Rapid online extraction analysis equipment for organic pollutants in water and detection method and application of rapid online extraction analysis equipment

Abstract

The invention provides rapid online extraction analysis equipment for organic pollutants in water as well as a detection method and application of the rapid online extraction analysis equipment. The equipment comprises an extraction separation device and an online detection device, the extraction separation device comprises an extraction cavity, a metal extractor and a stirrer; the metal extractor comprises a handle, a supporting block and at least one bent metal wire, and an extracting agent is loaded on the surface of the bent metal wire; the stirrer is arranged at the bottom of the extraction cavity and is used for stirring and mixing the sewage sample in the extraction cavity; the online detection device comprises a detection cavity, an electromagnetic induction coil, a controllable switch and a mass spectrometer; the detection cavity is connected with the mass spectrometer through the controllable switch; and the electromagnetic induction coil is arranged around the outside of the detection cavity. The invention provides rapid online extraction and analysis equipment for organic pollutants in water. The equipment integrates the functions of rapid extraction treatment and online analysis, and is simple to operate, high in detection efficiency, small in pollutant loss and accurate and reliable in detection and analysis result.

Description

Technical Field

[0001] The present application relates to a rapid online extraction and analysis device for organic pollutants in water, a detection method and application thereof, and belongs to the technical field of water pollutant detection. Background Art

[0002] As the core element that maintains the Earth's life system, water carries basic functions such as ecological balance, resource supply and environmental regulation. However, with the development of human society, water pollution has become increasingly serious, especially the impact of various organic pollutants. Taking the ocean as an example, among all types of water bodies, marine ecosystems account for 96.5% of the world's total water resources. Its strategic position as a protein resource bank, carbon sink regulator and shipping channel is highlighted. However, it is worth noting that with the acceleration of industrialization, the average annual growth rate of marine pollutants has reached 4.2% in the past four decades. Organic pollutants with multi-source emission characteristics, persistent pollution characteristics and transoceanic migration capabilities (including polycyclic aromatic hydrocarbons, pesticide residues, microplastics, etc.) have caused serious bioaccumulation effects, directly threatening the safety of the marine food chain.

[0003] The ocean provides many resources and services to mankind, but pollutants in the ocean have caused serious harm to the marine environment. Detecting pollutants in water and then taking targeted measures to prevent and control them has become a hot topic today. Pollutants in seawater have the characteristics of multiple pollution sources, strong persistence, wide diffusion range, and difficulty in control. Marine pollution has attracted increasing attention from the international community. The detection technology for seawater pollutants is also being updated, and people's requirements for fast and accurate detection methods have also emerged.

[0004] In the analysis of real samples, the presence of potential pollutants, ultra-trace concentrations of analytes, the complexity of the matrix, and the need to achieve increasingly lower detection limits necessitate the use of miniaturized and / or automated sample pretreatment techniques before sample determination. Sample pretreatment often requires a long extraction time, and sampling and detection are sometimes not completed on the same day due to time constraints, which can affect the concentration of volatile substances in seawater samples. Furthermore, current methods for detecting marine organic pollutants primarily employ post-sampling solid phase extraction / solid phase microextraction (SPE) pretreatment, followed by analysis using liquid chromatography-mass spectrometry (LC-MS) or gas chromatography-mass spectrometry (GC-MS). Using chromatography as a separation method and mass spectrometry as an analysis and detection method, this method enables the detection of organic matter in complex samples such as seawater. However, this traditional method is an offline operation, which can cause loss of pollutants and affect detection accuracy. Furthermore, the entire detection process is complex, time-consuming, and has low detection efficiency. Summary of the Invention

[0005] In order to solve the above problems, a rapid online extraction and analysis equipment for organic pollutants in water, a detection method and application thereof are provided. The equipment integrates rapid extraction processing and online analysis functions, and can realize online pretreatment and analytical detection of organic pollutants in water. It is simple to operate, has high detection efficiency and low pollutant loss, and the detection and analysis results are accurate and reliable.

[0006] According to one aspect of the present application, there is provided a rapid online extraction and analysis device for organic pollutants in water, comprising an extraction and separation device and an online detection device;

[0007] The extraction and separation device includes an extraction chamber, a metal extractor, and a stirrer; the metal extractor includes a handle, a support block, and at least one bent metal wire, the surface of which is loaded with an extractant; the stirrer is disposed at the bottom of the extraction chamber and is used to stir and mix the sewage sample in the extraction chamber;

[0008] The online detection device includes a detection cavity, an electromagnetic induction coil, a controllable switch and a mass spectrometer; the detection cavity is connected to the mass spectrometer through the controllable switch; and the electromagnetic induction coil is arranged around the outside of the detection cavity.

[0009] Optionally, the electromagnetic induction coil starts from the head end of the detection cavity, winds along the outer circumference of the detection cavity, and extends to a position at least 10 mm behind the end of the detection cavity.

[0010] Optionally, the bent metal wire is a surface-modified metal wire, and its bending radius is 1 / 2 of the radius of the support block.

[0011] Specifically, the bent metal wire is a metal wire with a diameter of 0.1-0.3 mm, or a metal wire with a diameter of 0.4-1.2 mm and a tip with a diameter less than 0.3 mm.

[0012] The bent metal wire is one of tungsten wire, copper wire, gold wire, and platinum wire, preferably tungsten wire; the extraction coating is polydimethylsiloxane (PMDS) or divinylbenzene (DVB), and the support block is made of quartz.

[0013] Optionally, a through hole is provided on the top of the extraction chamber to allow the metal extractor to be inserted therein;

[0014] The side of the extraction cavity is a hollow structure, and a heating component is provided inside to control the temperature rise or heat preservation of the sewage sample in the extraction cavity.

[0015] Specifically, the heating assembly includes a heating belt and a temperature sensor.

[0016] Optionally, the top of the extraction chamber is provided with an inlet and an exhaust port, and the bottom is provided with a drain port.

[0017] Optionally, when the metal extractor is inserted into the detection cavity, the central axis of the metal extractor forms an inclination angle of 3-10° with the central axis of the detection cavity.

[0018] Specifically, by inserting the metal extractor into the detection cavity at an inclination angle of 3-10°, so that the angle between it and the plane of the electromagnetic coil reaches 80-87°, the magnetic field cutting and heating efficiency is effectively improved, which is beneficial to the desorption of the extract.

[0019] Optionally, a metal plate is embedded in the detection cavity, the plane of which is perpendicular to the winding plane of the electromagnetic induction coil, and a through hole is provided in the metal plate so that the metal extractor can pass through it without contacting the metal extractor.

[0020] Specifically, the aperture of the through hole of the metal plate is larger than the diameter of the metal extractor, the material of the metal plate is one of tungsten, copper, gold, and platinum, preferably tungsten, and the detection cavity is a transparent quartz tube.

[0021] According to another aspect of the present application, a method for rapid online extraction and analysis of organic pollutants in water is provided, using the above-mentioned rapid online extraction and analysis device for organic pollutants in water, comprising the following steps:

[0022] (1) Sampling: Insert the metal extractor into the extraction chamber, open the exhaust port, add the sewage sample from the injection port, and close the injection port and exhaust port after the sewage sample is discharged from the exhaust port;

[0023] (2) Extraction: Turn on the heating component to heat, control the temperature at 30-90°C, turn on the stirrer, and the extractant on the surface of the metal extractor extracts the organic pollutants in the sewage sample. After extraction, the extracted sewage sample is discharged through the drain port;

[0024] (3) Flushing: After the sewage is discharged, close the drain port, open the exhaust port, add deionized water from the inlet, and rinse the surface of the metal extractor and the inner wall of the extraction chamber. After the deionized water overflows from the exhaust port for at least 30 seconds, close the inlet and exhaust port, open the drain port, and drain the remaining liquid;

[0025] (4) Emptying: Insert the extracted metal extractor into the detection cavity, turn on the controllable switch to connect the detection cavity with the mass spectrometer, turn on the mass spectrometer to evacuate the excess gas in the detection cavity, and turn off the controllable switch after emptying;

[0026] (5) Electromagnetic desorption: energize the electromagnetic induction coil to desorb the extracted organic pollutants from the metal extractor;

[0027] (6) Ionization: Turn off the power supply of the electromagnetic induction coil and immediately apply high voltage to the metal extractor, so that the end of the bent metal wire of the metal extractor discharges under the action of the electric field, ionizing the molecules in the detection cavity to produce ions. The generated ions can react with other molecules in the detection cavity;

[0028] (7) Detection: The mass spectrometer is in a vacuum state, and the controllable switch is turned on. The ionized substances in the detection chamber are sucked into the mass spectrometer for detection and analysis.

[0029] Optionally, in step (1), the extraction chamber is pre-loaded with inorganic salts; and in step (6), the applied voltage is 1.5-5 kV.

[0030] According to another aspect of the present application, an application of the above-mentioned rapid online extraction and analysis equipment for organic pollutants in water is also provided, which can be used for rapid online separation and detection of organic pollutants in high-salt liquid samples of seawater and non-high-salt liquid samples of lake water and river water.

[0031] The beneficial effects of this application include but are not limited to:

[0032] 1. According to the rapid online extraction and analysis equipment for organic pollutants in water of the present application, the metal extractor in the extraction and separation device is composed of multiple bent metal wires, which mainly play three roles: first, it serves as a carrier that can be used as an extraction matrix with stable load; second, it serves as a magnetic line cutting material that can spontaneously heat to promote the desorption of organic pollutants; third, its end can promote the ionization of organic pollutants in the detection cavity through corona discharge, so that the material components can be directly introduced into the mass spectrometer for accurate and rapid detection; by adopting a special metal extractor, the extraction and separation device and the online detection device are effectively connected in series, thereby realizing rapid online extraction and analysis of organic pollutants in water.

[0033] 2. According to the rapid online extraction and analysis equipment for organic pollutants in water of the present application, the metal wire surface is modified to load the extractant for the extraction of organic pollutants in water. By adding inorganic salts during the extraction process, the solubility of organic pollutants in the solution can be reduced by salting out, and then assisted by heating and stirring, the rapid extraction of organic pollutants in water is completed, and the time is shortened by more than 5 times compared with traditional extraction methods.

[0034] 3. According to the rapid online extraction and analysis equipment for organic pollutants in water of the present application, a high voltage is applied to the metal wire immediately after desorption, and the detection cavity is used as a discharge ionization chamber to ionize the molecules to produce ions. At the same time, the high temperature environment of the cavity makes the molecules and ions in the cavity less stable and more active, which greatly improves the reaction efficiency and ionization efficiency; at the same time, the detection cavity is directly connected to the inlet of the mass spectrometer, and the ionized organic pollutants can be quickly inhaled, and the detection is completed online, with good detection effect.

[0035] 4. According to the detection method of the rapid online extraction and analysis equipment for organic pollutants in water of this application, rapid, highly sensitive and accurate detection of organic pollutants in water is achieved through the online integrated design of extraction-desorption-ionization-detection and multi-parameter collaborative optimization. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] The drawings described herein are used to provide a further understanding of the present application and constitute a part of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

[0037] Figure 1 Schematic diagram of the three-dimensional structure of the extraction and separation device involved in Example 1 of the present application;

[0038] Figure 2 Schematic diagram of the front cross section of the extraction and separation device involved in Example 1 of the present application;

[0039] Figure 3 This is a schematic diagram of the three-dimensional structure of the online detection device involved in Example 1 of the present application;

[0040] Figure 4 Schematic diagram of the front cross section of the online detection device involved in Example 1 of the present application;

[0041] Figure 5 The secondary mass spectrum of the experimental results involved in the experimental examples of this application;

[0042] Note: Figure 5 (a) is the secondary mass spectrum of m / z 112 in the control group (deionized water), (b) is the secondary mass spectrum of m / z 112 of the p-fluoroaniline standard substance, (c) is the secondary mass spectrum of unspiked simulated seawater analyzed using the rapid online extraction and detection mass spectrometry method for marine organic pollutants, and (d) is the secondary mass spectrum of simulated seawater spiked with p-fluoroaniline.

[0043] Explanation of symbols in the figure:

[0044] 1. Exhaust port; 2. Inlet port; 3. Heating belt; 4. Stirrer; 5. Handle; 6. Bent wire; 7. Drain port; 8. Detection chamber; 9. Controllable switch; 10. Mass spectrometer; 11. Electromagnetic induction coil; 12. Metal plate; 13. Extraction chamber; 14. Support block; 15. Temperature sensor. DETAILED DESCRIPTION

[0045] In order to more clearly understand the above-mentioned purpose, features and advantages of the present application, the present application is further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be noted that, in the case of no conflict, the embodiments of the present application and the features in the embodiments can be combined with each other. In the following description, many specific details are set forth to fully understand the present application, but the present application can also be implemented in other ways different from those described herein. Therefore, the scope of protection of the present application is not limited by the specific embodiments disclosed below.

[0046] In addition, in the description of the present application, it should be understood that the terms "center", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application. In addition, the terms "first" and "second" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, features defined as "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the present application, "multiple" means two or more, unless otherwise clearly and specifically defined.

[0047] In this application, unless otherwise expressly specified or limited, terms such as "installed," "connected," "connect," and "fixed" should be understood in a broad sense. For example, they may refer to fixed connection, detachable connection, or integration; mechanical connection, electrical connection, or communication; direct connection or indirect connection through an intermediate medium; and internal communication between two components or interaction between two components. Those skilled in the art will understand the specific meanings of the above terms in this application based on specific circumstances.

[0048] In this application, unless otherwise expressly specified and limited, a first feature "above" or "below" a second feature may be that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in an appropriate manner in any one or more embodiments or examples.

[0049] Example 1

[0050] refer to Figure 1-Figure 4 Example 1 of the present application discloses a rapid online extraction and analysis device for organic pollutants in water, comprising an extraction and separation device and an online detection device; the extraction and separation device comprises an extraction chamber 13, a metal extractor, and an agitator 4; the metal extractor comprises a handle 5, a support block 14, and at least one bent metal wire 6, the surface of the bent metal wire 6 being loaded with an extractant (not shown); the agitator 4 is disposed at the bottom of the extraction chamber 13 and is used to agitate and mix the sewage sample in the extraction chamber 13;

[0051] The online detection device includes a detection cavity 8, an electromagnetic induction coil 11, a controllable switch 9 and a mass spectrometer 10; the detection cavity 8 is connected to the mass spectrometer 10 through the controllable switch 9; the electromagnetic induction coil 11 is arranged around the outside of the detection cavity 8.

[0052] The number of curved wires 6 in this application is not limited and can be adjusted by those skilled in the art based on actual testing requirements. Preferably, this embodiment uses three curved wires 6, and the handle 5 is made of the same material as the curved wires 6, namely tungsten. The extractant coating is preferably polydimethylsiloxane. The support block 14 is made of an inorganic non-metallic material, and in this embodiment, quartz is used to avoid the use of materials such as plastics and rubber, which may volatilize some substances during the test due to high temperatures and interfere with subsequent test accuracy.

[0053] In a preferred embodiment, extraction chamber 13 is made of metal, specifically stainless steel, to facilitate heat conduction. Agitator 4, electrically connected to an external power source, is also made of metal, specifically stainless steel, to prevent the adsorption of organic pollutants by materials such as plastics. It is used for stirring to accelerate extraction efficiency and promote the dissolution of inorganic salts within extraction chamber 13, further improving extraction efficiency. The blade type of agitator 4 is not limited; conventional blade types may be used.

[0054] As an embodiment, a through hole is opened on the top of the extraction chamber 13 to allow the metal extractor to be inserted therein; the side of the extraction chamber 13 is a hollow structure, and a heating component is provided inside to control the temperature rise or insulation of the sewage sample in the extraction chamber 13.

[0055] The diameter of the through-hole at the top of the extraction chamber 13 matches that of the support block 14, facilitating the insertion and securing of the metal extractor, which remains vertical during the extraction process. The heating assembly includes a heating belt 3 and a temperature sensor 15. These components, used within the side of the extraction chamber 13, are commercially available and connected to an external power source. They heat the wastewater sample within the chamber and maintain the temperature after reaching an appropriate temperature (anywhere from 30°C to 90°C). Higher temperatures accelerate the movement of molecules within the seawater sample, promoting the extraction of organic pollutants.

[0056] Furthermore, an inlet 2 and an exhaust port 1 are provided at the top of the extraction chamber 13, and a drain port 7 is provided at the bottom. The inlet 2 is used to connect with an external sampling device to introduce sewage samples, and a connecting pipe structure can be adopted; the exhaust port 1 is arranged at the top of the extraction chamber 13, and its main function is to maintain the pressure balance in the chamber by releasing the gas accumulated in the chamber (such as air, volatile organic vapor or reaction by-product gas). During the extraction process, gas retention will hinder the effective contact between the liquid and solid phases and reduce the extraction efficiency. The exhaust port 1 ensures that the extractant and the target are fully mixed by continuously discharging gas. Preferably, the bottom of the extraction chamber 13 is designed with a slope (the inclination angle is usually 5-15°), and the liquid is guided to converge to the drain port 7 by gravity to reduce the amount of residual liquid.

[0057] In one embodiment, the electromagnetic induction coil 11 starts at the front end of the detection cavity 8 and winds around the outer circumference of the detection cavity 8, extending to a position at least 10 mm behind the end of the detection cavity 8. The specific number of turns is not limited and can be adjusted by those skilled in the art based on the cavity length and experimental requirements. This winding method allows the electromagnetic induction coil 11 to completely cover the metal extractor, improving the metal extractor's magnetic flux cutting efficiency and, in turn, the thermal desorption efficiency.

[0058] Furthermore, the curved metal wire 6 is a surface-modified metal wire, and its bending radius is 1 / 2 of the radius of the support block 14. The curved structure can be realized by winding around an axis, spiral weaving, etc., and the curved winding structure increases its effective extraction surface area.

[0059] The bent metal wire 6 is a metal wire with a diameter of 0.1-0.3 mm, preferably 0.2 mm; or a metal wire with a diameter of 0.4-1.2 mm and a tip less than 0.3 mm is used. Preferably, a metal wire with a diameter of 0.5 mm and a tip of 0.2 mm is used. The thick main body provides structural stability, while the tip enhances surface energy through the local curvature effect, promoting the preferential adsorption or reaction of the target at the tip. At the same time, the tip of the metal wire has a small radius of curvature, and the electric field strength at the tip is significantly enhanced, inducing stable corona discharge. In addition, the distance between the bent metal wires is close, and under the action of the electric field, a discharge phenomenon can be induced inside the metal wire cluster. The combination of the two discharge modes enables the target to be efficiently ionized.

[0060] As an embodiment, when the metal extractor is inserted into the detection cavity 8, the central axis of the metal extractor forms an inclination angle of 3-10° with the central axis of the detection cavity 8. Preferably, the inclination angle is 8°.

[0061] According to Faraday's law of electromagnetic induction, when a closed conductor (such as a metal workpiece) is placed in a changing magnetic field, an induced electromotive force is generated within the conductor. This electromotive force drives the directional movement of free electrons, forming eddy currents. When a conductor (such as a metal container or workpiece) is placed in an alternating magnetic field, its surface cuts through the magnetic flux lines, generating closed circular currents (eddy currents). According to Joule's law, these eddy currents convert electrical energy into thermal energy under the action of the conductor's resistance. Therefore, by tilting the metal extractor, the area of ​​the tungsten wire cutting the magnetic flux lines can be increased, thereby improving heating efficiency and promoting the thermal desorption of organic pollutants.

[0062] If the angle of inclination exceeds this limit, causing the end of the metal wire to be positioned too low, the reaction efficiency between the ions and other active substances generated by the subsequent discharge and the desorbed target will be affected, thereby affecting the ionization efficiency and the sensitivity of subsequent detection. The insertion end of the detection chamber 8 is provided with an angled opening at an angle of 3-10° to facilitate the fixing of the support block 14 of the metal extractor, so that the metal extractor is at a limited angle when inserted.

[0063] As an embodiment, a metal plate 12 is embedded in the detection cavity 8, and its plane is perpendicular to the winding plane of the electromagnetic induction coil 11. The metal plate 12 is provided with a through hole so that the metal extractor can pass through it without contact. Preferably, the metal plate 12 is a tungsten plate, and the detection cavity 8 is grooved circumferentially to allow the tungsten plate to be embedded and fixed. The aperture of the through hole opened in the middle of the tungsten plate is not limited, as long as the metal extractor can pass through normally without contacting it. The metal plate 12 can cut the magnetic flux lines to play an auxiliary heating role. The detection cavity 8 is a high-temperature resistant quartz tube (either cylindrical or square), and the transparent tube body facilitates the observation of the desorption and ionization of the internal sample.

[0064] Within the detection chamber 8, the surrounding organic pollutant molecules are ionized into ions primarily through corona discharge at the end of the bent wire 6 and discharge within the bent wire cluster. The generated ions can then come into contact with other unionized molecules and undergo molecular ion reactions, ionizing molecules in other areas. Simultaneously, the high temperature within the chamber intensifies the movement of molecules and ions, increasing the efficiency of molecules ionized by the corona discharge at the end of the metal extractor and also improving the ionization efficiency of molecular ion reactions between ions and molecules. Furthermore, the high temperature can cause the organic pollutants within the chamber to enter a metastable state that is easily ionized, further improving the ionization efficiency of the pollutants.

[0065] When the controllable switch 9 is closed, the outer wall and the mass spectrometer entrance are sealed. The controllable switch 9 is a conventional commercially available product and can be controlled by electromagnetic, mechanical, or electric means to achieve the opening and closing function. The main function of the controllable switch 9 is to decompose ionization and mass spectrometry analysis into two independent events in time and space. During the ionization process, the switch is closed and the detection chamber 8 is sealed, which can ensure the efficient ionization of organic pollutants in the chamber. This is equivalent to an enrichment effect. After the ions accumulate in the chamber to reach the maximum ionization amount, the switch is opened to allow these ions to quickly flow into the mass spectrometer. The large amount of ions can reduce the detection limit. If a part of the ionization immediately enters the mass spectrometer, the signal will be relatively low, and the corresponding detection limit will be high.

[0066] Example 2

[0067] The present invention relates to a method for rapid online extraction and analysis of organic pollutants in water, comprising the following steps:

[0068] (1) Sampling: Insert the metal extractor into the extraction chamber 13, open the exhaust port 1, add the sewage sample from the injection port 2, and close the injection port 2 and the exhaust port 1 after the sewage sample is discharged from the exhaust port 1;

[0069] Figure 1 The extraction chamber 13 is pre-loaded with an inorganic salt, preferably NaCl. The amount of the added salt can be adjusted by those skilled in the art according to the injection volume. The inorganic salt can promote the subsequent extraction of organic pollutants through the "salting out" effect. In this embodiment 2, the extraction chamber volume is 15 mL, and 0.05-2.0 g of inorganic salt is added. If the extraction chamber volume is too large, the molecular motion space in the chamber is increased, reducing the adsorption of organic pollutant molecules on the metal wire. If the volume is too small, the absolute amount of organic pollutants is too small, which is not conducive to extraction.

[0070] (2) Extraction: Turn on the heating belt 3 to heat the sample and set the temperature to 80°C. At the same time, turn on the stirrer 4 and rotate it at a speed of 80-260 rpm, preferably 100 rpm. The stirring action can improve the extraction efficiency, heat the sample evenly, and accelerate the dissolution of inorganic salts to promote the "salting out" effect. At this time, the polydimethylsiloxane (PMDS) on the upper surface of the metal extractor extracts the organic pollutants in the sewage sample, and the extracted sewage sample is discharged through the drain port 7 after extraction.

[0071] (3) Flushing: After the sewage is discharged, close the drain port 7, open the exhaust port 1, introduce deionized water from the inlet 2, and flush the surface of the metal wire and the inner wall of the extraction chamber 13. This flushing process can remove the salt on the surface of the metal wire, prevent salt crystallization during the subsequent heating process to interfere with the desorption of organic pollutants, and prevent salt from following the metal wire into the online detection equipment at the front end of the mass spectrometer, and entering the mass spectrometer due to heating, vacuum, etc., thereby causing contamination to the mass spectrometer. At the same time, it can also reduce the memory effect and remove the interference of the current sewage sample on the next sample extraction analysis. After the deionized water overflows from the exhaust port 1 for 30 seconds, close the inlet 2 and the exhaust port 1, open the drain port 7, and discharge the remaining cleaning liquid;

[0072] (4) Emptying: Insert the extracted metal extractor into the detection cavity 8, connect the controllable switch 9 to the mass spectrometer, turn on the switch to connect the detection cavity 8 to the mass spectrometer, and use the vacuum characteristics of the mass spectrometer to empty the excess gas in the cavity to prevent the subsequent heating gas expansion from causing the cavity to explode or destroy the airtightness in the cavity, resulting in the loss of organic pollutants. After emptying, close the controllable switch 9;

[0073] (5) Electromagnetic desorption: The electromagnetic induction coil 11 is energized. The metal extractor is curved, which enables it to cut the magnetic flux lines for self-heating. The tungsten plate also cuts a large number of magnetic flux lines for auxiliary heating. In addition, the magnetic field also interferes with the organic molecules, which causes the extracted organic pollutants to be desorbed from the metal extractor under the action of heat and magnetism.

[0074] (6) Ionization: Turn off the power supply of the electromagnetic induction coil 11 and immediately use an external high-voltage discharge device to apply a high voltage (1.5 to 5 kV), preferably 3 kV, to the metal wire through the handle 5 of the metal extractor;

[0075] (7) Detection: The mass spectrometer is still in a vacuum state. Turn on the controllable switch 9 and connect the mass spectrometer. The ionized substances are automatically sucked into the mass spectrometer for detection and analysis.

[0076] Experimental example

[0077] Using the equipment and detection method of the embodiment of the present application, a test experiment was conducted with marine petroleum hydrocarbons (taking p-fluoroaniline as an example). The experimental results are as follows: Figure 5 shown.

[0078] In order to reduce the interference of background noise and improve the credibility of data, based on the tandem mass spectrometry results, the 4-fluoroaniline standard substance (m / z 112) was first analyzed by tandem mass spectrometry. Figure 5 As shown in (b), fragment ion peaks such as m / z 92 were generated. This result was compared with the tandem mass spectrum of m / z 112 (from impurities) in deionized water ( Figure 5 Comparison of the results (a) shows that the m / z 92 peak is absent in the tandem mass spectrum of the m / z 112 impurity in deionized water, whereas it is present in the tandem mass spectrum of p-fluoroaniline as a base peak. Therefore, in subsequent experiments, the characteristic m / z 92 fragment ion in the tandem mass spectrum was used as the criterion for the detection of p-fluoroaniline.

[0079] Prepare simulated seawater (without spiked p-fluoroaniline) and use this method for analysis. The results are as follows Figure 5 As shown in (c), no characteristic fragment ion m / z 92 was detected, proving that p-fluoroaniline was not detected. Subsequently, 10 ppm of p-fluoroaniline was spiked into simulated seawater and analyzed using this method. The results are shown in Figure 5 As shown in (d), the characteristic fragment ion peak of p-fluoroaniline, m / z 92, was clearly observed. By comparing the unspiked and spiked results, it was demonstrated that this method can be used for the online extraction and analysis of pollutants such as petroleum hydrocarbons in seawater, and the detection results are accurate.

[0080] The above description is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent replacements and improvements made within the spirit and principles of the present application should be included in the scope of protection of the present application.

Claims

1. A rapid online extraction and analysis device for organic pollutants in water, characterized in that: It includes extraction and separation device and online detection device; The extraction and separation device comprises an extraction chamber (13), a metal extractor and a stirrer (4); the metal extractor comprises a handle (5), a support block (14) and at least one bent metal wire (6), the surface of the bent metal wire (6) being loaded with an extractant; the stirrer (4) is arranged at the bottom of the extraction chamber (13) and is used to stir and mix the sewage sample in the extraction chamber (13); The online detection device comprises a detection cavity (8), an electromagnetic induction coil (11), a controllable switch (9) and a mass spectrometer (10); the detection cavity (8) is connected to the mass spectrometer (10) via the controllable switch (9); and the electromagnetic induction coil (11) is arranged around the outside of the detection cavity (8).

2. The rapid online extraction and analysis equipment for organic pollutants in water according to claim 1, characterized in that: The electromagnetic induction coil (11) starts from the head end of the detection cavity (8), is wound along the outer circumference of the detection cavity (8), and is wound to a position at least 10 mm behind the end of the detection cavity (8).

3. The rapid online extraction and analysis equipment for organic pollutants in water according to claim 1, characterized in that: The bent metal wire (6) is a surface-modified metal wire, and its bending radius is 1 / 2 of the radius of the support block (14).

4. The rapid online extraction and analysis equipment for organic pollutants in water according to claim 1, characterized in that: A through hole is provided on the top of the extraction chamber (13) so that the metal extractor can be inserted therein; The side of the extraction cavity (13) is a hollow structure, and a heating component is provided inside to control the temperature increase or heat preservation of the sewage sample in the extraction cavity (13).

5. The rapid online extraction and analysis equipment for organic pollutants in water according to claim 4, characterized in that: The top of the extraction chamber (13) is provided with a sample inlet (2) and an exhaust port (1), and the bottom is provided with a drain port (7).

6. The rapid online extraction and analysis equipment for organic pollutants in water according to claim 1, characterized in that: When the metal extractor is inserted into the detection cavity (8), the central axis of the metal extractor forms an inclination angle of 3-10° with the central axis of the detection cavity (8).

7. The rapid online extraction and analysis equipment for organic pollutants in water according to claim 1, characterized in that: A metal plate (12) is embedded in the detection cavity (8), the plane of which is perpendicular to the winding plane of the electromagnetic induction coil (11), and a through hole is provided in the metal plate (12) so that the metal extractor can pass through it without contact.

8. A method for rapid online extraction and analysis of organic pollutants in water, using the rapid online extraction and analysis device for organic pollutants in water as claimed in any one of claims 1 to 7, characterized in that: The following steps are involved: (1) Sampling: insert the metal extractor into the extraction chamber (13), open the exhaust port (1), add the sewage sample from the injection port (2), and after the sewage sample is discharged from the exhaust port (1), close the injection port (2) and the exhaust port (1); (2) Extraction: Turn on the heating component to heat, control the temperature at 30-90°C, turn on the stirrer (4), and the extractant on the surface of the metal extractor extracts the organic pollutants in the sewage sample. After extraction, the extracted sewage sample is discharged through the drain port (7); (3) Flushing: After the sewage is discharged, close the drain port (7), open the exhaust port (1), add deionized water from the injection port (2), and flush the surface of the metal extractor and the inner wall of the extraction chamber (13). After the deionized water overflows from the exhaust port (1) for at least 30 seconds, close the injection port (2) and the exhaust port (1), open the drain port (7), and drain the remaining liquid; (4) Emptying: inserting the extracted metal extractor into the detection cavity (8), opening the controllable switch (9), connecting the detection cavity (8) with the mass spectrometer (10), opening the mass spectrometer (10) to evacuate the excess gas in the detection cavity (8), and closing the controllable switch (9) after emptying; (5) Electromagnetic desorption: energizing the electromagnetic induction coil (11) to desorb the extracted organic pollutants from the metal extractor; (6) Ionization: Turn off the power supply of the electromagnetic induction coil (11) and immediately apply a high voltage to the metal extractor, so that the end of the bent metal wire (6) of the metal extractor discharges under the action of the electric field, ionizing the molecules in the detection cavity (8) to generate ions. The generated ions can react with other molecules in the detection cavity (8); (7) Detection: The mass spectrometer (10) is in a vacuum state, the controllable switch (9) is turned on, and the ionized substances in the detection cavity (8) are sucked into the mass spectrometer (10) for detection and analysis.

9. The method for rapid online extraction and analysis of organic pollutants in water according to claim 8, characterized in that: In step (1), the extraction chamber (13) is pre-loaded with inorganic salts; and in step (6), the applied voltage is 1.5-5 kV.

10. Use of the rapid online extraction and analysis device for organic pollutants in water according to any one of claims 1 to 7, characterized in that: It can be used for rapid online separation and detection of organic pollutants in high-salt liquid samples such as seawater and non-high-salt liquid samples such as lake water and river water.

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