Thermal desorption pipe full-process automatic analysis system
The fully automated analysis system solves the problems of low automation and poor sealing reliability in thermal desorption systems, achieving efficient and accurate analysis of volatile organic compounds, and is suitable for environmental monitoring and food safety fields.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-16
- Publication Date
- 2026-03-17
AI Technical Summary
Existing thermal desorption systems suffer from low automation, poor sealing reliability, large dead volume, uneven heating, and limited functionality, resulting in poor reproducibility and accuracy of analytical results. Furthermore, traditional seals are prone to wear and leakage under high-temperature conditions, affecting the sensitivity and accuracy of trace analysis.
A fully automated analysis system for thermal desorption tubes was designed, including sample carrying, labeling, aging, and desorption mechanisms. It adopts a cold-end single-sided sealing design, dynamic sealing module, and integrated gas path block to achieve unmanned operation throughout the entire process, eliminate the dependence on high-temperature sealing materials, simplify the gas path switching structure, and enhance analytical functions.
It achieves full automation of the thermal desorption tube processing, improves detection efficiency and the reproducibility and accuracy of analysis results, reduces maintenance frequency and cost, and provides higher stability and economy. It is suitable for volatile organic compound analysis in the fields of environmental monitoring and food safety.
Smart Images
Figure CN121669346A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of analytical chemistry instrument technology, specifically to a fully automated analytical system for the analysis of volatile organic compounds using thermal desorption tubes, and particularly to a fully automated analytical system for the analysis of thermal desorption tubes integrating automatic aging, automatic labeling, and automatic sample injection. Background Technology
[0002] Thermal desorption is a crucial sample pretreatment method in gas chromatography-mass spectrometry (GC-MS) analysis, widely used in environmental monitoring, occupational health, food safety, and odor analysis of materials. A complete thermal desorption analysis process typically includes: aging of the thermal desorption tube, addition of standard solutions, sample sampling, thermal desorption and injection, and other steps.
[0003] The main technical bottlenecks currently facing the thermal desorption systems on the market are as follows: 1. Fragmented workflow and low automation: Most systems can only achieve semi-automatic or fully automatic operation of the sample injection step, while pretreatment steps such as aging and spiking still rely on manual operation on different devices. Samples need to be handled and transferred manually multiple times, resulting in poor workflow integration, low efficiency, and the possibility of errors introduced by manual operation, leading to poor consistency in data analysis.
[0004] 2. Inherent defects in core components: The commonly used rotary six-way or multi-way valves have complex relative rotational structures between the valve core and body, requiring precise dynamic seals. These seals are prone to wear and aging under high temperatures, leading to gas leakage and increased dead volume. Dead volume causes peak broadening and tailing in samples, and cross-contamination, severely impacting the sensitivity and accuracy of trace analysis. Traditional devices require direct high-temperature dynamic sealing of both ends of the thermal desorption tube during the analysis process, commonly using polymers such as graphite and Vespel as seals. These materials are not only expensive but also degrade after repeated high-temperature use, releasing background contaminants, and their sealing performance gradually declines, limiting the system's maximum operating temperature and long-term stability. Furthermore, most devices use single-point or single-sided heating, resulting in severely uneven axial temperature distribution in the thermal desorption tube, creating cold spots and causing incomplete desorption of high-boiling-point compounds, leading to a memory effect.
[0005] 3. Poor automation compatibility and ease of operation: Traditional thermal desorption tube designs do not fully consider the operational characteristics of automated equipment. For example, the tube cap needs to be operated during automatic sample injection, increasing the complexity of the mechanical structure; or the sealing structure is not conducive to stable gripping and precise positioning of the clamp.
[0006] 4. Lack of advanced analytical functions: Many systems cannot easily implement functions such as primary thermal desorption, secondary thermal desorption, sample split injection, and crucial sample recovery on the same hardware platform. This makes the operation cumbersome and consumes a large amount of sample in some scenarios that require verification testing or method development. Summary of the Invention
[0007] This invention aims to solve at least one of the technical problems existing in the prior art. Therefore, the purpose of this invention is to provide a fully automated analysis system for thermal desorption tubes. Through innovative system architecture and core component design, this system achieves fully automated and integrated operation of the thermal desorption tube process, from sample introduction, standardization, aging, and analysis, solving the problems of low automation, poor sealing reliability, large dead volume, uneven heating, and limited functionality in the prior art.
[0008] The first aspect of this invention provides an automated analysis system for the entire process of thermal desorption tubes, comprising: frame; A sample carrying mechanism is provided on the frame and is used to centrally store multiple thermal desorption tubes to be processed or already processed. A labeling mechanism, which is mounted on the frame, is configured to add a standard sample solution or an internal standard solution to the thermal desorption tube; An aging mechanism is mounted on the frame and configured to perform high-temperature aging treatment on the thermal desorption tube. The analytical unit is mounted on the frame and is configured to perform thermal desorption analysis on the thermal desorption tube and deliver the sample to the analytical instrument. A transfer device, mounted on the frame, is used to automatically transfer the thermal desorption tube between the sample carrying mechanism, the labeling mechanism, the aging mechanism, and the analytical mechanism. The central controller is communicatively connected to the transfer device, the labeling mechanism, the aging mechanism, and the analytical mechanism.
[0009] In a first aspect of the invention, as a preferred embodiment, The frame includes a base, a gantry mounted on the base and located on one side of the base, a fixed seat fixedly mounted on the base, and a sliding seat movably mounted on the base; The analytical mechanism is mounted on a fixed base, while the sample carrying mechanism, the labeling mechanism, and the aging mechanism are mounted on a sliding base. The transfer device includes: The Y-axis motion assembly is mounted on the base and is used to drive the sliding block to move linearly along the Y-axis direction; The X-axis motion assembly is mounted on the gantry and is used to provide horizontal movement along the X-axis direction; A vertical lifting component is installed on the moving part of the X-axis motion component and is driven by the X-axis motion component to move along the X-axis. A tube clamping mechanism is installed on the moving part of the vertical lifting assembly and is driven by the vertical lifting assembly to perform vertical lifting; the tube clamping mechanism includes an actuator and a gripper driven by the actuator, the gripper being configured to directly clamp the outside of the heat desorption tube.
[0010] The Y-axis motion component drives the sliding seat to move, so that any one of the sample carrying mechanism, labeling mechanism and aging mechanism mounted on the sliding seat can move to below the movement path of the clamping mechanism on the vertical projection plane.
[0011] The fixed seat and the sliding seat are arranged separately on the base along the Y-axis, so that the position of the analytical mechanism is fixed, while the positions of the sample carrying mechanism, the labeling mechanism and the aging mechanism can be changed along the Y-axis.
[0012] In a first aspect of the invention, as a preferred embodiment, the central controller is configured to: adjust the position of the sliding seat by controlling the Y-axis motion component, and in combination with controlling the movement of the X-axis motion component and the vertical lifting component, so that the clamping mechanism can reach the analytical mechanism station on the fixed seat and any functional station on the sliding seat.
[0013] In a first aspect of the invention, as a preferred embodiment, the thermal desorption tube comprises: An adsorption tube filled with an adsorbent; An analytical cap is detachably connected to one end of the thermal desorption tube. The analytical cap includes a cap body, which is cylindrical in shape and includes a clamping part, an external sealing part, and a guide part in sequence along the axial direction. A first sealing ring and a second sealing ring are provided on the outer periphery of the external sealing part. The first sealing ring and the second sealing ring are arranged at intervals along the axial direction of the cap body, and a fluid channel hole is formed in the cap wall between the first sealing ring and the second sealing ring. The cap body has an internal cavity for receiving and sealing the thermal desorption tube, and the internal cavity has an internal sealing structure. The fluid channel hole is located on the axial upper side of the internal sealing structure, so that when the thermal desorption tube is sealed in the internal cavity, the fluid channel hole communicates with the internal cavity of the thermal desorption tube through the internal cavity. The internal sealing structure of the analytical cap forms a seal with the outer wall of the adsorption tube, so that the inner cavity of the adsorption tube is connected to the fluid channel hole of the analytical cap; The gripping surface shape of the gripper of the clamping mechanism is adapted to the external shape of the gripping part of the thermal desorption tube body, so as to achieve non-intervention gripping without the need to remove or cap the thermal desorption tube.
[0014] In a first aspect of the present invention, as a preferred embodiment, the outer diameter of the second sealing ring is smaller than the outer diameter of the first sealing ring; the clamping portion includes a clamping section with a smaller diameter and a limiting section with a larger diameter located on one axial side of the clamping section, the clamping section being used to be gripped by the gripper, and the limiting section being used to cooperate with the gripper to form an axial limit.
[0015] In a first aspect of the present invention, as a preferred embodiment, a needle-sticking device is further included, the needle-sticking device including a sample injection needle for delivering liquid samples and a needle-sticking drive mechanism for driving the sample injection needle to move, wherein the needle-sticking drive mechanism is mounted on the X-axis motion assembly. The labeling mechanism includes: A standard solution tray, which is mounted on the sliding seat, is used to hold sample vials containing various standard solutions or internal standard solutions of different concentrations. A labeling gas path device is mounted on the sliding seat and has an inlet for receiving the tip of the injection needle. A dynamic sealing module, comprising a first sealing element that can move with the needle insertion device, and a second sealing element that is fixed to the labeling gas circuit device and adapted to the first sealing element; When the injection needle reaches the injection position, the first seal and the second seal are pressed together to form a mechanical compression seal without a septum, thereby forming a closed purge chamber around the injection port.
[0016] In a first aspect of the present invention, as a preferred embodiment, the first sealing element is an elastic sealing ring, and the second sealing element is a conical sealing surface formed at the edge of the injection port. When the elastic sealing ring and the conical sealing surface are pressed together, the gas path is sealed, and the conical sealing surface is used to guide the tip of the injection needle for precise positioning.
[0017] In a first aspect of the present invention, as a preferred embodiment, the analytical apparatus includes: A heating chamber defining a sealed inner cavity, the heating chamber being configured to operatively house the thermal desorption tube; The heating chamber includes: a carrier gas inlet connected to a fluid channel hole of the analysis cap; and a carrier gas outlet connected to a sealed inner cavity of the heating chamber and located near the end of the suspended adsorption tube. A heating element, which is a heating coil that is attached to the outer wall of the heating cavity, is used to uniformly heat the heating cavity from all directions. When the thermal desorption tube is housed in the sealed inner cavity, the external sealing structure of the analytical cap forms a sealed connection with the inner wall of the heating cavity, so that the end of the thermal desorption tube not connected to the analytical cap is suspended in the sealed inner cavity without the need for a separate seal.
[0018] In a first aspect of the invention, as a preferred embodiment, a thermal desorption gas path switching device connected to the analytical apparatus is further included, the thermal desorption gas path switching device comprising: An integrated gas passage block, which has internally interconnected channels. Multiple external interfaces are respectively disposed on the side wall of the integrated air passage block and communicate with the internal channel; A linear drive mechanism, which extends partially into the internal channel of the integrated pneumatic block, is capable of linear motion between a first position and a second position; The internal channel has a first interface and a second interface. When the linear drive mechanism is in the first position, it blocks the passage between the first interface and the second interface; when the linear drive mechanism is in the second position, it opens the passage between the first interface and the second interface.
[0019] In a first aspect of the invention, as a preferred embodiment, the plurality of external interfaces include a third interface, a fourth interface, a fifth interface, a sixth interface, a seventh interface, and a cylinder interface; The internal channels include a first transverse channel, a first longitudinal channel, a second longitudinal channel, a first branch channel, a second branch channel, and a third branch channel; The first end of the first transverse channel penetrates the side wall of the integrated air circuit block to form the cylinder interface, and its second end is connected to the first end of the second longitudinal channel. The second end of the second longitudinal channel penetrates the side wall of the integrated air circuit block to form the sixth interface. The first end of the first longitudinal channel is connected to the first transverse channel to form the first interface, and its second end penetrates the side wall of the integrated gas block to form the third interface; The first end of the first branch channel is connected to the first transverse channel to form the second interface, and its second end penetrates the side wall of the integrated gas block to form the seventh interface; The first end of the second branch channel is connected to the first longitudinal channel, and its second end penetrates the side wall of the integrated gas block to form the fourth interface; The first end of the third branch channel is connected to the first longitudinal channel, and its second end penetrates the side wall of the integrated gas block to form the fifth interface.
[0020] Compared with the prior art, the beneficial effects of the present invention are as follows: This invention constructs a highly integrated, fully automated analytical system. By coordinating independent modules such as sample loading, labeling, aging, and analytical analysis with the transfer device and central controller, it achieves fully unmanned operation of the thermal desorption tube processing from sample introduction to analysis. This system completely changes the traditional segmented manual operation mode, significantly improves detection efficiency, avoids human error, and ensures high reproducibility and accuracy of analytical results. It provides a complete automated solution for volatile organic compound analysis in fields such as environmental monitoring and food safety.
[0021] The thermal desorption tube of this invention adopts a single-sided cold-end sealing design, achieving sealing only at the cold end of the thermal desorption tube through an analytical cap. No sealing element is required at the hot end; instead, the entire heating chamber's sealing structure completely encloses the thermal desorption tube within the sealed inner cavity, fundamentally avoiding the stringent requirements of high-temperature environments on sealing materials. This design not only completely solves the problems of high-temperature evaporation and leakage of sealing materials in existing technologies, but also eliminates the risk of sharp edges at the thermal desorption tube end damaging the sealing ring. Furthermore, it significantly widens the range of thermal desorption tube size selection; as long as the outer diameter of the tube is smaller than the inner cavity size of the heating chamber, it meets the usage requirements, reducing the dependence on the processing precision of the thermal desorption tube.
[0022] This invention completely eliminates the traditional septum-based puncture and sealing logic by constructing a core structure consisting of a needle insertion device, a labeling gas path device, and a dynamic sealing module. This fundamentally solves the gas path leakage problem caused by septum elasticity failure after repeated use, while also eliminating the risks of septum debris contaminating samples, clogging gas paths, and damaging downstream instruments. The design of the follow-up and fixed seals in the dynamic sealing module ensures precise linkage between the sealing state and the needle position, forming a sealed purge chamber only during the sample injection and purging phase. This guarantees a closed environment for standard injection and inert gas purging, improving the accuracy of labeling concentration, and avoiding unnecessary wear and tear on sealing components. Combined with the septum-free design, it completely eliminates the need for septum replacement, enabling the device to operate continuously and automatically for extended periods, reducing downtime for maintenance. Compared to traditional devices, it significantly improves batch labeling efficiency and drastically reduces sample contamination rates, providing greater stability and economy for analytical work in fields such as environmental monitoring and food safety.
[0023] This invention employs an integrated pneumatic circuit block combined with a linear drive component, a fundamentally different approach from the rotary flexible switching principle of traditional six-way valves. This invention utilizes pre-machined channels within the pneumatic circuit block to form a static interconnected network, achieving on / off control of the critical path solely through the linear motion of the piston rod. This static network and single-point control principle fundamentally solves the problems of leakage, residue, and maintenance caused by the complex mechanical structure of traditional valves. This invention simplifies the complex problem of flexible pneumatic circuit switching into a single linear motion control, significantly simplifying the structure and minimizing dead space. Furthermore, it achieves a breakthrough in reliability for long-term operation at 200°C, providing a completely new technological path for the field of thermal desorption instruments.
[0024] The present invention also includes an external gas path control system connected to the integrated gas path block. Through the coordinated switching and adjustment of multiple solenoid valves, mass flow controllers and throttle valves, a programmable airflow path matrix is constructed in conjunction with the core integrated gas path block. This enables precise control of the flow direction, flow rate and split ratio of the carrier gas and the desorption gas, achieving functional diversification and refined control. It can realize the functions of sample recovery, primary thermal desorption and secondary thermal desorption in the thermal desorption tube analysis process. Attached Figure Description
[0025] Figure 1 This is a schematic diagram of the structure of the fully automated analysis system for the thermal desorption tube of the present invention; Figure 2 This is another structural schematic diagram of the fully automated analysis system for the thermal desorption tube of the present invention; Figure 3 This is a top view of the fully automated analysis system for the thermal desorption tube of the present invention. Figure 4 This is a schematic diagram of the structure of the analytical cap of the present invention.
[0026] Figure 5 This is a cross-sectional structural diagram of the analytical cap of the present invention.
[0027] Figure 6 This is a schematic diagram of the analytical cap structure of the present invention after omitting the first and second sealing rings.
[0028] Figure 7 This is a schematic cross-sectional view of the thermal desorption tube of the present invention.
[0029] Figure 8 This is a schematic diagram of the needle insertion device and the labeling air circuit device of the present invention.
[0030] Figure 9 This is a schematic diagram of the needle insertion device of the present invention.
[0031] Figure 10 This is a schematic diagram of the needle insertion device of the present invention from another angle.
[0032] Figure 11 This is a partial cross-sectional structural diagram of the needle insertion device of the present invention.
[0033] Figure 12 This is a schematic diagram of the standard gas path device of the present invention.
[0034] Figure 13 This is a partial cross-sectional structural diagram of the standard gas path device of the present invention.
[0035] Figure 14 This is a schematic diagram of the analytical mechanism of the present invention.
[0036] Figure 15 This is a cross-sectional structural diagram of the analytical mechanism of the present invention.
[0037] Figure 16 This is a schematic diagram of the heating cavity of the present invention.
[0038] Figure 17 This is a schematic diagram of the overall gas path connection of the thermal desorption gas path switching device of the present invention.
[0039] Figure 18 This is a cross-sectional structural diagram of the integrated air passage block of the present invention.
[0040] In the picture: 10. Frame; 11. Base; 12. Gantry; 13. Fixed base; 14. Sliding base; 20. Sample carrying mechanism; 30. Labeling mechanism; 31. Labeling gas path device; 311. Guide needle cap; 312. Injection head; 313. Inlet gas path block; 314. Fluid pipeline; 315. Inner cavity tube; 316. Nitrogen inlet; 317. Exhaust pipe; 32. Standard solution tray; 33. Dynamic sealing module; 331. Elastic sealing ring; 332. Conical sealing surface; 40. Aging mechanisms; 50. Analysis mechanism; 51. Heating chamber; 511. Sealed inner cavity; 512. Carrier gas inlet; 513. Carrier gas outlet; 52. Heating coil; 60. Transfer device; 61. Y-axis motion assembly; 62. X-axis motion assembly; 63. Vertical lifting assembly; 64. Tube clamping mechanism; 641. Actuator; 642. Gripper; 70. Needle insertion device; 71. Injection needle; 72. Needle insertion drive mechanism; 73. Guide needle cavity; 74. Injection needle sealing block; 75. Sealing block clamping component; 76. Needle guard block; 77. Needle insertion seat; 78. Injection needle piston fixing position; 80. Thermal desorption gas path switching device; 81. Carrier gas source; 82. First pressure reducing valve; 83. First solenoid valve; 84. Second solenoid valve; 85. Third solenoid valve; 86. Throttling valve; 87. First vent; 88. Desorption gas source; 89. Fourth solenoid valve; 811. Third interface; 812. Fifth solenoid valve; 813. Mass flow controller; 814. Second vent; 815. Sixth solenoid valve; 816. Trapping trap; 817. Linear drive mechanism; 818. Fourth interface; 819. Fifth interface; 8 20. First interface; 821. Second interface; 822. Integrated pneumatic block; 8221. First transverse channel; 8222. First longitudinal channel; 8223. Second longitudinal channel; 8224. First branch channel; 8225. Second branch channel; 8226. Third branch channel; 823. Sixth interface; 824. Second pressure reducing valve; 825. First filter trap; 826. Second filter trap; 827. Cylinder interface; 828. Seventh interface; P1. First pressure sensor; P2. Second pressure sensor; 90. Thermal desorption tube; 91. Analytical cap; 910. Cap body; 911. Clamping part; 9111. Clamping section; 9112. Limiting section; 912. External sealing part; 9121. First sealing ring; 9122. Second sealing ring; 9123. Annular groove; 9124. Limiting part; 9125. Fluid channel hole; 913. Guide part; 914. Internal cavity; 915. Internal sealing structure; 9151. Annular groove; 9152. Internal sealing ring; 92. Adsorption tube body. Detailed Implementation
[0041] The invention will now be further described with reference to the accompanying drawings and specific embodiments. It should be noted that, without conflict, the various embodiments or technical features described below can be arbitrarily combined to form new embodiments. Unless otherwise specified, the materials and equipment used in this embodiment are commercially available. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this application, and should not be construed as limiting this application.
[0042] In the description of this application, it should be understood that the terms "upper," "lower," "front," "rear," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application 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, and therefore should not be construed as a limitation on this application. In the description of this application, "a plurality of" means two or more, unless otherwise precisely specified.
[0043] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "connected," "linked," and "connected" should be interpreted broadly. For example, they can refer to a fixed connection, a connection through an intermediary, or a connection within two elements or an interaction between two elements. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.
[0044] The terms "first," "second," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such process, method, product, or apparatus.
[0045] Example 1 Please refer to Figure 1-3 This embodiment provides an automated analysis system for the entire process of thermal desorption tubes, including: Rack 10; The sample carrying mechanism 20 is mounted on the frame 10 and is used to centrally store multiple thermal desorption tubes 90 that are to be processed or have been processed. The labeling mechanism 30 is mounted on the frame 10 and is configured to add standard sample solution or internal standard solution to the thermal desorption tube 90. The aging mechanism 40 is mounted on the frame 10 and is configured to perform thermal desorption analysis on the thermal desorption tube 90 and transport the sample to the analytical instrument. The analytical unit 50 is mounted on the frame 10 and is configured to perform high-temperature aging treatment on the thermal desorption tube 90. Transfer device 60, which is mounted on frame 10, is used to automatically transfer thermal desorption tube 90 between sample carrying mechanism 20, labeling mechanism 30, aging mechanism 40 and analytical mechanism 50. The central controller is communicatively connected to the transfer device 60, the labeling mechanism 30, the aging mechanism 40, and the analytical mechanism 50.
[0046] Based on the above structure, this invention constructs a highly integrated, fully automated analysis platform. By coordinating independent modules such as the sample carrying mechanism 20, the labeling mechanism 30, the aging mechanism 40, and the analytical mechanism 50 with the transfer device 60 and the central controller, it achieves fully unmanned operation of the thermal desorption tube 90 from sample introduction to analysis. This system completely changes the traditional segmented manual operation mode, significantly improves detection efficiency, avoids human error, and ensures high reproducibility and accuracy of analytical results. It provides a complete automated solution for volatile organic compound analysis in fields such as environmental monitoring and food safety.
[0047] In a first aspect of the invention, as a preferred embodiment, The frame 10 includes a base 11, a gantry 12 mounted on the base 11 and located on one side of the base 11, a fixed seat 13 fixedly mounted on the base 11, and a sliding seat 14 movably mounted on the base 11; Among them, the analytical mechanism 50 is installed on the fixed base 13, and the sample carrying mechanism 20, the labeling mechanism 30 and the aging mechanism 40 are installed on the sliding base 14. The transfer device 60 includes: Y-axis motion assembly 61 is mounted on base 11 and is used to drive slide block 14 to move linearly along the Y-axis direction; X-axis motion assembly 62, mounted on gantry 12, is used to provide horizontal movement along the X-axis direction; The vertical lifting component 63 is mounted on the moving part of the X-axis motion component 62 and is driven by the X-axis motion component 62 to move along the X-axis. The tube clamping mechanism 64 is mounted on the moving part of the vertical lifting assembly 63 and is driven by the vertical lifting assembly 63 to perform vertical lifting. The tube clamping mechanism 64 includes an actuator 641 and a gripper 642 driven by the actuator 641. The gripper 642 is configured to directly clamp the outside of the heat desorption tube 90.
[0048] Y-axis motion assembly 61 drives slide seat 14 to move, so that any one of the sample carrying mechanism 20, labeling mechanism 30 and aging mechanism 40 mounted on slide seat 14 can move to below the movement path of clamping mechanism 64 on the vertical projection plane.
[0049] The fixed seat 13 and the sliding seat 14 are arranged separately on the base 11 along the Y-axis, so that the position of the analytical mechanism 50 is fixed, while the positions of the sample carrying mechanism 20, the labeling mechanism 30 and the aging mechanism 40 can be changed along the Y-axis.
[0050] Based on the aforementioned structure, this invention achieves an organic combination of active positioning of the functional workstation and precise pick-and-place of the transfer device 60 through the coordinated operation of the fixed base 13, the sliding base 14, and the transfer device 60. This design not only significantly simplifies the movement trajectory and structural complexity of the transfer device 60, improving positioning accuracy and long-term operational reliability, but also enables the system to perform pretreatment work on other samples in parallel during time-consuming analytical processes, increasing equipment utilization. Simultaneously, it optimizes spatial layout, reduces wear on pipelines, and significantly enhances maintenance convenience.
[0051] In a preferred embodiment of the present invention, the central controller is configured to: adjust the position of the sliding seat 14 by controlling the Y-axis motion component 61, and in combination with controlling the movement of the X-axis motion component 62 and the vertical lifting component 63, so that the clamping mechanism 64 can reach the analytical mechanism 50 station on the fixed seat 13 and any functional station on the sliding seat 14.
[0052] Please refer to Figure 4-7 In a preferred embodiment of the present invention, the thermal desorption tube 90 includes: Adsorption tube 92, which is filled with adsorbent; An analytical cap 91 is detachably connected to one end of a thermal desorption tube 90. The analytical cap 91 includes a cap body 910, which is cylindrical in shape and includes a clamping part 911, an external sealing part 912, and a guide part 913 in sequence along the axial direction. A first sealing ring 9121 and a second sealing ring 9122 are provided on the outer periphery of the external sealing part 912. The first sealing ring 9121 and the second sealing ring 9122 are arranged at intervals along the axial direction of the cap body 910, and a fluid channel hole 9125 is opened in the cap wall between the first sealing ring 9121 and the second sealing ring 9122. The cap body 910 has an internal cavity 914 for receiving and sealing the thermal desorption tube 90. The internal cavity 914 has an internal sealing structure 915. The fluid channel hole 9125 is located on the axial upper side of the internal sealing structure 915, so that when the thermal desorption tube 90 is sealed in the internal cavity 914, the fluid channel hole 9125 communicates with the inner cavity of the thermal desorption tube 90 through the internal cavity 914. The internal sealing structure 915 of the analysis cap 91 forms a seal with the outer wall of the adsorption tube 92, so that the inner cavity of the adsorption tube 92 is connected to the fluid channel hole 9125 of the analysis cap 91. The shape of the gripping surface of the gripper 642 of the gripping mechanism is adapted to the external shape of the gripping part 911 of the thermal desorption tube 90 body, so as to achieve non-intervention gripping without the need to remove or cap the thermal desorption tube 90.
[0053] In a preferred embodiment of the present invention, the outer diameter of the second sealing ring 9122 is smaller than the outer diameter of the first sealing ring 9121.
[0054] Based on the above structure, this invention designs the diameter of the lower second sealing ring 9122 to be smaller than that of the upper first sealing ring 9121, forming a natural guiding structure at the insertion end. This reduces the centering difficulty and frictional resistance when the analytical cap 91 is inserted into the heating chamber 51, making the automated sample introduction process smoother and more reliable. The smooth insertion process reduces scratching and wear on the sealing rings, especially in frequent automated cycles, effectively extending the replacement cycle of these critical sealing elements and reducing maintenance costs.
[0055] In a preferred embodiment of the present invention, the clamping part 911 includes a clamping section 9111 with a smaller diameter and a limiting section 9112 with a larger diameter located on one axial side of the clamping section 9111. The clamping section 9111 is used to be gripped by the mechanical gripper 642, and the limiting section 9112 is used to cooperate with the mechanical gripper 642 to form an axial limit.
[0056] In a preferred embodiment of the present invention, the guide portion 913 is located at one end of the cap body 910 for insertion into the heating cavity 51, and the end of the guide portion 913 is provided with a guide chamfer.
[0057] In a preferred embodiment of the present invention, the internal sealing structure 915 includes an annular groove 9151 disposed on the inner wall of the internal cavity 914 and an internal sealing ring 9152 installed in the annular groove 9151.
[0058] In a preferred embodiment of the present invention, the inner wall of the inner cavity 914 is located in the region outside the axial ends of the annular groove 9151, and its inner diameter is smaller than that of the region where the annular groove 9151 is located. This difference in inner wall size forms a stepped limiting structure, thereby achieving axial limiting of the inner sealing ring 9152.
[0059] In a preferred embodiment of the present invention, the first sealing ring 9121 and the second sealing ring 9122 are respectively housed in an annular groove 9123 formed on the outer periphery of the cap body 910, and radially protruding limiting portions 9124 are formed on both axial sides of the annular groove 9123.
[0060] Please refer to Figure 8-13In a preferred embodiment of the present invention, a needle piercing device 70 is further included. The needle piercing device 70 includes a sample injection needle 71 for delivering liquid samples and a needle piercing drive mechanism 72 for driving the sample injection needle 71 to move. The needle piercing drive mechanism 72 is mounted on the X-axis motion assembly 62. The 30 labeling organizations include: The standard solution tray 32 is mounted on the sliding seat 14 and is used to hold sample bottles containing various standard solutions or internal standard solutions of different concentrations. The labeling gas path device 31 is mounted on the sliding seat 14 and has an inlet for receiving the tip of the injection needle 71. The dynamic sealing module 33 includes a first sealing element that can move with the needle insertion device 70, and a second sealing element that is fixed on the labeling gas circuit device 31 and adapted to the first sealing element. When the injection needle 71 reaches the injection position, the first seal and the second seal are pressed together to form a mechanical compression seal without a septum, thereby forming a closed purge chamber around the injection port.
[0061] Based on the above structure, this invention completely eliminates the traditional septum puncture sealing logic by constructing a core structure without a septum, consisting of a needle insertion device 70, a labeling gas path device 31, and a dynamic sealing module 33. This fundamentally solves the gas path leakage problem caused by the elastic failure of the septum after multiple uses, while also eliminating the risks of septum debris contaminating samples, blocking gas paths, and damaging downstream instruments. The design of the follow-up and fixed sealing components in the dynamic sealing module 33 ensures precise linkage between the sealing state and the position of the injection needle 71, forming a sealed purging chamber only during the sample injection and purging stage. This not only ensures a closed environment for standard solution injection and inert gas purging, improving the accuracy of labeling concentration, but also avoids ineffective wear of sealing components. Combined with the septum-free design, it completely eliminates the need for septum replacement, enabling the device to achieve long-term continuous automated operation, reducing downtime maintenance time. Compared with traditional devices, it significantly improves batch labeling efficiency and greatly reduces sample contamination rate, providing higher stability and economy for analytical work in fields such as environmental monitoring and food safety.
[0062] In a preferred embodiment of the present invention, the first sealing element is an elastic sealing ring 331, and the second sealing element is a conical sealing surface 332 formed at the edge of the injection port. When the elastic sealing ring 331 and the conical sealing surface 332 are pressed together, the gas path is sealed, and the conical sealing surface 332 is used to guide the tip of the injection needle 71 to be accurately positioned.
[0063] Based on the above structure, the first sealing element is set as an elastic sealing ring 331 and the second sealing element is set as a conical sealing surface 332. This not only utilizes the deformation capability of the elastic sealing ring 331 to form a tight seal with the conical sealing surface 332, significantly improving the sealing reliability, but also utilizes the tapered guiding characteristics of the conical sealing surface 332 to allow the needle tip to automatically correct its position along the inclined surface when the injection needle 71 moves downward. Even if there is a slight installation deviation in the needle insertion device 70, it can accurately align with the injection port, effectively solving the problem of needle bending and needle tip damage caused by misalignment between the needle and the injection port in traditional devices, and extending the service life of the injection needle 71. At the same time, the flexible sealing method avoids rigid collisions, reduces the wear rate of the sealing components, and the simple fitting design facilitates assembly and maintenance. The sealing ring replacement operation is convenient and far superior to the replacement process of traditional septa, further reducing the operating cost and maintenance difficulty of the device.
[0064] In a preferred embodiment, the conical sealing surface 332 is disposed at the top of the guide needle cap 311, and the lower end of the guide needle cavity 73 of the needle insertion device 70 is provided with a tapered structure that matches the conical sealing surface 332. The sealing ring is embedded in the groove at the lower end of the guide needle cavity 73, moves synchronously with the guide needle cavity 73, and is in contact with or separate from the conical sealing surface 332.
[0065] In a preferred embodiment, the needle insertion device 70 further includes a guide needle cavity 73 and a sample injection needle sealing block 74. The sample injection needle 71 is slidably inserted into the guide needle cavity 73, and the sample injection needle sealing block 74 is sleeved on the needle shaft of the sample injection needle 71 to seal the gap between the sample injection needle 71 and the guide needle cavity 73 when not in the sample injection state.
[0066] In a preferred embodiment, the needle puncture device 70 further includes a sealing block clamping member 75 for fixing the injection needle sealing block 74, and a needle guard block 76 for limiting the radial sway of the injection needle 71. The needle guard block 76 is fixed on the needle puncture seat 77 of the needle puncture device 70, and its central channel is coaxial with the inner cavity of the guide needle cavity 73.
[0067] In a preferred embodiment, when the injection needle 71 is pulled out, its tip is always located outside the lower end of the injection needle sealing block 74, and the piston end of the injection needle 71 is fixed to the needle holder 77 through the injection needle piston fixing position 78. The driving mechanism drives the needle holder 77 through a lead screw or linkage mechanism to move the entire needle device 70 up and down.
[0068] In a preferred embodiment, the labeling gas path device 31 includes a guide needle cap 311, an injection head 312, an inlet gas path block 313, and a base connected in sequence. The contact surface between the guide needle cap 311 and the injection head 312 is provided with a first O-ring groove, the contact surface between the injection head 312 and the inlet gas path block 313 is provided with a second O-ring groove, and the contact surface between the inlet gas path block 313 and the base is provided with a third O-ring groove. Each groove is provided with an O-ring for sealing.
[0069] In a preferred embodiment, the labeling gas path device 31 further includes an inner cavity tube 135 coaxially passing through the sample inlet head 312. The upper end of the inner cavity tube 135 is connected to the sample inlet, and the lower end is connected to the fluid pipeline 314 in the base. The gas inlet block 313 is provided with a nitrogen inlet 316, which is connected to the annular channel between the sample inlet head 312 and the inner cavity tube 135.
[0070] In a preferred embodiment, the nitrogen inlet 316 is opened only when the first seal and the second seal are pressed together to form a seal, and is closed after the sample injection and purging are completed; a tapered flow channel is formed at the connection between the inner tube 135 and the fluid pipeline 314 to accelerate the purging airflow.
[0071] In a preferred embodiment, the needle drive mechanism 72 is a stepper motor or a servo motor; the base of the labeling gas path device 31 is provided with an interface for installing the adsorption tube, the fluid pipeline 314 is connected to the adsorption tube, the adsorption tube is sealed to the base through the analysis cap 91, and the side of the analysis cap 91 is provided with an exhaust hole connected to the exhaust pipe 317.
[0072] The needle insertion drive mechanism uses a stepper motor or servo motor as the sole power source. The power is output through a mechanical structure, which simultaneously drives the entire needle insertion device to move, achieving dynamic sealing and advancing / removing the injection needle piston to inject the standard solution. Alternatively, the needle drive mechanism can use two independent drive devices: a needle motor and an injection motor. The needle motor is dedicated to driving the overall movement of the needle insertion device, while the injection motor is dedicated to driving the piston movement of the injection needle. The precise linkage of the action timing and status is achieved through an electronic control system (PLC / microcontroller).
[0073] In a preferred embodiment of the present invention, the aging mechanism 40 includes: The aging chamber has multiple cavities for accommodating the thermal desorption tube 90. The multiple cavities are arranged in an array within the aging chamber, and the size of each cavity is matched to that of a single thermal desorption tube 90. An aging heating device is installed inside or outside the aging chamber to synchronously control the temperature of multiple chambers. The purge gas path system includes multiple inlet branches, each with an outlet corresponding to a receiving cavity for introducing purge gas into the thermal desorption tube 90 within the receiving cavity.
[0074] Please refer to Figure 14-16 In a preferred embodiment, the analytical unit 50 includes: Heating chamber 51, which defines a sealed inner cavity 511, heating chamber 51 is configured to operatively house thermal desorption tube 90; The heating chamber 51 includes a carrier gas inlet 512, which is connected to a fluid channel hole 9125 of the analysis cap 91; and a carrier gas outlet 513, which is connected to a sealed inner cavity 511 of the heating chamber 51 and located near the end of the suspended adsorption tube 92. The heating element is a heating coil 52 that is attached to the outer wall of the heating cavity 51, and is used to uniformly heat the heating cavity 51 from all directions. When the thermal desorption tube 90 is housed in the sealed inner cavity 511, the external sealing structure of the analysis cap 91 forms a sealed connection with the inner wall of the heating cavity 51, so that the end of the thermal desorption tube 90 that is not connected to the analysis cap 91 is suspended in the sealed inner cavity 511 without the need for a separate seal.
[0075] Based on the above structure, this invention employs a suspended sealing principle, where the hot end of the thermal desorption tube 90 is enclosed within a completely sealed high-temperature cavity, eliminating the need for any moving seals. This completely eliminates a series of problems caused by the short lifespan, high cost, limited temperature resistance, and susceptibility to background interference of high-temperature sealing materials, allowing the resolution temperature to be easily raised to over 350°C, enabling the analysis of high-boiling-point compounds. Furthermore, a heating coil 52 is used as the heating element and is attached to the outer wall of the cavity, achieving rapid and uniform heating of the entire metal cavity, thereby indirectly ensuring the uniformity of heating of the thermal desorption tube 90 within the cavity. Compared to traditional single-sided contact heating, it eliminates the significant temperature difference between the two sides of the thermal desorption tube 90, ensuring complete and thorough resolution, reducing sample residue caused by cold spots, and improving analytical accuracy. As long as the thermal desorption tube 90 can be placed within the heating cavity 51, its length and diameter no longer affect the sealing performance of the hot end, relaxing the dimensional tolerance requirements for consumables and allowing the equipment to accommodate thermal desorption tubes 90 from a wider range of sources, enhancing the system's flexibility and applicability.
[0076] Please refer to Figure 17-18 In a preferred embodiment of the present invention, a thermal desorption gas path switching device 80 connected to the analytical unit 50 is further included. The thermal desorption gas path switching device 80 includes: The integrated pneumatic block 822 has internally interconnected channels machined inside it. Multiple external interfaces are respectively located on the side wall of the integrated air passage block 822 and connected to the internal channel; The linear drive mechanism 817 extends partially into the internal channel of the integrated pneumatic block 822 and is capable of linear motion between the first position and the second position. The internal channel has a first interface 820 and a second interface 821. When the linear drive mechanism 817 is in the first position, it blocks the passage between the first interface 820 and the second interface 821. When the linear drive mechanism 817 is in the second position, it opens the passage between the first interface 820 and the second interface 821.
[0077] Traditional six-way valves rely on the relative rotation of the valve core and valve body to achieve flexible switching between multiple paths. This principle inevitably leads to complex sealing structures and motion mechanisms. In contrast, this invention utilizes a pre-machined channel network within the integrated gas path block 822 to form static interconnections. Only a linearly moving piston rod is needed to block or open one critical path. This channel network and single-point control principle fundamentally simplify the structure. The linear motion of the linear drive mechanism 817, compared to rotary motion, facilitates precise positioning and sealing, and the reduced number of moving parts significantly lowers the probability of wear. Simultaneously, the smooth and continuous internal channels of the integrated gas path block 822 avoid the dead volume at multiple interface connections found in traditional valves. This is crucial for trace analysis, as any dead volume becomes a site for sample residue. Furthermore, this design allows the integrated gas path block 822 to be disassembled and maintained as an independent module, solving the high cost problem of replacing the entire traditional valve.
[0078] The integrated gas passage block 822 of this invention can be made of Teflon (PTFE), PEEK, stainless steel (including 304 / 316, etc.), or any material with a temperature resistance exceeding 200°C. At the same time, the material cannot release volatile organic compounds at the operating temperature. The gas passages in the gas passage block are machined and drilled by CNC, lathe, or Swiss-type lathe, with a hole diameter within 1.6mm. The material of the piston rod can be matched with the material of the gas passage block to ensure that the gas passages do not leak when the piston rod is inserted or removed.
[0079] In a preferred embodiment of the present invention, the plurality of external interfaces include a third interface 811, a fourth interface 818, a fifth interface 819, a sixth interface 823, a seventh interface 828, and a cylinder interface 827. The internal passage includes a first transverse passage 8221, a first longitudinal passage 8222, a second longitudinal passage 8223, a first branch passage 8224, a second branch passage 8225, and a third branch passage 8226; The first end of the first transverse channel 8221 penetrates the side wall of the integrated air passage block 822 to form a cylinder interface 827, and its second end is connected to the first end of the second longitudinal channel 8223. The second end of the second longitudinal channel 8223 penetrates the side wall of the integrated air passage block 822 to form a sixth interface 823. The first end of the first longitudinal channel 8222 is connected to the first transverse channel 8221 to form a first interface 820, and its second end passes through the side wall of the integrated gas block 822 to form a third interface 811. The first end of the first branch channel 8224 is connected to the first transverse channel 8221 to form the second interface 821, and its second end passes through the side wall of the integrated gas block 822 to form the seventh interface 828. The first end of the second branch channel 8225 is connected to the first longitudinal channel 8222, and its second end penetrates the side wall of the integrated gas block 822 to form a fourth interface 818. The first end of the third branch channel 8226 is connected to the first longitudinal channel 8222, and its second end penetrates the side wall of the integrated gas block 822 to form the fifth interface 819. The third interface 811 is configured to connect to the thermal desorption tube 90; the fifth interface 819 is configured to connect to the trap 816; and the sixth interface 823 is configured to connect to the analytical instrument. The linear drive mechanism 817 is a linear cylinder, and its end forms a piston rod; the first position is the position where the piston rod extends into and blocks the passage between the first interface 820 and the second interface 821; the second position is the position where the piston rod retracts and opens the passage between the first interface 820 and the second interface 821.
[0080] Based on the above scheme, the six interfaces of this invention (the third to seventh interfaces 828 and the cylinder interface 827) are organically connected through transverse channels, longitudinal channels, and branch channels. This topology not only ensures smooth airflow but, more importantly, provides a physical basis for the realization of multiple working modes. The direct connection between the first transverse channel 8221 and the cylinder interface 827 makes the control of the drive mechanism more direct and effective, while the reasonable layout of multiple branch channels achieves the optimal allocation of airflow paths, reducing flow resistance and pressure loss.
[0081] In a preferred embodiment of the present invention, an external pneumatic control system connected to the integrated pneumatic block 822 is further included, the external pneumatic control system comprising: The carrier gas input branch is configured as follows: the carrier gas source 81 is connected to the inlet of the first solenoid valve 83 and the inlet of the second solenoid valve 84 after passing through the first pressure reducing valve 82; the outlet of the first solenoid valve 83 is connected to the second interface 821 through the seventh interface 828; the outlet of the second solenoid valve 84 is split into two paths, one path is connected to the inlet of the third solenoid valve 85, and the other path is connected to the inlet of the trap 816. The desorbed gas input branch is configured as follows: the desorbed gas source 88 is connected to the inlet of the fourth solenoid valve 89 after passing through the second pressure reducing valve 824; the outlet of the fourth solenoid valve 89 is connected to the inlet of the thermal desorption tube 90. The exhaust and diversion branch is configured as follows: the outlet of the third solenoid valve 85 is connected to the first vent 87 via the first filter trap 825 and the throttle valve 8686; the inlet of the fifth solenoid valve 812 is connected to the pipeline between the outlet of the fourth solenoid valve 89 and the inlet of the thermal desorption tube 90, and its outlet is connected to the second vent 814 via the second filter trap 826 and the mass flow controller 813; the inlet of the sixth solenoid valve 815 is connected to the pipeline between the outlet of the thermal desorption tube 90 and the third interface 811 of the integrated gas path block 822, and its outlet is connected to the fourth interface 818 of the integrated gas path block 822.
[0082] Based on the above scheme, a programmable airflow path matrix is constructed by coordinating the switching and regulation of multiple solenoid valves, mass flow controller 813 (MFC) and throttle valve 86, in conjunction with the core integrated gas path block 822. This enables precise control of the flow direction, flow rate and split ratio of carrier gas and desorption gas, achieving functional diversification and refined control.
[0083] In a preferred embodiment of the present invention, the external air circuit control system further includes a first pressure sensor P1 and a second pressure sensor P2: The first pressure sensor P1 is installed in the desorption gas supply unit to monitor the pressure of the desorption gas path; The second pressure sensor P2 is located in the carrier gas supply unit and is used to monitor the pressure in the carrier gas path.
[0084] In a preferred embodiment of the present invention, a mass flow controller 813 is disposed on the exhaust path of the fifth solenoid valve 812 and / or the sixth solenoid valve 815, for precisely controlling and regulating the gas flow rate through its branch.
[0085] In a preferred embodiment of the present invention, the first filter trap 825 is disposed on the exhaust path of the third solenoid valve 85; the second filter trap 826 is disposed on the common exhaust path of the fifth solenoid valve 812 and the sixth solenoid valve 815; the first filter trap 825 and the second filter trap 826 are respectively used to adsorb impurities and moisture in the gas.
[0086] In a preferred embodiment of the present invention, a throttle valve 86 is disposed on the exhaust path of the third solenoid valve 85 and cooperates with the mass flow controller 813 to adjust the flow ratio of the branch where the trap 816 is located.
[0087] In a preferred embodiment of the present invention, the external air circuit control system is uniformly controlled by a central controller, which is configured to: send control commands to the first solenoid valve 83, the second solenoid valve 84, the third solenoid valve 85, the fourth solenoid valve 89, the fifth solenoid valve 812, the sixth solenoid valve 815 and the linear drive mechanism 817; and receive feedback signals from the first pressure sensor P1, the second pressure sensor P2 and the mass flow controller 813; and coordinate the operation of each component by executing a preset program to achieve different working modes.
[0088] In a preferred embodiment of the invention, the device is configured to perform a sample recovery mode, wherein: the piston rod of the linear drive mechanism 817 is in a second position; the second solenoid valve 84 and the fifth solenoid valve 812 are open; the first solenoid valve 83, the third solenoid valve 85, the fourth solenoid valve 89 and the sixth solenoid valve 815 are closed; after the carrier gas purges the trap 816 through the second solenoid valve 84, a portion of the sample enters the analyzer, and the other portion of the sample flows in reverse into the thermal desorption tube 90 for recovery.
[0089] Based on the above scheme, when the device is configured in this mode, the airflow path is precisely controlled as follows: the main airflow carries the sample in the trap 816 into the analyzer for detection, while a portion of the split airflow carries a portion of the sample back into the thermal desorption tube 90. This mechanism solves the problem that traditional thermal desorbers cannot retain samples in a single analysis, providing a sample source for result retesting, method validation, or further analysis, greatly improving the reliability and efficiency of the analytical process. The successful implementation of this mode directly relies on the low dead volume characteristics brought by the integrated gas path block, avoiding cross-contamination and loss of samples in complex flow paths.
[0090] In a preferred embodiment of the invention, the device is configured to perform a first-stage thermal desorption mode, wherein: the piston rod of the linear drive mechanism 817 is in the second position; the fourth solenoid valve 89 and the sixth solenoid valve 815 are open; the first solenoid valve 83, the second solenoid valve 84, the third solenoid valve 85 and the fifth solenoid valve 812 are closed; and the sample desorbed by the desorption gas purging thermal desorption tube 90 directly enters the analytical instrument.
[0091] Based on the above scheme, in this mode, the device bypasses the enrichment / desorption process of the trap 816, directly introducing the sample desorbed from the thermal desorption tube 90 into the analytical instrument, significantly shortening the analysis cycle. This mode is suitable for high-concentration samples or scenarios where certain standard methods require direct sample introduction. Through simple valve state combinations (only opening the fourth and sixth solenoid valves 815) and drive component positioning, the airflow path can be reconstructed, achieving the same function as traditional single-tube thermal desorption, demonstrating the core advantage of this invention: multi-functionality. It avoids sample discrimination or residue that may result from using the trap 816, simplifies the operation steps, and improves the analysis speed.
[0092] In a preferred embodiment of the invention, the device is configured to perform a two-stage thermal desorption mode, wherein: the piston rod of the linear drive mechanism 817 is in a first position; the first solenoid valve 83, the third solenoid valve 85, and the fourth solenoid valve 89 are open; the second solenoid valve 84, the fifth solenoid valve 812, and the sixth solenoid valve 815 are closed; the sample desorbed by the desorption gas purging thermal desorption tube 90 is enriched in the trap 816, while the carrier gas provides background gas flow for the analytical instrument.
[0093] Based on the above scheme, in this mode, the sample desorbed by the thermal desorption tube 90 is first captured and focused by the low-temperature trap 816. Then, the trap 816 is rapidly heated, delivering the concentrated sample into the analyzer in a narrow band. This process greatly reduces the detection limit, the drive component blocks a specific flow path, and the carrier gas provides a stable background for the analyzer. The desorption gas path and the enrichment path of the trap 816 are precisely controlled, solving the problem of peak broadening or sensitivity loss caused by the large dead volume and poor sealing of traditional six-way valves in this mode, thus ensuring the accuracy and reproducibility of the analytical results.
[0094] Although only certain components and embodiments of this application have been illustrated and described, many modifications and alterations will be apparent to those skilled in the art without actually departing from the scope and spirit of the claims, such as variations in the size, dimensions, structure, shape and proportion of the various elements, installation arrangement, material use, color, orientation, etc.
[0095] The above embodiments are merely preferred embodiments of the present invention and should not be construed as limiting the scope of protection of the present invention. Any non-substantial changes and substitutions made by those skilled in the art based on the present invention shall fall within the scope of protection claimed by the present invention.
Claims
1. A thermal desorption tube full-process automated analysis system, characterized in that, The system comprises: a rack; a sample carrying mechanism arranged on the rack for centralized storage of a plurality of thermal desorption tubes to be processed or processed; a standard addition mechanism arranged on the rack, configured to add a standard sample solution or an internal standard solution to the thermal desorption tube; an aging mechanism arranged on the rack, configured to perform high-temperature aging treatment on the thermal desorption tube; an analytical analysis mechanism arranged on the rack, configured to perform thermal desorption analysis on the thermal desorption tube and deliver the sample to an analytical instrument; a transfer device mounted on the rack for automatic transfer of the thermal desorption tube between the sample carrying mechanism, the standard addition mechanism, the aging mechanism and the analytical analysis mechanism; a central controller in communication with the transfer device, the standard addition mechanism, the aging mechanism and the analytical analysis mechanism, respectively.
2. The thermal desorption tube full-process automated analysis system according to claim 1, wherein: the rack comprises a base, a gantry mounted on the base and located on one side of the base, a fixed seat fixedly mounted on the base, and a sliding seat movably mounted on the base; wherein the analytical analysis mechanism is mounted on the fixed seat, and the sample carrying mechanism, the standard addition mechanism and the aging mechanism are mounted on the sliding seat; the transfer device comprises: a Y-axis movement assembly mounted on the base for driving the sliding seat to move linearly along the Y-axis direction; an X-axis movement assembly mounted on the gantry for providing horizontal movement along the X-axis direction; a vertical lifting assembly mounted on the moving part of the X-axis movement assembly and driven by the X-axis movement assembly to move along the X-axis; a tube clamping mechanism mounted on the moving part of the vertical lifting assembly and driven by the vertical lifting assembly to vertically lift; the tube clamping mechanism comprises an actuator and a clamping jaw driven by the actuator, and the clamping jaw is configured to directly clamp the outer part of the tube body of the thermal desorption tube.
3. The full flow automated thermal desorption tube analysis system of claim 2, wherein, The central controller is configured to adjust the position of the sliding seat by controlling the Y-axis movement assembly, and in combination with the control of the movement of the X-axis movement assembly and the vertical lifting assembly, so that the tube clamping mechanism can reach the analytical analysis mechanism station on the fixed seat and any functional station on the sliding seat.
4. The full flow automated thermal desorption tube analysis system of claim 2, wherein, The thermal desorption tube comprises: an adsorption tube body filled with adsorbent; An analysis cap detachably connected to one end of the thermal desorption tube; the analysis cap comprises a cap body which is cylindrical as a whole and sequentially comprises a clamping portion, an outer sealing portion and a guide portion in the axial direction; the outer periphery of the outer sealing portion is provided with a first sealing ring and a second sealing ring, the first sealing ring and the second sealing ring are arranged at intervals in the axial direction of the cap body, and a fluid passage hole is formed in the cap wall between the first sealing ring and the second sealing ring; the inside of the cap body is provided with an internal cavity for receiving and sealing the thermal desorption tube, and the internal cavity is provided with an internal sealing structure; the fluid passage hole is located on the axial upper side of the internal sealing structure, so that when the thermal desorption tube is sealed in the internal cavity, the fluid passage hole is communicated with the inner cavity of the thermal desorption tube through the internal cavity; The internal sealing structure of the analysis cap is sealed with the outer wall of the adsorption tube body, so that the inner cavity of the adsorption tube body is communicated with the fluid passage hole of the analysis cap; The clamping surface shape of the clamping jaw of the clamping mechanism is matched with the outer shape of the clamping portion of the thermal desorption tube body, so that the thermal desorption tube can be gripped without being uncapped or capped.
5. The full flow automated thermal desorption tube analysis system of claim 4, wherein, The outer diameter of the second sealing ring is smaller than the outer diameter of the first sealing ring; the clamping portion comprises a clamping segment with a smaller diameter and a limiting segment with a larger diameter located on one axial side of the clamping segment, the clamping segment is used to be gripped by the clamping jaw, and the limiting segment is used to cooperate with the clamping jaw to form axial limiting.
6. The automated thermal desorption tube full-process analysis system of claim 4, wherein, Further comprising a needle device, the needle device comprises a sample injection needle for delivering a liquid sample and a needle driving mechanism for driving the sample injection needle to move, wherein the needle driving mechanism is mounted on the X-axis movement assembly; The standard solution dispensing mechanism comprises: A standard solution disc is mounted on the sliding seat, and the standard solution disc is used to place sample bottles containing standard solutions or internal standard solutions with different concentrations; A standard solution dispensing gas path device is mounted on the sliding seat, and the standard solution dispensing gas path device is provided with a sample injection port for receiving the needle tip of the sample injection needle; A dynamic sealing module comprises a first sealing member movable with the needle device and a second sealing member fixed to the standard solution dispensing gas path device and matched with the first sealing member; When the sample injection needle reaches the sample injection position, the first sealing member and the second sealing member are pressed together to form a mechanical compression seal without a gasket, thereby forming a sealed purge chamber around the sample injection port.
7. The full flow automated thermal desorption tube analysis system of claim 6, wherein, The first sealing member is an elastic sealing ring, and the second sealing member is a tapered sealing surface formed on the edge of the sample injection port, the elastic sealing ring and the tapered sealing surface are pressed together to achieve gas path sealing, and the tapered sealing surface is used to guide the accurate positioning of the needle tip of the sample injection needle.
8. The automated thermal desorption tube full-process analysis system of claim 4, wherein, The analysis mechanism comprises: A heating cavity defining a sealed inner cavity, the heating cavity is configured to operatively receive the thermal desorption tube; the heating cavity comprises: a carrier gas inlet connected to the fluid passage hole of the analysis cap; and a carrier gas outlet connected to the sealed inner cavity of the heating cavity and located near the end of the suspended adsorption tube body; A heating element is a heating coil attached to the outer wall of the heating cavity for uniform and all-around heating of the heating cavity. When the thermal desorption tube is accommodated in the sealed inner cavity, the outer sealing structure of the analysis cap is in sealing connection with the inner wall of the heating cavity, so that the end of the thermal desorption tube not connected to the analysis cap is suspended in the sealed inner cavity without a separate sealing element.
9. The full flowpath automated thermal desorption tube analysis system of claim 1, wherein, Further comprising a thermal desorption gas path switching device connected with the analysis analysis mechanism, the thermal desorption gas path switching device comprises: An integrated gas path block is internally processed with internal channels in communication with each other; A plurality of external interfaces are respectively arranged on the side wall of the integrated gas path block and are in communication with the internal channels; A linear drive mechanism partially extends into the internal channel of the integrated gas path block and can move linearly between a first position and a second position; Wherein, the internal channel is formed with a first interface and a second interface, when the linear drive mechanism is in the first position, the passage between the first interface and the second interface is blocked; when the linear drive mechanism is in the second position, the passage between the first interface and the second interface is conducted.
10. The full flow automated thermal desorption tube analysis system of claim 9, wherein, A plurality of external interfaces include a third interface, a fourth interface, a fifth interface, a sixth interface, a seventh interface and a cylinder interface; The internal channel includes a first transverse channel, a first longitudinal channel, a second longitudinal channel, a first branch channel, a second branch channel and a third branch channel; The first end of the first transverse channel penetrates the side wall of the integrated gas path block to form the cylinder interface, and the second end thereof is in communication with the first end of the second longitudinal channel, and the second end of the second longitudinal channel penetrates the side wall of the integrated gas path block to form the sixth interface; The first end of the first longitudinal channel is in communication with the first transverse channel to form the first interface, and the second end thereof penetrates the side wall of the integrated gas path block to form the third interface; The first end of the first branch channel is in communication with the first transverse channel to form the second interface, and the second end thereof penetrates the side wall of the integrated gas path block to form the seventh interface; The first end of the second branch channel is in communication with the first longitudinal channel, and the second end thereof penetrates the side wall of the integrated gas path block to form the fourth interface; The first end of the third branch channel is in communication with the first longitudinal channel, and the second end thereof penetrates the side wall of the integrated gas path block to form the fifth interface.