A device and method for tracing nitrate in water bodies based on stable isotope analysis technology

Abstract

The application discloses a device for tracing and analyzing nitrate in water bodies based on stable isotope analysis technology, which comprises a workbench, a rotating seat rotatably arranged on the workbench, and a support fixedly arranged on the workbench, a plurality of groups of through holes for mounting sample containers are arranged on the rotating seat in an annular array, a mounting plate is arranged above the rotating seat and is driven to move up and down through telescopic equipment, a copper-cadmium-plated particle reservoir, an azide acid solution reservoir and a stable isotope ratio mass spectrometer are arranged on the mounting plate, and the discharge ends of the copper-cadmium-plated particle reservoir and the azide acid solution reservoir are respectively communicated with a first quantity control device and a second quantity control device. The rotating seat is rotated to make the sample containers correspond to the first quantity control device, the second quantity control device and the docking pipe in the stable isotope ratio mass spectrometer, so that the copper-cadmium-plated particles and the azide acid solution are added, and the stable isotope ratio mass spectrometer is used for detection. This kind of mode is suitable for the case that the number of water body samples is relatively large, and the efficiency of tracing and analyzing work is improved.

Description

Technical Field

[0001] This invention relates to the field of nitrate source analysis technology, specifically to a device and method for nitrate source analysis in water bodies based on stable isotope analysis technology. Background Technology

[0002] Nitrates easily lead to acidification of aquatic ecosystems, stimulate the growth and proliferation of primary producers, cause eutrophication, and can even reach toxic levels that harm aquatic animals. To reduce nitrate input, Improving the aquatic ecosystem of polluted water bodies and accurately identifying the sources of nitrate pollution in the water are crucial. Currently, stable isotope analysis technology has become an effective technical means to identify the sources of nitrate pollution in water bodies.

[0003] Stable isotope analysis technology uses a stable isotope mass spectrometer to determine nitrate nitrogen isotopes. Pretreatment of the water body is usually required before measurement. Common pretreatment methods include chemical methods and bacterial denitrification methods, with the chemical method being more widely used. This method uses copper-cadmium-plated particles to convert nitrates to nitrites, and then uses azidoic acid to convert nitrites to N2O. The N2O is then detected by a stable isotope mass spectrometer. However, this method typically involves manually adding the copper-cadmium-plated particles and azidoic acid to a test tube containing the water sample and shaking it manually. This method severely impacts the efficiency of the entire water source analysis process when the number of water samples is large. Furthermore, since copper-cadmium-plated particles and azidoic acid are toxic, this method can easily pose health hazards and safety risks to operators. Therefore, we propose a device and method for source analysis of nitrates in water bodies based on stable isotope analysis technology. Summary of the Invention

[0004] The purpose of this invention is to provide a device and method for tracing and analyzing nitrates in water bodies based on stable isotope analysis technology, so as to solve the problems mentioned in the background art.

[0005] To achieve the above objectives, the present invention provides the following technical solution: A source tracing and analysis device for nitrates in water based on stable isotope analysis technology, comprising: The workbench has a rotating seat and a fixed support. The rotating seat has several sets of through holes for mounting sample containers in a circular array. A mounting plate is located above the rotating base and is driven to move up and down by a telescopic device. The telescopic device is located on a bracket. The mounting plate is equipped with a copper-cadmium-plated particle storage device, an azido acid solution storage device, and a stable isotope ratio mass spectrometer. The discharge ends of the copper-cadmium-plated particle storage device and the azido acid solution storage device are respectively connected to a control element one and a control element two for controlling the discharge amount. The discharge ends of the control element one and the control element two, as well as the gas inlet end of the stable isotope ratio mass spectrometer, are all connected to a connecting pipe. The control element one and the control element two are driven to work by a driving element. Each time the rotating seat rotates by a preset angle, each connecting pipe corresponds to a sample container on the rotating seat, so that it can be inserted into the corresponding sample container when the mounting plate moves downward.

[0006] A further improvement is that the control element one includes: The outer shell has an inlet and an outlet at its upper and lower ends respectively connected to the copper-cadmium granule storage container and the connecting pipe. The inner cavity is equipped with a matching measuring disc. The shaft of the measuring disc is connected to the driving component. The outer circumference of the measuring disc is provided with several sets of granule grooves for accommodating copper-cadmium granules.

[0007] A further improvement is that the second control element includes: A transparent cylinder has a matching piston that moves inside. The outer wall of the transparent cylinder has scale lines. One end of the transparent cylinder is connected to the discharge end of the azido acid solution storage device through a one-way pipe, and the other end is connected to the connecting pipe through a one-way pipe. An adjusting screw is rotatably disposed inside a transparent cylinder and moves through a piston. One end of the adjusting screw extends to the outer end of the transparent cylinder and is connected to a handwheel. A limiting block for restricting the movement of the piston is threaded on the outer wall of the adjusting screw and on the side inside the transparent cylinder. A magnetic pull rod is connected to a piston at one end and extends to the outside of the transparent cylinder after passing through a limiting block and the other end of the transparent cylinder. It is driven to move by a driving component. The outer wall of the magnetic pull rod is fitted with a reset elastic element for driving the piston to reset.

[0008] A further improvement is that the driving element includes: A protective shell is mounted on the mounting plate and movably sleeved on one end of the shaft of the control disc; Rotating device two is mounted on the protective shell. The output end of the rotating device two extends into the protective shell and is connected to one end of the shaft of the measuring disc via a bevel gear set. An electromagnetic ring is fixedly fitted onto the outer wall of the protective shell and is used to attract magnetic pull rods when energized.

[0009] A further improvement is that the sample container includes: The container body is hollow at the top, and a sealing cap is detachably provided on the top. The sealing cap has an opening for inserting the connecting pipe, and a discharge port is provided on the side wall of one end of the connecting pipe insertion opening. A sealing block, fitted to the bottom of the sealing cap, is used to seal the opening. The sealing block is connected to the sealing cap via an elastic connector.

[0010] A further improvement is that an arc-shaped groove is provided at the bottom of the container body, a stirring element is rotatably provided inside the container body, one end of the stirring element extends into the arc-shaped groove, a torsion spring is provided at the connection between the stirring element and the container body, a pull rope is wound around one end of the stirring element, one end of the pull rope is connected to a magnetic arc-shaped slider, the magnetic arc-shaped slider is slidably disposed in the arc-shaped groove, and the magnetic arc-shaped slider is connected to one side of the inner wall of the arc-shaped groove through a connecting elastic element. The bottom of the rotating seat is rotatably equipped with a driven disk, which is rotatably mounted on the worktable. A transmission telescopic rod is connected to the top of the driven disk. One end of the transmission telescopic rod passes through the rotating seat and is connected to the driving component, which drives the rotation. The top of the driven disk is embedded in a circular array with several sets of magnetic blocks for adsorbing magnetic arc-shaped sliders. When the magnetic blocks correspond to the magnetic arc-shaped sliders, they adsorb the magnetic arc-shaped sliders and drive the magnetic arc-shaped sliders to move in the arc-shaped grooves when the driven disk rotates. When the magnetic arc-shaped sliders move, the stirring component is pulled to rotate by a pull rope. When the magnetic blocks and the magnetic arc-shaped sliders separate, the stirring component resets and rotates under the action of a torsion spring.

[0011] A further improvement is that the workbench is equipped with a rotating device for driving the rotating seat to rotate.

[0012] A further improvement is that a counter is provided on the outer wall of the connecting pipe connected to the control component to measure the number of copper-cadmium-plated particles discharged from the connecting pipe. The counter and the stable isotope ratio mass spectrometer are electrically connected to the display screen. The counter, the telescopic device, and the drive component are all electrically connected to the controller. When the number of copper-cadmium-plated particles discharged reaches a threshold, the counter sends a signal to the controller, causing the controller to control the telescopic device to move the mounting plate upward and close the drive component.

[0013] A further improvement is that a solenoid valve is also provided inside the connecting pipe.

[0014] A method for source apportionment of nitrates in water based on stable isotope analysis technology, utilizing the aforementioned apportionment apparatus, includes the following steps: S1: Place the water sample in the sample container and then put it into the through hole on the rotating seat; S2: The rotating seat rotates, and when the sample container aligns with control element one, the telescopic device drives the mounting plate to descend, allowing the connecting pipe on control element one to enter the sample container. Through control element one, copper-cadmium-plated particles in the copper-cadmium-plated particle storage container are quantitatively introduced into the sample container and mixed with the water sample, converting nitrates in the water sample into nitrites. Then, the telescopic device drives the mounting plate to rise, and the rotating seat rotates again until the sample container aligns with control element two. The telescopic device drives the mounting plate to descend, allowing the connecting pipe on control element two to enter the sample container. Through control element two, azidoacid solution in the azidoacid solution storage container is introduced into the sample container and mixed with the water sample, converting nitrites into NO. The above steps are then repeated, and the NO in the sample container is detected by a stable isotope ratio mass spectrometer to obtain nitrogen-oxygen isotope ratio data. S3: Compare the nitrogen and oxygen isotope ratio data with the isotope fingerprint database of known pollution sources, and calculate the contribution ratio of each pollution source through the calculation ratio module to determine the source of nitrate pollution in the water.

[0015] Compared with the prior art, the beneficial effects of the present invention are: This invention allows the rotating base to align the sample container containing the water sample with control components one, two, and the connecting pipe in the stable isotope ratio mass spectrometer. This enables the quantitative addition of copper-cadmium plating particles and azidoic acid solution to the sample container via control components one and two, respectively. The nitrate in the sample container is then converted to N₂O, which is detected by the stable isotope ratio mass spectrometer. This method is suitable for situations with a large number of water samples, improving the efficiency of the entire water source tracing and analysis process. Simultaneously, the automatic quantitative addition of copper-cadmium plating particles and azidoic acid solution avoids health hazards and safety risks to operators while reducing waste of these materials. Furthermore, the operation of control components one and two also causes the driven disk to rotate. During rotation, the driven disk, through structures such as magnetic blocks, pull ropes, magnetic arc-shaped sliders, and connecting elastic components, activates the stirring element, uniformly mixing the liquid in the sample container and further improving the efficiency of the entire source tracing and analysis process. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the analytical device structure of the present invention; Figure 2 For the present invention Figure 1 Another perspective structural diagram; Figure 3 This is a partial structural cross-sectional view of the first and second control components of the present invention; Figure 4 This is a cross-sectional view of the sample container structure of the present invention; Figure 5 This is a schematic diagram of the driven disk structure of the present invention; Figure 6 This is a schematic diagram of the sample container of the present invention from another perspective.

[0017] In the diagram: 1. Workbench; 2. Rotating seat; 3. Rotating device one; 4. Sample container; 41. Container body; 42. Sealing cap; 43. Arc groove; 44. Stirring component; 45. Pull rope; 46. Magnetic arc slider; 47. Connecting elastic component; 48. Sealing block; 49. Elastic connector; 5. Bracket; 6. Mounting plate; 7. Copper-plated cadmium particle storage container; 8. Azide acid solution storage container; 9. Stable isotope ratio mass spectrometer; 10. Telescopic device; 11. Volume control device. Component 1; 111. Outer shell; 112. Measuring disc; 113. Particle trough; 12. Measuring component 2; 121. Transparent cylinder; 122. Piston; 123. Adjusting screw; 124. Limiting block; 125. Magnetic pull rod; 126. Reset elastic element; 13. Rotating device 2; 14. Protective shell; 15. Electromagnetic ring; 16. Connecting pipe; 17. Discharge port; 18. Driven disc; 19. Transmission telescopic rod; 20. Magnetic block; 21. Display screen; 22. Counter. Detailed Implementation

[0018] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0019] Example 1

[0020] Please see the appendix Figure 1 - Appendix Figure 2 A device for nitrate source analysis in water based on stable isotope analysis technology, comprising: A workbench 1 has a rotating seat 2 rotatably mounted on it and a fixed support 5. The rotating seat 2 has several sets of through holes arranged in a circular array for mounting sample containers 4. Furthermore, the workbench 1 is equipped with a rotating device 3 for driving the rotating seat 2 to rotate. This rotating device 3 includes a motor and a gear set (two sets of meshing gears) that connect the motor output to the rotating seat 2. The rotating device 3 can control the rotating seat 2 to rotate intermittently by a preset angle to accommodate... Figure 1 As shown, there are four sets of through holes, so the rotating device 3 can control the rotating seat 2 to rotate 90 degrees each time; Mounting plate 6 is located above rotating base 2 and is driven up and down by telescopic device 10 (e.g., electric telescopic rod). Telescopic device 10 is located on bracket 5. Mounting plate 6 is equipped with copper-cadmium granule storage 7, azidoic acid solution storage 8, and stable isotope ratio mass spectrometer 9. Copper-cadmium granule storage 7 is used to store copper-cadmium granules, azidoic acid solution storage 8 is used to store azidoic acid solution, and stable isotope ratio mass spectrometer 9 is a conventional instrument in this field and will not be described in detail here. The discharge ends of copper-cadmium granule storage 7 and azidoic acid solution storage 8 are respectively connected to control element one 11 and control element two 12 for controlling the discharge amount. The discharge ends of control element one 11 and control element two 12, as well as the gas inlet end of stable isotope ratio mass spectrometer 9, are all connected to connecting pipe 16 for docking with sample container 4. Furthermore, the connecting pipe 16 is also equipped with a solenoid valve. When there is only one set of sample containers 4, the copper-plated cadmium particles can be discharged by independently controlling the solenoid valve in the connecting pipe 16. When there are two or more sets of sample containers 4, all the solenoid valves in the connecting pipe 16 can be opened. Control component 11 and control component 212 are driven to work by the drive component; Each time the rotating seat 2 rotates by a preset angle, each connecting pipe 16 corresponds to a sample container 4 on the rotating seat 2, so that it can be inserted into the corresponding sample container 4 when the mounting plate 6 moves downward. This method facilitates efficient source analysis of nitrates in water bodies, eliminating the need for manual addition of copper-cadmium-plated particles, azidocyanate solution, and detection using a stable isotope ratio mass spectrometer. It is convenient to use while avoiding health hazards and safety risks to operators posed by copper-cadmium-plated particles and azidocyanate solution.

[0021] A method for source apportionment of nitrates in water based on stable isotope analysis technology, utilizing the aforementioned apportionment apparatus, includes the following steps: S1: Place the water sample in the sample container 4, and then put it into the through hole on the rotating seat 2; S2: Rotating seat 2 rotates, and when sample container 4 corresponds to control element 11, the telescopic device 10 drives the mounting plate 6 to descend, allowing the connecting pipe 16 on control element 11 to enter sample container 4. Through control element 11, copper-cadmium granules in copper-cadmium granule storage container 7 are quantitatively introduced into sample container 4 and mixed with the water sample, converting nitrates in the water sample into nitrites. Then, the telescopic device 10 drives the mounting plate 6 to rise, and the rotating seat 2 rotates again until sample container 4 corresponds to control element 212. The telescopic device 10 drives the mounting plate 6 to descend, allowing the connecting pipe 16 on control element 212 to enter sample container 4. Through control element 212, azidoacid solution in azidoacid solution storage container 8 is introduced into sample container 4 and mixed with the water sample, converting nitrites into N2O. The above steps are then repeated, and the N2O in sample container 4 is detected by stable isotope ratio mass spectrometer 9 to obtain nitrogen-oxygen isotope ratio data. S3: Compare the nitrogen and oxygen isotope ratio data with the isotope fingerprint database of known pollution sources, and calculate the contribution ratio of each pollution source through the calculation ratio module to determine the source of nitrate pollution in the water body. The aforementioned isotopic fingerprint database of known pollution sources refers to a database that records and stores the proportion or characteristics of stable isotopes in pollution sources. It is existing technology and will not be described in detail here. The proportion calculation module is a standard module in this field. It's a tool based on an isotope mixing model. By comparing measured nitrogen and oxygen isotope ratios with an isotope fingerprint database of known pollution sources, and combining mass balance equations and Bayesian probabilistic methods, it quantifies the contribution ratio of each pollution source (such as agricultural fertilizers, domestic sewage, industrial emissions, and atmospheric deposition) to nitrate pollution in water bodies. This module typically uses stable isotope analysis models (such as SIAR, MixSIAR) or the IsoSource model, inputting measured isotope values. The module generates the probability distribution of the contribution ratio of each pollution source using Markov Chain Monte Carlo (MCMC) simulation, based on the isotopic characteristics (mean ± standard deviation) and isotopic fractionation coefficient (optional). It outputs the contribution ratio and its confidence interval (e.g., agricultural fertilizer accounts for 40%, and the 95% confidence interval is 35-45%). This module can upgrade from qualitative identification of pollution sources to quantitative analysis of the contribution ratio of each pollution source, providing a scientific basis and priority decision support for the treatment of nitrate pollution in water bodies. Of course, the above-mentioned calculation ratio module is not limited to this one.

[0022] Example 2

[0023] Please see the appendix Figure 3 Based on Example 1, the control component 11 in this example includes: The outer shell 111 has an inlet and an outlet 17 at its upper and lower ends respectively connected to the copper-cadmium granule storage container 7 and the connecting pipe 16. The inner cavity of the outer shell 111 has a circular vertical cross section. A matching control plate 112 is rotatably provided in the inner cavity. The shaft of the control plate 112 is connected to the drive component. Several sets of particle grooves 113 for accommodating a copper-cadmium granule are opened on the outer circumference of the control plate 112. When the connecting pipe 16 of the control element 11 corresponds to the sample container 4, the control plate 112 is driven to rotate by the drive element. The control plate 112 receives a copper-cadmium plated particle discharged from the discharge end of the copper-cadmium plated particle storage 7 through the particle tank 113 and the feed port. When the particle tank 113 corresponds to the connecting pipe 16, a copper-cadmium plated particle located in the particle tank 113 enters the connecting pipe 16 from the discharge port 17, and then enters the sample container 4 from the connecting pipe 16 to mix with the water sample, converting the nitrate in the water sample into nitrite.

[0024] Preferably, the second control element 12 in this embodiment includes: A transparent cylinder 121 has a matching piston 122 inside. The outer wall of the transparent cylinder 121 has scale lines. One end of the transparent cylinder 121 is connected to the discharge end of the azide solution storage tank 8 through a one-way pipe 1, and the other end is connected to the connecting pipe 16 through a one-way pipe 2. Both one-way pipe 1 and one-way pipe 2 are pipes with one-way valves. An adjusting screw 123 is rotatably disposed inside the transparent cylinder 121 and moves through the piston 122. One end of the adjusting screw 123 extends to the outer end of the transparent cylinder 121 and is connected to a handwheel. A limiting block 124 for limiting the movement of the piston 122 is threadedly fitted on the outer wall of the adjusting screw 123 and on the side inside the transparent cylinder 121. Initially, observe the scale line and turn the handwheel to drive the limiting block 124 to move inside the transparent cylinder 121 and adjust it to the desired position. It should be noted that both the limiting block 124 and the outer wall of the transparent cylinder 121 away from the adjusting screw 123 are provided with vents so that when the piston 122 moves, external gas can enter and exit the transparent cylinder 121 to maintain the internal air pressure balance of the transparent cylinder 121. A magnetic pull rod 125 is connected to a piston 122 at one end and extends to the outside of the transparent cylinder 121 after passing through the limiting block 124 and the other end of the transparent cylinder 121. It is driven to move by a driving member. A reset elastic member 126 for driving the piston 122 to reset is sleeved on the outer wall of the magnetic pull rod 125. When the connecting pipe 16 of the control element 2 12 corresponds to the sample container 4, the magnetic pull rod 125 is driven to move by the driving element. The magnetic pull rod 125 pulls the piston 122 to contact the limiting block 124. When the piston 122 moves towards the limiting block 124, the azido acid solution in the azido acid solution storage container 8 is drawn into the transparent cylinder 121 through the one-way pipe. After the driving element is turned off, the magnetic pull rod 125 drives the piston 122 to reset under the action of the reset elastic element 126. The piston 122 resets and compresses the azido acid solution in the transparent cylinder 121 to the connecting pipe 16 through the one-way pipe. Then the azido acid solution enters the sample container 4 through the connecting pipe 16 and mixes with the water sample to convert nitrite into N2O. The amount of azido acid solution entering the sample container 4 can be limited by adjusting the position of the limiting block 124.

[0025] Preferably, the driving component in this embodiment includes: The protective shell 14 is mounted on the mounting plate 6 and movably sleeved on one end of the shaft of the measuring disc 112. A bearing is provided at the connection between the protective shell 14 and the shaft of the measuring disc 112. Rotating device 2 13 is mounted on protective housing 14. Rotating device 2 13 includes a motor and a reducer. The output end of rotating device 2 13 extends into protective housing 14 and is connected to one end of the shaft of control disc 112 via a bevel gear set (two sets of bevel gears combined). An electromagnetic ring 15 is fixedly sleeved on the outer wall of the protective shell 14 and is used to attract the magnetic pull rod 125 (e.g., made of metal) when energized.

[0026] When the driving component is working, the rotating device 2 13 and the electromagnetic ring 15 are energized, which in turn drives the control disk 112 to rotate. The electromagnetic ring 15 is energized and attracts the magnetic pull rod 125, causing the magnetic pull rod 125 to move. When the driving component is closed, the rotating device 2 13 and the electromagnetic ring 15 are de-energized.

[0027] Example 3

[0028] Please see the appendix Figure 4 - Appendix Figure 6 Based on Example 1, as a preferred embodiment, the sample container 4 in this example includes: The container body 41 is hollow at the top, and a sealing cap 42 is detachably provided on the top. The sealing cap 42 and the container body 41 can be connected by thread or snap-fit. The sealing cap 42 has an opening for inserting the connecting pipe 16. The side wall of the end of the connecting pipe 16 that is inserted into the opening has a discharge port 17. The bottom end of the connecting pipe 16 is closed. The sealing block 48 is attached to the bottom of the sealing cover 42 to seal the opening. The sealing block 48 is connected to the sealing cover 42 through the elastic connector 49 (including a guide rod that is connected to the bottom of the sealing cover 42 at one end and moves through the sealing block 48, and a spring sleeved on the outer wall of the guide rod, with one end of the spring connected to the bottom end of the guide rod and the other end connected to the sealing block 48).

[0029] When the connecting pipe 16 is inserted downward into the opening, the sealing block 48 is squeezed and moved downward, thereby creating a gap between the sealing block 48 and the sealing cap 42. At this time, the connecting pipe 16 communicates with the inner cavity of the container body 41 through the discharge port 17. When the connecting pipe 16 is moved upward, the sealing block 48 is reset and the opening is closed under the action of the elastic connector 49 to prevent the liquid or gas in the container body 41 from leaving the container body 41.

[0030] Preferably, the bottom of the container body 41 in this embodiment is provided with an arc-shaped groove 43, and a stirring element 44 (including a stirring rod and blades provided on the outer wall of the stirring rod) is rotatably provided inside the container body 41. One end of the stirring element 44 extends into the arc-shaped groove 43. A torsion spring is provided at the connection between the stirring element 44 and the container body 41. A pull rope 45 is wound around one end of the stirring element 44. One end of the pull rope 45 is connected to a magnetic arc-shaped slider 46. The magnetic arc-shaped slider 46 (for example, made of metal) is slidably provided in the arc-shaped groove 43. The magnetic arc-shaped slider 46 is connected to one side of the inner wall of the arc-shaped groove 43 by a connecting elastic element 47 (for example, a spring). A driven plate 18 is rotatably mounted on the bottom of the rotating seat 2 via a bearing. The driven plate 18 is rotatably mounted on the worktable 1 via a bearing. A transmission telescopic rod 19 is connected to the top of the driven plate 18. The transmission telescopic rod 19 allows the mounting rod to move up and down while transmitting the rotational force of the driving component. The transmission telescopic rod 19 includes a sleeve rod and a movable rod inserted into one end of the sleeve rod. The movable rod and the sleeve rod can be slidably connected by a slider and a groove. One end of the transmission telescopic rod 19 movably passes through the rotating seat 2 and is connected to the driving component, and is driven to rotate by the driving component. Specifically, the transmission telescopic rod 1... The movable rod of 9 is connected to the output end of the rotating device of the drive component 13. The top of the driven disk 18 is embedded with several sets of magnetic blocks 20 in a ring array for adsorbing the magnetic arc slider 46. When the magnetic block 20 corresponds to the magnetic arc slider 46, it adsorbs the magnetic arc slider 46 and drives the magnetic arc slider 46 to move in the arc groove 43 when the driven disk 18 rotates. When the magnetic arc slider 46 moves, it pulls the stirring component 44 to rotate through the pull rope 45. When the magnetic block 20 and the magnetic arc slider 46 separate, the stirring component 44 resets and rotates under the action of the torsion spring. When the drive unit is working, it also drives the driven plate 18 to rotate through the transmission telescopic rod 19. When the driven plate 18 rotates, it cooperates with the magnetic arc slider 46 through the magnetic block 20, so that the magnetic arc slider 46 moves and pulls the stirring component 44 to rotate through the pull rope 45. The rotation of the stirring component 44 mixes the water inside with the copper-cadmium granules or azido acid solution, thereby improving the reaction efficiency and uniformity.

[0031] Example 4

[0032] Please see the appendix Figure 4 - Appendix Figure 6 Based on Example 1, in this example, the outer wall of the connecting pipe 16 connected to the control component 11 is provided with a counter 22 for measuring the number of copper-cadmium-plated particles discharged from the connecting pipe 16. The counter 22 can be, for example, a pipeline particulate detector, but is not limited to this type. The counter 22 and the stable isotope ratio mass spectrometer 9 are both electrically connected to the display screen 21. The display screen 21 can be set on the workbench 1. The display screen 21 displays the count value of the counter 22 and the nitrogen and oxygen isotope ratio data detected by the stable isotope ratio mass spectrometer 9. The counter 22 and the telescopic device 10 are both electrically connected to the controller. When the number of copper-cadmium-plated particles discharged reaches the threshold, the counter 22 sends a signal to the controller, causing the controller to control the telescopic device 10 to move the mounting plate 6 upward and close the drive component. For example, if the counting threshold is set to 5, when the number of copper-plated cadmium particles discharged reaches 5, the counter 22 causes the controller to control the telescopic device 10 and the drive component, thereby resetting the mounting plate 6 upward so that the connector 16 is disengaged from the sample container 4, and at the same time, N2O is no longer discharged or circulated at the connector 16.

[0033] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A device for tracing and analyzing the source of nitrates in water based on stable isotope analysis technology, characterized in that, include: The workbench (1) is rotatably provided with a rotating seat (2) and a fixed support (5). The rotating seat (2) is provided with several sets of through holes for installing sample containers (4) in a circular array. Mounting plate (6) is located above rotating seat (2) and is driven up and down by telescopic device (10). The telescopic device (10) is located on bracket (5). Mounting plate (6) is equipped with copper-cadmium granule storage (7), azido acid solution storage (8) and stable isotope ratio mass spectrometer (9). The discharge ends of copper-cadmium granule storage (7) and azido acid solution storage (8) are respectively connected to control element one (11) and control element two (12) for controlling the discharge amount. The discharge ends of control element one (11) and control element two (12) and the gas inlet end of stable isotope ratio mass spectrometer (9) are all connected to connecting pipe (16). Control element one (11) and control element two (12) are driven by driving element. Each time the rotating seat (2) rotates by a preset angle, each connecting pipe (16) corresponds to a sample container (4) on the rotating seat (2) so that it can be inserted into the corresponding sample container (4) when the mounting plate (6) moves downward. The control component (11) includes: The outer shell (111) has an inlet and an outlet (17) at its upper and lower ends respectively connected to the copper-cadmium granule storage container (7) and the connecting pipe (16). The inner cavity is rotatably equipped with a matching control plate (112). The shaft of the control plate (112) is connected to the driving component. The outer circumferential wall of the control plate (112) is provided with several sets of granule grooves (113) for accommodating a copper-cadmium granule. The second control component (12) includes: A transparent cylinder (121) is provided with a matching piston (122) inside. The outer wall of the transparent cylinder (121) is provided with scale lines. One end of the transparent cylinder (121) is connected to the discharge end of the azido acid solution storage tank (8) through a one-way pipe, and the other end is connected to the connecting pipe (16) through a one-way pipe. An adjusting screw (123) is rotatably disposed inside a transparent cylinder (121) and moves through a piston (122). One end of the adjusting screw (123) extends to the outer end of the transparent cylinder (121) and is connected to a handwheel. A limiting block (124) for limiting the movement of the piston (122) is threadedly fitted on the outer wall of the adjusting screw (123) and on the side inside the transparent cylinder (121). A magnetic pull rod (125) is connected to a piston (122) at one end and extends to the outside of the transparent cylinder (121) after passing through the limiting block (124) and the other end of the transparent cylinder (121). It is driven to move by a driving member. The outer wall of the magnetic pull rod (125) is fitted with a reset elastic member (126) for driving the piston (122) to reset. The sample container (4) includes: The container body (41) is hollow at the top, and a sealing cap (42) is detachably provided on the top. The sealing cap (42) has an opening for inserting the connecting pipe (16), and a discharge port (17) is provided on the side wall of one end of the connecting pipe (16) that is inserted into the opening. A sealing block (48) is attached to the bottom of the sealing cover (42) to seal the opening. The sealing block (48) is connected to the sealing cover (42) by an elastic connector (49). The bottom of the container body (41) is provided with an arc-shaped groove (43). A stirring element (44) is rotatably provided inside the container body (41). One end of the stirring element (44) extends into the arc-shaped groove (43). A torsion spring is provided at the connection between the stirring element (44) and the container body (41). A pull rope (45) is wound around one end of the stirring element (44). One end of the pull rope (45) is connected to a magnetic arc-shaped slider (46). The magnetic arc-shaped slider (46) is slidably disposed in the arc-shaped groove (43). The magnetic arc-shaped slider (46) is connected to one side of the inner wall of the arc-shaped groove (43) through a connecting elastic element (47). The bottom of the rotating seat (2) is provided with a driven disk (18), which is rotatably mounted on the worktable (1). The top of the driven disk (18) is connected to a transmission telescopic rod (19). One end of the transmission telescopic rod (19) passes through the rotating seat (2) and is connected to the driving component. It is driven to rotate by the driving component. The top of the driven disk (18) is provided with a number of magnetic blocks (20) in a ring array for adsorbing the magnetic arc slider (46). When the magnetic block (20) corresponds to the magnetic arc slider (46), it adsorbs the magnetic arc slider (46). When the driven disk (18) rotates, it drives the magnetic arc slider (46) to move in the arc groove (43). When the magnetic arc slider (46) moves, it pulls the stirring component (44) to rotate through the pull rope (45). When the magnetic block (20) and the magnetic arc slider (46) separate, the stirring component (44) resets and rotates under the action of the torsion spring.

2. The analytical apparatus according to claim 1, characterized in that: The driving component includes: A protective shell (14) is mounted on the mounting plate (6) and movably sleeved on one end of the shaft of the control plate (112); Rotating device two (13) is mounted on the protective shell (14). The output end of the rotating device two (13) extends into the protective shell (14) and is connected to one end of the shaft of the control plate (112) via a bevel gear set. An electromagnetic ring (15) is fixedly sleeved on the outer wall of the protective shell (14) and is used to attract the magnetic pull rod (125) when energized.

3. The analytical apparatus according to claim 1, characterized in that: The workbench (1) is provided with a rotating device (3) for driving the rotating seat (2) to rotate.

4. The analytical apparatus according to claim 1, characterized in that: A counter (22) is provided on the outer wall of the connecting pipe (16) connected to the control component (11) for measuring the number of copper-cadmium granules discharged from the connecting pipe (16). The counter (22) and the stable isotope ratio mass spectrometer (9) are electrically connected to the display screen (21). The counter (22), the telescopic device (10) and the drive component are electrically connected to the controller. When the number of copper-cadmium granules discharged reaches the threshold, the counter (22) sends a signal to the controller, causing the controller to control the telescopic device (10) to move the mounting plate (6) upward and close the drive component.

5. The analytical apparatus according to claim 1, characterized in that: The connecting pipe (16) is also equipped with a solenoid valve.

6. A method for source apportionment analysis of nitrates in water based on stable isotope analysis technology, utilizing the analysis apparatus as described in any one of claims 1-5, characterized in that: Includes the following steps: S1: Place the water sample in the sample container (4) and then place it into the through hole on the rotating seat (2); S2: The rotating seat (2) rotates. When the sample container (4) corresponds with the control element (11), the telescopic device (10) drives the mounting plate (6) to descend, so that the connecting pipe (16) on the control element (11) enters the sample container (4). The control element (11) causes the copper-cadmium granules in the copper-cadmium granule storage container (7) to quantitatively enter the sample container (4) and mix with the water sample, converting the nitrates in the water sample into nitrites. Then, the telescopic device (10) drives the mounting plate (6) to rise, and the rotating seat (2) rotates again. Until the sample container (4) corresponds to the control element two (12), the mounting plate (6) is driven down by the telescopic device (10), so that the connecting pipe (16) on the control element two (12) enters the sample container (4). The control element two (12) allows the azido acid solution in the azido acid solution storage container (8) to enter the sample container (4) and mix with the water sample, converting nitrite into N2O. Then the above steps are repeated, and the N2O in the sample container (4) is detected by the stable isotope ratio mass spectrometer (9) to obtain nitrogen oxygen isotope ratio data. S3: Compare the nitrogen and oxygen isotope ratio data with the isotope fingerprint database of known pollution sources, and calculate the contribution ratio of each pollution source through the calculation ratio module to determine the source of nitrate pollution in the water.

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