Novel non-radioactive electron capture detector

Abstract

The invention belongs to the technical field of ionization detectors, and particularly discloses a novel non-radioactive electron capture detector which comprises a shell, a protection cavity is formed in the shell, a discharge electrode, a polarization electrode and a signal electrode are sequentially arranged on the surface of the protection cavity from top to bottom, and a sapphire tube is fixedly connected to the inner wall of the shell. A first air inlet pipe is arranged on one side of the shell, a guide-in pipe communicated with the sapphire pipe is arranged at the bottom of the shell, one side of the surface of the guide-in pipe is communicated with a second air inlet pipe, and the other side of the surface of the guide-in pipe is communicated with a blow-down pipe; the plasma electronegativity is improved through doping gas combination, and the detection sensitivity is remarkably enhanced; the optimized polarization voltage range and the electrode spacing design effectively suppress noise; the anti-pollution capacity of the device adapts to low-purity helium carrier gas, the use cost is reduced, the non-radioactive design is adopted, and the radioactive pollution risk is avoided.

Description

Technical Field

[0001] This invention belongs to the field of ionization detector technology, and specifically discloses a novel non-radioactive electron capture detector. Background Technology

[0002] Traditional electron capture detectors (ECDs) typically use radioactive isotopes (such as...) or As an ionization source, electron capture detectors (ECDs) pose risks of radioactive contamination, operational limitations, and short lifespans. Existing non-radioactive ECDs mostly employ helium plasma discharge technology, but they generally suffer from low sensitivity, high noise interference, and insufficient stability. Their performance deteriorates significantly, especially when the carrier gas purity is insufficient or the dopant gas is improperly selected. Therefore, those skilled in the art have proposed a novel non-radioactive electron capture detector. Summary of the Invention

[0003] In view of this, the technical problem to be solved by the present invention is to propose a novel non-radioactive electron capture detector to solve the problems of low sensitivity, large noise interference and insufficient stability of the prior art.

[0004] To achieve the above objectives, the present invention provides a novel non-radioactive electron capture detector, comprising a housing, an inner protective cavity, and a discharge electrode, a polarization electrode, and a signal electrode arranged sequentially from top to bottom on the surface of the protective cavity. A sapphire tube is fixedly connected to the inner wall of the housing. A first air inlet pipe is provided on one side of the housing, and an inlet pipe communicating with the sapphire tube is provided at the bottom of the housing. A second air inlet pipe is connected to one side of the surface of the inlet pipe, and an vent pipe is connected to the other side of the surface of the inlet pipe. A dehumidification structure is provided at the bottom of the second air inlet pipe. The first air inlet pipe is connected to the sapphire tube, and the upper end of the inlet pipe is connected to the sapphire tube. An auxiliary component is provided inside the sapphire tube. The discharge electrode, polarization electrode, and signal electrode are respectively connected to protrusions on the surface of the sapphire tube. A discharge cavity is formed inside the sapphire tube, and a discharge needle extending into the discharge cavity is provided inside the housing.

[0005] In the above technical solution, preferably, the auxiliary component includes a partition tube disposed inside the sapphire tube, one end of the partition tube extends through the interior of the inlet tube and is fixedly connected to a first partition ring fixed to the inner wall of the inlet tube, a separation cavity is formed between the inner wall of the inlet tube and the surface of the partition tube, and the second air inlet tube is connected to the separation cavity.

[0006] In the above technical solution, preferably, the other end of the separator tube extends through the sapphire tube and is fixedly connected to an inlet shell. A second separator ring is fixedly connected to the surface of the separator tube and the inner wall of the sapphire tube. A reaction chamber is formed between the top of the second separator ring and the sapphire tube. The surface of the separator tube is provided with uniformly distributed discharge holes, and the separator tube is connected to the reaction chamber through the discharge holes.

[0007] In the above technical solution, preferably, the surface of the second separator ring is provided with uniformly distributed through grooves.

[0008] In the above technical solution, preferably, the auxiliary component further includes two partitions fixedly connected to the inner wall of the discharge hole, and the surface of the partitions is provided with uniformly distributed through holes, and the through holes provided on the two partitions are staggered.

[0009] In the above technical solution, preferably, the dehumidification structure includes a connecting pipe and two connecting shells disposed on one side of the outer shell. A molecular sieve is disposed inside the connecting shell. A second mounting pipe is connected to the top of the connecting shell. The other end of the second mounting pipe is connected to a second air inlet pipe. A first mounting pipe is connected to the bottom of the connecting shell and the top of the connecting pipe.

[0010] In the above technical solution, preferably, the lower end of the surface of the connecting shell is connected to an exhaust pipe, the surface of the connecting shell is connected to a regeneration pipe located above the exhaust pipe, and the surfaces of the exhaust pipe, the first mounting pipe and the second mounting pipe are all provided with solenoid valves.

[0011] In the above technical solution, preferably, a filter element is provided inside the inlet tube.

[0012] In the above technical solution, preferably, the distance between the discharge electrode, the polarization electrode and the signal electrode is 6-10 mm.

[0013] In the above technical solution, preferably, the sapphire tube includes four sapphire tube bodies arranged in a ring, and a metal ring is fixedly connected between two adjacent sapphire tube bodies. The surface of the metal ring is provided with a probe, and the metal ring is connected to a discharge electrode, a polarization electrode and a signal electrode respectively through adjacent probes.

[0014] Compared with the prior art, the present invention has the following beneficial effects: 1. Through the combination of doped gases ( It enhances plasma electronegativity, significantly improving detection sensitivity; the optimized polarization voltage range (-12V to +12V) and electrode spacing design effectively suppress noise; its anti-contamination capability adapts to low-purity helium carrier gas, reducing usage costs; and its non-radioactive design avoids the risk of radioactive contamination. 2. By setting auxiliary components, the separator tube can prevent the gas introduced into the chromatographic column from contacting the inner wall of the sapphire tube and causing deposition. It also separates the gas introduced into the chromatographic column from the dopant gas, preventing pre-mixing and pre-capture, thus improving detection accuracy. The gas discharged from the chromatographic column through the separator tube is mixed with the helium introduced into the inlet shell and finally introduced into the discharge chamber through the outlet hole for capture. During this process, the staggered arrangement of the through holes can separate the discharged mixed gas into multiple gas streams, which are further separated and mixed as they enter the next through hole, improving the mixing effect of helium and chromatographic column gas. 3. By setting up a dehumidification structure, doped gas can be introduced. During this process, the molecular sieve can be used to filter the moisture in the doped gas, thereby reducing the possibility of moisture entering the discharge chamber and affecting the capture accuracy. The regeneration tube can be used for nitrogen input, thereby regenerating the internal molecular sieve. By opening and closing the solenoid valve, one molecular sieve can be used to filter while another molecular sieve connected to the shell is being regenerated. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the structure of the present invention; Figure 2 This is a cross-sectional schematic diagram of the present invention; Figure 3 This is a schematic diagram of the dehumidification structure of the present invention; Figure 4 This is a schematic diagram showing the connection between the auxiliary component of the present invention and the first and second sapphire tubes. Figure 5 for Figure 4 Enlarged view of A in the middle; Figure 6 This is a schematic diagram showing the distribution of the through holes in this invention; Figure 7 This is the circuit diagram for the polarization voltage module.

[0016] In the diagram: 1. Outer shell; 101. First air inlet pipe; 102. Discharge electrode; 103. Polarization electrode; 104. Signal electrode; 105. Probe; 106. Second air inlet pipe; 107. Inlet pipe; 108. Discharge chamber; 109. Vent pipe; 110. Discharge needle; 2. Dehumidification structure; 201. Connecting shell; 202. Molecular sieve; 203. Connecting pipe; 204. First mounting pipe; 205. Exhaust pipe; 206. Regeneration pipe; 207. Second mounting pipe; 3. Auxiliary components; 301. Separator pipe; 302. First separator ring; 303. Partition plate; 304. Through groove; 305. Second separator ring; 306. Through hole; 307. Inlet shell; 4. Sapphire tube; 5. Filter element. Detailed Implementation

[0017] To better understand the above-mentioned objectives, features, and advantages of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0018] Numerous specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein, and therefore the invention is not limited to the specific embodiments disclosed below.

[0019] like Figures 1-7 The novel non-radioactive electron capture detector shown includes a housing 1. A protective cavity is formed inside the housing 1. From top to bottom, a discharge electrode 102, a polarization electrode 103, and a signal electrode 104 are sequentially arranged on the surface of the protective cavity. A sapphire tube 4 is fixedly connected to the inner wall of the housing 1. A first air inlet pipe 101 is provided on one side of the housing 1. An inlet pipe 107 connected to the sapphire tube 4 is provided at the bottom of the housing 1. A second air inlet pipe 106 is connected to one side of the surface of the inlet pipe 107. The surface of the inlet pipe 107 is further... One side is connected to an vent pipe 109, and the bottom of the second air intake pipe 106 is provided with a dehumidification structure 2. The first air intake pipe 101 is connected to the sapphire tube 4, and the upper end of the inlet pipe 107 is connected to the sapphire tube 4. An auxiliary component 3 is provided inside the sapphire tube 4. The discharge electrode 102, polarization electrode 103 and signal electrode 104 are respectively connected to the protrusions on the surface of the sapphire tube 4. A discharge cavity 108 is formed inside the sapphire tube 4, and a discharge needle 110 extending into the discharge cavity 108 is provided inside the outer shell 1.

[0020] The first inlet pipe 101 is used for the input of helium, and the input nitrogen can be introduced into the interior of the inlet shell 307. The second inlet pipe 106 inputs the doped gas into the interior of the first sapphire tube 4 and, with the help of the auxiliary component 3, introduces it into the interior of the discharge cavity 108. Specifically, through the combination of doped gases ( This improves plasma electronegativity and significantly enhances detection sensitivity.

[0021] like Figures 1-7 As shown, the auxiliary component 3 includes a partition tube 301 disposed inside the sapphire tube 4. One end of the partition tube 301 extends through the interior of the inlet tube 107 and is fixedly connected to a first partition ring 302 fixed to the inner wall of the inlet tube 107. A separation cavity is formed between the inner wall of the inlet tube 107 and the surface of the partition tube 301. The second air inlet tube 106 is connected to the separation cavity.

[0022] The other end of the separator tube 301 extends through the sapphire tube 4 and is fixedly connected to the inlet shell 307. A second separator ring 305 is fixedly connected to the surface of the separator tube 301 and the inner wall of the sapphire tube 4. A reaction chamber is formed between the top of the second separator ring 305 and the sapphire tube 4. The surface of the separator tube 301 is provided with uniformly distributed discharge holes, and the separator tube 301 is connected to the reaction chamber through the discharge holes.

[0023] The surface of the second separator ring 305 is provided with uniformly distributed through grooves 304.

[0024] The auxiliary component 3 also includes two partitions 303 fixedly connected to the inner wall of the discharge hole. The surface of the partitions 303 is provided with uniformly distributed through holes 306, and the through holes 306 provided on the two partitions 303 are staggered. The partition tube 301 prevents the gas introduced into the chromatographic column from contacting the inner wall of the sapphire tube 4, thus preventing deposition. It also prevents the gas introduced into the chromatographic column from contacting the dopant gas, thus preventing pre-mixing and pre-capture, thereby improving detection accuracy. The doped gas can be introduced into the interior of the sapphire tube 4 through the separation cavity and finally into the interior of the discharge cavity 108 through the through groove 304. Under the combined action of the discharge needle 110, the discharge electrode 102 and the polarization electrode 103, the electronegativity of the plasma is enhanced.

[0025] Simultaneously, the chromatographic column gas discharged through the separator tube 301 is mixed with the helium introduced through the inlet shell 307, and finally introduced into the discharge chamber 108 through the discharge hole for capture. During this process, the staggered arrangement of the through holes 306 can separate the discharged mixed gas into multiple gas streams, and further mix them as they enter the next through hole 306, thereby improving the mixing effect of helium and chromatographic column gas.

[0026] like Figures 1-7 As shown, the dehumidification structure 2 includes a connecting pipe 203 and two connecting shells 201 disposed on one side of the outer shell 1. A molecular sieve 202 is disposed inside the connecting shell 201. A second mounting pipe 207 is connected to the top of the connecting shell 201. The other end of the second mounting pipe 207 is connected to the second air inlet pipe 106. A first mounting pipe 204 is connected to the bottom of the connecting shell 201 and the top of the connecting pipe 203.

[0027] The lower end of the surface of the connecting shell 201 is connected to the exhaust pipe 205, and the surface of the connecting shell 201 is connected to the regeneration pipe 206 located above the exhaust pipe 205. Solenoid valves are provided on the surfaces of the exhaust pipe 205, the first mounting pipe 204, and the second mounting pipe 207. The connecting pipe 203 is used to introduce doped gas. During this process, the molecular sieve 202 can filter the moisture in the doped gas, thereby reducing the possibility of moisture entering the discharge chamber 108 and affecting the capture accuracy. The regeneration pipe 206 is used to input nitrogen gas, thereby regenerating the internal molecular sieve 202. By opening and closing the solenoid valve, the molecular sieve 202 inside the other connecting shell 201 can be regenerated while one molecular sieve 202 is filtering.

[0028] like Figures 1-7 As shown, a filter element 5 is installed inside the inlet tube 107.

[0029] The distance between the discharge electrode 102, the polarization electrode 103 and the signal electrode 104 is 6-10 mm; The sapphire tube 4 includes four sapphire tube bodies arranged in a ring. A metal ring is fixedly connected between two adjacent sapphire tube bodies. A probe 105 is provided on the surface of the metal ring. The metal ring is connected to the discharge electrode 102, the polarization electrode 103 and the signal electrode 104 through adjacent probes, respectively.

[0030] The optimized polarization voltage range (-12V to +12V) and electrode spacing design effectively suppress noise. The filter element 5 prevents particulate matter in the gas from entering the discharge chamber 108 and avoids deposition that could affect subsequent use.

[0031] Working principle: The first inlet pipe 101 is used for helium input. The input nitrogen gas can be introduced into the interior of the inlet shell 307 and then into the interior of the separator pipe 301. The second inlet pipe 106 introduces the dopant gas into the interior of the first sapphire tube 4. The separator pipe 301 prevents the gas introduced into the column from contacting the inner wall of the sapphire tube 4, thus preventing deposition. It also prevents pre-mixing and pre-capture caused by contact between the gas introduced into the column and the dopant gas, thereby improving detection accuracy. The dopant gas can be introduced into the interior of the sapphire tube 4 through the separation chamber and finally into the interior of the discharge chamber 108 through the through-slot 304. Under the combined action of the discharge electrode 102 and the polarization electrode 103, the dopant gas is further enhanced. The electronegativity of the strong plasma, the gas discharged from the chromatographic column through the separator tube 301 and the helium introduced through the inlet shell 307 are mixed and finally introduced into the discharge chamber 108 for capture through the discharge hole. The connecting tube 203 is set to introduce doping gas. During this process, the molecular sieve 202 can filter the moisture in the doping gas, thereby reducing the possibility of moisture entering the discharge chamber 108 and affecting the capture accuracy. The regeneration tube 206 is set to input nitrogen gas, thereby regenerating the internal molecular sieve 202. By opening and closing the solenoid valve, the molecular sieve 202 inside the connecting shell 201 can be regenerated while one molecular sieve 202 is filtering.

[0032] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claimed invention. The scope of protection claimed by the appended claims and their equivalents is defined.

Claims

1. A novel non-radioactive electron capture detector, comprising a housing (1), characterized in that, The outer casing (1) has a protective cavity inside. From top to bottom, a discharge electrode (102), a polarization electrode (103), and a signal electrode (104) are arranged on the surface of the protective cavity. A sapphire tube (4) is fixedly connected to the inner wall of the outer casing (1). A first air inlet pipe (101) is provided on one side of the outer casing (1). A guide pipe (107) connected to the sapphire tube (4) is provided at the bottom of the outer casing (1). A second air inlet pipe (106) is connected to one side of the guide pipe (107), and a vent pipe (109) is connected to the other side of the guide pipe (107). The bottom of the second air intake pipe (106) is provided with a dehumidification structure (2). The first air intake pipe (101) is connected to the sapphire tube (4). The upper end of the inlet pipe (107) is connected to the sapphire tube (4). An auxiliary component (3) is provided inside the sapphire tube (4). The discharge electrode (102), polarization electrode (103) and signal electrode (104) are respectively connected to the protrusions on the surface of the sapphire tube (4). A discharge cavity (108) is formed inside the sapphire tube (4). A discharge needle (110) extending into the discharge cavity (108) is provided inside the outer shell (1).

2. The novel non-radioactive electron capture detector according to claim 1, characterized in that, The auxiliary component (3) includes a partition tube (301) disposed inside the sapphire tube (4). One end of the partition tube (301) extends through the interior of the inlet tube (107) and is fixedly connected to a first partition ring (302) fixed to the inner wall of the inlet tube (107). A separation cavity is formed between the inner wall of the inlet tube (107) and the surface of the partition tube (301). The second air inlet tube (106) is connected to the separation cavity.

3. A novel non-radioactive electron capture detector according to claim 2, characterized in that, The other end of the separator tube (301) extends through the sapphire tube (4) and is fixedly connected to the inlet shell (307). A second separator ring (305) is fixedly connected to the surface of the separator tube (301) and the inner wall of the sapphire tube (4). A reaction chamber is formed between the top of the second separator ring (305) and the sapphire tube (4). The surface of the separator tube (301) is provided with uniformly distributed discharge holes. The separator tube (301) is connected to the reaction chamber through the discharge holes.

4. A novel non-radioactive electron capture detector according to claim 3, characterized in that, The surface of the second separator ring (305) is provided with uniformly distributed through grooves (304).

5. A novel non-radioactive electron capture detector according to claim 4, characterized in that, The auxiliary component (3) also includes two partitions (303) fixedly connected to the inner wall of the discharge hole. The surface of the partitions (303) is provided with uniformly distributed through holes (306), and the through holes (306) provided on the two partitions (303) are staggered.

6. A novel non-radioactive electron capture detector according to claim 1, characterized in that, The dehumidification structure (2) includes a connecting pipe (203) and two connecting shells (201) disposed on one side of the outer shell (1). A molecular sieve (202) is disposed inside the connecting shell (201). A second mounting pipe (207) is connected to the top of the connecting shell (201). The other end of the second mounting pipe (207) is connected to the second air inlet pipe (106). A first mounting pipe (204) is connected to the bottom of the connecting shell (201) and the top of the connecting pipe (203).

7. A novel non-radioactive electron capture detector according to claim 6, characterized in that, The lower end of the surface of the connecting shell (201) is connected to the exhaust pipe (205), and the surface of the connecting shell (201) is connected to the regeneration pipe (206) located above the exhaust pipe (205). Solenoid valves are provided on the surfaces of the exhaust pipe (205), the first mounting pipe (204), and the second mounting pipe (207).

8. A novel non-radioactive electron capture detector according to claim 1, characterized in that, The inlet tube (107) is equipped with a filter element (5).

9. A novel non-radioactive electron capture detector according to claim 1, characterized in that, The distance between the discharge electrode (102), polarization electrode (103) and signal electrode (104) is 6-10 mm.

10. A novel non-radioactive electron capture detector according to claim 1, characterized in that, The sapphire tube (4) includes four sapphire tube bodies arranged in a ring. A metal ring is fixedly connected between two adjacent sapphire tube bodies. A probe (105) is provided on the surface of the metal ring. The metal ring is connected to the discharge electrode (102), the polarization electrode (103), and the signal electrode (104) respectively through adjacent probes.

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