Boric acid functionalized porous organic polymer as well as preparation method and application thereof

Abstract

The invention provides a boric acid functionalized porous organic polymer as well as a preparation method and application thereof. The boric acid functionalized porous organic polymer provided by the invention is prepared by the following steps: firstly, mixing cyanuric chloride and triphenylmethane to react to obtain a porous organic polymer; then the obtained porous organic polymer reacts with 4-(bromomethyl) phenylboronic acid to obtain the boric acid functionalized porous organic polymer, and the result shows that the boric acid functionalized porous organic polymer provided by the invention reacts by selecting a specific monomer, so that the obtained polymer is applied to pretreatment of a phenol-containing EDCs sample; the method can be used for measuring trace phenolic EDCs in a sample, is high in accuracy and can be repeatedly used.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of high polymers, in particular to a boronic acid functionalized porous organic polymer and a preparation method and application thereof. BACKGROUND

[0002] Endocrine disrupting compounds (EDCs) are exogenous substances that disrupt the stability of the endocrine system by interfering with hormones in living organisms. The sources of EDCs are mainly divided into two categories: natural and synthetic. Among them, typical synthetic EDCs include bisphenol S (BPS), bisphenol F (BPF), p-tert-butylphenol (PTBP), bisphenol B (BPB) and bisphenol A (BPA), which are widely used in the industrial manufacturing of plastic food packaging, cosmetics, children's toys. Endocrine disruptors can easily cause serious pollution to food and aquaculture, and then have a negative impact on animal and human health. More and more epidemiological evidence shows that EDC exposure can cause colorectal cancer, breast cancer, diabetes and obesity. In 2018, the European Union regulation determined the migration limit of BPA in food to be 50 μg kg -1 . Therefore, in order to protect human health, it is necessary to develop a rapid, convenient and sensitive detection method to detect the pollution level of phenolic EDCs in food.

[0003] The quantitative analysis of EDCs usually uses high performance liquid chromatography (HPLC) combined with ultraviolet (UV), mass spectrometry (MS) and fluorescence detector. Since the MS detector has high selectivity and specificity, HPLC-MS is the preferred tool as the standard detection method (European Commission implementing regulation (EU) 2021 / 808). Since phenolic EDCs exist at trace levels in complex food matrices, sample pretreatment is required before HPLC-MS determination to meet the international limit of 0.05 μg g -1 . Various sample pretreatment methods for extracting phenolic EDCs have been developed, including solid phase extraction (SPE), dispersive solid phase microextraction (d-μ-SPE), liquid-liquid extraction (LLE), solid phase microextraction (SPME) and magnetic solid phase extraction (MSPE). Among them, SPE has become a powerful and popular sample preparation method due to its high degree of automation, simple operation and low solvent consumption. In solid phase extraction, the adsorbent has a decisive influence on its performance. Several types of commercial adsorbents have been used for phenolic EDCs, including hydrophilic-lipophilic balance adsorbents, mixed cation exchangers, carbon nanotubes, octadecylsilane C18 and graphitized carbon. However, these commercial adsorbents usually have low adsorption capacity for phenolic EDCs.

[0004] Therefore, it is of great significance to develop new high-performance adsorbent materials for sample pretreatment to improve the detection ability of phenolic pollutants. SUMMARY

[0005] Therefore, the technical problem to be solved by the present application is to provide a boronic acid functionalized porous organic polymer, a preparation method and application thereof, and the polymer provided by the present application is used for pretreatment of phenolic EDCs pollutants, can realize determination of residual phenolic EDCs content in shrimp and chicken samples, and has low detection limit and high accuracy.

[0006] Compared with the prior art, the present application provides a boronic acid functionalized porous organic polymer, a preparation method and application thereof, and the boronic acid functionalized porous organic polymer provided by the present application is obtained by first mixing cyanuric chloride and triphenylmethane to react to obtain a porous organic polymer, and then reacting the obtained porous organic polymer with 4-(bromomethyl)phenylboronic acid to obtain a boronic acid functionalized porous organic polymer, and the experimental results show that the boronic acid functionalized porous organic polymer provided by the present application is obtained by selecting specific monomers for reaction, so that the obtained polymer is applied to pretreatment of a sample containing phenolic EDCs, can realize determination of trace phenolic EDCs in the sample, has high accuracy, and can be reused. BRIEF DESCRIPTION OF DRAWINGS

[0007] Figure 1 It is a schematic diagram for preparation of B-TC-POP;

[0008] Figure 2 It is an infrared chromatogram of TC-POP and B-TC-POP;

[0009] Figure 3 It is a thermogravimetric test diagram of TC-POP and B-TC-POP;

[0010] Figure 4 It is a water contact angle test result of TC-POP;

[0011] Figure 5 It is a water contact angle test result of B-TC-POP;

[0012] Figure 6 It is a SEM diagram of TC-POP;

[0013] Figure 7 It is a SEM diagram of B-TC-POP;

[0014] Figure 8 It is a comparison diagram of adsorption capacity of the boronic acid functionalized porous organic polymer provided by the present application and a commercial adsorbent;

[0015] Figure 9 It is a reuse frequency diagram of B-TC-POP;

[0016] Figure 10 It is a batch repeatability diagram of B-TC-POP. DETAILED DESCRIPTION

[0017] The present application provides a boronic acid functionalized porous organic polymer, which is prepared by the following method: 1) mixing cyanuric chloride and triphenylmethane to obtain a porous organic polymer, wherein the molar ratio of cyanuric chloride to triphenylmethane is 1:(1-1.5); 2) reacting the obtained porous organic polymer with 4-(bromomethyl)phenylboronic acid to obtain a boronic acid functionalized porous organic polymer; wherein the mass ratio of the porous organic polymer to the 4-(bromomethyl)phenylboronic acid is 2:(0.8-1.2).

[0018] According to the present application, cyanuric chloride and triphenylmethane are mixed to obtain a porous organic polymer, wherein the molar ratio of cyanuric chloride to triphenylmethane is 1:(1-1.5), preferably the molar ratio of cyanuric chloride to triphenylmethane is 1:(1-1.2); the catalyst of the reaction is preferably one or more of anhydrous aluminum chloride, anhydrous ferric chloride and anhydrous tin tetrachloride, more preferably anhydrous aluminum chloride; the use amount ratio of cyanuric chloride to the catalyst is 1 mmol:(1-1.5) g, more preferably 1 mmol:(1-1.2) g. The solvent of the reaction is preferably chloroform or carbon tetrachloride, more preferably chloroform; the use amount ratio of cyanuric chloride to the solvent is preferably 1 mmol:(15-20) mL, more preferably 1 mmol:(16-17) mL. The temperature of the reaction is preferably 55-80°C, more preferably 60-70°C. The time of the reaction is preferably 20-30 hours, more preferably 24-28 hours. After the reaction is completed, the obtained porous organic polymer is preferably washed with 1M HCl, 1M NaOH, water and methanol in turn. Finally, the porous organic polymer is obtained by using methanol soxhlet extraction for 12 hours and vacuum drying.

[0019] According to the application, the obtained porous organic polymer is reacted with 4-(bromomethyl)phenylboronic acid to obtain a boronic acid functionalized porous organic polymer; the mass ratio of the porous organic polymer to the 4-(bromomethyl)phenylboronic acid is 2:(0.8-1.2), preferably 2:(1-1.1); the catalyst for the reaction is preferably one or more of anhydrous aluminum chloride, anhydrous ferric chloride and anhydrous tin tetrachloride, more preferably anhydrous aluminum chloride; the mass ratio of the porous organic polymer to the catalyst is 1:(3-5), more preferably 1:(3-4). The solvent for the reaction is preferably chloroform or 1,2-dichloroethane, more preferably 1,2-dichloroethane; the dosage ratio of the porous organic polymer to the solvent is preferably 1g:(80-100)mL, more preferably 1mmol:(80-90)mL. The temperature for the reaction is preferably 75-90℃, more preferably 80-85℃. The time for the reaction is preferably 20-30 hours, more preferably 24-28 hours. After the reaction is completed, the obtained porous organic polymer is preferably extracted by using methanol by means of a Soxhlet extractor for 12 hours, and vacuum dried to obtain a boronic acid functionalized porous organic polymer.

[0020] The application also provides a preparation method of a boronic acid functionalized porous organic polymer, comprising:

[0021] 1) mixing cyanuric chloride and triphenylmethane to obtain a porous organic polymer,

[0022] wherein the molar ratio of the cyanuric chloride to the triphenylmethane is 1:(1-1.5);

[0023] 2) reacting the obtained porous organic polymer with 4-(bromomethyl)phenylboronic acid to obtain a boronic acid functionalized porous organic polymer,

[0024] wherein the mass ratio of the porous organic polymer to the 4-(bromomethyl)phenylboronic acid is 2:(0.8-1.2).

[0025] In the preparation method, the dosage of each reaction raw material, the type and dosage of the catalyst and the solvent, and the limitation of the reaction conditions are the same as those in the aforementioned product.

[0026] The application also provides a detection method of phenolic EDCs residues in a sample, comprising pretreatment and detection, wherein the pretreatment is pretreatment of a sample to be tested by using solid phase extraction; the solid phase extraction uses an extractant which is the boronic acid functionalized porous organic polymer according to the application; the sample to be tested is preferably a chicken sample or a shrimp sample; the detection is preferably HPLC-UV method, HPLC-MS / MS method, UHPLC method or LC-MS / MS method.

[0027] The application provides a boronic acid functionalized porous organic polymer and a preparation method and application thereof. The boronic acid functionalized porous organic polymer is prepared by mixing cyanuric chloride and triphenylmethane to obtain a porous organic polymer, and then reacting the obtained porous organic polymer with 4-(bromomethyl)phenylboronic acid to obtain the boronic acid functionalized porous organic polymer. It is found that the boronic acid functionalized porous organic polymer is prepared by selecting specific monomers for reaction, so that the obtained polymer is applied to the pretreatment of a sample containing phenolic EDCs, the determination of trace phenolic EDCs in the sample can be realized, the accuracy is high, and the boronic acid functionalized porous organic polymer can be repeatedly used.

[0028] The technical solutions in the embodiments of the application will be described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the application, rather than all the embodiments. Based on the embodiments in the application, all other embodiments obtained by those skilled in the art without creative work fall within the protection scope of the application.

[0029] Embodiment

[0030] 1. Synthesis of boronic acid functionalized porous organic polymer (B-TC-POP)

[0031] The synthesis reaction of B-TC-POP is divided into the following two steps:

[0032] 1) Disperse cyanuric chloride (2 mmol) and triphenylmethane (2 mmol) in 33 mL of chloroform. Then, add 2 g of anhydrous aluminum chloride, and ultrasonically mix uniformly. Then, reflux the mixture at 60 DEG C under magnetic stirring for 24 h. Collect the product by filtration, and then wash with 1M HCl, 1M NaOH, water and methanol. Finally, obtain the porous organic polymer (TC-POP) by using methanol soxhlet extraction for 12 h, and then drying under vacuum at 60 DEG C for 8 h.

[0033] 2) Disperse 0.6 g of TC-POP, 0.3 g of 4-(bromomethyl)phenylboronic acid and 2 g of anhydrous aluminum chloride uniformly in 50 mL of 1,2-dichloroethane, and reflux at 80 DEG C under magnetic stirring for 24 h. Purify by using methanol soxhlet extraction for 12 h, and dry under vacuum at 60 DEG C for 8 h to obtain B-TC-POP.

[0034] The specific preparation process is shown in Figure 1 , Figure 1 which is a preparation schematic diagram of B-TC-POP.

[0035] The obtained B-TC-POP is characterized, and the results are shown in Figures 2-7 .

[0036] Figure 2The infrared spectra of TC-POP and B-TC-POP are shown in Figure 1. Figure 2 It can be seen that in both spectra, the appearance of triazine ring vibration peaks at 1492 cm -1 and 1526 cm -1 , and the disappearance of C-Cl bond at 850 cm -1 indicate the successful synthesis of POP. Compared with TC-POP, the characteristic peaks of -OH, B-O and -CH2- appearing at 3423 cm -1 , 1355 cm -1 and 2930 cm -1 in the spectrum of B-TC-POP prove that the boronic acid group is successfully modified to TC-POP to obtain B-TC-POP. The collective existence of these diagnostic spectral characteristics provides strong evidence for the successful synthesis of the target compound.

[0037] In order to evaluate the thermal stability of the material, thermogravimetric analysis was performed, and the results are shown in Figure 3. Figure 3 Figure 3 The thermogravimetric test graphs of TC-POP and B-TC-POP are shown in Figure 3, from which it can be seen that both of them exhibit excellent thermal stability, with only 10% mass loss at 375°C. Compared with TC-POP, the thermal stability of B-TC-POP is slightly better.

[0038] The synthesized polymer was subjected to hydrophilic and hydrophobic analysis, and the results are shown in Figure 4. Figures 4-5 Figure 4 The water contact angle test results of TC-POP are shown in Figure 5, Figure 5 and the water contact angle test results of B-TC-POP are shown in Figure 6. From the figures, it can be seen that the water contact angle of TC-POP is 128.2°, and the water contact angle of B-TC-POP is 110.6°, which confirms that the hydrophilicity of the material is improved after modification by boronic acid.

[0039] The synthesized polymer was subjected to morphology analysis by scanning electron microscopy (SEM), and the results are shown in Figure 7. Figures 6-7 Figure 6 The SEM graph of TC-POP is shown in Figure 7(a); Figure 7 and the SEM graph of B-TC-POP is shown in Figure 7(b). From the SEM, it can be seen that TC-POP and B-TC-POP show a morphology formed by the accumulation of roughly spherical particles.

[0040] 2. Adsorption application

[0041] 1) In order to obtain the best extraction efficiency of B-TC-POP for EDCs, the experiment was optimized according to the existing known method in terms of elution solvent type, elution volume, sample solution flow rate, sample solution volume and sample solution pH. The results show that the elution solvent type is methanol; the elution volume is 400 μL; the sample solution flow rate is 5 mL·min​​​-1 Sample solution volume: 100 mL; sample solution pH: no adjustment of sample pH.

[0042] 2) To investigate the adsorption performance of B-TC-POP for EDCs, it was compared with TC-POP and common commercially available adsorbents, including mixed cation exchange (PCX), mixed strong anion (PXA), graphitized carbon (GCB), octadecylsilane C18 (C18) and carbon nanotubes (CNTS).

[0043] The experimental procedure was as follows: 3 mg of each material was dispersed in 8 mL of aqueous solution containing 5 EDCs at a concentration of 150 pg mL -1 The mixture was continuously shaken for 30 min to reach adsorption equilibrium, and the suspension was filtered through a glass fiber membrane (0.22 pm) to remove all suspended adsorption materials. The resulting solution was then injected into the HPLC system for analysis. The results are shown in Figure 8 Figure 8 The adsorption capacity comparison chart of boronic acid functionalized porous organic polymers provided by the present application and commercial adsorbents, from which it can be seen that B-TC-POP exhibits higher adsorption capacity for EDCs compared with C-POP and commercial adsorbents. Notably, the superior adsorption performance of B-TC-POP over TC-POP can be attributed to the important role of boronic acid groups in B-TC-POP in the adsorption process. Therefore, B-TC-POP is an effective EDCs adsorbent.

[0044] 3) The reusability and batch-to-batch reproducibility of B-TC-POP are crucial for large-scale practical applications, cost-effectiveness of the analytical process, and environmental sustainability. Therefore, a recycling experiment was conducted to investigate the reusability of B-TC-POP.

[0045] The recycling experiment was performed as follows: the SPE procedure was performed using 30 mg of B-TC-POP in a SPE cartridge, followed by regeneration of the B-TC-POP-SPE column using methanol (1 mL) and water (3 mL) as eluents to obtain the EDCs adsorption performance, followed by repetition for the SPE procedure. The results are shown in Figure 9 Figure 9 The reusability times chart of B-TC-POP; from which it can be seen that the B-TC-POP-SPE column can be reused up to 40 times without significantly reducing its adsorption capacity for EDCs. This finding highlights the excellent reusability potential and practical applicability of B-TC-POP.

[0046] Five batches of TC-B-POP were prepared under the same conditions at different time intervals, and then EDCs extraction experiments were performed using the same procedure. The results are shown in Figure 10 ​​shown, Figure 10 Batch reproducibility plot for B-TC-POP Figure 4 It can be seen that there is no significant difference in the extraction recovery of EDCs in different batches of B-TC-POP, indicating that the synthesis of B-TC-POP has excellent reproducibility.

[0047] 4) To evaluate the performance of the developed method, under the optimal conditions, the linear range (LR), correlation coefficient (R 2 ), limit of detection (LODs), limit of quantification (LOQs) and reproducibility (RSD) were investigated. Different concentrations of EDCs (1.00, 2.00, 5.00, 30.0, 80.0, 150, 250 ng g -1 ) were added to chicken and shrimp samples, respectively, and extracted for analysis. The results are shown in Table 1, which shows the quantitative parameters of the B-TC-POP-based method for real samples (n = 5). As can be seen from the figure, for chicken samples, the linear correlation coefficient method established in this study showed excellent linearity (R 2 > 0.9936) with a LR of 1.00-250 ng g -1 . The LODs and LOQs were 0.30-1.50 ng g -1 and 1.00-5.00 ng g -1 , respectively. For shrimp samples, the method showed good linearity (R -1 > 0.9942) in the concentration range of 0.85-250 ng g 2 , with low detection limit (0.25-1.30 ng g -1 ) and quantification limit (0.85-4.50 ng g -1 ). The RSD of the current method was evaluated by five consecutive analyses of spiked samples (10 ng g -1 and 30 ng g -1 ) within 1 day and 5 days. The inter-day RSD of the method was less than 7.4%, and the intra-day RSD was also less than 4.4%. The enrichment factors (EFs) (ratio of the concentration of phenolic EDCs in 0.4 mL methanol to the concentration of EDCs in 100 mL sample solution) were calculated to be 103-150 and 120-150 for chicken and shrimp, respectively. These results show that the SPE-HPLC-MS method established in this study has good reproducibility. That is, the B-TC-POP method has a wide linear range, low LODs and LOQs, indicating that the method can provide an alternative method for the determination of trace EDCs in real chicken and shrimp samples.

[0048] Table 1 Quantitative parameters of the B-TC-POP-based method for real samples (n = 5)

[0049]

[0050] Note: The unit of analyte concentration is ng g -1 .

[0051] 5) Comparison with other literature methods

[0052] A comparative analysis was performed between the B-TC-POP-based method developed in this study and previously established methods for determining EDCs. As shown in Table 2, the developed method for determining EDCs achieved a lower detection limit compared to the methods reported in [1], [2], [3], [4], [5], and [6], indicating higher sensitivity in detecting EDCs. Notably, the developed method eliminated the requirement for pre-column derivatization described in reference [1] and exhibited better precision than the QuEChERS-UPLC-MS / MS [2] protocol. These results indicate that the B-TC-POP-based method has higher sensitivity and acceptable precision for the analysis of EDCs in meat matrices compared to existing methods. Furthermore, the B-TC-POP adsorbent has characteristics such as simple synthesis, cost-effectiveness, and excellent reusability, highlighting its practical advantages in routine monitoring applications.

[0053] Table 2 Comparative results of the developed method for determining EDCs with other literature

[0054]

[0055]

[0056] [1] N. Li, D. Wu, J. Liu, N. Hu, X. Shi, C. Dai, Z. Sun, Y. Suo, G. Li, Y. Wu, Magnetic covalent organic frameworks based on magnetic solid phase extraction for determination of six steroidal and phenolic endocrine disrupting chemicals in food samples, Microchemical Journal 143 (2018) 350-358.

[0057] [2] X. Tan, Q. Jin, J. Lu, B. Zhao, W. Gou, R. Yang, Y. Fu, D. Xu, L. Zhang, Development and Validation of a Modified QuEChERS Method for the Analysis of Bisphenols in Meats by UPLC-MS / MS, Chromatographia 85(5) (2022) 433-445.

[0058] [3] G. Zhao, C. Wang, Q. Wang, Z. Wang, C. Wang, Q. Wu, Cyano-functionalized porous hyper-crosslinked cationic polymers for efficient preconcentration and detection of phenolic endocrine disruptors in fresh water and fish, Talanta 281 (2025) 126822.

[0059] [4] C. Fan, C. Wang, B. Zhao, Z. Cai, Q. Wang, L. Hao, Z. Wang, Q. Wu, C. Wang, Preparation of ionic porous polymers for extraction of four phenolic endocrine disrupting chemicals from fish and water samples, Food Chemistry 449 (2024) 139270.

[0060] [5] C. Fan, Y. Dong, Z. Li, Q. Wang, Z. Wang, Q. Wu, C. Wang, Preparation of novel cationic porous polymers for effective pre-concentration and sensitive detection of endocrine disruptors in water and fish, Analytica Chimica Acta 1353 (2025) 343956.

[0061] [6] G. Zhao, Y. Zhao, Q. Wang, C. Wang, C. Wang, Z. Wang, Q. Wu, Recoverable and recyclable porous polymer for extraction of trace endocrine disrupting compounds from seafood products prior to LC / MS analysis, Food Chemistry 473 (2025) 143129.

[0062] [7] Z. Cai, B. Zhao, L. Hao, Q. Wang, Z. Wang, Q. Wu, C. Wang, Fabrication of imidazoline-linked cationic covalent triazine framework for enrichment of environmental estrogens, Talanta 272 (2024) 125750.

[0063] The above description of the embodiments is only used to help understand the method of the present application and its core idea. It should be pointed out that for those skilled in the art, without departing from the principles of the present application, some improvements and modifications can be made to the present application, and these improvements and modifications also fall within the protection scope of the claims of the present application.

Claims

1. A boric acid functionalized porous organic polymer, wherein the boric acid functionalized porous organic polymer is prepared by the following method: 1) mixing cyanuric chloride and triphenylmethane to obtain a porous organic polymer, wherein: The molar ratio of the cyanuric chloride to the triphenylmethane is 1:(1-1.5); 2) reacting the obtained porous organic polymer with 4-(bromomethyl)phenylboronic acid to obtain a boronic acid-functionalized porous organic polymer; wherein the mass ratio of the porous organic polymer to the 4-(bromomethyl)phenylboronic acid is 2:(0.8-1.2).

2. The boric acid functionalized porous organic polymer according to claim 1, characterized in that The solvent for the reaction in step 1) is chloroform or carbon tetrachloride.

3. The boric acid functionalized porous organic polymer according to claim 1, characterized in that The catalyst for the reaction in step 1) is one or more of anhydrous aluminum chloride, anhydrous ferric chloride and anhydrous tin tetrachloride.

4. The boric acid functionalized porous organic polymer according to claim 1, characterized in that The reaction temperature of step 1) is 55-80° C., and the reaction time is 20-30 hours.

5. The boric acid functionalized porous organic polymer according to claim 1, characterized in that The solvent for the reaction in step 2) is 1,2-dichloroethane, chloroform or carbon tetrachloride.

6. The boric acid functionalized porous organic polymer according to claim 1, characterized in that The catalyst for the reaction in step 2) is one or more of anhydrous aluminum chloride, anhydrous ferric chloride and anhydrous tin tetrachloride.

7. The boric acid functionalized porous organic polymer according to claim 1, characterized in that The reaction temperature of step 2) is 75-90° C., and the reaction time is 20-30 hours.

8. A method for preparing a boric acid functionalized porous organic polymer, comprising: 1) Mixing cyanuric chloride and triphenylmethane to obtain a porous organic polymer, Wherein, the molar ratio of the cyanuric chloride to the triphenylmethane is 1:(1-1.5); 2) reacting the obtained porous organic polymer with 4-(bromomethyl)phenylboronic acid to obtain a boronic acid functionalized porous organic polymer; Wherein, the mass ratio of the porous organic polymer to the 4-(bromomethyl)phenylboronic acid is 2:(0.8-1.2).

9. A method for detecting phenolic EDCs residues in a sample, comprising pretreatment and detection. The pretreatment is to use solid phase extraction to pretreat the sample to be tested; the extractant for solid phase extraction is the boric acid functionalized porous organic polymer according to any one of claims 1 to 7 or the boric acid functionalized porous organic polymer prepared by the preparation method according to claim 8.

10. The detection method according to claim 9, characterized in that: The detection is HPLC-UV method, HPLC-MS / MS method, UHPLC method or LC-MS / MS method.

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