Soil heavy metal pollution detection system and detection method

Abstract

The invention discloses a soil heavy metal pollution detection system and method, a main body of a pretreatment component is internally provided with a slideway with an arc-shaped path, a slide block is in sliding fit in the slideway, and the end part of the slide block is fixedly connected with an arc-shaped sampling rod; an ejector rod is elastically and slidably mounted on the inner wall of the embedded section of the slide way, and when the sampling pipe is inserted into the embedded section and before the sampling rod enters the sampling pipe, the sliding block is in contact with the bottom end of the sliding piece; a plurality of pneumatic blades are arranged at the end, located outside the material receiving groove, of the crushing part, the pneumatic blades are installed in a pneumatic bin, the pneumatic bin is connected with the outlet end of the compressed air pipeline, and when the sliding block slides away from the sampling pipe, the scraper rotates clockwise to push crushed samples in the material receiving groove to a notch in the groove bottom of the material receiving groove; and a sample digestion chamber is arranged below the notch and is connected with the detection component. The device is simple and compact in structure, centralized and rapid in process and convenient and efficient to use.

Description

Technical Field

[0001] This invention relates to the field of soil testing technology, specifically to a soil heavy metal pollution detection system and method. Background Technology

[0002] In soil testing, heavy metal detection is typically performed using atomic absorption spectrometry, voltammetric polarography, and X-ray fluorescence spectrometry. These existing methods usually require manual cleaning of the collected samples, manual crushing of the soil sample from the sampling tube, transfer to a digestion container for digestion, and finally transfer for heavy metal detection. This process is complex, involves numerous supporting devices and tools, and is highly dependent on manual labor. It is not only inconvenient and inefficient, but also prone to sample loss due to multiple transfers. Furthermore, the straight-through design of existing sampling devices can lead to leakage or detachment during sample removal and transfer of the sampling tube and testing equipment. Therefore, it is essential to design an integrated system that facilitates sample storage and allows for automated and rapid sampling, crushing, digestion, and detection. Summary of the Invention

[0003] (a) Technical problems to be solved

[0004] To address the shortcomings of existing technologies, this invention provides a soil heavy metal pollution detection system and method, which solves the problems of complicated procedures, numerous auxiliary tools and supporting equipment, inconvenient detection, and easy sample omission in current soil heavy metal detection.

[0005] (II) Technical Solution

[0006] To achieve the above objectives, the present invention provides the following technical solution: a soil heavy metal pollution detection system, comprising a sampling tube, a pretreatment component for sample pretreatment, and a detection component for heavy metal detection. The sampling tube is an arc-shaped tubular structure, with one end being a sharp end capable of penetrating the soil. The pretreatment component includes a main body, within which is a slide with an arc-shaped path. A slider is slidably fitted within the slide, and an arc-shaped sampling rod is fixedly connected to the end of the slider. At the port of the slide is an insertion section for inserting the sampling tube. A push rod is elastically and slidably installed on the inner wall of the insertion section. When the sampling tube is inserted into the insertion section, it pushes against the push rod, and at this time, the push rod is subjected to an upward force. The elastic tension within the embedded section is used to press the sampling tube firmly. A hinge rod is also hingedly installed inside the main body. One end of the hinge rod abuts against the top of the top rod, and the other end is connected to a sliding member that is vertically slidably installed inside the main body through a cylindrical spring. When the sampling tube is inserted into the embedded section, the top rod presses the sliding member downward, so that the through hole of the upper section of the sliding member is completely misaligned with the pipe hole of a compressed air pipe that is horizontally set above the main body. When the slider slides towards the sampling tube, the bottom end of the sliding member can be pushed upward by the slider to make the through hole and the pipe hole coaxially aligned. Furthermore, before the sampling rod enters the sampling tube, the slider has already contacted the bottom end of the sliding member.

[0007] A receiving trough for catching soil samples falling from the sampling tube is also installed on one side of the main body. A crushing component for crushing the sample is rotatably installed in the receiving trough. The end of the crushing component outside the receiving trough has several pneumatic blades. The pneumatic blades are installed in a pneumatic chamber. The pneumatic chamber is connected to the outlet end of the compressed air pipeline to drive the crushing component to rotate.

[0008] It also includes a rotatably mounted scraper, one end of which is fixed to the slider, and the center of rotation is located at the center of the arc path. The other end of the scraper is in smooth contact with the bottom of the receiving trough. When the slider slides away from the sampling tube, the scraper rotates clockwise and pushes the crushed sample in the receiving trough to the opening at the bottom of the receiving trough. Below the opening is a sample digestion chamber, which is connected to the detection component.

[0009] Preferably, the sliding member includes a sliding plate, a lifting plate, and a sliding part from top to bottom. The sliding plate has a through hole in the center, and the diameter of the through hole is larger than the diameter of the tube hole. The lifting plate extends horizontally towards the hinge rod. The cylindrical spring is connected between the lifting plate and the hinge rod. The bottom end of the sliding part has a rounded surface.

[0010] Preferably, the slider is an arc-shaped block structure with a curvature consistent with the arc path, and the side of the slider that contacts the bottom end of the sliding part is covered with a hard alloy layer.

[0011] Preferably, a piston plate is fixed to the end of the sampling rod, the piston plate being able to slide inside the sampling tube to completely squeeze out the soil sample inside the sampling tube.

[0012] Preferably, the detection component is one of the following: inductively coupled plasma mass spectrometer, flame atomic absorption spectrometer, graphite furnace atomic absorption spectrometer, atomic fluorescence spectrometer, or inductively coupled plasma emission spectrometer.

[0013] Preferably, the slider has a cylindrical rod protruding from the main body surface. One end of the scraper is fixed to the cylindrical rod. The cylindrical rod is slidably installed in an inclined hole on a drive component. The drive component is pneumatic or hydraulically driven and reciprocates in the vertical direction, driving the slider to slide in the slide rail.

[0014] Preferredly, the soil heavy metal pollution detection system described above is used for detection. During detection,

[0015] After confirming that the main switch of the compressed air source is turned off, insert the non-sharp end of the sampling tube into the embedded section and fix it in place. At the same time, move the top rod up and press down on the sliding member to completely disengage the through hole and the pipe hole, thereby shutting off the supply of pneumatic power from the compressed air pipeline to the crushing component.

[0016] Then push the slider towards the sampling tube side. Before the sampling rod enters the sampling tube, the slider contacts the bottom end of the sliding part that enters the slide, pushing the sliding part upward so that the through hole is aligned with the tube hole, and the compressed air pipeline is opened.

[0017] Turn on the main switch of the compressed air source to make the crushing component rotate and continue to move the slider forward, so that the sampling rod is inserted into the sampling tube, and the soil sample in the sampling tube is gradually pushed out and falls from the sharp end of the sampling tube onto the crushing component, where it is then fully crushed and falls into the receiving trough.

[0018] The slider retracts and resets, causing the scraper to push the crushed soil sample in the receiving trough forward along the bottom of the trough, and it falls from the opening of the receiving trough into the digestion chamber for digestion;

[0019] The soil in the digestion chamber is transferred to the detection component for detection of the corresponding heavy metal elements.

[0020] The amount of acid added in the digestion chamber must meet the following requirements: for every 0.2g soil sample, add 6mL hydrochloric acid, 4.5mL nitric acid, 8mL hydrofluoric acid, and 1mL perchloric acid; then cover the digestion chamber and heat the mixture inside.

[0021] After opening the lid and confirming that the perchloric acid is fuming, heat it with nitric acid or hydrochloric acid to extract the salts. For soil samples that are difficult to digest, it is necessary to repeat the addition of hydrochloric acid, nitric acid, hydrofluoric acid and perchloric acid.

[0022] (III) Beneficial Effects

[0023] This invention provides a soil heavy metal pollution detection system and method, which mainly have the following beneficial effects:

[0024] 1. Samples inside the sampling tube are less likely to fall freely. This reduces sample spillage during sampling and carrying the sampling tube for testing. The sampling tube that comes with the system also helps to gather and compress soil samples during collection due to the resistance generated by the internal curvature of the tube. This increases the amount of sample collected and improves the sample density while preventing free scattering during the transfer of the sampling tube.

[0025] 2. The sampling process, including sample extraction, crushing, and digestion, is a linked mechanism integrated into one device. It is a fully mechanical, automatic, and efficient operation that is very convenient, easy to use, and easy to manage. Attached Figure Description

[0026] Figure 1 This is a schematic diagram illustrating the use of the sampling tube;

[0027] Figure 2 This is a schematic diagram of the core structure of the present invention;

[0028] Figure 3 This is a detailed structural diagram of a sliding component.

[0029] In the diagram: 1. Main body; 2. Slide rail; 3. Sliding component; 4. Sliding part; 401. Sliding plate; 402. Picking plate; 403. Through hole; 5. Compressed air pipe; 6. Cylindrical spring; 7. Hinge rod; 8. Top rod; 9. Sampling rod; 10. Piston plate; 11. Sampling tube; 12. Scraper; 13. Receiving trough; 14. Crushing component; 15. Pneumatic blade; 16. Pneumatic chamber; 17. Digestion chamber; 18. Driving component; 19. Detailed Implementation

[0030] 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.

[0031] This embodiment specifically introduces a soil heavy metal pollution detection system, which first includes a sampling tube 12, a pretreatment component for sample pretreatment, and a detection component for heavy metal detection. The sampling tube 12 differs from typical sampling instruments, such as... Figure 1As shown, it is a slightly curved, plowshare-shaped container with a flat end and an angled end. That is, the sampling tube 12 has an arc-shaped tubular structure, with one end being a sharp, angled end that can pierce the soil. After insertion, the soil sample enters the sampling tube 12. Due to its curved structure, compared to a straight tube, the sample is less likely to leak out, and the sample is more easily compressed and adhered together inside the curved tube, minimizing the risk of sample detachment when the sampling tube 12 is pulled out. Figure 1 As shown, the sampling tube 12 can be fixed to the handle for manual sampling. The pretreatment components include a main body 1, within which is a slide 2 with an arc-shaped path. A slider 3 slides within the slide 2, allowing the slider 3 to move in an arc within the slide 2. An arc-shaped sampling rod 10 is fixed to the end of the slider 3, which can eject soil samples from the sampling tube 12. The size of the sampling rod 10 is adaptively designed according to the size of the sampling tube 12. Alternatively, a piston plate 11 can be fixed to the end of the sampling rod 10, allowing the piston plate 11 to slide within the sampling tube 12 to completely squeeze out the soil samples. At the end of the slide 2 is an insert section for inserting the sampling tube 12. This insert section can be designed with a limiting stop for installing the sampling tube 12. To install and fix the sampling tube 12, a push rod 9 is elastically and slidably installed on the inner wall of the embedding section. When the sampling tube 12 is inserted into the embedding section, it pushes the push rod 9, and at this time, the push rod 9 is subjected to an elastic pulling force towards the embedding section to press against the sampling tube 12, thereby securing the sampling tube 12. Simultaneously, a hinge rod 8 is also hingedly installed inside the main body 1. One end of the hinge rod 8 abuts against the top of the push rod 9, and the other end is connected to a sliding member 4 vertically slidably installed inside the main body 1 via a cylindrical spring 7. When the sampling tube 12 is inserted into the embedding section, the push rod 9, through its pushing action on the hinge rod 8, presses the sliding member 4 downwards, so that the through hole 5 on the upper section of the sliding member 4 is completely misaligned with the pipe hole of a compressed air pipe 6 horizontally positioned above the main body 1. In actual manufacturing, if... Figure 2 As shown, the part of the sliding member 4 where the through hole 5 is located is slidably installed in the compressed gas pipe 6, thus realizing a valve-like function. Similarly, when the slider 3 slides towards the sampling tube 12, the bottom end of the sliding member 4 can be pushed upward by the slider 3 to make the through hole 5 coaxially aligned with the pipe hole, thereby opening the compressed gas pipe 6. Furthermore, it must be satisfied that before the sampling rod 10 enters the sampling tube 12, the slider 3 has already contacted the bottom end of the sliding member 4. That is, before opening the compressed gas pipe 6, the sampling rod 10 has not yet pushed or squeezed the sample in the sampling tube 12, so as to prevent the crushing component 15 mentioned later from opening too late and not being able to fully crush the sample falling from the sampling tube 12.

[0032] As a specific implementation detail, in this embodiment, such as Figure 2As shown, a receiving trough 14 for catching soil samples falling from the sampling tube 12 is also installed on one side of the main body 1. A crushing component 15 for crushing the sample is rotatably installed inside the receiving trough 14. The end of the crushing component 15 outside the receiving trough 14 has several pneumatic blades 16. The pneumatic blades 16 are installed inside the pneumatic chamber 17. The pneumatic chamber 17 is connected to the outlet end of the compressed air pipeline 6. When the compressed air pipeline 6 is opened, high-pressure gas enters the pneumatic chamber 17, pushing the blades to rotate, thereby driving the crushing component 15 to rotate and crush the falling soil sample.

[0033] As a specific implementation detail, this embodiment also includes a rotatably mounted scraper 13, see further details. Figure 2 The scraper 13 is strip-shaped, with one end fixed to the slider 3 and its rotation center located at the center of the arc path. The other end smoothly contacts the bottom of the receiving trough 14. Thus, when the slider 3 slides, the scraper 13 rotates accordingly. Specifically, when the slider 3 slides away from the sampling tube 12, the scraper 13 rotates clockwise, pushing the pulverized sample in the receiving trough 14 to the notch at the bottom of the trough 14, where it falls. To create a greater horizontal distance between the notch and the pulverizing blades of the pulverizing component 15, the arc-shaped portion of the receiving trough 14 can be offset to the left. Simultaneously, the scraper 13 is designed as a telescopic structure, ensuring constant contact with the bottom of the receiving trough 14. A sample digestion chamber 18 is also located below the notch for digesting the soil sample. This digestion chamber 18 is connected to the detection component for detecting heavy metals in the soil. In practice, the detection component is one of the following: inductively coupled plasma mass spectrometer, flame atomic absorption spectrometer, graphite furnace atomic absorption spectrometer, atomic fluorescence spectrometer, or inductively coupled plasma emission spectrometer. These are some existing heavy metal detection devices that can rapidly detect soil samples after digestion.

[0034] In this embodiment, as Figure 3 The aforementioned sliding member 4 comprises, from top to bottom, a sliding plate 402, a lifting plate 403, and a sliding part 401. The sliding plate 402 has a through hole 5 in its center, and the diameter of the through hole 5 is larger than the diameter of the pipe hole. The lifting plate 403 extends horizontally towards the hinge rod 8. A cylindrical spring 7 connects the lifting plate 403 and the hinge rod 8. The bottom end of the sliding part 401 has a rounded surface to facilitate the smooth upward movement of the sliding member 4 by the slider 3. The use of the cylindrical spring 7 serves two purposes: firstly, it better secures the sampling tube 12; secondly, when the sliding member 4 moves upward, since the aforementioned top rod 9 is already in rigid contact with the sampling tube 12, the cylindrical spring 7 can adaptively shorten, allowing the sliding member 4 to move upward smoothly and open the compressed air pipe 6. Specifically, the slider 3 is an arc-shaped block structure with a curvature consistent with the arc path, and the side of the slider 3 that contacts the bottom end of the sliding part 401 is covered with a hard alloy layer.

[0035] Preferably, the slider 3 has a cylindrical rod protruding from the surface of the main body 1. One end of the scraper 13 is fixed to the cylindrical rod. The cylindrical rod is slidably installed in an inclined hole opened in a drive member 19. The drive member 19 is pneumatic or hydraulically driven to reciprocate in the vertical direction, simply and reliably driving the slider 3 to slide in the slide rail 2 and drive the slider 3 to reciprocate. At the same time, if pneumatic is used, it is possible to share the compressed air source with the crushing component 15.

[0036] Based on the hardware of the above testing system, the testing process shall be carried out according to the following steps:

[0037] (1) Confirm that the main switch of the compressed air source has been closed, insert the non-sharp end of the sampling tube 12 into the embedded section and fix it, while making the push rod 9 move up and press down the sliding part 4, so that the through hole 5 and the pipe hole are completely misaligned, and the compressed air pipeline 6 is shut off from the pneumatic power supply to the crushing part 15, so as to avoid the phenomenon that the crushing part 15 will run dry once the main switch of the compressed air source is turned on.

[0038] (2) Then, using the corresponding power equipment, the slider 3 is pushed to slide towards the sampling tube 12. Before the sampling rod 10 enters the sampling tube 12, the slider 3 contacts the bottom end of the sliding member 4 that enters the slide 2. The sliding member 4 is pushed upwards step by step so that the through hole 5 is aligned with the tube hole, the compressed air pipeline 6 is opened, and the compressed air source can be output.

[0039] (3) Turn on the main switch of the compressed air source, and the compressed air pipeline 6 will officially output compressed air, which will impact the blades and cause the crushing component 15 to rotate; then, continue to move the slider 3 forward, so that the sampling rod 10 is inserted into the sampling tube 12, and the soil sample in the sampling tube 12 is gradually pushed out. The soil sample will fall section by section from the sharp end of the sampling tube 12 onto the crushing component 15, and then be fully crushed and fall into the receiving trough 14, that is, in front of the scraper 13 at this time. Figure 2 The sample is placed in the receiving trough 14 on the left side of the scraper 13, but usually does not exceed the opening. If it exceeds the opening, a corresponding baffle must be set to block the falling sample so that the sample falls in front of the scraper 13.

[0040] (4) When the slider 3 retracts and resets, it drives the scraper 13 to push the crushed soil sample in the receiving trough 14 forward along the bottom of the trough, and it falls into the digestion chamber 18 for digestion, and then is ready for testing. For example, the digested extract can be placed in a polarograph for direct measurement. The principle is to apply a changing voltage signal to the electrode and then measure the response current of the electrode to measure the content of heavy metals. Compared with atomic absorption spectrometry, this method has higher measurement accuracy, lower operating cost, and can be used for speciation analysis, etc.

[0041] (5) Transfer the soil in the digestion chamber 18 to the detection component for detection of the corresponding heavy metal elements and obtain the content of the corresponding heavy metal elements.

[0042] As a preferred embodiment, in the above operation, the amount of acid added to the digestion chamber 18 must meet the following requirements: for every 0.2g soil sample, add 6mL hydrochloric acid, 4.5mL nitric acid, 8mL hydrofluoric acid, and 1mL perchloric acid; then cover the digestion chamber 18, heat the mixture in the digestion chamber 18, open the cover, and after confirming that the perchloric acid is fuming, heat with nitric acid or hydrochloric acid to extract the salts. For soil samples that are difficult to digest, it is necessary to repeat the addition of hydrochloric acid, nitric acid, hydrofluoric acid, and perchloric acid once.

[0043] It should be noted that, in this document, the terms “comprising,” “including,” or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0044] 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 soil heavy metal pollution detection system, comprising a sampling tube (12), a pretreatment component for sample pretreatment, and a detection component for heavy metal detection, characterized in that: The sampling tube (12) is an arc-shaped tubular structure, with one end being a sharp end that can penetrate into the soil; The pretreatment component includes a main body (1), which has an arc-shaped slide (2) inside. A slider (3) is slidably fitted inside the slide (2), and an arc-shaped sampling rod (10) is fixed to the end of the slider (3). At the end of the slide (2) is an embedding section for inserting the sampling tube (12). A top rod (9) is elastically and slidably installed on the inner wall of the embedding section. When the sampling tube (12) is inserted into the embedding section, it pushes the top rod (9), and at this time the top rod (9) is subjected to an elastic pulling force towards the embedding section to press against the sampling tube (12). A hinge rod (8) is also hinged inside the main body (1), and one end of the hinge rod (8) abuts against the top end of the top rod (9). The other end is connected to the sliding member (4) which is vertically slidably installed in the main body (1) via a cylindrical spring (7). When the sampling tube (12) is inserted into the embedded section, the top rod (9) presses the sliding member (4) downward, so that the through hole (5) of the upper section of the sliding member (4) is completely misaligned with the pipe hole of a compressed air pipe (6) which is horizontally set above the main body (1). When the slider (3) slides toward the sampling tube (12), the bottom end of the sliding member (4) can be pushed upward by the slider (3) to make the through hole (5) coaxially aligned with the pipe hole. Furthermore, before the sampling rod (10) enters the sampling tube (12), the slider (3) has already contacted the bottom end of the sliding member (4). A receiving trough (14) for catching soil samples falling from the sampling tube (12) is also installed on one side of the main body (1). A crushing component (15) for crushing samples is rotatably installed in the receiving trough (14). The crushing component (15) has several pneumatic blades (16) at one end outside the receiving trough (14). The pneumatic blades (16) are installed in the pneumatic chamber (17). The pneumatic chamber (17) is connected to the outlet end of the compressed air pipe (6) to drive the crushing component (15) to rotate. It also includes a rotatably mounted scraper (13), one end of which is fixed to the slider (3), the center of rotation is located at the center of the arc path, and the other end is in smooth contact with the bottom of the receiving trough (14). When the slider (3) slides away from the sampling tube (12), the scraper (13) rotates clockwise and pushes the crushed sample in the receiving trough (14) to the opening at the bottom of the receiving trough (14). Below the opening is a sample digestion chamber (18), which is connected to the detection component.

2. The soil heavy metal pollution detection system as described in claim 1, characterized in that, The sliding member (4) includes a sliding plate (402), a pick plate (403), and a sliding part (401) from top to bottom. The sliding plate (402) has a through hole (5) in the center, and the diameter of the through hole (5) is larger than the diameter of the tube hole. The pick plate (403) extends horizontally toward the hinge rod (8). The cylindrical spring (7) is connected between the pick plate (403) and the hinge rod (8). The bottom end of the sliding part (401) has a rounded surface.

3. The soil heavy metal pollution detection system as described in claim 2, characterized in that, The slider (3) is an arc-shaped block structure with a curvature consistent with the arc path, and the side of the slider (3) that contacts the bottom end of the sliding part (401) is covered with a hard alloy layer.

4. The soil heavy metal pollution detection system as described in claim 1, characterized in that, A piston plate (11) is fixed to the end of the sampling rod (10), and the piston plate (11) can slide inside the sampling tube (12) to completely squeeze out the soil sample inside the sampling tube (12).

5. The soil heavy metal pollution detection system as described in claim 1, characterized in that, The detection component is one of the following: inductively coupled plasma mass spectrometer, flame atomic absorption spectrometer, graphite furnace atomic absorption spectrometer, atomic fluorescence spectrometer, and inductively coupled plasma emission spectrometer.

6. The soil heavy metal pollution detection system as described in claim 1, characterized in that, The slider (3) has a cylindrical rod protruding from the surface of the main body (1). One end of the scraper (13) is fixed to the cylindrical rod. The cylindrical rod is slidably installed in an inclined hole opened on a drive member (19). The drive member (19) is pneumatic or hydraulically driven to reciprocate in the vertical direction, driving the slider (3) to slide in the slide rail (2).

7. A method for detecting heavy metals in soil, characterized in that: The soil heavy metal pollution detection system according to any one of claims 1-6 is used for detection. During the detection, T1. Confirm that the main switch of the compressed air source has been turned off, insert the non-sharp end of the sampling tube (12) into the embedded section and fix it, while making the top rod (9) move up and press down the sliding member (4) so ​​that the through hole (5) is completely misaligned with the pipe hole, and shut off the supply of pneumatic power from the compressed air pipeline (6) to the crushing component (15); T2. Then push the slider (3) to slide towards the sampling tube (12). Before the sampling rod (10) enters the sampling tube (12), the slider (3) contacts the bottom end of the slider (4) that enters the slide (2), pushes the slider (4) upward, so that the through hole (5) is aligned with the tube hole, and the compressed gas pipe (6) is opened. T3. Turn on the main switch of the compressed air source, make the crushing component (15) rotate, and continue to move the slider (3) forward, so that the sampling rod (10) is inserted into the sampling tube (12), and the soil sample in the sampling tube (12) is gradually pushed out and falls from the sharp end of the sampling tube (12) onto the crushing component (15), and is then fully crushed and falls into the receiving trough (14); T4. The slider (3) retracts and resets, driving the scraper (13) to push the crushed soil sample in the receiving trough (14) forward along the bottom of the trough, and fall from the opening of the receiving trough (14) into the digestion chamber (18) for digestion; T5. Transfer the soil in the digestion chamber (18) into the detection component for detection of the corresponding heavy metal elements.

8. The method for detecting heavy metals in soil as described in claim 7, characterized in that: The amount of acid added in the digestion chamber (18) must meet the following requirements: for every 0.2g soil sample, add 6mL hydrochloric acid, 4.5mL nitric acid, 8mL hydrofluoric acid and 1mL perchloric acid; then cover the digestion chamber (18) and heat the mixture in the digestion chamber (18).

9. The method for detecting heavy metals in soil as described in claim 8, characterized in that: After opening the lid and confirming that the perchloric acid is fuming, heat it with nitric acid or hydrochloric acid to extract the salts. For soil samples that are difficult to digest, it is necessary to repeat the addition of hydrochloric acid, nitric acid, hydrofluoric acid and perchloric acid.

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