Method and system for detecting concentration of organic pollutants

Abstract

The invention discloses a method and system for detecting the concentration of organic pollutants, and the method comprises the following steps: collecting a to-be-detected sample, and pretreating the to-be-detected sample: selectively enriching the organic pollutants in the sample by using a nano adsorption material with a specific aperture and a surface functional group, the nano adsorption material is synthesized through a sol-gel method, rare earth elements are doped in the synthesis process, enriched organic pollutants are desorbed from the nano adsorption material to form a desorption solution, and the desorption solution is detected by adopting a multi-wavelength laser-induced fluorescence spectrum technology. And constructing a quantitative relation model between the multi-wavelength fluorescence intensity and the concentration of the organic pollutants to obtain the concentration of the organic pollutants in the to-be-detected sample, so that the adsorption selectivity on the target organic pollutants is improved, the organic pollutants can be effectively enriched, accurate and rapid detection on the concentration of the organic pollutants is realized, and the method is suitable for large-scale popularization and application. The sensitivity, the selectivity and the stability are very good.

Description

Technical Field

[0001] The present invention relates to the technical field of organic pollutant concentration detection, and in particular to a method and system for detecting organic pollutant concentration. Background Art

[0002] With the rapid development of industrialization and urbanization, a large number of organic pollutants are discharged into the environment, such as water, soil and atmosphere. These organic pollutants are of various types, including polycyclic aromatic hydrocarbons (PAHs), pesticides, dyes and volatile organic compounds (VOCs). They are toxic, carcinogenic, mutagenic and teratogenic, and pose a serious threat to ecosystems and human health. For example, some PAHs are difficult to degrade in the environment and will be enriched through the food chain and eventually enter the human body, increasing the risk of diseases such as cancer. At the same time, the abuse of pesticides will lead to soil and water pollution, affect the growth and quality of crops, and also cause poisoning to aquatic organisms and birds. Therefore, accurate and rapid detection of the concentration of organic pollutants in the environment is of great significance for environmental monitoring, pollution control and protecting human health.

[0003] Chromatography is one of the most widely used methods for detecting organic pollutants. It mainly includes gas chromatography (GC) and liquid chromatography (LC). Gas chromatography is suitable for the analysis of volatile organic compounds and has the advantages of high separation efficiency and fast analysis speed. However, it has difficulties in analyzing organic pollutants with high boiling points and thermal instability. Liquid chromatography can analyze various types of organic pollutants, especially for thermally unstable and highly polar compounds. It has a good separation effect. However, chromatography also has some limitations: first, chromatographic instruments and equipment are expensive and have high operating costs, and require professional technicians to operate and maintain them. Second, the sample pretreatment process is complicated and usually requires multiple steps such as extraction and concentration, which is time-consuming and prone to errors. Finally, although the detection sensitivity of chromatography is relatively high, it is still unable to complete the detection of some trace organic pollutants.

[0004] Mass spectrometry is often used in conjunction with chromatography, such as gas chromatography-mass spectrometry (GC-MS) and liquid chromatography-mass spectrometry (LC-MS), which can provide structural information and quantitative analysis of organic pollutants. Mass spectrometry itself has the advantages of high sensitivity, high selectivity, and high resolution, and can accurately analyze complex samples. However, mass spectrometers are relatively expensive, and have higher requirements for operation and maintenance. They require strict environmental conditions and professional technicians, which limits their scope of use. At the same time, mass spectrometry has a relatively slow analysis speed, making it unsuitable for rapid detection of large-scale samples and unsuitable for large-scale promotion.

[0005] Spectroscopic methods such as ultraviolet-visible spectrophotometry and fluorescence spectroscopy are also commonly used for the detection of organic pollutants. Ultraviolet-visible spectrophotometry is simple to operate and low in cost, but its sensitivity and selectivity are relatively poor, and it is difficult to accurately distinguish some organic pollutants with similar structures. Although traditional fluorescence spectroscopy has high sensitivity, it usually uses a single wavelength for excitation and detection, which is easily interfered by other fluorescent substances in the sample and has limited analytical capabilities for complex samples. At the same time, existing spectral detection methods also have some problems in sample pretreatment, such as poor enrichment effect on organic pollutants, which limits further improvement of detection sensitivity.

[0006] Biosensors exploit the specific interactions between biomolecules (such as enzymes, antibodies, and nucleic acids) and organic pollutants, converting biological signals into measurable electrical or optical signals to detect organic pollutants. While biosensors offer advantages such as high sensitivity, selectivity, and rapid response, the stability and activity of biomolecules are susceptible to environmental factors such as temperature, pH, and ionic strength, resulting in a shorter sensor lifespan and poor repeatability and stability. Furthermore, the complex and costly preparation process for biosensors currently hinders their large-scale commercial application.

[0007] Therefore, a method and system for detecting the concentration of organic pollutants is urgently needed to solve the problems of high detection cost, susceptibility to interference from other interfering substances, low detection accuracy, slow response speed and low repeatability in the existing organic pollutant concentration detection process. Summary of the Invention

[0008] In view of this, the present invention proposes a method and system for detecting the concentration of organic pollutants, which are applied to the technical field of detection of the concentration of organic pollutants, to solve the existing technical problems of high detection cost, susceptibility to interference from other interfering substances, low detection accuracy, slow detection speed, slow response speed and low repeated stability, and has high application and promotion value.

[0009] In order to achieve the above technical objectives, the specific technical solutions adopted by the present invention are: A method for detecting the concentration of organic pollutants comprises the following steps: S1. Collecting a sample to be tested and pre-treating the sample to be tested. The pre-treatment includes selectively enriching organic pollutants in the sample using a nano-adsorbent material with a specific pore size and surface functional groups. The nano-adsorbent material is synthesized by a sol-gel method and doped with rare earth elements during the synthesis process. S2, desorbing the enriched organic pollutants from the nano-adsorption material to form a desorption liquid; S3. Use multi-wavelength laser-induced fluorescence spectroscopy to detect the desorption liquid. By simultaneously collecting fluorescence signals at multiple specific wavelengths, a quantitative relationship model between multi-wavelength fluorescence intensity and organic pollutant concentration is constructed. The model is used to calculate the concentration of organic pollutants in the sample to be detected.

[0010] Furthermore, the pore size range of the nano-adsorbent material is 2-10 nm, the surface functional groups are one or more of amino, carboxyl or sulfonic acid groups, the rare earth elements are one or more of lanthanum, cerium or yttrium, and the doping amount of the rare earth elements is 0.5% to 5% of the total mass of the nano-adsorbent material.

[0011] Furthermore, the desorption process uses a mixed solution of an organic solvent and an acidic solution as a desorbent, the organic solvent is one or more of methanol, ethanol or acetone, the acidic solution is hydrochloric acid, sulfuric acid or phosphoric acid solution, and the volume ratio of the organic solvent to the acidic solution is 1:1-5:1.

[0012] Furthermore, when constructing a quantitative relationship model between multi-wavelength fluorescence intensity and organic pollutant concentration, the partial least squares (PLS) or support vector machine regression (SVR) algorithm is used to process the collected multi-wavelength fluorescence intensity data and standard sample data of known concentration to obtain the optimal quantitative relationship model.

[0013] A detection system for the above-mentioned method for detecting the concentration of organic pollutants includes a sample pretreatment module, a desorption module, a fluorescence detection module and a concentration calculation module. The sample pretreatment module is used to pretreatment the collected sample to be detected. The sample pretreatment module includes an adsorption column equipped with nano-adsorption material. The desorption module is connected to the sample pretreatment module and is used to desorb organic pollutants enriched on the nano-adsorption material to form a desorption liquid. The desorption module includes a desorbent storage device and a desorption reaction container. The fluorescence detection module is connected to the desorption module and is used to detect the desorption liquid using multi-wavelength laser-induced fluorescence spectroscopy technology. The fluorescence detection module includes a multi-wavelength laser generator, a fluorescence signal acquisition device and a data processing unit. The concentration calculation module is connected to the fluorescence detection module and is used to calculate the concentration of organic pollutants in the sample to be detected based on a constructed quantitative relationship model between multi-wavelength fluorescence intensity and organic pollutant concentration.

[0014] Furthermore, the sample pretreatment module also includes a sample filtering device and a sample concentrating device. The sample filtering device is arranged before the adsorption column to remove large particle impurities in the sample. The sample concentrating device is arranged after the adsorption column to perform preliminary concentration on the sample before desorption.

[0015] Furthermore, the desorbent storage device includes a plurality of storage units, each for storing an organic solvent and an acidic solution, and the desorbent storage device is equipped with a flow control device for accurately controlling the mixing ratio of the organic solvent and the acidic solution.

[0016] Furthermore, the fluorescence signal acquisition device includes multiple photomultiplier tubes, and each photomultiplier tube corresponds to a specific laser wavelength and is used to collect fluorescence signals at that wavelength; the data processing unit is used to amplify, filter and digitize the collected fluorescence signals.

[0017] Furthermore, the concentration calculation module includes a model updating unit for regularly optimizing and updating the quantitative relationship model between the multi-wavelength fluorescence intensity and the organic pollutant concentration according to new standard sample data.

[0018] By adopting the above technical solution, the present invention can also bring the following beneficial effects: The present invention relates to a method and system for detecting the concentration of organic pollutants, which uses a nano-adsorption material with a specific pore size and surface functional groups to selectively enrich the organic pollutants in the sample. The nano-adsorption material is synthesized by a sol-gel method and doped with rare earth elements during the synthesis process, thereby improving the adsorption selectivity for the target organic pollutants. Compared with traditional adsorption materials, the nano-adsorption material has a larger specific surface area and more active sites, and can more effectively enrich organic pollutants, thereby improving the detection sensitivity. At the same time, the selective enrichment effect of the nano-adsorption material can reduce the influence of other interfering substances in the sample and improve the accuracy of detection.

[0019] The present invention provides a method and system for detecting the concentration of organic pollutants, which uses multi-wavelength laser-induced fluorescence spectroscopy technology to detect the desorption liquid. By simultaneously collecting fluorescence signals at multiple specific wavelengths, a quantitative relationship model between multi-wavelength fluorescence intensity and organic pollutant concentration is constructed. Compared with traditional single-wavelength fluorescence spectroscopy, multi-wavelength laser-induced fluorescence spectroscopy technology can provide richer information, reduce interference from other fluorescent substances in the sample, and improve the selectivity and accuracy of detection. In addition, multi-wavelength laser-induced fluorescence spectroscopy technology has the characteristics of high sensitivity and rapid response, and can realize rapid detection of organic pollutant concentration.

[0020] The present invention provides a method and system for detecting the concentration of organic pollutants, which integrate functional modules such as sample pretreatment, desorption, fluorescence detection and concentration calculation into one system, thereby realizing the automation and integration of organic pollutant concentration detection. The operation is simple, convenient and fast, reducing interference from human factors, and improving the repeatability and stability of detection. It has the advantages of simple operation, high repeatability stability and suitability for large-scale promotion. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0022] Figure 1 The present invention provides a flow chart of a method for detecting the concentration of organic pollutants. DETAILED DESCRIPTION

[0023] The embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0024] The following describes the embodiments of the present invention through specific examples. Those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that, in the absence of conflict, the following embodiments and features in the embodiments can be combined with each other. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0025] It should be noted that various aspects of the embodiments within the scope of the appended claims are described below. It should be apparent that the aspects described herein can be embodied in a wide variety of forms, and any specific structure and / or function described herein is merely illustrative. Based on the present invention, it should be understood by those skilled in the art that an aspect described herein can be implemented independently of any other aspect, and two or more of these aspects can be combined in various ways. For example, any number of aspects described herein can be used to implement an apparatus and / or practice a method. In addition, other structures and / or functionalities other than one or more of the aspects described herein can be used to implement this apparatus and / or practice this method.

[0026] It should also be noted that the illustrations provided in the following embodiments are merely schematic illustrations of the basic concept of the present invention. The illustrations only show components related to the present invention and are not drawn according to the number, shape, and size of components in actual implementation. In actual implementation, the type, quantity, and proportion of each component may be changed arbitrarily, and the component layout may also be more complex.

[0027] Additionally, in the following description, specific details are provided to provide a thorough understanding of the examples. However, one skilled in the art will appreciate that the aspects described can be practiced without these specific details. Example

[0028] like Figure 1 As shown, a method for detecting the concentration of organic pollutants includes the following steps: S1. Collect the sample to be tested and pre-treat the sample to be tested. The pre-treatment includes selectively enriching the organic pollutants in the sample using a nano-adsorbent material with a specific pore size and surface functional groups. The nano-adsorbent material is synthesized by a sol-gel method and doped with a rare earth element during the synthesis process. The pore size of the nano-adsorbent material is in the range of 2-10 nm, and the surface functional groups are one or more of amino, carboxyl, or sulfonic acid groups. The rare earth element is at least one of lanthanum (La), cerium (Ce), or yttrium (Y), and the doping amount of the rare earth element is 0.5% to 5% of the total mass of the nano-adsorbent material. S2. Desorbing the enriched organic pollutants from the nano-adsorption material to form a desorption solution, wherein the desorption process uses a mixed solution of an organic solvent and an acidic solution as a desorbent, the organic solvent is one or more of methanol, ethanol or acetone, and the acidic solution is hydrochloric acid, sulfuric acid or phosphoric acid solution, and the volume ratio of the organic solvent to the acidic solution is 1:1-5:1; S3. Detect the desorbed liquid using multi-wavelength laser-induced fluorescence spectroscopy. By simultaneously collecting fluorescence signals at multiple specific wavelengths, a quantitative relationship model between the multi-wavelength fluorescence intensity and the concentration of organic pollutants is constructed. The concentration of organic pollutants in the sample to be detected is calculated using this model. When constructing the quantitative relationship model between the multi-wavelength fluorescence intensity and the concentration of organic pollutants, the collected multi-wavelength fluorescence intensity data and the standard sample data of known concentration are processed using the partial least squares (PLS) method or the support vector machine regression (SVR) algorithm to obtain the optimal quantitative relationship model. A detection system for the above-mentioned detection method for organic pollutant concentration includes a sample pretreatment module, a desorption module, a fluorescence detection module, and a concentration calculation module. The sample pretreatment module is used to pretreatment the collected sample to be detected, and the sample pretreatment module includes an adsorption column loaded with nano-adsorption material; the desorption module is connected to the sample pretreatment module and is used to desorb organic pollutants enriched on the nano-adsorption material to form a desorption liquid, and the desorption module includes a desorbent storage device and a desorption reaction container; the fluorescence detection module is connected to the desorption module and is used to detect the desorption liquid using multi-wavelength laser-induced fluorescence spectroscopy technology, and the fluorescence detection module includes a multi-wavelength laser generator, a fluorescence signal acquisition device, and a data processing unit. The concentration calculation module is connected to the fluorescence detection module and is used to calculate the concentration of organic pollutants in the sample to be detected based on a constructed quantitative relationship model between multi-wavelength fluorescence intensity and organic pollutant concentration.

[0029] The sample pretreatment module also includes a sample filtration device and a sample concentrator. The sample filtration device is arranged before the adsorption column to remove large particles of impurities in the sample. The sample concentrator is arranged after the adsorption column to perform preliminary concentration on the sample before desorption. The adsorption column is filled with nanomaterials. The adsorption column can adopt a columnar structure and be filled with an appropriate amount of nano-adsorbent material. The sample filtration device is arranged before the adsorption column and can adopt a common filter structure with a filter membrane with a pore size of 0.45μm installed inside. The sample concentrator can adopt a rotary evaporator, including a rotary evaporation flask, a heating device, a vacuum pump and other components. The rotary evaporation flask is used to hold the sample, the heating device provides the appropriate temperature, and the vacuum pump is used to reduce the pressure in the system to achieve sample concentration.

[0030] The desorbent storage device contains multiple storage units, one for storing an organic solvent and the other for an acidic solution. The desorbent storage device is equipped with a flow control device for precisely controlling the mixing ratio of the organic solvent and the acidic solution. The desorbent storage device is equipped with a flow control device, either a peristaltic pump or a syringe pump, to precisely control the mixing ratio and flow rate of the organic solvent and the acidic solution. The desorption reactor is used to hold the nano-adsorbent material enriched with organic pollutants and the desorbent, ensuring the desorption reaction proceeds fully. The desorption reaction vessel is made of glass, which has a certain capacity and corrosion resistance.

[0031] The fluorescence signal acquisition device includes multiple photomultiplier tubes, each corresponding to a specific laser wavelength, and is used to collect fluorescence signals at that wavelength. The data processing unit is used to amplify, filter, and digitize the collected fluorescence signals. The photomultiplier tubes should have high sensitivity and low noise to accurately collect fluorescence signals. The acquisition device should also be equipped with corresponding optical components, such as lenses and filters, for focusing and filtering fluorescence signals. The data processing unit is equipped with a corresponding data acquisition card and software, which has the functions of amplifying, filtering, digitizing, and interacting with the concentration calculation module.

[0032] The concentration calculation module includes a model update unit, which regularly optimizes and updates the quantitative relationship model between multi-wavelength fluorescence intensity and organic pollutant concentration based on new standard sample data. This module is implemented using computer software. During system operation, the concentration calculation module receives fluorescence intensity data transmitted by the fluorescence detection module and uses a pre-established quantitative relationship model to calculate the concentration of organic pollutants in the sample being tested. The result is displayed on the screen or output to a file.

[0033] In summary, during use, the operating system of the present invention first passes the collected sample to be detected through the sample filtration device and sample concentration device (if necessary) of the sample pretreatment module in sequence, and then enters the adsorption column containing the nano-adsorption material for enrichment. After the enrichment is completed, the organic solvent and the acidic solution in the desorbent storage device are mixed according to a set ratio, and the desorbent is transported to the desorption reaction container through the flow control device to desorb the nano-adsorption material enriched with organic pollutants to form a desorption liquid. The desorption liquid is transferred to the detection pool of the fluorescence detection module, the multi-wavelength laser generator is started, the multi-wavelength fluorescence signal is collected, and the signal is transmitted to the data processing unit for processing. The concentration calculation module calculates the concentration of organic pollutants in the sample to be detected based on the processed fluorescence signal data and the pre-constructed quantitative relationship model, and displays the result. The quantitative relationship model is regularly updated and optimized using new standard sample data to ensure the accuracy and reliability of the detection. In short, the present invention can achieve accurate and rapid detection of the concentration of organic pollutants with very good sensitivity, selectivity and stability.

[0034] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in the present invention should be included in the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be based on the scope of protection of the claims.

Claims

1. A method for detecting the concentration of organic pollutants, characterized in that: The steps include: S1. Collecting a sample to be tested and pre-treating the sample to be tested, wherein the pre-treatment includes selectively enriching organic pollutants in the sample using a nano-adsorbent material having a specific pore size and surface functional groups, wherein the nano-adsorbent material is synthesized by a sol-gel method and doped with a rare earth element during the synthesis process; S2, desorbing the enriched organic pollutants from the nano-adsorption material to form a desorption liquid; S3. Use multi-wavelength laser-induced fluorescence spectroscopy technology to detect the desorption liquid. By simultaneously collecting fluorescence signals at multiple specific wavelengths, a quantitative relationship model between multi-wavelength fluorescence intensity and organic pollutant concentration is constructed, and the concentration of organic pollutants in the sample to be detected is calculated using this model.

2. The method for detecting the concentration of organic pollutants according to claim 1, wherein: The pore size of the nano-adsorption material is in the range of 2-10 nm, the surface functional groups are one or more of amino, carboxyl or sulfonic acid groups, the rare earth elements are one or more of lanthanum, cerium or yttrium, and the doping amount of the rare earth elements is 0.5% to 5% of the total mass of the nano-adsorption material.

3. The method for detecting the concentration of organic pollutants according to claim 2, wherein: The desorption process uses a mixed solution of an organic solvent and an acidic solution as a desorbent, the organic solvent is one or more of methanol, ethanol or acetone, the acidic solution is hydrochloric acid, sulfuric acid or phosphoric acid solution, and the volume ratio of the organic solvent to the acidic solution is 1:1-5:

1.

4. The method for detecting the concentration of organic pollutants according to claim 3, wherein: When constructing the quantitative relationship model between multi-wavelength fluorescence intensity and organic pollutant concentration, one of the partial least squares method and support vector machine regression algorithm is used to process the collected multi-wavelength fluorescence intensity data and standard sample data of known concentration to obtain the optimal quantitative relationship model.

5. A detection system for the method for detecting the concentration of organic pollutants according to claim 1, characterized in that: The invention comprises a sample pretreatment module, a desorption module, a fluorescence detection module and a concentration calculation module. The sample pretreatment module is used to pretreatment the collected sample to be detected, and the sample pretreatment module comprises an adsorption column equipped with nano-adsorption material; the desorption module is connected to the sample pretreatment module and is used to desorb organic pollutants enriched on the nano-adsorption material to form a desorption liquid, and the desorption module comprises a desorbent storage device and a desorption reaction container; the fluorescence detection module is connected to the desorption module and is used to detect the desorption liquid using a multi-wavelength laser-induced fluorescence spectroscopy technology, and the fluorescence detection module comprises a multi-wavelength laser generator, a fluorescence signal acquisition device and a data processing unit; the concentration calculation module is connected to the fluorescence detection module and is used to calculate the concentration of organic pollutants in the sample to be detected based on a constructed quantitative relationship model between the multi-wavelength fluorescence intensity and the concentration of organic pollutants.

6. The organic pollutant concentration detection system according to claim 5, characterized in that: The sample pretreatment module also includes a sample filtering device and a sample concentrating device. The sample filtering device is arranged before the adsorption column to remove large particle impurities in the sample. The sample concentrating device is arranged after the adsorption column to preliminarily concentrate the sample before desorption.

7. The organic pollutant concentration detection system according to claim 5, characterized in that: The desorbent storage device comprises a plurality of storage units, each for storing an organic solvent and an acidic solution. The desorbent storage device is equipped with a flow control device for precisely controlling the mixing ratio of the organic solvent and the acidic solution.

8. The organic pollutant concentration detection system according to claim 5, characterized in that: The fluorescence signal acquisition device includes a plurality of photomultiplier tubes, and each photomultiplier tube corresponds to a specific laser wavelength and is used to acquire fluorescence signals at the wavelength. The data processing unit is used to amplify, filter and digitize the collected fluorescence signals.

9. The organic pollutant concentration detection system according to claim 5, characterized in that: The concentration calculation module includes a model updating unit for regularly optimizing and updating the quantitative relationship model between the multi-wavelength fluorescence intensity and the organic pollutant concentration according to new standard sample data.

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