A surface molecularly imprinted polymer DESMyr-NMIP adsorbent, and a preparation method and application thereof

Abstract

The application belongs to the technical field of preparation and application of functional polymer, and specifically discloses a surface molecular imprinting polymer DES Myr The application combines deep eutectic solvents, metal organic frameworks and surface molecular imprinting technology to prepare a novel adsorbent: template molecule myricetin and functional monomers are used as hydrogen bond donors, and are mixed with hydrogen bond acceptors to obtain a four-component template molecule pre-combined deep eutectic solvent system; then, the system is used as a functional monomer to initiate a polymerization reaction on the surface of a three-dimensional mesoporous metal organic framework matrix material; and finally, the surface molecular imprinting polymer adsorbent DES Myr NMIP is obtained after elution and drying. The application has simple process, mild conditions, green environmental protection, and cheap and easily available raw materials, and the prepared molecular imprinting polymer has excellent adsorption performance and good selectivity, can realize rapid and efficient selective adsorption of myricetin, and has wide application prospect in the field of separation and purification of myricetin in food.

Description

Technical Field

[0001] This invention belongs to the field of preparation and application technology of functional polymers, and relates to the preparation of surface molecularly imprinted polymer adsorbents for molecular recognition and adsorption separation in the food and pharmaceutical fields. Specifically, it relates to a surface molecularly imprinted polymer DESMyr-NMIP adsorbent, its preparation method, and its application in the separation and purification of myricetin. Background Technology

[0002] Myricetin (Myr) is a plant-based flavonoid with high medicinal and health benefits, exhibiting significant bioactivity for human health and abundantly distributed in higher plants. Reports indicate that myricetin possesses antioxidant, anti-inflammatory, antibacterial, and anticancer effects. It is currently widely used in the food and health product industries and has developed into an important adjunctive drug for treating hypertension, diabetes, and neurological disorders. However, the presence of multiple structurally similar flavonoid components in plant samples, coupled with the low content of myricetin, makes the separation and purification process costly. Therefore, researching a green, rapid, and highly selective process for the separation and purification of myricetin is of significant research importance.

[0003] Currently, the main methods for extracting myricetin from plants include chromatographic separation and solvent extraction. These methods often require large amounts of organic solvents, leading to environmental pollution. Solid-phase extraction (SPE) is a highly efficient sample pretreatment technique due to its advantages such as high recovery rate, ease of operation, and low solvent consumption. Based on the principle of adsorption separation, this technology holds promise for achieving efficient and selective separation of myricetin.

[0004] Surface molecularly imprinted polymers (SMIPs) are highly cross-linked polymer networks formed between template molecules and functional monomers under the action of cross-linking agents and initiators. A molecularly imprinted polymer layer is synthesized on the surface of a matrix material with a large specific surface area. The template molecules are then removed by elution, leaving "imprinted cavities" in the polymer that are complementary to the shape, size, and functional groups of the target molecules. These cavities specifically recognize target molecules through covalent or non-covalent interactions, enabling the selective separation and enrichment of specific analytes. The prepared SMIPs are highly efficient adsorbent materials with specific selectivity for target molecules.

[0005] Deep eutectic solvents (DESs) possess excellent environmental friendliness and specific recognition capabilities. Myricetin, rich in hydroxyl groups, can serve as a good hydrogen bond donor. Introduced into the DES system along with functional monomers, the high-density hydrogen bond network of DES further enhances the solubility and selectivity of myricetin and improves the greenness of the adsorption process. This provides a green and efficient separation method for natural products and shows promising application prospects as an additive in the health supplement industry. Summary of the Invention

[0006] To address the shortcomings of existing technologies, the present invention aims to provide a surface molecularly imprinted polymer (DESMyr-NMIP) adsorbent. This invention utilizes template molecules pre-bound to a deep eutectic solvent to obtain the DESMyr-NMIP adsorbent, which is used for the selective separation and purification of myricetin in food. This invention achieves rapid, efficient, and selective adsorption of myricetin, demonstrating broad application prospects in the field of myricetin separation and purification in food.

[0007] This invention is achieved through the following technical solution: A method for preparing a surface molecularly imprinted polymer DESMyr-NMIP adsorbent includes the following steps: (1) The hydrogen bond donor and the hydrogen bond acceptor were mixed and heated and stirred to obtain a homogeneous and stable template molecule pre-bound deep eutectic solvent DESMyr; (2) Add the porous matrix material and DESMyr to the polymerization solvent and stir thoroughly to carry out prepolymerization; (3) Add crosslinking agent and initiator to the prepolymerization solution, heat and polymerize under nitrogen protection, and obtain the surface molecular imprinted polymer DESMyr-NMIP after washing and drying.

[0008] A further improvement to the present invention is as follows: The hydrogen bond acceptor in step (1) is choline chloride; the hydrogen bond donor is the template molecule, methacrylic acid and ethylene glycol; the template molecule is myricetin.

[0009] Furthermore, the molar ratio of choline chloride, myricetin, methacrylic acid and ethylene glycol in step (1) is 1:0.01-0.05:0.01-0.3:1.5-2.5.

[0010] Furthermore, the heating and stirring temperature in step (1) is 70-90℃, and the time is 20-40 min.

[0011] Furthermore, the porous matrix material in step (2) is metal-organic framework material NU-1000; the polymerization solvent is methanol; and the DESMyr is a functional monomer.

[0012] Furthermore, the mass ratio of NU-1000 to hydrogen bond acceptor in step (2) is 8-10:1; Furthermore, in step (2), the feeding ratio of NU-1000 to methanol is 1 mg: 1-2 mL.

[0013] Furthermore, the crosslinking agent in step (3) is ethylene glycol dimethacrylate; the initiator is azobisisobutyronitrile; Furthermore, the heating polymerization in step (3) is carried out at a temperature of 50-80°C for 4-5 hours; Furthermore, the elution process in step (3) uses a methanol and acetic acid mixture with a volume ratio of 8:2 as the eluent; Furthermore, the drying temperature in step (3) is 60-80℃ and the time is 8-12 h.

[0014] Furthermore, in step (3), the molar ratio of ethylene glycol dimethacrylate to myricetin is 20-60:1; and the molar ratio of azobisisobutyronitrile to hydrogen bond acceptor is 0.1-0.15:1.

[0015] A further improvement of the present invention is as follows: A surface molecularly imprinted polymer DESMyr-NMIP adsorbent prepared by the above method.

[0016] A further improvement to the present invention is as follows: Application of the above-mentioned surface molecularly imprinted polymer DESMyr-NMIP adsorbent in the separation and purification of myricetin in fruit juice and food.

[0017] Compared with the prior art, the beneficial effects of the present invention are as follows: This invention provides a method for preparing surface molecularly imprinted polymers based on template molecules pre-bound to a deep eutectic solvent. The method introduces the target molecule myricetin and the functional monomer methacrylic acid as hydrogen bond donors into a DES system, using methacrylic acid as the functional monomer for the synthesis of the surface molecularly imprinted polymer. Utilizing the high-density hydrogen bond network of DES, a stable, ordered, and highly matched template-monomer pre-bound system can be formed. Furthermore, the poorly soluble myricetin can be pre-dissolved and "fixed" in a stable and homogeneous DES solution, simplifying the prepolymerization steps and increasing the number of imprinted sites. The use of porous matrix materials provides a larger effective specific surface area, which is beneficial for improving the accessibility of the target molecule and the elution of the template molecule. This provides more surface active sites, improves mass transfer efficiency, and enhances the stability of the surface molecularly imprinted polymer. It achieves highly efficient and selective adsorption of myricetin, and the preparation method is simple, environmentally friendly, and has certain versatility.

[0018] The DESMyr-NMIP adsorbent prepared by this invention has strong stability, rapid adsorption, and excellent adsorption performance and specific selectivity for myricetin.

[0019] The surface molecularly imprinted polymer adsorbent prepared by this invention can be used to achieve rapid, efficient and selective separation and enrichment of myricetin in fruit juice. The molecularly imprinted polymer synthesized by different matrix materials and microemulsions can achieve a maximum adsorption capacity of 79.12~83.13 mg / g for myricetin. Attached Figure Description

[0020] Figure 1 This is a comparison of the adsorption capacity of surface molecularly imprinted polymers prepared using different amounts of myricetin in Example 1. Figure 2 Example 2 compares the adsorption capacity of surface molecularly imprinted polymers prepared using different myricetin / methacrylic acid molar ratios; Figure 3 This is a comparison of the adsorption capacity of surface molecularly imprinted polymers prepared using different amounts of ethylene glycol dimethacrylate in Example 3; Figure 4 This is a comparison chart of the adsorption capacities of different imprinted polymers and non-imprinted polymers prepared in Example 4 and Comparative Examples 1-4; Figure 5 This is a scanning electron microscope (SEM) image of the surface molecularly imprinted polymer DESMyr-NMIP. Figure 6 Fourier transform infrared (FTIR) spectra of matrix material NU-1000, surface molecularly imprinted polymer DESMyr-NMIP, and non-imprinted polymer DES-NNIP. Figure 7The adsorption capacities (A) and corresponding IF and SC values ​​(B) of DESMyr-NMIP and DES-NNIP obtained in Test Example 4 for myricetin and its structural analogues are shown. Detailed Implementation

[0021] This invention provides a surface molecularly imprinted polymer DESMyr-NMIP adsorbent, its preparation method, and its application in the separation and purification of myricetin. In the specific embodiments, unless otherwise specified, the experimental methods used are conventional methods, and the materials and reagents used are commercially available. The invention will be described in detail below with reference to specific embodiments.

[0022] Example 1 A method for preparing DESMyr-NMIP, a surface molecularly imprinted polymer adsorbent based on template molecules pre-bound to a deep eutectic solvent: (1) Hydrogen bond donor myricetin, methacrylic acid, 2.0 mmol ethylene glycol and hydrogen bond acceptor 1.0 mmol choline chloride were mixed and heated and stirred continuously at 80 °C for 30 min to obtain a homogeneous and stable template molecule pre-bound deep eutectic solvent DESMyr. The amounts of myricetin used were 0.01 mmol, 0.02 mmol, 0.03 mmol and 0.05 mmol, respectively, and the molar ratio of myricetin to methacrylic acid was 1:4.

[0023] (2) Add 15.0 mg NU-1000 and the functional monomer DESMyr to 15.0 mL of methanol and stir thoroughly to carry out prepolymerization.

[0024] (3) Ethylene glycol dimethacrylate and 20.0 mg of azobisisobutyronitrile were added to the prepolymerization solution, nitrogen gas was introduced for 10 min, and the polymerization reaction was carried out in an oil bath at 65 ℃ for 4-5 h. After elution and drying, the surface molecularly imprinted polymer DESMyr-NMIP was obtained. The eluent was a methanol / acetic acid mixture with a volume ratio of 8:2, and elution was carried out until there was no UV-Vis absorption peak at a wavelength of 375 nm in the eluent. The drying temperature was 70 ℃, and the drying time was 8-12 h. The amount of ethylene glycol dimethacrylate added was 20 times that of myricetin.

[0025] Adsorption experiment results are as follows Figure 1 As shown in the figure, the effect of different amounts of myricetin on the synthesized surface molecularly imprinted polymers is compared. It can be seen that DESMyr-NMIP prepared with 0.03 mmol of myricetin has the highest binding capacity.

[0026] The aforementioned Qe (mg·g⁻¹) is the equilibrium adsorption capacity, used to evaluate the adsorption capacity of surface molecularly imprinted polymer adsorbents. The formula for calculating Qe is:

[0027] Where C0 (mg·L⁻¹) and Ce (mg·L⁻¹) are the initial concentration of myricetin in the myricetin solution and the residual concentration of myricetin when adsorption equilibrium is reached, respectively; V (mL) is the volume of myricetin solution added; and M (mg) represents the mass of the imprinted polymer adsorbent.

[0028] Example 2 According to the preparation method in Example 1, the amount of myricetin was 0.03 mmol, the amount of ethylene glycol dimethacrylate was 0.6 mmol, and the molar ratio of myricetin to methacrylic acid was 1:1, 1:2, 1:3, 1:5 and 1:6, respectively. The remaining steps were the same as the preparation process of DESMyr-NMIP.

[0029] Adsorption experiment results are as follows Figure 2 As shown in the figure, the effect of different myricetin / methacrylic acid molar ratios on the synthesized surface molecularly imprinted polymers is compared. It can be seen that DESMyr-NMIP prepared with a myricetin / methacrylic acid molar ratio of 1:2 has the highest binding capacity.

[0030] Example 3 According to the preparation method in Example 1, the amounts of myricetin and methacrylic acid were 0.03 mmol and 0.06 mmol, respectively, and the amounts of ethylene glycol dimethacrylate were 0.6, 0.9, 1.2, 1.5 and 1.8 mmol, respectively. The remaining steps were consistent with the preparation process of DESMyr-NMIP.

[0031] Adsorption experiment results are as follows Figure 3 As shown in the figure, the effect of different amounts of ethylene glycol dimethacrylate on the synthesized surface molecularly imprinted polymers is compared. It can be seen that DESMyr-NMIP prepared with 1.2 mmol of ethylene glycol dimethacrylate has the highest binding capacity.

[0032] Example 4 DESMyr-NMIP was prepared under optimal synthetic conditions according to the preparation method in Example 1. The amounts of myricetin and methacrylic acid were 0.03 mmol and 0.06 mmol, respectively, and the amount of ethylene glycol dimethacrylate was 1.2 mmol. The remaining steps were consistent with the preparation process of DESMyr-NMIP.

[0033] Comparative Example 1 The non-molecularly imprinted polymer DES-NNIP was prepared according to the steps of Example 4. The corresponding DES-NNIP did not add the template molecule myricetin in the preparation of the deep eutectic solvent in step (1) (the deep eutectic solvent obtained at this time is named DES). The amount of methacrylic acid and ethylene glycol dimethacrylate added were 0.06 mmol and 1.2 mmol, respectively. The remaining steps were consistent with the preparation process of DESMyr-NMIP.

[0034] Comparative Example 2 The non-molecularly imprinted polymer DESMyr-MIP was prepared according to the steps of Example 4. In step (2), the matrix material NU-1000 was not added to the corresponding DESMyr-MIP, and the remaining steps were the same as the preparation process of DESMyr-NMIP.

[0035] Comparative Example 3 The surface molecularly imprinted polymer DESMyr-UMIP was prepared according to the steps of Example 4. The corresponding DESMyr-UMIP had a matrix material UiO-66 added in step (2), and the remaining steps were the same as the preparation process of DESMyr-NMIP.

[0036] Comparative Example 4 Surface molecularly imprinted polymers (NMIPs) were prepared using traditional imprinting methods, as follows: (1) Add 0.03 mmol of the template molecule myricetin, 0.06 mmol of the functional monomer methacrylic acid and 15.0 mg of NU-1000 to 15.0 mL of methanol and stir thoroughly to carry out prepolymerization.

[0037] (2) 1.2 mmol of ethylene glycol dimethacrylate and 20.0 mg of azobisisobutyronitrile were added to the prepolymerization solution, nitrogen gas was introduced for 10 min, and the polymerization reaction was carried out in an oil bath at 65 ℃ for 4-5 h. After elution and drying, the surface molecularly imprinted polymer DESMyr-NMIP was obtained. The eluent was a methanol / acetic acid mixture with a volume ratio of 8:2, and elution was carried out until there was no UV-Vis absorption peak at a wavelength of 375 nm in the eluent. The drying temperature was 70 ℃, and the drying time was 8-12 h.

[0038] Under the same conditions, the adsorption capacity of the imprinted polymers synthesized in Comparative Examples 2-4 for myricetin was compared with that of DESMyr-NMIP and DES-NNIP, and the results are as follows: Figure 4 As shown, the introduction of mesoporous NU-1000 and the construction of the DESMyr system have a significant effect on improving the adsorption capacity of the final surface molecularly imprinted polymer.

[0039] Test Example 1 The surface molecularly imprinted polymer DESMyr-NMIP prepared according to Example 4 has the following SEM image: Figure 5 As shown, a molecularly imprinted polymer layer uniformly distributed on the rod-shaped NU-1000 can be clearly observed.

[0040] Test Example 2 The FTIR spectra of the matrix material NU-1000 prepared in Example 4, the surface molecularly imprinted polymer DESMyr-NMIP, and the non-imprinted polymer DES-NNIP prepared in Comparative Example 1 are shown below. Figure 6 As shown, the successful synthesis of NU-1000, DESMyr-NMIP, and DES-NNIP can be seen.

[0041] Test Example 3 The adsorption conditions were optimized by controlling the variables, and the adsorption performance was evaluated by adsorption isotherms, adsorption kinetics and cycle regeneration experiments. The results showed that DESMyr-NMIP has a high maximum adsorption capacity (83.13 mg / g), fast adsorption rate (60 min) and excellent regeneration (it still maintains 60.64% adsorption rate after 5 reuses).

[0042] Test Example 4 Adsorption selectivity experiments were conducted under identical adsorption conditions to evaluate the adsorption performance of DESMyr-NMIP on myricetin and its structural analogs. Eight flavonoids and polyphenols were selected as structural analogs: naringenin (Nar), baicalin (Bai), luteolin (Lut), rutin (Rut), quercetin (Que), oxytetracycline (Ter), gallic acid (GA), and p-nitrophenol (p-NP). The adsorption capacity of DESMyr-NMIP for each component was calculated, and each experiment was repeated in triplicate.

[0043] To better illustrate the selectivity of DESMyr-NMIP, the imprinting factor (IF) and selectivity coefficient (SC) are introduced to evaluate the selective adsorption capacity of DESMyr-NMIP.

[0044] The IF stands for Imprinting Factor, used to evaluate the imprinting effect of the surface molecular imprinting polymer DESMyr-NMIP. The formula for calculating the IF value is as follows:

[0045] Where Qe is the equilibrium adsorption capacity.

[0046] The SC value is a selectivity coefficient used to evaluate the selectivity of the surface molecularly imprinted polymer DESMyr-NMIP. The formula for calculating the SC value is as follows:

[0047] Qe(X) and Qe(Myr) represent the equilibrium adsorption capacities of DESMyr-NMIP for the structural analogue and myricetin, respectively.

[0048] The results obtained according to test case 4 are as follows: Figure 7 As shown in Table 1. Figure 7 Figure A shows the adsorption capacities of DESMyr-NMIP and DES-NNIP for myricetin and eight structural analogs. Figure 7 Figure B shows the IF and SC values ​​of DESMyr-NMIP for each component. It can be seen that DESMyr-NMIP has the largest adsorption capacity for myricetin, reaching 22.70 mg·g⁻¹, with an IF value of 1.28. DESMyr-NMIP also exhibits high adsorption capacities for Que, Lut, and Nar (21.20 mg·g⁻¹, 18.35 mg·g⁻¹, and 19.30 mg·g⁻¹, respectively), but their IF values ​​are lower than Myr. The IF values ​​for Que, Lut, and Nar are 0.74, 0.82, and 0.93, respectively, indicating that the adsorption of these components by DESMyr-NMIP mainly comes from non-specific binding, with the blotted space tending to recognize and bind myricetin molecules. DESMyr-NMIP has high IF values ​​for Rut and GA, at 2.57 and 1.98, respectively, but the adsorption capacities are only 3.93 mg·g⁻¹ and 0.91 mg·g⁻¹. The SC values ​​were all less than 1, indicating that DESMyr-NMIP had good selectivity for myricetin.

[0049] Table 1 Adsorption capacity, imprinting factor, and selectivity of DESMyr-NMIP and DES-NNIP

[0050] Application Example 1 DESMyr-NMIP was used as an adsorbent in the analysis of actual samples. Fresh bayberry juice and grape juice were selected as the actual samples. The specific experimental steps are as follows: (1) The actual sample was pretreated before analysis. First, an appropriate amount of fresh juice was taken and the pulp and solid impurities in the juice were removed by centrifugation and filtration. 1 mL of juice supernatant was taken and transferred to a 100 mL volumetric flask and diluted to the mark with adsorption solution.

[0051] (2) In the spiked recovery experiment, 3 mL of three different levels of Myr standard solution (6.00, 8.00, 10.00 mg·L-1) were added to 5 mL of the actual sample solution. After the adsorption and elution were completed by shaking, the concentration of the eluent was detected by UV-vis.

[0052] (3) The spiked recovery rate and relative standard deviation (RSD) were calculated.

[0053] The results are shown in Table 2. The recoveries of DESMyr-NMIP in grape juice samples ranged from 90.44% to 102.55%, with RSD values ​​between 0.09% and 0.16%; while the recoveries in bayberry juice samples ranged from 89.64% to 100.62%, with RSD values ​​between 0.13% and 0.33%. The satisfactory recoveries and insignificant RSD values ​​indicate that this method can be successfully applied to practical sample analysis, confirming the high application value of this adsorbent in the separation and purification of myricetin.

[0054] Table 2. Spike recoveries and RSDs in grape juice and bayberry juice.

[0055] This invention uses the template molecule myricetin directly as a component of the deep eutectic solvent system, enabling myricetin and methacrylic acid to pre-form a uniform and stable template-functional monomer composite structure within a choline chloride-ethylene glycol hydrogen bond network. This pre-bonded system is then used as a whole for imprinted polymerization on the NU-1000 surface. This method helps reduce the randomness of template-monomer bonding in traditional prepolymerization processes, improves the uniformity of template molecule dispersion, the effective utilization rate of functional monomers, and the matching degree between the imprinted sites and myricetin in terms of spatial configuration and functional group distribution. This method maintains high adsorption capacity even with low template dosage, and is independent of boric acid groups and specific basic or weakly acidic bonding conditions, offering a simplified preparation process.

[0056] This invention involves first having template molecules participate in the formation of DES, then completing the pre-organization of the template and functional monomers through the DES hydrogen bond network, and finally fixing this pre-organized structure onto the NU-1000 surface. The binding between the template and functional monomers is more stable and uniform, and the formation of imprinted sites shifts from random self-assembly to pre-organization, independent of the dynamic covalent bonds of boric acid and specific pH. Compared with microemulsions and dual-DES boron affinity systems, the preparation process is relatively direct.

[0057] The above description of the embodiments is only for illustrating the technical concept and features of the present invention. Its purpose is to enable those skilled in the art to understand the content of the present invention and implement it accordingly. Those skilled in the art can obviously easily make various modifications to these embodiments and apply the general principles described herein to other embodiments without creative effort. Therefore, the above embodiments should not be used to limit the scope of protection of the present invention. All improvements and modifications made by those skilled in the art based on the disclosure of the present invention without departing from the scope of the present invention should be covered within the scope of protection of the present invention.

Claims

1. A surface molecularly imprinted polymer DES Myr The method for preparing -NMIP adsorbent is characterized by, Includes the following steps: (1) The hydrogen bond donor and the hydrogen bond acceptor were mixed and heated and stirred to obtain a homogeneous and stable template molecule pre-bound deep eutectic solvent DES. Myr ; (2) Integrating porous matrix material with DES Myr Add to the polymerization solvent and stir thoroughly to carry out prepolymerization; (3) Add crosslinking agent and initiator to the prepolymerization solution, heat and polymerize under nitrogen protection, and obtain surface molecularly imprinted polymer DES after elution and drying of the product. Myr -NMIP.

2. The surface molecularly imprinted polymer DES according to claim 1 Myr The method for preparing -NMIP adsorbent is characterized by: The hydrogen bond acceptor in step (1) is choline chloride; the hydrogen bond donor is the template molecule, methacrylic acid and ethylene glycol; the template molecule is myricetin.

3. The surface molecularly imprinted polymer DES according to claim 2 Myr The method for preparing -NMIP adsorbent is characterized by: The molar ratio of choline chloride, myricetin, methacrylic acid and ethylene glycol in step (1) is 1:0.01-0.05:0.01-0.3:1.5-2.

5.

4. The surface molecularly imprinted polymer DES according to claim 1 Myr The method for preparing -NMIP adsorbent is characterized by: The heating and stirring temperature in step (1) is 70-90℃ and the time is 20-40min.

5. The surface molecularly imprinted polymer DES according to claim 1 Myr The method for preparing -NMIP adsorbent is characterized by: The porous matrix material in step (2) is metal-organic framework material NU-1000; the polymerization solvent is methanol; the DES Myr It is a functional monomer.

6. The surface molecularly imprinted polymer DES according to claim 5 Myr The method for preparing -NMIP adsorbent is characterized by: The mass ratio of NU-1000 to hydrogen bond acceptor in step (2) is 8-10:1; And / or, the feeding ratio of NU-1000 to methanol is 1 mg: 1-2 mL.

7. The surface molecularly imprinted polymer DES according to claim 1 Myr The method for preparing -NMIP adsorbent is characterized by: The crosslinking agent mentioned in step (3) is ethylene glycol dimethacrylate; the initiator is azobisisobutyronitrile; And / or, the heating polymerization in step (3) is carried out at a temperature of 50-80°C for 4-5 hours; And / or, the elution process in step (3) uses a methanol and acetic acid mixture with a volume ratio of 8:2 as the eluent; And / or, the drying temperature in step (3) is 60-80℃ and the time is 8-12 h.

8. The surface molecularly imprinted polymer DES according to claim 7 Myr The method for preparing -NMIP adsorbent is characterized by: In step (3), the molar ratio of ethylene glycol dimethacrylate to myricetin is 20-60:1; the molar ratio of azobisisobutyronitrile to hydrogen bond acceptor is 0.1-0.15:

1.

9. A surface molecularly imprinted polymer DES Myr -NMIP adsorbent, characterized in that... Prepared by the method described in any one of claims 1 to 8.

10. The surface molecularly imprinted polymer DES prepared by the method of claim 9 Myr Application of -NMIP adsorbent in the separation and purification of myricetin in fruit juice and food.

Images