A method for analyzing aromatic organophosphates in water samples

Abstract

The present application relates to the field of water quality detection, in particular to a method for analyzing aromatic organophosphate esters in water samples. At present, the method for detecting aromatic organophosphate esters in water environment is relatively blank, the present application uses sponge composite heteroporous covalent organic framework material, through vortex-assisted extraction, selectively enriches different sizes of aromatic organophosphate esters in water, and realizes the rapid determination of aromatic organophosphate esters in environmental water by combining ultra-high performance liquid chromatography-tandem mass spectrometry. The analysis and detection method developed by the present application not only selectively enriches a plurality of aromatic organophosphate esters in water through the heteroporous characteristics and strong hydrophobicity of the extraction material, effectively reduces the detection limit of the flame retardant in water, and reduces the sample pretreatment time, improves the analysis efficiency. The present application is suitable for water quality detection of ultratrace flame retardant.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of water quality detection, and particularly relates to a sponge composite heteroporous covalent organic framework material and application of the material as a swirl-assisted extraction material of aryl-organophosphate esters in the field of water quality detection. BACKGROUND

[0002] The information disclosed in this Background section is only for the purpose of increasing an understanding of the general background of the application and does not necessarily constitute an acknowledgement or a suggestion that this information forms the prior art already known to a person of ordinary skill in the art.

[0003] Aryl-organophosphate esters (aryl-OPEs) are a class of additive phosphorus flame retardants, which can prevent or delay the occurrence of fire by mixing with flammable materials in a physical way, and are widely used in electrical / electronic equipment, automobiles and textiles. However, as an additive flame retardant, aryl-OPEs are easily released into the environment through volatilization, wear and leaching during production and use, resulting in the detection of aryl-OPEs in various environmental media such as air, water, soil and sediments. At the same time, toxicological studies have shown that aryl-OPEs have high toxicity, such as endocrine disrupting effects, reproductive toxicity and carcinogenicity. With the continuous use and discharge of aryl-OPEs, the health hazards caused by these compounds have become an environmental problem that cannot be ignored. Since aryl-OPEs are new flame retardant substitutes, there are no laws and regulations to limit their concentration levels in the environment, and most of the analysis methods for aryl-OPEs are based on environmental air, and there is a lack of relevant analysis methods for environmental water. Therefore, it is urgent to establish an analysis method for aryl-OPEs in environmental water to provide scientific technical support for the field of water quality detection.

[0004] In the past ten years of research, gas chromatography-mass spectrometry is usually used to detect aryl-OPEs in environmental air, but this method is only limited to several aryl-OPEs with volatility and thermal stability, and is not suitable for determining two non-volatile aryl-OPEs, resorcinol tetraphenyl diphosphate and bisphenol A bis(diphenyl phosphate). At present, a few studies use liquid chromatography-mass spectrometry to determine aryl-OPEs in air and dust samples, which has even better sensitivity than gas chromatography-mass spectrometry and can determine compounds with non-volatility. For the determination of aryl-OPEs in environmental water, liquid chromatography-mass spectrometry is a better choice. The concentration of aryl-OPEs in environmental water is in the order of trace (ng / L), and the water matrix is complex, which is difficult to directly determine by instrument. It is necessary to use sample pretreatment technology to extract, separate and enrich aryl-OPEs in complex water to make the instrument detectable. The traditional sample pretreatment technology, such as Soxhlet extraction, liquid-liquid extraction method and the like, has the limitations of long time consumption, large amount of organic solvent and complex operation. It is urgent to develop a new type of sample pretreatment technology which is rapid, efficient and simple, and the key is the selection of extraction materials.

[0005] Covalent organic frameworks (COFs) are a new type of nanoporous material connected by light elements and covalent bonds. COFs are applied to various new sample pretreatment technologies due to their large specific surface area, adjustable pore size, and functional modification. As an extraction material, COFs have the problem of low density and difficulty in recovery when dispersed in water samples. To solve this problem, researchers have used various matrices (such as cotton, sponge, Fe3O4, membrane, and quartz fiber) as carriers to complex with COFs, thereby achieving the purpose of easy recovery. SUMMARY

[0006] The present application aims to overcome the shortcomings of the prior art and seeks to provide a method for analyzing and detecting nine kinds of aromatic organophosphate esters in environmental water samples. The method uses vortex-assisted extraction technology and sponge-complexed heteroporous covalent organic framework materials for extraction. According to the pore matching principle and hydrophobic interaction, the method can not only selectively analyze and detect nine kinds of aromatic organophosphate esters in environmental water samples, but also has the advantages of simple and rapid operation and wide application prospect.

[0007] Specifically, the present application provides the following technical solutions:

[0008] In a first aspect, a method for preparing a sponge-complexed heteroporous covalent organic framework material is provided, comprising the following steps:

[0009] 4',4",4"",4"",4""""-(1,2-ethenediylyl)tetra[1,1'-biphenyl]-4-carboxaldehyde and benzidine are dissolved in an organic solvent, sponge is added, and the reaction is carried out at room temperature; acetic acid is added to the above-mentioned mixed system after the reaction, and the reaction is carried out for a period of time to obtain.

[0010] The feeding ratio of 4',4",4"",4"",4""""-(1,2-ethenediylyl)tetra[1,1'-biphenyl]-4-carboxaldehyde to benzidine is 1:1-2, further, 1:1-1.8, and specific examples are 1:1-1.5.

[0011] The present application investigates the extraction efficiency of the above-mentioned organic skeleton material as a solid-phase extraction material. Since the content of aromatic organophosphate in environmental water samples is usually at the ng / L level, the present application investigates the dosage of the corresponding heteroporous covalent organic skeleton (4',4",4"",4"",4""""-(1,2-ethenediylyl)tetra[1,1'-biphenyl]-4-carboxaldehyde and benzidine in total). The investigation results show that when the dosage of the heteroporous covalent organic skeleton is 0.01-0.015 mmol, the extraction efficiency and preparation cost can be considered. In the better effect verified example of the present application, the concentration of the aromatic organophosphate is 2 ng / L, and the dosage of the heteroporous covalent organic skeleton is 0.013 mmol.

[0012] The organic solvent is a mixed solvent of n-butanol and o-dichlorobenzene, wherein the mixing ratio of n-butanol to o-dichlorobenzene is 1:8-10; further, 1:9. After the above-mentioned reaction raw materials are put into the mixed solvent, auxiliary means such as stirring, magnetic stirring, ultrasonic, etc. can be used to make them fully dissolved.

[0013] The sponge material includes natural sponge and synthetic sponge. Examples of natural sponge are wood cellulose or sponge animal products. Synthetic sponge is foamed plastic, and specific materials are low-density polyether, polyvinyl alcohol or polyester. In one embodiment verified by the present application, the sponge is melamine sponge. In the above-mentioned preparation method, the morphology and volume of the sponge do not change before and after the reaction. The mechanical properties of the sponge organization are still maintained after the reaction. Suitable sponge size is, for example, 1 cm*1 cm*1 cm. The sponge is added to the above-mentioned mixed system and reacted at room temperature for 20-25 h.

[0014] In the above-mentioned method, the so-called room temperature condition refers to indoor environmental temperature. The feasible temperature range is, for example, 15℃-40℃. In a further scheme, the room temperature is 20-25℃.

[0015] In the preferred reaction step, the addition amount of acetic acid is 0.1-0.3 mL, and specifically, for example, 0.2 mL. After adding acetic acid, the reaction system is heated to 90-110℃ and heated for 10-14 h.

[0016] In some embodiments, after the above-mentioned temperature rising reaction, the product is washed and dried, the washing process can be carried out several times by using tetrahydrofuran and ethanol alternately, the number of washing times can be determined according to the experience of the skilled person, the drying temperature is 55-65℃, the drying method is, for example, oven drying or hot air drying, and the drying time is 10-14h.

[0017] In a second aspect, the sponge composite heteroporous covalent organic framework material prepared by the method of the first aspect is provided.

[0018] The sponge composite heteroporous covalent organic framework material provided by the present application has the advantages of low cost, good mechanical properties and stability, and provides a large number of binding sites for the organic framework material. In addition, the sponge can be cut into any shape and combined with the material for convenient recovery in water. The sponge composite heteroporous covalent organic framework material is used for the analysis and detection of aromatic organophosphate esters, and has the advantages of rapidness and sensitivity.

[0019] In a third aspect, the sponge composite heteroporous covalent organic framework material of the second aspect is used as a vortex-assisted extraction material for aromatic organophosphate esters.

[0020] In the verified embodiments of the present application, the aromatic organophosphate esters at least include the following nine kinds: trimethylphenyl phosphate (TMPP), resorcinol tetraphenyl diphosphate (RDP), bisphenol A bis(diphenyl phosphate) (BPA-BDPP), triphenyl phosphate (TPHP), cresyl diphenyl phosphate (CDP), t-butylphenyl diphenyl phosphate (4tBPDPP), tris(2-isopropylphenyl) phosphate (T2IPPP), 2-naphthyl diphenyl phosphate (NDPHP), and di-p-t-butylphenyl phosphate (B4tBPPP).

[0021] In a fourth aspect, a method for analyzing aromatic organophosphate esters in a water sample is provided, which comprises using the sponge composite heteroporous covalent organic framework material of the second aspect as a vortex-assisted extraction material, adding the water sample to be tested into the vortex-assisted extraction material, vortexing, and then using 3-5% ammonia-acetonitrile solution to elute the sample to be tested, and analyzing the aromatic organophosphate esters in the sample to be tested.

[0022] In order to improve the adsorption efficiency of the target to be tested, the vortex-assisted extraction method is used, and through investigation, the above-mentioned extraction method only needs 4-6min to reach adsorption equilibrium; at the same time, the elution process also needs vortexing, and the time is 0.5-1.5min.

[0023] The above-mentioned analysis method of the sample to be tested can adopt conventional detection means in the field, such as ultraviolet spectrophotometry, colorimetry, liquid phase detection, ultrahigh performance liquid phase detection, liquid phase-mass spectrometry detection, ultrahigh performance liquid phase-mass spectrometry detection, gas phase detection or gas phase-mass spectrometry detection method, etc.; In one embodiment of the verification of the present invention, the sample to be tested is analyzed by liquid phase-mass spectrometry:

[0024] The liquid phase detection conditions are as follows: the chromatographic column filler is bonded silica gel, the mobile phase is 0.09-0.11% formic acid-water solution and 0.09-0.11% formic acid-methanol solution; a gradient elution program is used, and the elution program is as follows:

[0025]

[0026] Furthermore, the chromatographic column is a Waters ACQUITY HSS T3 ultra-high performance liquid chromatography column, and its specifications are as follows: length 100 mm, inner diameter 2.1 mm, and filler particle diameter 1.8 μm.

[0027] The mass spectrometry detection conditions are as follows: the detector is a triple quadrupole mass spectrometer, ESI source, positive ion mode, ion source temperature: 550° C., ion source voltage: 4500 V; automatic sample injection, injection volume: 10 μL.

[0028] The beneficial effects of one or more of the above technical solutions are:

[0029] A sponge-based composite heteroporous covalent organic framework (HPOF) material enables highly selective extraction of nine aromatic organophosphates from water. Based on vortex-assisted extraction (VEE) technology and combined with ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS / MS), a method for the analysis of these nine aromatic organophosphates in environmental water samples has been established. This method is highly selective for these compounds and is simple to operate, requiring only 6 minutes of sample pretreatment, significantly shortening analysis time and improving efficiency. The method also exhibits high sensitivity, accuracy, and reproducibility, making it suitable for the analysis of ultra-trace levels of flame retardants in complex water samples and promising for future applications. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The accompanying drawings, which constitute a part of the present invention, are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0031] Figure 1 This is a scanning electron micrograph of the covalent organic framework material described in Example 1;

[0032] Figure 1 (A) is a scanning electron micrograph of a heteroporous covalent organic framework material;

[0033] Figure 1(B) is a scanning electron microscope image of the sponge composite hetero- porous covalent organic framework material.

[0034] Figure 2 is a flow chart of the preparation of the sponge composite hetero- porous covalent organic framework material in Example 1.

[0035] Figure 3 is an infrared spectrum of the covalent organic framework material described in Example 1;

[0036] Figure 3 (A) is a hetero-porous covalent organic framework material;

[0037] Figure 3 (B) is a sponge composite hetero-porous covalent organic framework material;

[0038] Figure 3 (C) is the sponge composite hetero-porous covalent organic framework material after extraction elution.

[0039] Figure 4 is a graph of the effect of the amount of hetero-porous covalent organic framework material involved in Example 2 on extraction efficiency.

[0040] Figure 5 is a graph of the effect of extraction time on extraction efficiency involved in Example 2.

[0041] Figure 6 is a graph of the effect of eluent on extraction efficiency involved in Example 2.

[0042] Figure 7 is a graph of the effect of elution time on extraction efficiency involved in Example 2. DETAILED DESCRIPTION

[0043] It should be noted that the following detailed description is exemplary in nature and is intended to provide further description of the application. 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 application belongs.

[0044] It is also important to note that the terms "comprises", "comprising", "includes", "including", "contains", "containing" or variations thereof herein, do not specify an exhaustive or complete list of elements or steps as they can be subject to revision by the skilled person depending on the specific application.

[0045] The application provides an analysis method for nine aromatic organophosphates in environmental water samples.

[0046] In order to enable those skilled in the art to more clearly understand the technical solutions of the present application, the technical solutions of the present application will be described in detail below in combination with specific examples.

[0047] Example 1: Preparation of sponge composite heteroporous covalent organic framework material

[0048] In this embodiment, a sponge composite heteroporous covalent organic framework material and a preparation method thereof are provided, which specifically include the following steps:

[0049] (1) 0.013 mmol of 4',4'',4''',4''''',4'''''''-(1,2-ethenediylyl) tetrakis[1,1'-biphenyl]-4-carboxaldehyde (CAS No.: 1624970-54-2) and 0.0195 mmol of benzidine are dissolved in n-butanol and o-dichlorobenzene and ultrasonically dissolved; sponge is added to the mixture and reacted at room temperature for 24 h;

[0050] The molar ratio of 4',4'',4''',4''''',4'''''''-(1,2-ethenediylyl) tetrakis[1,1'-biphenyl]-4-carboxaldehyde and benzidine is 1:1.5, and the molar ratio of n-butanol and o-dichlorobenzene is 1:9;

[0051] (2) 0.2 ml of acetic acid is added to the mixture in step (1) and heated at 100 DEG C for 12 h;

[0052] (3) The mixture in step (2) is cooled to room temperature, the product is washed with tetrahydrofuran and ethanol for several times, and dried at 60 DEG C for 12 h to obtain the sponge composite heteroporous covalent organic framework material.

[0053] Example 2: Analysis method for aromatic organophosphates

[0054] 1. Analysis method

[0055] In this embodiment, an analysis method for aromatic organophosphates in water samples is provided, which can simultaneously realize the detection of nine kinds of aromatic organophosphates, and the specific types are as follows:

[0056] Cresyl phosphate (TMPP), resorcinol tetraphenyl diphosphate (RDP), bisphenol A bis(diphenyl phosphate) (BPA-BDPP), triphenyl phosphate (TPHP), cresyldiphenyl phosphate (CDP), t-butylphenyl diphenyl phosphate (4tBPDPP), tris(2-isopropylphenyl) phosphate (T2IPPP), phospho-2-naphthyl diphenyl phosphate (NDPHP), di-p-t-butylphenyl phenyl phosphate (B4tBPPP).

[0057] The method for analyzing the nine aromatic organophosphate esters in the water sample specifically comprises the following steps:

[0058] S1, prepare the sponge composite heteroporous covalent organic framework material according to the steps described in Example 1;

[0059] S2, analyze the nine aromatic organophosphate esters in the water sample by vortex-assisted extraction using the sponge composite heteroporous covalent organic framework material and ultra-high performance liquid chromatography-tandem mass spectrometry, and the specific steps are as follows:

[0060] (1) Put the sponge composite heteroporous covalent organic framework material into the water sample, vortex for 5 min, discard the supernatant, add 5% ammonia / acetonitrile solution for elution, continue to vortex for 1 min, and take out the supernatant;

[0061] (2) The supernatant obtained in step (1) is detected by ultra-high performance liquid chromatography-tandem mass spectrometry.

[0062] The detection conditions of ultra-high performance liquid chromatography-tandem mass spectrometry are as follows: Waters ACQUITY HSS T3 ultra-high performance liquid chromatography column is selected, with the following specifications: length of 100 mm, inner diameter of 2.1 mm, filler particle diameter of 1.8 μm, and filler of bonded silica gel; the detector is a triple quadrupole mass spectrometer detector, ESI source, positive ion mode, ion source temperature: 550 ℃, ion source voltage: 4500 V; automatic sampler injection, injection volume: 10 μL; the gradient elution program of the nine compounds is shown in the following table:

[0063]

[0064] 2, investigation of extraction influencing factors

[0065] In this example, the main factors affecting the extraction efficiency of the nine aromatic organophosphate esters are investigated, and the best values of each factor are selected when the extraction efficiency is the highest. Then, under the conditions of the best values of each factor, the working curve regression equation, linear range, correlation coefficient, method detection limit and quantification limit of the nine aromatic organophosphate esters are determined. The specific process includes the following steps:

[0066] S1, select the best value of each factor when the extraction efficiency of the nine aromatic organophosphate esters is the highest:

[0067] (1) The influence of the amount of heteroporous covalent organic frameworks on extraction efficiency is investigated

[0068] In this embodiment, the influence of the amount of heteroporous covalent organic frameworks on extraction efficiency is investigated. 0.0065 mmol, 0.013 mmol, 0.026 mmol and 0.052 mmol of heteroporous covalent organic frameworks (based on the amount of 4', 4'', 4''', 4''''', 4'''''''-(1, 2-ethenediylidene) tetra[1, 1'-biphenyl]-4-carbaldehyde) are weighed to prepare a sponge composite heteroporous covalent organic framework material. The concentration of nine kinds of aromatic organophosphate esters in the water sample is 2 ng / L. When the amount of heteroporous covalent organic frameworks increases from 0 to 0.013 mmol, the extraction efficiency increases with the increase of the amount of adsorbent, which indicates that the increase of the amount of heteroporous covalent organic frameworks increases the adsorption sites and thus increases the extraction amount. However, when the amount of heteroporous covalent organic frameworks is greater than 0.013 mmol, the extraction efficiency of the nine kinds of aromatic organophosphate esters tends to be stable. Therefore, the amount of heteroporous covalent organic frameworks in the present application is selected as 0.013 mmol;

[0069] (2) The influence of extraction time on extraction efficiency is investigated

[0070] In this embodiment, the influence of extraction time on extraction efficiency is investigated. The response intensity of nine kinds of aromatic organophosphate esters is investigated when the extraction time is 1, 2, 3, 4, 5 and 6 min. When the extraction time increases from 1 min to 5 min, the response intensity of the nine kinds of aromatic organophosphate esters increases significantly. When the extraction time is greater than 5 min, the adsorption reaches equilibrium and the extraction efficiency does not change significantly. In order to reduce the sample pretreatment time, the extraction time in the present application is selected as 5 min;

[0071] (3) The influence of eluent on extraction efficiency is investigated

[0072] In this embodiment, the influence of eluent concentration on extraction efficiency is investigated. The response intensity of nine kinds of aromatic organophosphate esters is investigated when the eluent is acetonitrile solution, 1% ammonia acetonitrile solution, 3% ammonia acetonitrile solution, 5% ammonia acetonitrile solution and 7% ammonia acetonitrile solution. When the eluent is 5-7% ammonia acetonitrile solution, the extraction efficiency of the nine kinds of aromatic organophosphate esters is the highest. Excessive use of alkaline solution may cause damage to the liquid chromatography column. Therefore, the eluent selected in the present application is 5% ammonia acetonitrile solution;

[0073] (4) The influence of elution time on extraction efficiency is investigated

[0074] The elution time of the present embodiment has an effect on the extraction efficiency. If the elution time is too short, the target substance cannot be completely eluted. The present invention investigates the response intensity of nine aromatic organophosphates when the elution time is 0.5, 1, 2, 3 and 4 min. When the elution time increases from 0.5 min to 1 min, the elution efficiency increases sharply. When the elution time is greater than 1 min, the elution efficiency does not increase significantly. Therefore, the elution time in the present embodiment is 1 min.

[0075] S2, determine the working curve regression equation, linear range, correlation coefficient, method detection limit and quantification limit, inter-day and intra-day precision of nine aromatic organophosphates:

[0076] (1) Prepare 50 mL water samples of cresyl phosphate (TMPP), resorcinol tetraphenyl diphosphate (RDP), bisphenol A bis(diphenyl phosphate) (BPA-BDPP), triphenyl phosphate (TPHP), cresyl diphenyl phosphate (CDP), t-butylphenyl diphenyl phosphate (4tBPDPP), tris(2-isopropylphenyl) phosphate (T2IPPP), 2-naphthyl diphenyl phosphate (NDPHP), and di-p-t-butylphenyl phosphate (B4tBPPP) at concentrations of 0.01 ng / L, 0.05 ng / L, 0.1 ng / L, 1 ng / L, 10 ng / L, 50 ng / L, and 100 ng / L. Under the optimized vortex-assisted extraction conditions, determine the working curve regression equation, linear range, correlation coefficient, method detection limit and quantification limit of nine aromatic organophosphates by ultra-high performance liquid chromatography-tandem mass spectrometry.

[0077] Table 1 Working curve regression equation, linear range, correlation coefficient, method detection limit and quantification limit of nine aromatic organophosphates

[0078]

[0079] (2) Prepare 50 mL simulated water samples of nine aromatic organophosphates at low, medium and high concentrations of 0.4 / 0.8 ng / L, 4 / 8 ng / L, and 40 / 80 ng / L. Then, according to the vortex-assisted extraction procedure, determine the intra-day precision of each concentration point by measuring six times in one day, and express the results as relative standard deviation. Measure the inter-day precision of the three concentrations by measuring once a day for six days, and express the results as relative standard deviation. The intra-day precision of the nine aromatic organophosphates is in the range of 1.07% to 17.8%, and the inter-day precision is in the range of 4.89% to 17.6%, which meets the requirements for analysis accuracy.

[0080] Table 2 Intra-day and inter-day precision of nine aromatic organophosphates

[0081]

[0082]

[0083] 3. Accuracy of the analysis method

[0084] The concentration levels of nine aromatic organophosphates in tap water and seawater in a testing laboratory were determined. After collecting two water samples, the water samples were filtered using a 0.45 μm filter membrane. The filtered water samples were determined using the method described in Example 1, and the accuracy was tested using the method described in Example 2. Actual water samples of 50 mL at low, medium and high concentrations of 0.4 / 0.8 ng / L, 4 / 8 ng / L and 40 / 80 ng / L of the nine aromatic organophosphates were prepared for the determination of the recovery rate of the standard addition. Each concentration point was determined three times, and the average value, relative standard deviation and recovery rate of the standard addition of the three determinations were calculated. Among them, the two water samples were detected to contain aromatic organophosphates. The concentration level of NDNP in tap water was 0.37 ng / L, and the concentration levels of four aromatic organophosphates in seawater were 0.24-2.02 ng / L. The recovery rate of the standard addition in tap water in this example was 75.96%-117.39% ± 0.66%-10.89%, and the recovery rate of the standard addition in seawater was 65.31%-119.54% ± 0.36%-18.72%. The results showed that the extraction efficiency of this example was high, the analysis results were accurate, and the reproducibility was good.

[0085] Table 3 Recovery rate of the standard addition of nine aromatic organophosphates in tap water and seawater (n = 3)

[0086]

[0087]

[0088] The above only describes the preferred embodiments of the present application and is not intended to limit the present application. For those skilled in the art, the present application can have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A method for preparing a sponge composite heteroporous covalent organic framework material, characterized in that: The steps include: Dissolve 4',4''',4''''',4'''''''-(1,2-ethylenediylene)tetrakis[1,1'-biphenyl]-4-carboxaldehyde and benzidine in an organic solvent, add a sponge and react at room temperature for 20-25 hours; add acetic acid to the mixed system after the above reaction, heat to 90-110°C and heat to react for 10-14 hours to obtain the product; The molar ratio of the 4',4''',4''''',4'''''''-(1,2-ethylenediylene)tetrakis[1,1'-biphenyl]-4-carbaldehyde to benzidine is 1:1-1.5; The organic solvent is a mixed solvent of n-butanol and o-dichlorobenzene, wherein the molar ratio of n-butanol to o-dichlorobenzene is 1:

9.

2. The method for preparing the sponge composite heteroporous covalent organic framework material according to claim 1, characterized in that: The sponge material is melamine sponge.

3. The method for preparing the sponge composite heteroporous covalent organic framework material according to claim 1, characterized in that: After the temperature-raising reaction is completed, the preparation method further comprises the steps of washing and drying the product, wherein tetrahydrofuran and ethanol are used in turn for washing during the washing process; the drying temperature is 55-65° C., and the drying time is 10-14 hours.

4. A sponge composite heteroporous covalent organic framework material prepared by the method according to any one of claims 1 to 3.

5. The use of the sponge composite heteroporous covalent organic framework material according to claim 4 as a solid phase extraction material for aromatic organophosphates, characterized in that: The aromatic organic phosphates include at least the following nine types: tricresyl phosphate, resorcinol tetraphenyl diphosphate, bisphenol A bis(diphenyl phosphate), triphenyl phosphate, toluene diphenyl phosphate, tert-butylphenyl diphenyl phosphate, tri(2-isopropylphenyl)phosphate, 2-naphthyl diphenyl phosphate, and di-p-tert-butylphenyl phenyl phosphate.

6. A method for analyzing aromatic organophosphates in water samples, characterized in that: The method comprises using the sponge composite heteroporous covalent organic framework material according to claim 4 as a solid phase extraction material, adding it to a water sample to be tested and vortexing it for extraction, eluting it with a 3-5% ammonia-acetonitrile solution after the extraction is completed to obtain a sample to be tested, and analyzing the aromatic organophosphates in the sample to be tested.

7. The method for analyzing aromatic organophosphates in water samples according to claim 6, wherein: The extraction time is 4 to 6 minutes, and the elution time is 0.5 to 1.5 minutes.

8. The method for analyzing aromatic organophosphates in water samples according to claim 6, wherein: The analysis method of the sample to be tested is an ultra-high performance liquid chromatography-mass spectrometry detection method, and the liquid phase detection conditions are as follows: the chromatographic column filler is bonded silica gel, the mobile phase is 0.09~0.11% formic acid-water solution and 0.09~0.11% formic acid-methanol solution; a gradient elution program is used.

9. The method for analyzing aromatic organophosphates in water samples according to claim 8, wherein: The chromatographic column was a Waters ACQUITY HSS T3 ultra-high performance liquid chromatography column with the following specifications: length 100 mm, inner diameter 2.1 mm, and filler particle diameter 1.8 μm; Alternatively, the mass spectrometry detection conditions are as follows: the detector is a triple quadrupole mass spectrometer detector, ESI source, positive ion mode, ion source temperature: 550 ° C, ion source voltage: 4500 V; automatic sampler injection, injection volume: 10 μL.

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