfere with subsequent sample analysis. Furthermore, because they are independent devices, they are often limited by different communication protocols used by different chromatography manufacturers, which can easily lead to various communication and connection problems when used with a gas chromatograph, affecting test results and efficiency.

[0023] This solution provides an integrated enrichment device that utilizes the temperature control, gas path, and electrical system of a gas chromatograph to achieve highly consistent enrichment operations. It can easily interface with mainstream gas chromatograph detectors to achieve ppb-level chromatographic analysis. The device itself requires no complex structure, and the entire device is fully integrated into the gas chromatograph, resulting in a small dead volume and consistent communication. It can be uniformly controlled by a chromatography workstation, thereby reducing testing errors and improving testing accuracy. The following is a detailed description of this solution with reference to the accompanying drawings: In one embodiment, refer to the appendix to the specification. Figure 1 To be continued Figure 3 This application provides a sample pre-concentration trap (SPT) device that can be integrated with a gas chromatograph, including: device body 10, mounting bracket 20, enrichment trap 30, temperature control module, and multi-way switching valve.

[0024] The device body 10 is provided with a refrigerant inlet 11, a refrigerant outlet 12, a sample inlet 13, and a sample outlet 14, with an enrichment pipeline for sample flow formed between the sample inlet 13 and the sample outlet 14. The refrigerant inlet 11 and the refrigerant outlet 12 are used to inject refrigerant into the device body 10 to regulate the temperature of the enrichment trap 30. This application does not limit the type of refrigerant or the injection method. For example, in one example, a cryogenic nozzle 15 can be used to inject refrigerant into the refrigerant inlet 11 during refrigerant injection. The sample inlet 13 and the sample outlet 14 are connected to the enrichment trap 30 to allow the sample (gas or liquid-derived sample) to flow through the enrichment trap 30 for adsorption.

[0025] The enrichment trap 30 (also known as an adsorption trap), coated with an inert material (such as a Siltek coating), is located within the device body 10. It is used to adsorb target components (such as sulfides, VOCs, and other active components) from the sample, preventing component loss and adapting to trace analysis requirements from ppb to ppt levels. It is a core component for the SPT device to achieve its concentration function. In existing technologies, the enrichment trap 30 is generally designed as a straight tube structure, while the enrichment trap 30 in this application is spiral-shaped. Compared to the traditional straight tube type, this design provides a longer effective adsorption path, more sufficient contact, stronger turbulence, and more complete adsorption. Furthermore, the enrichment trap 30 in this application is configured with adjustable adsorption materials, allowing selection of suitable adsorption materials (such as Tenax TA, Carbograph 1TD, etc.) according to the detected components.

[0026] The mounting bracket 20 is compatible with a gas chromatograph (GC) and is used to mount the device body 10 onto the GC. This application integrates the sample enrichment trap device with the GC, eliminating the need for a separate pretreatment unit. This reduces system dead volume and equipment space, lowering maintenance costs. Simultaneously, it reduces vibration interference during equipment operation, ensuring the stability of the connection between the enrichment trap 30 and the flow path, and solving the problems of large space occupation and vibration affecting enrichment accuracy in traditional independent concentration devices. This application does not limit the specific structural form of the mounting bracket 20. For example, in one example, the mounting bracket 20 uses a positioning slot + fastening bolt + thermal insulation seal to fix the entire unit to the heating module mounting position above the GC column oven, ensuring uniform heating, no loosening, and no air leakage. During installation, align the mounting bracket 20 with the dedicated mounting base and positioning slot directly above the GC column temperature chamber, ensuring that the plane is completely flush with the GC without any gaps. Then, tighten the high-temperature resistant fastening bolts symmetrically and evenly to rigidly connect the mounting bracket 20 to the GC body, preventing displacement and vibration during operation. After that, install a high-temperature resistant heat insulation pad and seals to reduce heat loss, prevent air leakage, and ensure stable temperature control. The bracket also has a reserved groove for connecting the heating wire and the temperature sensor circuit, which is fixed with limit buckles to prevent the circuit from shaking, wearing, or coming into contact with high-temperature components.

[0027] Since this solution integrates the sample enrichment trap device with the gas chromatograph, to ensure the proper functioning of the sample enrichment trap device, it relies on the gas chromatograph's temperature control, gas path, and electrical system. That is, the adsorption, enrichment, and desorption operations of the sample enrichment trap device are achieved through the gas chromatograph's temperature control, gas path, and electrical system, ensuring consistency in the testing process and eliminating the need to set up a separate pretreatment device. Specifically, the temperature control module of the sample enrichment trap device is connected to the gas chromatograph's control unit, used to send the current temperature of the enrichment trap 30 to the control unit and receive control commands from the control unit to adjust the temperature of the enrichment trap.

[0028] The temperature control module includes: a temperature sensor connected to the control host, used to detect the current temperature of the enrichment trap 30 and send the current temperature to the control host; and a trap heating assembly 40 connected to the control host, used to receive control commands from the control host and heat the enrichment trap 30 to the target temperature. The temperature control module is an integrated low-inertia heating assembly with a planar thin-plate heating element as its core, combined with a heat spreader, temperature sensor, and insulation and fastening structure. This application allows for flexible setting of the enrichment temperature, desorption temperature, and holding time via the phase chromatograph's control host, supports parameter saving and recall, adapts to the detection needs of different target components, and supports LIMS system integration to meet compliant testing requirements.

[0029] Preferably, in this solution, the trap heating assembly 40 is configured as a hollow cylinder, and the enrichment trap 30 is disposed inside the cavity of the trap heating assembly 40, so that the heating surface can completely surround the enrichment trap 30 360°, resulting in an extremely short heat conduction path and a heating speed much faster than that of a traditional single heating rod; moreover, the heating element is thin and light with a very small heat capacity, heats up instantly upon power-on, and achieves a temperature rise in seconds, with high power per unit area. With a stable power supply, it can quickly reach the set temperature without the preheating lag of traditional heating blocks; and there is no intermediate heat insulation layer to block the heat, so the heat is directly conducted to the heated body with almost no energy loss.

[0030] Simultaneously, a multi-way switching valve is connected to the control unit. Under the control of the control unit, the enrichment pipeline can be connected to any one of the sampling, enrichment, or desorption lines of the gas chromatograph to achieve sampling, enrichment, and desorption operations on the sample respectively. The multi-way switching valve (e.g., a six-way switching valve) uses a dedicated inert valve component and has a dead volume-free design. It is used to switch between the three flow path states of "sampling-enrichment-desorption" without manual disassembly, realizing automated flow path switching, reducing human operation error, and is compatible with both sample loop injection and SPT enrichment modes, which can be flexibly switched according to the component concentration.

[0031] The sample enrichment trap device provided in this application also includes a pressure / flow monitoring module connected to the control unit of the gas chromatograph. This module sends the current pressure / flow rate of the enrichment pipeline to the control unit, enabling the control unit to control the flow rate of the carrier gas (nitrogen, helium, etc.) in real time. This application sets up a shared carrier gas system between the SPT device and the GC control unit, allowing for switching of the carrier gas type (nitrogen, helium) according to detection requirements, reducing experimental costs while ensuring stable carrier gas flow rate.

[0032] The temperature control module and pressure / flow monitoring module of the SPT device in this application are linked with the control host (or workstation) of the GC through signal connection lines, which can realize full-process automated control.

[0033] This solution can significantly reduce the dead volume of the system's detection circuit and integrates communication with gas chromatography equipment, making the test results more sensitive, accurate, and stable. The entire process is fully controlled by software, and the instrument is easy and intelligent to operate.

[0034] In one embodiment, under the premise of the foregoing embodiments, in the first state (i.e., the sampling phase), refer to the appendix to the specification. Figure 4 Under the control of the main control unit, the multi-way switching valve connects the enrichment pipeline to the sampling line of the gas chromatograph. The sample flows in from the first inlet of the gas chromatograph under the push of the carrier gas, flows through the inert pipeline and the enrichment pipeline, and finally flows out from the first outlet of the gas chromatograph.

[0035] This application can be adapted to the detection of components of different concentrations (normal concentration and trace concentration). In the normal concentration detection, the multi-way switching valve is switched to the "sampling position", and the enrichment pipeline is connected to the sampling line of the gas chromatograph. The sample (gas or liquid derivative sample) enters through the first injection port of the GC and flows through the enrichment trap 30 under the propulsion of the carrier gas. The target trace components (such as ppb-level sulfides and VOCs) are captured by the adsorption material in the enrichment trap 30, while the matrix impurities are discharged from the first outlet with the carrier gas, realizing the initial separation of the target components and impurities.

[0036] In the second state (i.e., the enrichment stage), refer to the attached instruction manual. Figure 5 Under the control of the main control unit, the multi-way switching valve connects the enrichment pipeline to the enrichment circuit of the gas chromatograph. The sample flows in from the second inlet of the gas chromatograph under the push of the carrier gas, and flows through the inert pipeline through the circulation pipeline containing the enrichment pipeline, and finally flows out from the second outlet of the gas chromatograph.

[0037] During the enrichment stage, the multi-way switching valve is switched to the "enrichment position", and the enrichment pipeline is connected to the enrichment line of the gas chromatograph. The sample flows in through the second injection port of the GC and flows through the circulation pipeline containing the enrichment pipeline under the propulsion of the carrier gas. This allows the sample to be continuously and stably adsorbed by the enrichment trap 30 through the circulation pipeline, while the matrix impurities are discharged from the second outlet with the carrier gas, thus achieving the enrichment of the target component.

[0038] In the second state, the temperature control module receives control instructions from the control host to maintain the enrichment trap at a first preset temperature (e.g., 50-80℃), so that the target component in the sample is stably adsorbed by the enrichment trap 30, while avoiding overload of the adsorption material. This temperature can be flexibly adjusted by the workstation to adapt to the adsorption characteristics of different components.

[0039] In the third state, refer to the instruction manual appendix. Figure 6Under the control of the main control unit, the multi-way switching valve connects the enrichment line to the desorption line of the gas chromatograph. In the second state, after the target component in the sample adsorbed by the enrichment trap is desorbed from the enrichment trap, it flows from the enrichment line through the inert line into the injection end of the chromatographic column of the gas chromatograph under the push of the carrier gas.

[0040] After enrichment is completed, the multi-way switching valve is switched to the "desorption position", and the enrichment pipeline is connected to the desorption line of the gas chromatograph. In the second state, the target component in the sample adsorbed by the enrichment trap 30 is desorbed from the enrichment trap 30 and can flow directly from the enrichment pipeline through the inert pipeline to the injection end of the chromatographic column of the gas chromatograph under the drive of the carrier gas, so as to carry out subsequent separation and detection.

[0041] Furthermore, in the third state, the temperature control module receives control commands from the control host to maintain the enrichment trap 30 at a second preset temperature (e.g., 200-350℃), causing the target component in the sample adsorbed by the enrichment trap to desorb from the enrichment trap. By rapidly heating the enrichment trap 30 to 200-350℃ (set according to the boiling point of the component), the adsorbed target component can be rapidly desorbed.

[0042] Compared to traditional independent concentration devices, the sample enrichment trap device provided by this invention integrates the sample pre-concentration trap with the gas chromatograph, resulting in a smaller dead volume, reduced space occupation, and lower maintenance costs. Furthermore, it allows switching between different analytical flow paths to achieve trace detection or routine concentration analysis according to different concentration ranges, making it more versatile.

[0043] In addition, when connecting the various lines, this solution uses inert connecting lines, such as Siltek inert coated quartz lines with a diameter of 0.32 mm or 0.53 mm. This can reduce the adsorption loss of target components (especially active components), ensure that the enriched components are completely transferred to the chromatographic column, and be compatible with the GC injection system specifications.

[0044] The entire sample enrichment trap device needs to be sealed. PTFE inert seals can be used for sealing the enrichment trap, switching valve and pipeline connections to prevent carrier gas leakage and air ingress, avoid contamination of target components, and ensure the connection is airtight to accommodate various GC interface specifications.

[0045] In one embodiment, based on the foregoing embodiments, this application provides a gas chromatography detection system, including a gas chromatograph and a sample enrichment trap device as described in the foregoing embodiments, wherein the sample enrichment trap device is fixed on the gas chromatograph by a mounting bracket.

[0046] The technical concept of the gas chromatography detection system provided in this application is the same as that of the sample enrichment trap device in the aforementioned embodiments, and will not be described in detail here.

[0047] The gas chromatography detection system provided in this application, during the sampling stage, controls the multi-way switching valve of the gas chromatograph to switch the flow direction, so that the enrichment pipeline of the sample enrichment trap device is connected to the sampling line of the gas chromatograph, and controls the carrier gas to flow in the sampling line, so that the sample can flow in from the first inlet of the gas chromatograph under the impetus of the carrier gas, and flow through the inert pipeline through the enrichment pipeline, and the target component in the sample is adsorbed in the enrichment pipeline, while other components flow out from the first outlet of the gas chromatograph.

[0048] During the enrichment stage, the control unit receives the current temperature of the enrichment trap from the temperature control module on the sample enrichment trap device, and maintains the enrichment trap at the first preset temperature through the temperature control module. At the same time, the control unit controls the multi-way switching valve to switch the flow direction, connecting the enrichment pipeline of the sample enrichment trap device to the enrichment line of the gas chromatograph, and controls the carrier gas to flow in the enrichment line, so that the sample can flow in from the second inlet of the gas chromatograph under the impetus of the carrier gas, and flow through the inert pipeline through the circulation pipeline containing the enrichment pipeline, and the target component in the sample is enriched in the enrichment pipeline, while other components flow out from the second outlet of the gas chromatograph.

[0049] During the desorption stage, the control unit maintains the enrichment trap at a second preset temperature through the temperature control module, causing the target components in the sample adsorbed by the enrichment trap to desorb from the enrichment trap. At the same time, the control unit controls the multi-way switching valve to switch the flow direction, connecting the enrichment pipeline of the sample enrichment trap device to the desorption line of the gas chromatograph, and controls the carrier gas to flow in the desorption line, so that the sample can flow from the enrichment pipeline through the inert pipeline into the injection end of the chromatographic column of the gas chromatograph under the impingement of the carrier gas.

[0050] Preferably, the control unit is also used to receive the current pressure / flow rate of the enrichment pipeline collected by the pressure / flow monitoring module on the sample enrichment trap device, and to control the flow rate of the carrier gas in the sampling line, enrichment line, or desorption line.

[0051] The gas chromatography detection system provided in this application has the following characteristics: In terms of structural design, an integrated design is adopted. The SPT device can be fixed inside the GC host through a dedicated bracket, eliminating the need for separate placement space, reducing equipment occupation, and minimizing operational vibration interference while ensuring the stability of the flow path connection. An inert full flow path design is adopted, with enrichment traps, connecting pipelines, and switching valves all using Siltek inert coating or PTFE inert material, eliminating dead volume and preventing the adsorption and loss of trace target components (especially active components such as sulfides), thus ensuring detection accuracy. The switchable flow path structure, relying on multi-way switching valves, realizes automated switching between the three flow paths of "sampling-enrichment-desorption", while being compatible with the SPT enrichment flow path and the sample loop injection flow path, adapting to the detection needs of different concentration components.

[0052] In terms of functionality, it can achieve trace enrichment. The enrichment trap is equipped with special adsorption materials (Tenax TA, Carbograph 1TD, etc.) adapted to different components. Combined with precise temperature control, it can achieve efficient adsorption and enrichment of trace components from ppb to ppt level. It can achieve rapid desorption. The heating component of the enrichment trap can achieve a wide temperature control range of 50-350℃, supporting rapid heating and desorption, ensuring that the adsorbed target components are released quickly and completely without residual pollution. It can achieve sealing and leakage prevention. It adopts PTFE inert seals to achieve seamless sealing of the enrichment trap, switching valve, and pipeline, preventing carrier gas leakage and air ingress, and avoiding contamination of the target components.

[0053] In terms of linkage control, this application enables seamless linkage between the SPT device and the GC host. The temperature controller and pressure / flow monitoring unit of the SPT device are linked with the GC host and workstation via signal connection lines to achieve fully automated control of the entire process. It can achieve precise parameter adjustment, and the enrichment temperature, desorption temperature, holding time and carrier gas flow rate can be flexibly set through the workstation. It supports parameter saving and recall to adapt to the detection requirements of different target components. It also supports LIMS system docking to meet compliance detection. It can realize carrier gas sharing between the SPT device and the GC. The SPT device and the GC host share the carrier gas system. The carrier gas type (nitrogen, helium) can be switched according to the detection requirements to reduce experimental costs while ensuring stable carrier gas flow rate.

[0054] It should be noted that the above embodiments can be freely combined as needed. The above description is only a preferred embodiment of the present invention. It should be pointed out that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A sample enrichment and trapping device that can be integrated with a gas chromatograph, characterized in that, include: The device body is provided with a refrigerant inlet, a refrigerant outlet, a sample inlet, and a sample outlet, and an enrichment pipeline for sample flow is formed between the sample inlet and the sample outlet. Mounting bracket, adapted to a gas chromatograph, for mounting the device body onto the gas chromatograph; An enrichment trap, disposed within the device body, is used to adsorb target components from the sample; A temperature control module is connected to the control host of the gas chromatograph and is used to send the current temperature of the enrichment trap to the control host and to receive control commands from the control host to adjust the temperature of the enrichment trap. A multi-way switching valve, connected to the control host, is used to connect the enrichment pipeline to any one of the sampling line, enrichment line, and desorption line of the gas chromatograph under the control of the control host. In the first state, under the control of the control host, the multi-way switching valve connects the enrichment pipeline to the sampling line of the gas chromatograph. The sample flows in from the first inlet of the gas chromatograph under the push of the carrier gas, flows through the inert pipeline through the enrichment pipeline, and finally flows out from the first outlet of the gas chromatograph. In the second state, under the control of the control host, the multi-way switching valve connects the enrichment pipeline to the enrichment circuit of the gas chromatograph. The sample flows in from the second inlet of the gas chromatograph under the push of the carrier gas, flows through the inert pipeline through the circulation pipeline containing the enrichment pipeline, and finally flows out from the second outlet of the gas chromatograph. In the third state, under the control of the control host, the multi-way switching valve connects the enrichment pipeline to the desorption line of the gas chromatograph. After the target component in the sample adsorbed by the enrichment trap in the second state is desorbed from the enrichment trap, it flows from the enrichment pipeline through the inert pipeline into the injection end of the chromatographic column of the gas chromatograph under the push of the carrier gas.

2. The sample enrichment trap device according to claim 1, characterized in that, In the second state, the temperature control module receives the control command from the control host to maintain the enrichment trap at a first preset temperature, so that the target component in the sample is adsorbed by the enrichment trap. In the third state, the temperature control module receives a control command from the control host to maintain the enrichment trap at a second preset temperature, thereby desorbing the target component in the sample adsorbed by the enrichment trap from the enrichment trap.

3. The sample enrichment trap device according to claim 1, characterized in that, The enrichment trap is spiral-shaped and configured with adjustable adsorption material.

4. The sample enrichment trap device according to claim 1, characterized in that, The temperature control module includes: A temperature sensor, connected to the control host, is used to detect the current temperature of the enrichment trap and send the current temperature to the control host; The trap heating assembly is connected to the control host and is used to receive control commands from the control host and heat the enrichment trap to the target temperature.

5. The sample enrichment trap device according to claim 4, characterized in that, The trap heating assembly is a hollow cylinder, and the enrichment trap is disposed inside the cavity of the trap heating assembly.

6. The sample enrichment trap device according to claim 1, characterized in that, Also includes: The pressure / flow monitoring module is connected to the control host of the gas chromatograph and is used to send the current pressure / flow of the enrichment pipeline to the control host.

7. A gas chromatography detection system, characterized in that, The invention includes a gas chromatograph and a sample enrichment trap device as described in any one of claims 1-6, wherein the sample enrichment trap device is fixed to the gas chromatograph by a mounting bracket.

8. The gas chromatography detection system according to claim 7, characterized in that, During the sampling phase, the control unit of the gas chromatograph controls the multi-way switching valve to switch the flow direction, so that the enrichment pipeline of the sample enrichment trap device is connected to the sampling line of the gas chromatograph, and controls the carrier gas to flow in the sampling line, so that the sample can flow in from the first inlet of the gas chromatograph under the impetus of the carrier gas, and flow through the enrichment pipeline through the inert pipeline, and the target component in the sample is adsorbed in the enrichment pipeline, while other components flow out from the first outlet of the gas chromatograph. During the enrichment stage, the control host receives the current temperature of the enrichment trap from the temperature control module on the sample enrichment trap device, and maintains the enrichment trap at a first preset temperature through the temperature control module. At the same time, the control host controls the multi-way switching valve to switch the flow direction, connecting the enrichment pipeline of the sample enrichment trap device to the enrichment line of the gas chromatograph, and controls the carrier gas to flow in the enrichment line, so that the sample can flow in from the second inlet of the gas chromatograph under the push of the carrier gas, and flow through the inert pipeline through the circulation pipeline containing the enrichment pipeline, and the target component in the sample is enriched in the enrichment pipeline, while other components flow out from the second outlet of the gas chromatograph. During the desorption stage, the control host maintains the enrichment trap at a second preset temperature through the temperature control module, so that the target component in the sample adsorbed by the enrichment trap is desorbed from the enrichment trap. Simultaneously, the host controller controls the multi-way switching valve to switch the flow direction, connecting the enrichment pipeline of the sample enrichment trap device to the desorption line of the gas chromatograph, and controls the carrier gas to flow in the desorption line, so that under the impetus of the carrier gas, the sample can flow from the enrichment pipeline through the inert pipeline into the injection end of the chromatographic column of the gas chromatograph.

9. The gas chromatography detection system according to claim 8, characterized in that, The control host is also used to receive the current pressure / flow rate of the enrichment pipeline collected by the pressure / flow monitoring module on the sample enrichment trap device, and to control the flow rate of the carrier gas in the sampling line, the enrichment line, or the desorption line.

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