Vacuum differential pyrolysis product sample introduction analysis cell

Abstract

The application belongs to the technical field of mass spectrum analysis, and particularly relates to a vacuum differential pyrolysis product sampling analysis cavity. Two-stage vacuum differential ion transmission channels are formed in the integrated main vacuum cavity, a cooling water circulation cavity in the differential sampling cooling seat assembly completely wraps the outer wall of the quartz cone, and is in communication with the cooling circulation water inlet and outlet, thereby forming a circulating cooling loop covering the side wall of the cavity and the outer wall of the sampling seat, and realizing the synergistic balance of efficient introduction of high-temperature pyrolysis products and the circulating cooling of the vacuum cavity; the pyrolysis products are ionized after being introduced into the ionization cavity through the quartz cone, and enter the ion flight cavity for mass spectrum detection through the two-stage vacuum differential ion transmission channels, thereby realizing the mass spectrum analysis of the pyrolysis products; by shortening the path of the high-temperature pyrolysis products from the external pyrolysis furnace to the quartz cone, and cooperating with the cooling of the covering circulating cooling loop, the chemical state of the free radicals is fixed, so that the high-temperature pyrolysis products can be effectively detected.

Description

Technical Field

[0001] This invention belongs to the field of mass spectrometry analysis technology, specifically relating to a vacuum differential pyrolysis product sample introduction and analysis chamber. Background Technology

[0002] Mass spectrometry is a key technology for analyzing trace components in biological, environmental, and material pyrolysis products. Mass spectrometry involves ionizing sample molecules in an ion source to generate ions with different mass-to-charge ratios. These ions are then separated in a mass analyzer based on their mass-to-charge ratios, detected, and recorded to form a mass spectrum, thereby enabling the identification of the composition and structure of substances. Currently, common mass spectrometers typically consist of an ion source, an ion transport system, a mass analyzer, and an ion detector. These components often need to operate at different vacuum levels to achieve optimal performance. To achieve a smooth transition from atmospheric pressure or low vacuum to high vacuum and to ensure that ions are not disturbed by collisions with gas molecules during transport and separation, multi-stage vacuum differential systems are currently used to achieve a step-by-step transition in pressure using throttling orifices or throttling pipes. These systems are combined with vacuum pump sets with different pumping speeds to maintain the target vacuum level of each chamber, thus achieving a smooth transition from atmospheric pressure or low vacuum to high vacuum. Current multi-chamber, multi-stage differential structures typically involve multiple independent chambers connected by flanges and seals. However, the numerous connection points in existing multi-chamber structures increase the risk of vacuum leakage and complicate the chamber structure, making long-term stable operation and maintenance difficult. When analyzing high-temperature, highly reactive samples such as pyrolysis products, the high-temperature characteristics of these products mean that direct introduction into the vacuum chamber may accelerate the aging of temperature-sensitive vacuum seals, affecting the long-term stability and sealing performance of the vacuum. Furthermore, reactive intermediates such as free radicals are characterized by short lifespans, low concentrations, and high chemical reactivity. During transport at ambient temperature and pressure, they are easily quenched by collisions with the carrier gas or tube walls, rendering conventional sample introduction methods ineffective for their detection. Organic pyrolysis products are also prone to condensation and adsorption at low temperatures, leading not only to sample loss and cross-contamination but also reducing the sensitivity and accuracy of mass spectrometry detection. Summary of the Invention

[0003] The purpose of this invention is to provide a vacuum differential pyrolysis product injection and analysis chamber to solve problems that cannot be solved by existing technologies.

[0004] The specific technical solution adopted by this invention is as follows: A vacuum differential pyrolysis product sample introduction and analysis chamber, comprising: An integrated main vacuum chamber includes an ionization chamber and an ion flight chamber that are separated from each other. A two-stage vacuum differential ion transport channel is formed between the ionization chamber and the ion flight chamber to maintain different pressure environments. The cooling water inlet and outlet are located on the side wall of the integrated main vacuum chamber and are used to connect to an external constant temperature cooling water pipe to continuously remove heat from the chamber. The differential sampling cooling seat assembly is installed as an independent pre-assembled component on the integrated main vacuum chamber. An external pyrolysis furnace extends into the differential sampling cooling seat assembly to receive the high-temperature pyrolysis products from the external pyrolysis furnace and introduce the high-temperature pyrolysis products into the ionization chamber. The ion transport introducer assembly, as an independent module, can be extracted axially from the integrated main vacuum chamber via a guide mechanism, and can be detachably installed inside the ionization chamber and communicated with the ion flight chamber. The differential sampling cooling base assembly includes a quartz cone and a cooling water circulation chamber disposed around the quartz cone: the cooling water circulation chamber completely surrounds the outer wall of the differential sampling cooling base assembly, which is used to block heat conduction to the ionization chamber and the external environment of the ionization chamber; The cooling water inlet and outlet are connected to the cooling water circulation chamber, forming a circulating cooling circuit that covers the side wall of the integrated main vacuum chamber and the outer wall of the differential sampling cooling seat assembly. This circuit continuously removes heat from the chamber to prevent the high temperature at the sampling end from being conducted to the ionization chamber and beyond, thus preventing the vacuum seal from aging and failing due to high temperature.

[0005] Preferably, the differential sampling cooling mount assembly further includes: A cooling water sealing ring is fitted onto the connection between the cooling water inlet / outlet and the cooling water circulation chamber to seal the cooling water pipe. A vacuum differential sealing ring is disposed between the pyrolysis product channel inside the quartz cone and the external atmospheric pressure environment, and is used to form two independent vacuum isolation barriers between the differential exhaust chamber and the external atmospheric pressure environment at the pyrolysis product channel. The external thread nut is fitted onto the outer wall of the quartz cone and threadedly connected to the housing of the differential sampling cooling base assembly to lock the internal components. A silicone gasket is placed between the external thread nut and the cooling water circulation chamber for buffering and auxiliary sealing. The transition metal ring, which is a ring-shaped structure, is sleeved between the external thread nut and the silicone gasket to uniformly transmit the clamping force during axial clamping.

[0006] Preferably, the differential sampling cooling base assembly has two differential exhaust ports symmetrically arranged along the axis of the differential sampling cooling base assembly on the side near the quartz cone. The differential exhaust ports are used to cooperate with the vacuum differential sealing ring to stably maintain a preset vacuum differential degree inside the differential exhaust chamber. The differential exhaust port is used to connect to an external vacuum pump and adjust the vacuum level of the differential region through a series differential pressure regulating valve to adapt to different pyrolysis product testing conditions and stabilize the ion sampling efficiency of the ion transport introducer assembly.

[0007] Preferably, the ion transport introducer assembly includes: An ultraviolet lamp is placed inside the ionization chamber to ionize the pyrolysis products within the ionization chamber. The guide rod is a rod-shaped structure extending along the axial direction, which is set on one side of the ultraviolet lamp to provide a track for picking up and putting in the ultraviolet lamp, so as to facilitate the cleaning and replacement of the ultraviolet lamp; A heating rod is disposed within the wall of the ionization region of the ionization chamber to heat the ionization region of the ionization chamber and prevent the pyrolysis products from condensing. An ion importer assembly is disposed in the transmission channel between the ionization cavity and the ion flight cavity, and is used to repel, focus and guide ions to be transported to the ion flight cavity. A grounding conductive spring is disposed on the side of the ion transport introducer assembly near the inner wall of the integrated main vacuum chamber, for physical contact with the chamber wall to achieve a reliable grounding connection; An aviation plug is located at the end of the ion transport inlet assembly closest to the outside, for unified access to external power supply and signals.

[0008] Preferably, the ultraviolet lamp is detachably installed in the ion transporter assembly via a quick-release mechanism consisting of a spring and a voltage-conducting plate; The spring is sleeved on the guide rod and located at the end of the ultraviolet lamp away from the voltage-conducting plate; the voltage-conducting plate is located at the other end of the ultraviolet lamp; The quick-release mechanism releases the limit by compressing the spring to enable tool-free quick replacement of the ultraviolet lamp, and achieves automatic conductive contact by relying on spring pressure.

[0009] Preferably, the ion transport introducer assembly further includes: The first flange is located at the end of the ion transport introducer assembly closest to the outside environment, and is used to seal the ionization chamber from the external environment. A second flange is disposed at one end of the ion transport inlet assembly near the ion flight chamber, for isolating the ionization chamber from the ion flight chamber; The first flange and the second flange work together in a differential pumping system to stably maintain the vacuum pressure difference between the ionization chamber and the ion flight chamber.

[0010] Preferably, the outlet end of the quartz cone is at the same horizontal level as the lower edge of the light path of the ultraviolet lamp, so that the pyrolysis products are photoionized as soon as they reach the outlet of the quartz cone; The differential exhaust port is located on one side of the quartz cone and is designed to fit the shape of the quartz cone so that dust and impurities carried by the pyrolysis products can be discharged through the differential exhaust port. Beneficial effects

[0011] This invention integrates the ionization chamber and the ion flight chamber into a single main vacuum chamber, reducing the number of connecting flanges and seals between chambers, lowering the risk of vacuum leakage, and providing a stable high-vacuum environment for pyrolysis products to enter mass spectrometry detection. A circulating cooling water loop forms a covering cooling circuit between the side wall of the vacuum chamber and the outer wall of the sample holder, effectively absorbing the high temperature of the pyrolysis products before they enter the ionization chamber, avoiding the thermal aging effect of high temperature on the differential vacuum seal ring, ensuring long-term stable operation of the vacuum system, and providing reliable front-end conditions for mass spectrometry detection of pyrolysis products. Furthermore, through a double-layer independent sealing structure, two independent vacuum isolation barriers are formed between the pyrolysis product channel of the quartz cone, the differential exhaust chamber, and the external atmospheric pressure environment. Even if the first sealing structure leaks, the second sealing structure maintains the vacuum environment, ensuring the long-term stable high-vacuum performance of the ion analysis chamber and ensuring that the pyrolysis products are not disturbed by the external environment before entering mass spectrometry detection.

[0012] This invention features symmetrical differential exhaust ports at both the upper and lower ends of the differential sampling cooling base assembly. Adjusting the differential pressure regulating valves connected in series with these ports controls the vacuum level in the differential region, adapting to variations in carrier gas flow rate and product concentration for different pyrolysis products. Furthermore, because the external pyrolysis furnace extends into the differential sampling cooling base assembly, the path of high-temperature pyrolysis products from the external furnace to the quartz cone is shortened. Combined with the cooling of the covered circulating cooling circuit, this significantly reduces the molecular thermal motion rate and lengthens the molecular mean free path, effectively reducing free radical recombination and quenching in the high-temperature pyrolysis products. This fixes the chemical state of the free radicals, enabling effective detection of the high-temperature pyrolysis products.

[0013] The ion transport introducer assembly of the present invention is an independent module that can be extracted axially from the integrated main vacuum chamber via a guiding mechanism. The power supply can be disconnected uniformly via an aviation plug, eliminating the need to manually disassemble the internal wiring. Maintenance can be completed simply by extracting the entire ion transport introducer assembly. During reinstallation, a reliable grounding connection is automatically established through physical contact between the grounding conductive spring and the chamber wall, making the operation simple and reliable.

[0014] This invention uses an ultraviolet lamp to photoionize pyrolysis products in an ionization chamber, and maintains the ionization region in a high-temperature constant-temperature environment by a heating rod. This avoids the problem of organic products condensing and adsorbing due to low temperature, reduces the loss and cross-contamination of pyrolysis products, and improves the sensitivity of pyrolysis products for mass spectrometry detection. Maintaining the ionization chamber under low vacuum conditions increases the probability of collision between pyrolysis product molecules and photons, thereby improving ionization efficiency. Attached Figure Description

[0015] Figure 1 This is a three-dimensional structural schematic diagram of the vacuum differential pyrolysis product injection and analysis chamber of the present invention; Figure 2 This is a horizontal cross-sectional view of the vacuum differential pyrolysis product injection and analysis chamber of the present invention; Figure 3 This is a partial exploded view of the differential sampling cooling base assembly of the present invention; Figure 4 This is a horizontal sectional view of the differential sampling cooling base assembly of the present invention; Figure 5 For the present invention Figure 4 Enlarged view of part A; Figure 6 This is a full sectional view of the differential sampling cooling base assembly of the present invention; Figure 7 This is a cross-sectional view of the piping of the differential sampling cooling base assembly of the present invention; Figure 8 This is a vertical cross-sectional view of the ion transport introducing device assembly of the present invention; Figure 9 This is a schematic diagram of the vacuum isolation seal of the ion transport introducer assembly of the present invention; Figure 10 This is a schematic diagram showing the replacement of the ultraviolet lamp in the ion transport introducer assembly of the present invention; Figure 11 This is a perspective view of the ion transport introducing device assembly of the present invention.

[0016] In the diagram: 1. Integrated main vacuum chamber; 11. Ionization chamber; 12. Ion flight chamber; 2. Cooling circulating water inlet and outlet; 3. Differential sampling cooling seat assembly; 31. Cooling water circulation chamber; 32. Quartz cone; 33. Cooling water sealing ring; 34. Vacuum differential sealing ring; 35. Pyrolysis product channel; 36. Differential exhaust chamber; 37. Differential exhaust port; 38. Pressing external thread nut; 39. Silicone gasket; 310. Transition metal ring; 4. Ion transport introducer assembly; 41. Ultraviolet lamp; 42. Conductive voltage plate; 43. Aviation plug; 44. Spring; 45. Guide rod; 46. Heating rod; 47. First flange; 48. Second flange; 49. Grounding conductive spring. Detailed Implementation

[0017] The technical solution of the present invention will be further described in detail below with reference to specific embodiments. The following embodiments are used to illustrate the present invention, but should not be used to limit the scope of protection of the present invention. The conditions in the embodiments can be further adjusted according to specific conditions, and simple improvements to the method of the present invention under the premise of the concept of the present invention are all within the scope of protection claimed by the present invention.

[0018] Please refer to Figures 1-11This embodiment provides a vacuum differential pyrolysis product sample introduction and analysis chamber, including: 1. Integrated main vacuum chamber; 2. Cooling circulating water inlet and outlet; 3. Differential sampling cooling base assembly; and 4. Ion transfer introducer assembly. The integrated main vacuum chamber 1 includes an ionization chamber 11 and an ion flight chamber 12 that are separated from each other. A two-stage vacuum differential ion transport channel is formed between the ionization chamber 11 and the ion flight chamber 12 to maintain different pressure environments. Cooling water inlet and outlet 2 are located on the side wall of the integrated main vacuum chamber 1 and are used to connect to an external constant temperature cooling water pipe to continuously remove heat from the chamber. The ionization chamber 11 is used to receive high-temperature pyrolysis products from an external pyrolysis furnace. It maintains a low vacuum condition inside to increase the number of collisions between pyrolysis product molecules and photons, thereby improving ionization efficiency. The ion flight chamber 12 is used for mass analysis. Its internal vacuum level is maintained higher than that of the ionization chamber 11 to ensure the vacuum conditions required for the normal operation of the time-of-flight analyzer; specifically, it can maintain a vacuum level of 10⁻⁻⁶. 4 A vacuum level on the order of Pa; through a two-stage vacuum differential design of ionization chamber 11 and ion flight chamber 12, a smooth gas pressure transition from the pyrolysis product introduction area to the mass analysis area is achieved, ensuring ion transport efficiency; The differential sampling cooling seat assembly 3 is installed as an independent pre-assembled component on the integrated main vacuum chamber 1. The external pyrolysis furnace extends into the differential sampling cooling seat assembly 3 to receive the high-temperature pyrolysis products of the external pyrolysis furnace and introduce the high-temperature pyrolysis products into the ionization chamber 11. The differential sampling cooling seat assembly 3 includes: a quartz cone 32 for guiding the flow of pyrolysis products; a cooling water circulation chamber 31, which is located around the quartz cone 32 and completely surrounds the outer wall of the differential sampling cooling seat assembly 3 to form an all-round isolation barrier to block heat conduction to the ionization chamber 11 and the external environment; and cooling water inlet and outlet 2 connected to the cooling water circulation chamber 31 to form a circulating cooling circuit covering the side wall of the integrated main vacuum chamber 1 and the outer wall of the differential sampling cooling seat assembly 3, which continuously removes heat from the chamber to block the high temperature at the sampling end from conducting to the ionization chamber 11 and the external environment, and to prevent the vacuum seal from aging and failing at high temperature. Cooling water sealing ring 33 is fitted at the connection between the cooling water inlet / outlet 2 and the cooling water circulation chamber 31 to seal the cooling water pipe and prevent cooling water leakage into the high vacuum area; vacuum differential sealing ring 34 is located between the pyrolysis product channel 35 inside the quartz cone 32 and the external atmospheric pressure environment to seal the pyrolysis product channel 35 of the quartz cone 32, forming two independent vacuum isolation barriers between the differential exhaust chamber 36 and the external atmospheric pressure environment, so that even if there is a slight leakage in the first structure, the second sealing structure can still maintain the vacuum environment; tightening external thread nut 38, fitted A silicone gasket 39 is located on the outer wall of the quartz cone 32 and is threadedly connected to the housing of the differential sampling cooling seat assembly 3 for locking the internal components; a silicone gasket 39 is located between the clamping external thread nut 38 and the cooling water circulation chamber 31 for buffering and auxiliary sealing; a transition metal ring 310 is sleeved between the clamping external thread nut 38 and the silicone gasket 39 for uniformly transmitting clamping force during axial clamping; wherein, the external pyrolysis furnace extends into the pyrolysis product channel 35 of the differential sampling cooling seat assembly 3, extending close to the quartz cone 32, so as to shorten the path of high-temperature pyrolysis products from the external pyrolysis furnace to the quartz cone.

[0019] Two differential exhaust ports 37 are symmetrically arranged along the axis of the differential sampling cooling base assembly 3 on the side near the quartz cone 32. The differential exhaust ports 37 are used to work with the vacuum differential sealing ring 34 to stably maintain the preset vacuum differential degree inside the differential exhaust chamber 36 and prevent ion loss caused by pressure differential disturbance. The differential exhaust ports 37 are used to connect an external vacuum pump and adjust the vacuum degree of the differential region through a differential pressure regulating valve connected in series to adapt to different pyrolysis product testing conditions and stabilize the ion sampling efficiency of the ion transport introducer assembly 4. The vacuum levels of the ionization chamber 11 and the ion flight chamber 12 can be adjusted by a differential pressure regulating valve connected in series on the differential exhaust port 37.

[0020] The ion transport importer assembly 4, as an independent module, can be extracted axially from the integrated main vacuum chamber 1 via a guide mechanism such as a slide common in the prior art, and can be detachably installed inside the ionization chamber 11 and connected to the ion flight chamber 12. Ion transport implanter assembly 4 includes: The ultraviolet lamp 41 is set in the ionization chamber 11 and is used to ionize pyrolysis products in the ionization chamber 11. It is suitable for the analysis of complex pyrolysis products such as pyrolysis products. The guide rod 45 is a rod-shaped structure extending along the axial direction, located on one side of the ultraviolet lamp 41, and is used to provide a track for picking up and putting in the ultraviolet lamp 41, making it easy to clean and replace the ultraviolet lamp 41; the heating rod 46 is used to heat the ionization region of the ionization chamber 11 to prevent the condensation of pyrolysis products. The organic components in the pyrolysis products are easily condensed and adsorbed on the chamber wall and electrode surface at low temperature, causing loss of pyrolysis products and cross-contamination. The heating rod 46 maintains the ionization region within an appropriate temperature range, effectively avoiding condensation; An ion implanter assembly is disposed in the transmission channel between the ionization chamber 11 and the ion flight chamber 12, and is used to repel, focus and guide ions to be transported to the ion flight chamber 12. The ion implanter assembly is a common technical solution in the prior art, and the specific principles of its ion repulsion, focusing and guiding of ions to be transported to the ion flight chamber 12 are also common technical solutions in the prior art. A grounding conductive spring 49 is located on the side of the ion transfer inductor assembly 4 near the inner wall of the integrated main vacuum chamber 1, for physical contact with the chamber wall to achieve a reliable grounding connection; an aviation plug 43 is located at the end of the ion transfer inductor assembly 4 near the outside, for unified access to external power supply and signals, realizing modular integrated wiring and leadless self-contact grounding shielding; the ultraviolet lamp 41 is detachably installed in the ion transfer inductor assembly 4 through a quick-release mechanism composed of a spring 44 and a voltage-conducting plate 42; the spring 44 is sleeved on the guide rod 45 and located at the end of the ultraviolet lamp 41 away from the voltage-conducting plate 42; the voltage-conducting plate 42 is located at the other end of the ultraviolet lamp 41; the quick-release mechanism releases the limit by compressing the spring 44 to achieve tool-free quick replacement of the ultraviolet lamp 41, and achieves automatic conductive contact by relying on spring pressure.

[0021] The ion transport introducer assembly 4 further includes: a first flange 47, located at the end of the ion transport introducer assembly 4 closest to the outside environment, for sealing the ionization chamber 11 from the external environment; and a second flange 48, located at the end of the ion transport introducer assembly 4 closest to the ion flight chamber 12, for isolating the ionization chamber 11 from the ion flight chamber 12; both the first flange 47 and the second flange 48 are provided with evacuation ports, which are connected to an external differential evacuation system; the first flange 47 and the second flange 48, in conjunction with the differential evacuation system, stably maintain the vacuum pressure difference between the ionization chamber 11 and the ion flight chamber 12. Specifically, when maintaining or replacing the ion transfer introducer assembly 4, the ion transfer introducer assembly 4 is pulled out of the integrated main vacuum chamber 1 along the guide rail that corresponds to and fits the ion transfer introducer assembly 4. The power is disconnected uniformly through the aviation plug 43. There is no need to manually disassemble the internal wiring. During the reinstallation process, the grounding connection is reliably established through the physical contact between the grounding conductive spring 49 and the chamber wall. The modular ion transfer introducer assembly 4, combined with the dual flange sealing structure, enables rapid module replacement and reduces maintenance downtime.

[0022] The outlet end of the quartz cone 32 is at the same horizontal level as the light path of the ultraviolet lamp 41, so that the pyrolysis products are photoionized as soon as they pass through the outlet of the quartz cone 32. By using a coaxial straight-through method, the transmission distance of the pyrolysis products from the outlet to the ionization region is reduced, thereby reducing the loss of pyrolysis products due to adsorption or diffusion. The differential exhaust port 37 is located on one side of the quartz cone 32 and is designed to fit the shape of the quartz cone 32. It allows dust and impurities carried by the pyrolysis products to be discharged through the differential exhaust port 27, reducing interference from dust and impurities on the pyrolysis products and minimizing contamination of the integrated main vacuum chamber 1. By shortening the path of the high-temperature pyrolysis products from the external pyrolysis furnace to the quartz cone, and in conjunction with the cooling of the covered circulating cooling circuit, the molecular thermal motion rate is significantly reduced, and the molecular mean free path is lengthened. This effectively reduces free radical recombination and quenching in the high-temperature pyrolysis products, fixing the chemical state of the free radicals and enabling effective detection of the high-temperature pyrolysis products. Simultaneously, the differential exhaust port 37 effectively removes dust and impurities carried by the pyrolysis products, reducing interference from dust and impurities on the pyrolysis products and minimizing contamination of the integrated main vacuum chamber 1. This ensures the accuracy of the high-temperature pyrolysis product analysis and reduces the maintenance of the integrated main vacuum chamber 1.

[0023] Working principle: High-temperature pyrolysis products from an external pyrolysis furnace are introduced into the ionization chamber 11 through the quartz cone 32 of the differential sampling cooling seat assembly 3. At the same time, the circulating cooling water in the cooling water circulation chamber 31 forms an all-round isolation barrier to prevent high temperature from being conducted to the ionization chamber 11. This thermal management measure protects the vacuum seals from high-temperature aging and ensures the long-term stability of the vacuum system. Inside the ionization chamber 11, a heating rod 46 is used to maintain the ionization region in a high-temperature constant-temperature environment to prevent the condensation and adsorption of organic products. An ultraviolet lamp 41 is used to photo-ionize the pyrolysis products under low vacuum conditions. By maintaining the ionization region in a high-temperature constant-temperature environment higher than the condensation point of the organic components in the pyrolysis products, organic products are prevented from condensing and adsorbing on the walls of the ionization chamber, the electrode surfaces, or the inner walls of the ion transport channels due to low temperatures, thus reducing the loss of pyrolysis products and cross-contamination. The quick-release mechanism releases the limit through a compression spring 44 to achieve tool-free quick replacement of the ultraviolet lamp 41, and automatic conductive contact is achieved by relying on spring pressure. The ion importer assembly overcomes the problem of ion dispersion due to gas collision in a low vacuum environment, and efficiently focuses and guides ions to be transported to the ion flight chamber 12 for mass analysis. Specifically, when it is necessary to maintain or replace the ion transfer introducer assembly 4, the ion transfer introducer assembly 4 is pulled out as a whole from the integrated main vacuum chamber 1 along the guide rail, and the power is disconnected uniformly through the aviation plug 43, simplifying the operation process, eliminating the need to manually disassemble the internal wiring, and reducing the risk of failure due to wiring errors. During reinstallation, the ion transport introducer assembly 4 is reinstalled into the integrated main vacuum chamber 1 along the guide rail. The grounding connection is reliably established through the physical contact between the grounding conductive spring 49 and the chamber wall, without the need for additional grounding operations, achieving leadless self-contact grounding shielding. Specifically, when the ion transport introducer assembly 4 is pushed into the installation position, the spring is squeezed by the chamber wall and tightly adheres to the metal chamber, relying on physical contact to complete the grounding, suppressing electromagnetic interference generated by ultraviolet ionization and improving the signal-to-noise ratio of the mass spectrometry ion signal.

[0024] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A vacuum differential pyrolysis product sample introduction and analysis chamber, characterized in that, include: An integrated main vacuum chamber includes an ionization chamber and an ion flight chamber that are separated from each other, and a two-stage vacuum differential ion transport channel is formed between the ionization chamber and the ion flight chamber to maintain different pressure environments; The cooling water inlet and outlet are located on the side wall of the integrated main vacuum chamber and are used to connect to an external constant temperature cooling water pipe to continuously remove heat from the chamber. The differential sampling cooling seat assembly is installed as an independent pre-assembled component on the integrated main vacuum chamber. An external pyrolysis furnace extends into the differential sampling cooling seat assembly to receive the high-temperature pyrolysis products from the external pyrolysis furnace and introduce the high-temperature pyrolysis products into the ionization chamber. The ion transport introducer assembly, as an independent module, can be extracted axially from the integrated main vacuum chamber via a guide mechanism, and can be detachably installed inside the ionization chamber and communicated with the ion flight chamber. The differential sampling cooling base assembly includes a quartz cone and a cooling water circulation chamber disposed around the periphery of the quartz cone: the cooling water circulation chamber completely surrounds the outer wall of the differential sampling cooling base assembly, which is used to block heat conduction to the ionization chamber and the external environment of the ionization chamber; The cooling water inlet and outlet are connected to the cooling water circulation chamber, forming a circulating cooling circuit that covers the side wall of the integrated main vacuum chamber and the outer wall of the differential sampling cooling seat assembly. This circuit continuously removes heat from the chamber to prevent the high temperature at the sampling end from being conducted to the ionization chamber and beyond, thus preventing the vacuum seal from aging and failing due to high temperature.

2. The vacuum differential pyrolysis product sample introduction and analysis chamber according to claim 1, characterized in that, The differential sampling cooling mount assembly also includes: A cooling water sealing ring is fitted onto the connection between the cooling water inlet / outlet and the cooling water circulation chamber to seal the cooling water pipe. A vacuum differential sealing ring is disposed between the pyrolysis product channel inside the quartz cone and the external atmospheric pressure environment, and is used to form two independent vacuum isolation barriers between the differential exhaust chamber and the external atmospheric pressure environment at the pyrolysis product channel. The external thread nut is tightened, fitted onto the outer wall of the quartz cone, and threadedly connected to the housing of the differential sampling cooling base assembly to lock the internal components. A silicone gasket is placed between the external thread nut and the cooling water circulation chamber for buffering and auxiliary sealing. The transition metal ring, which is a ring-shaped structure, is sleeved between the external thread nut and the silicone gasket to uniformly transmit the clamping force during axial clamping.

3. The vacuum differential pyrolysis product sample introduction and analysis chamber according to claim 2, characterized in that: The differential sampling cooling base assembly has two differential exhaust ports symmetrically arranged along the axis of the differential sampling cooling base assembly on the side near the quartz cone. The differential exhaust ports are used to cooperate with the vacuum differential sealing ring to stably maintain the preset vacuum differential degree inside the differential exhaust chamber. The differential exhaust port is used to connect to an external vacuum pump and adjust the vacuum level of the differential region through a series differential pressure regulating valve to adapt to different pyrolysis product testing conditions and stabilize the ion sampling efficiency of the ion transport introducer assembly.

4. The vacuum differential pyrolysis product sample introduction and analysis chamber according to claim 2, characterized in that, The ion transport introducer assembly includes: An ultraviolet lamp is placed inside the ionization chamber to ionize the pyrolysis products within the ionization chamber. The guide rod is a rod-shaped structure extending along the axial direction, which is set on one side of the ultraviolet lamp to provide a track for picking up and putting in the ultraviolet lamp, making it easy to clean and replace the ultraviolet lamp; A heating rod is disposed within the wall of the ionization region of the ionization chamber to heat the ionization region of the ionization chamber and prevent condensation of pyrolysis products. An ion importer assembly is disposed in the transmission channel between the ionization cavity and the ion flight cavity, and is used to repel, focus and guide ions to be transported to the ion flight cavity. A grounding conductive spring is disposed on the side of the ion transport introducer assembly near the inner wall of the integrated main vacuum chamber, for physical contact with the chamber wall to achieve a reliable grounding connection; An aviation plug is located at the end of the ion transport inlet assembly closest to the outside, for unified access to external power supply and signals.

5. The vacuum differential pyrolysis product sample introduction and analysis chamber according to claim 4, characterized in that: The ultraviolet lamp is detachably installed in the ion transporter assembly via a quick-release mechanism consisting of a spring and a voltage-conducting plate. The spring is sleeved on the guide rod and located at the end of the ultraviolet lamp away from the voltage-conducting plate; the voltage-conducting plate is located at the other end of the ultraviolet lamp; The quick-release mechanism releases the limit by compressing the spring to enable tool-free quick replacement of the ultraviolet lamp, and achieves automatic conductive contact by relying on spring pressure.

6. The vacuum differential pyrolysis product sample introduction and analysis chamber according to claim 4, characterized in that, The ion transporter assembly also includes: The first flange is located at the end of the ion transport introducer assembly closest to the outside environment, and is used to seal the ionization chamber from the external environment. A second flange is disposed at one end of the ion transport inlet assembly near the ion flight chamber, for isolating the ionization chamber from the ion flight chamber; The first flange and the second flange work together in a differential pumping system to stably maintain the vacuum pressure difference between the ionization chamber and the ion flight chamber.

7. The vacuum differential pyrolysis product sample introduction and analysis chamber according to claim 4, characterized in that: The outlet end of the quartz cone is at the same horizontal level as the lower edge of the light path of the ultraviolet lamp, so that the pyrolysis products are photoionized as soon as they reach the outlet of the quartz cone. The differential exhaust port is located on one side of the quartz cone and is designed to fit the shape of the quartz cone so that dust and impurities carried by the pyrolysis products can be discharged through the differential exhaust port.

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