Determination system for polycyclic aromatic hydrocarbon in water body

Abstract

The utility model relates to the technical field of water body detection, in particular to a system for measuring polycyclic aromatic hydrocarbon in water body, which comprises a sampling device, a liquid-liquid extraction purifier and a liquid chromatograph, the sampling device comprises a collecting barrel, a piston rod is connected inside the collecting barrel, a hand wheel is fixedly connected to the top of the piston rod, and the liquid chromatograph is fixedly connected to the top of the piston rod. A collecting head is connected to the lower portion of the collecting cylinder, the liquid chromatograph comprises a chromatograph body, a hydraulic pump, a chromatographic column and a detector are further arranged in the chromatograph body, the liquid-liquid extraction purifier comprises an extraction main machine, a funnel support is arranged above the extraction main machine, and the funnel support is connected with the liquid chromatograph body. A plurality of second liquid storage devices are installed on the funnel support, sample injectors are connected to the upper portions of the second liquid storage devices, separating funnels are connected to the lower portions of the second liquid storage devices, and the whole measuring process ensures the measuring accuracy and reliability.

Description

Technical Field

[0001] This utility model relates to the field of water body detection technology, specifically a system for measuring polycyclic aromatic hydrocarbons in water. Background Technology

[0002] Currently, gas chromatography-mass spectrometry (GC-MS), liquid-liquid extraction and solid-phase extraction high-performance liquid chromatography (HPLC), ultra-high performance liquid chromatography (UHPLC), online solid-phase extraction-high performance liquid chromatography (On-line SPE-HPLC), large-volume splitless injection technology combined with GCMS, and ultrasonic extraction methods are mainly used to determine polycyclic aromatic hydrocarbons (PAHs) in water. However, the above methods are not suitable for situations where the concentration of PAHs in water is low, usually involve some environmental pollution, and the entire determination process is relatively cumbersome.

[0003] Therefore, it is necessary to design a system for measuring polycyclic aromatic hydrocarbons in water to solve the problems mentioned above. Utility Model Content

[0004] The purpose of this invention is to provide a system for measuring polycyclic aromatic hydrocarbons in water, so as to solve the problems mentioned in the background art.

[0005] To achieve the above objectives, this utility model provides the following technical solution:

[0006] A system for determining polycyclic aromatic hydrocarbons in water, used to sample and detect polycyclic aromatic hydrocarbon components in water, includes a sampling device, a liquid-liquid extraction purification instrument, and a liquid chromatograph.

[0007] The sampling device includes a collection cylinder, a piston rod connected inside the collection cylinder, a handwheel fixedly connected to the top of the piston rod, and a collection head connected to the bottom of the collection cylinder;

[0008] The liquid chromatograph includes a chromatograph body, with multiple vessel placement slots on the top of the chromatograph body. Multiple first liquid reservoirs are placed inside the vessel placement slots. The chromatograph body is also equipped with a hydraulic pump, a chromatographic column, and a detector.

[0009] The liquid-liquid extraction and purification instrument includes an extraction host, a funnel support is provided above the extraction host, a plurality of second liquid reservoirs are installed on the funnel support, an injector is connected above the second liquid reservoirs, and a separating funnel is connected below the second liquid reservoirs.

[0010] As a preferred embodiment of this utility model, the piston rod and the collecting cylinder are internally slidably connected, and the internal cavity of the collecting head is connected to the inside of the collecting cylinder.

[0011] As a preferred embodiment of this utility model, one side of the hydraulic pump is fixedly connected to the chromatographic column via a connector and a pipe, and the output end of the chromatographic column is also connected to the detector.

[0012] As a preferred embodiment of this utility model, a limiting sleeve is also fixedly connected to the top of the chromatograph body, and the limiting sleeve has multiple limiting grooves inside that match the positions of the vessel placement slots.

[0013] In a preferred embodiment of this utility model, an elastic compression block is connected inside the plurality of the limiting grooves, and a soft pad is fixedly connected to the outer side of the elastic compression block, with the inner wall of the soft pad in contact with the outer wall of the first liquid reservoir.

[0014] As a preferred embodiment of this invention, the chromatographic column is provided with a hydrophobic stationary phase material layer inside.

[0015] As a preferred embodiment of this utility model, one side of the injector is placed inside the second liquid reservoir, and the bottom of the second liquid reservoir and the top of the dispensing funnel are fixedly connected.

[0016] As a preferred embodiment of this utility model, the extraction host is also equipped with a control system.

[0017] Compared with the prior art, the beneficial effects of this utility model are:

[0018] This invention provides a system for determining polycyclic aromatic hydrocarbons (PAHs) in water. The process begins with sampling the water sample, followed by extraction with different organic solvents. After separation by settling, the organic phase is collected, and the extraction is repeated and combined. Two different concentration methods are used to concentrate the extract to 1 ml to determine the optimal concentration. During testing, the injection volume, test temperature, and the rate of increase in the solvent-mobile phase ratio are adjusted to achieve the best chromatographic separation. Using the optimized conditions, a high-performance liquid chromatograph (HPLC) is employed for separation and detection to determine the PAH content in the water. In summary, this project establishes an accurate, simple, and environmentally friendly method for PAH detection by using liquid-liquid extraction-liquid chromatography (PLC-HPLC) with equipment such as the Shimadzu LC-20AT HPLC system. By optimizing the extraction solvent, concentration conditions, solvent replacement method, and HPLC conditions, the entire process, including liquid-liquid extraction, concentration and solvent replacement, chromatographic condition optimization, and HPLC testing, ensures the accuracy and reliability of the determination. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the overall structure of the entire measuring system of this utility model;

[0020] Figure 2This is a three-dimensional structural schematic diagram of the sampling device of this utility model;

[0021] Figure 3 This is a three-dimensional structural schematic diagram of the liquid chromatograph of this invention;

[0022] Figure 4 This utility model Figure 3 A three-dimensional structural diagram of the middle limiting sleeve after separation;

[0023] Figure 5 This is a schematic diagram of the internal structure of the liquid chromatograph of this invention;

[0024] Figure 6 This is a top view of the limiting sleeve structure of this utility model;

[0025] Figure 7 This is a three-dimensional structural schematic diagram of the liquid-liquid extraction purification device of this utility model;

[0026] Figure 8 This is a flowchart of the measurement process for this utility model.

[0027] In the diagram: 1. Sampling device; 2. Liquid chromatograph; 21. Chromatograph body; 22. Glassware placement tank; 23. First reservoir; 24. Hydraulic pump; 26. Chromatographic column; 27. Detector; 3. Liquid-liquid extraction and purification system; 31. Extraction unit; 32. Funnel support; 33. Second reservoir; 34. Injector; 35. Separating funnel; 4. Collection cylinder; 5. Piston rod; 6. Handwheel; 7. Collection head; 8. Limiting sleeve; 9. Limiting groove; 10. Elastic compression block; 11. Pad. Detailed Implementation

[0028] The technical solutions of the present utility model will be clearly and completely described below with reference to the embodiments of the present utility model. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present utility model without creative effort are within the protection scope of the present utility model.

[0029] To facilitate understanding of this utility model, a more comprehensive description will be given below with reference to the accompanying drawings. Several embodiments of this utility model are provided. However, this utility model can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided so that the disclosure of this utility model will be more thorough and complete.

[0030] It should be noted that when a component is said to be "fixed to" another component, it can be directly on the other component or there may be an intervening component. When a component is said to be "connected to" another component, it can be directly connected to the other component or there may be an intervening component. The terms "vertical," "horizontal," "left," "right," and similar expressions used in this document are for illustrative purposes only.

[0031] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0032] For examples, please refer to Figure 1-8 This utility model provides a technical solution:

[0033] A system for determining polycyclic aromatic hydrocarbons (PAHs) in water is used to sample and detect PAH components in water, including a sampling device 1, a liquid-liquid extraction and purification instrument 3, and a liquid chromatograph 2.

[0034] Specifically, the sampling device 1 includes a collection cylinder 4, a piston rod 5 connected inside the collection cylinder 4, a handwheel 6 fixedly connected to the top of the piston rod 5, and a collection head 7 connected to the bottom of the collection cylinder 4; the piston rod 5 and the collection cylinder 4 are slidably connected inside, and the internal cavity of the collection head 7 is connected to the inside of the collection cylinder 4; by pulling the handwheel 6, the water to be measured outside is absorbed into the collection cylinder 4, ensuring that the water sample is representative for subsequent measurement.

[0035] Specifically, the liquid chromatograph 2 includes a chromatograph body 21, with multiple vessel placement slots 22 on the top of the body 21. Multiple first liquid reservoirs 23 are placed inside the vessel placement slots 22. The body 21 also houses a hydraulic pump 24, a chromatographic column 26, and a detector 27. One side of the hydraulic pump 24 is fixedly connected to the chromatographic column 26 via a connector and pipe. The chromatographic column 26 contains a hydrophobic stationary phase material layer. The output end of the chromatographic column 26 is also connected to the detector 27. After adjusting the liquid chromatograph to its optimal operating state and selecting appropriate parameters such as the chromatographic column, mobile phase, and detector, the concentrated polycyclic aromatic hydrocarbon (PAH) solution is injected into the liquid chromatograph for separation and detection. The liquid chromatograph records the separation of PAHs on the chromatographic column and converts it into an electrical signal through the detector. These signals are recorded and processed by the data acquisition system to obtain parameters such as the concentration and peak area of ​​polycyclic aromatic hydrocarbons (PAHs). Based on the retention time and characteristic peak shape of PAHs on the chromatogram, the types of PAHs present in the sample can be determined. Furthermore, by comparing the peak area of ​​PAHs with that of the standard, the concentration of PAHs in the sample can be calculated.

[0036] The chromatograph body 21 is also fixedly connected to a limiting sleeve 8. The limiting sleeve 8 has multiple limiting grooves 9 that match the positions of the vessel placement grooves 22. The limiting grooves 9 are connected to elastic compression blocks 10, and soft pads 11 are fixedly connected to the outside of the elastic compression blocks 10. The inner wall of the soft pads 11 is in contact with the outer wall of the first liquid reservoir 23. The soft pads 11 are pressed against the outer wall of the first liquid reservoir 23 by the elastic action of the elastic compression blocks 10, thereby limiting their position.

[0037] Specifically, the liquid-liquid extraction purification instrument 3 includes an extraction host 31, a funnel support 32 above the extraction host 31, multiple second liquid reservoirs 33 mounted on the funnel support 32, an injector 34 connected above the second liquid reservoirs 33, and a separating funnel 35 connected below the second liquid reservoirs 33; one side of the injector 34 is placed inside the second liquid reservoir 33, and the bottom of the second liquid reservoir 33 is fixedly connected to the top of the separating funnel 35; the extraction host 31 also has a control system inside; extraction is performed by selecting a suitable organic solvent (such as n-hexane, dichloromethane, etc.) based on the solubility and polarity of polycyclic aromatic hydrocarbons; the water sample and extraction solvent are added to the extraction bottle of the liquid-liquid extraction purification instrument, and the transfer of polycyclic aromatic hydrocarbons from the aqueous phase to the organic phase is promoted by shaking, stirring or sonication; after extraction, the extract is allowed to stand for a period of time to allow it to naturally separate into layers. The upper layer is the organic phase, containing the extracted polycyclic aromatic hydrocarbons (PAHs); the lower layer is the aqueous phase, mainly containing unextracted substances. The organic phase is separated from the extraction flask using a separatory funnel and collected in a clean container. The collected organic phase is then purified using a solid-phase extraction (SPE) column to remove impurities and interfering substances. SPE columns are typically packed with specific adsorbents that selectively adsorb PAHs while excluding other substances. The PAHs adsorbed on the SPE column are eluted using a suitable elution solvent and collected in another clean container. The purified PAH solution is then concentrated to reduce the solvent volume and increase the PAH concentration. This can be achieved using a rotary evaporator, nitrogen drying, or other methods. The concentrated PAH solution is then brought to a final volume for subsequent liquid chromatography analysis.

[0038] The workflow of this utility model is as follows: When using the system for determining polycyclic aromatic hydrocarbons (PAHs) in water, firstly, by pulling the handwheel 6, the water sample to be measured is drawn into the collection cylinder 4, ensuring the water sample is representative for subsequent determination. Then, based on the solubility and polarity of PAHs, a suitable organic solvent (such as n-hexane, dichloromethane, etc.) is selected for extraction. The water sample and extraction solvent are added to the extraction flask of the liquid-liquid extraction purifier, and the transfer of PAHs from the aqueous phase to the organic phase is promoted by shaking, stirring, or ultrasound. After extraction, the extract is allowed to stand for a period of time to allow natural stratification. The upper layer is the organic phase, containing the extracted PAHs; the lower layer is the aqueous phase, mainly containing unextracted substances. The organic phase is separated from the extraction flask using a separatory funnel and collected in a clean container. The collected organic phase is then purified using a solid-phase extraction column to remove impurities and interfering substances. Solid-phase extraction (SPE) columns are typically packed with specific adsorbents that selectively adsorb polycyclic aromatic hydrocarbons (PAHs) while excluding other substances. The PAHs adsorbed on the SPE column are eluted using a suitable elution solvent and collected in a clean container. The purified PAH solution is then concentrated to reduce the solvent volume and increase the PAH concentration. This can be achieved using methods such as rotary evaporation or nitrogen drying. The concentrated PAH solution is then brought to a specific volume for subsequent liquid chromatography (LC) analysis. The LC is then optimized, with appropriate column, mobile phase, and detector parameters selected. The concentrated PAH solution is injected into the LC for separation and detection. The LC records the separation of PAHs on the column and converts this information into an electrical signal using the detector. These signals are recorded and processed by the data acquisition system to obtain parameters such as the concentration and peak area of ​​polycyclic aromatic hydrocarbons (PAHs). Based on the retention time and characteristic peak shape of PAHs on the chromatogram, the types of PAHs present in the sample can be determined. Furthermore, by comparing the peak area of ​​PAHs with that of the standard, the concentration of PAHs in the sample can be calculated.

[0039] In summary, this project established an accurate, simple, and environmentally friendly method for the determination of polycyclic aromatic hydrocarbons (PAHs) in water using liquid-liquid extraction-liquid chromatography (LC-LC) with equipment such as the Shimadzu LC-20AT high-performance liquid chromatograph. By optimizing the extraction solvent, concentration conditions, solvent replacement method, and LC conditions, the entire determination process, including liquid-liquid extraction, concentration and solvent replacement, chromatographic condition optimization, and LC testing, ensured the accuracy and reliability of the determination.

[0040] Although embodiments of the present 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 present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A system for determining polycyclic aromatic hydrocarbons in a water body for enabling sampling and detection of polycyclic aromatic hydrocarbon components in a water body, characterized by: It includes sampling device (1), liquid-liquid extraction purifier (3) and liquid chromatograph (2); The sampling device (1) includes a collection cylinder (4), a piston rod (5) is connected inside the collection cylinder (4), a hand wheel (6) is fixedly connected to the top of the piston rod (5), and a collection head (7) is connected below the collection cylinder (4); The liquid chromatograph (2) includes a chromatograph body (21), a plurality of vessel placing grooves (22) are formed above the chromatograph body (21), a plurality of first liquid reservoirs (23) are placed inside the vessel placing grooves (22), a hydraulic pump (24), a chromatographic column (26) and a detector (27) are further arranged inside the chromatograph body (21); The liquid-liquid extraction purifier (3) includes an extraction host (31), a funnel support (32) is arranged above the extraction host (31), a plurality of second liquid reservoirs (33) are installed on the funnel support (32), a sample injector (34) is connected above the second liquid reservoirs (33), and a separation funnel (35) is connected below the second liquid reservoirs (33).

2. The system for determining polycyclic aromatic hydrocarbons in a water body according to claim 1, characterized in that: The piston rod (5) and the collection cylinder (4) are slidably connected, and the inner cavity of the collection head (7) is connected with the inside of the collection cylinder (4).

3. The system for determining polycyclic aromatic hydrocarbons in water according to claim 1, characterized by: One side of the hydraulic pump (24) is fixedly connected to the chromatographic column (26) through a connecting head and a pipeline, and the output end of the chromatographic column (26) is further connected with the detector (27).

4. The system for determining polycyclic aromatic hydrocarbons in water according to claim 1, characterized by: The upper side of the chromatograph body (21) is further fixedly connected with a limiting sleeve (8), a plurality of limiting grooves (9) matched with the positions of the vessel placing grooves (22) are formed in the limiting sleeve (8).

5. The system for determining polycyclic aromatic hydrocarbons in water according to claim 4, characterized by: A plurality of elastic extrusion blocks (10) are connected inside the limiting grooves (9), the outer side of the elastic extrusion blocks (10) is fixedly connected with a soft pad (11), and the inner wall of the soft pad (11) is in contact with the outer wall of the first liquid reservoir (23).

6. The system for determining polycyclic aromatic hydrocarbons in water according to claim 1, characterized by: A hydrophobic stationary phase material layer is arranged inside the chromatographic column (26).

7. The system for determining polycyclic aromatic hydrocarbons in water according to claim 1, characterized by: One side of the sample injector (34) is placed inside the second liquid reservoir (33), and the bottom of the second liquid reservoir (33) is fixedly connected with the top of the separation funnel (35).

8. The system for determining polycyclic aromatic hydrocarbons in water according to claim 1, characterized by: A control system is further arranged inside the extraction host (31).

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