阅读说明：本技术 吡氟草胺分子印迹聚合物的制备方法及其性能表征方法 (Preparation method and performance characterization method of diflufenican molecularly imprinted polymer ) 是由 王岩松 祝军 王冬妍 刘鑫 罗景阳 袁帅 李巧莲 周长民 李娇 张承昕 许文雅 于 2021-07-09 设计创作，主要内容包括：本发明涉及化学技术领域,具体为一种吡氟草胺分子印迹聚合物的制备方法及其性能表征方法。本发明提供的一种吡氟草胺分子印迹聚合物的制备方法,以吡氟草胺为模板分子,TFMAA为功能单体,EGDMA为交联剂,AIBN为引发剂,成功制备了吡氟草胺分子印迹聚合物,并且本发明制备的吡氟草胺分子印迹聚合物具有较好的吸附性和较强的选择性。本发明提供的一种吡氟草胺分子印迹聚合物的性能表征方法,可对吡氟草胺分子印迹聚合物的吸附性能进行准确测试。(The invention relates to the technical field of chemistry, in particular to a preparation method and a performance characterization method of diflufenican molecularly imprinted polymers. The diflufenican molecularly imprinted polymer is successfully prepared by using diflufenican as a template molecule, TFMAA as a functional monomer, EGDMA as a cross-linking agent and AIBN as an initiator, and has good adsorbability and strong selectivity. The diflufenican molecularly imprinted polymer performance characterization method provided by the invention can accurately test the adsorption performance of the diflufenican molecularly imprinted polymer.)

1. A preparation method of diflufenican molecularly imprinted polymer is characterized by comprising the following steps:

step one, weighing 0.394g diflufenican in a 250mL triangular flask;

step two, adding 100mL of acetonitrile into the triangular flask until diflufenican in the triangular flask is completely dissolved, adding TFMAA, and carrying out prepolymerization for 12h at room temperature;

step three, adding 25mmol of EGDMA and 0.5mmol of AIBN in sequence, carrying out ultrasonic treatment for 5min, continuously introducing nitrogen for 10min, sealing, carrying out magnetic stirring for 24h at the temperature of 60 ℃, and taking out the prepared white polymer to a Soxhlet extractor;

step four, extracting with 60mL of absolute ethyl alcohol-acetic acid with the volume ratio of 8: 2 for 6h, and repeatedly performing ultrasonic elution with methanol-water with the volume ratio of 1: 1 for multiple times until the eluent is neutral;

step five, eluting with methanol until diflufenican molecules cannot be detected by LC-MS/MS;

sixthly, drying the polymer in a 60 ℃ drying oven to obtain the diflufenican molecularly imprinted polymer, and placing the diflufenican molecularly imprinted polymer in a dryer for later use.

2. The method for preparing diflufenican molecularly imprinted polymer according to claim 1, wherein in the second step, the mass ratio of diflufenican to TFMAA is 1: 3.

3. the method for preparing diflufenican molecularly imprinted polymer according to claim 1, wherein in the second step, TFMAA is added in an amount of 3 mmol.

4. A method for characterizing the properties of diflufenican molecularly imprinted polymers prepared by the method for preparing diflufenican molecularly imprinted polymers as claimed in any one of claims 1-3, comprising:

respectively preparing a D-MIP substance and a D-NIP substance by using diflufenican and thiram according to the same method;

weighing 7 parts of 20mg of D-MIP and 20mg of D-NIP respectively, and placing the two parts in 10mL plastic centrifuge tubes respectively;

5mL of 10mg/L diflufenican solution is added into a plastic centrifuge tube, and the mixture is oscillated in a constant temperature water bath at the temperature of 30 ℃;

simultaneously taking out 1 part of D-MIP and D-NIP at 10min, 20min, 30 min, 40 min, 50min, 60 min and 80min respectively, centrifuging, and putting 100 mu L of supernatant into a 100mL volumetric flask;

fixing the volume to the scale with distilled water, and filtering 1mL of the solution through a 0.22-micron filter membrane for LC-MS/MS measurement;

the adsorption capacity Q at 10,20,30,40,50,60 and 80min was plotted against the adsorption time t, and an adsorption kinetics curve was plotted, and the adsorption capacity was calculated as follows:

in the formula: q represents the adsorption amount in μ g/g; v represents the volume of the diflufenican solution in mL; c0 represents the initial concentration of diflufenican in ng/mL; c1 represents diflufenican concentration after adsorption in ng/mL; w represents the mass of D-MIP or D-NIP in mg.

5. The method for characterizing the diflufenican molecularly imprinted polymer performance according to claim 4, further comprising:

weighing 6 parts of 20mg of D-MIP and 20mg of D-NIP respectively, and placing the D-MIP and the 20mg of D-NIP in a 10mL plastic centrifuge tube;

respectively adding 5mL of diflufenican standard solutions with the concentrations of 2,4,6,8,10 and 12 mu g/mL into a plastic centrifuge tube, and oscillating for 50min at constant temperature of 30 ℃;

centrifuging, and placing 100 mu L of supernatant into a 100mL volumetric flask;

fixing the volume to the scale with distilled water, and filtering 1mL of the solution through a 0.22-micron filter membrane for LC-MS/MS measurement;

and (5) plotting the adsorption quantity Q and the diflufenican concentration C to draw an isothermal adsorption curve.

6. The method for characterizing the diflufenican molecularly imprinted polymer performance as recited in claim 5, further comprising:

2 parts of 20mg D-MIP are put into a 10mL plastic centrifuge tube;

respectively adding 5mL of diflufenican and thiram aqueous solution with the concentration of 10 mu g/mL, and oscillating for 50min at constant temperature for LC-MS/MS determination;

the adsorption performance of D-MIP on diflufenican and thiram is compared.

7. A diflufenican molecularly imprinted polymer prepared by the preparation method of the diflufenican molecularly imprinted polymer as claimed in any one of claims 1-3, and application of the diflufenican molecularly imprinted polymer in purification of diflufenican and research on trace diflufenican residues in complex substrates of foods and environments.

Technical Field

The invention relates to the technical field of chemistry, in particular to a preparation method and a performance characterization method of diflufenican molecularly imprinted polymers.

Background

The Molecular imprinting technique is a technique of artificially synthesizing a template molecule by simulating the antigen-antibody principle to form a Molecular Imprinted Polymer (MIP) having a memory function in a spatial structure and a binding site. The specific adsorbability of the molecularly imprinted polymer is gradually discovered and applied to the fields of biosensors, extraction and purification of compounds, chromatographic separation and the like. The molecular imprinting solid-phase extraction successfully integrates the characteristics of the molecular imprinting polymer into the solid-phase extraction technology, and finds a new solution for the extraction and separation of target compounds in a complex matrix.

The diflufenican molecularly imprinted polymer can be used for purifying diflufenican and can also be used for researching trace diflufenican residues in complex matrixes such as food, environment and the like. However, no literature report is available on the preparation of diflufenican molecularly imprinted polymers. Therefore, how to prepare the diflufenican molecularly imprinted polymer with better adsorbability and stronger selectivity and test the adsorbability of the diflufenican molecularly imprinted polymer are problems to be solved urgently in the industry.

Disclosure of Invention

The invention provides a preparation method of diflufenican molecularly imprinted polymer and a performance characterization method thereof, aiming at the technical problems in the prior art.

In a first aspect, the invention provides a preparation method of diflufenican molecularly imprinted polymer, which comprises the following steps:

step one, weighing 0.394g diflufenican in a 250mL triangular flask;

step two, adding 100mL of acetonitrile into the triangular flask until diflufenican in the triangular flask is completely dissolved, adding TFMAA, and carrying out prepolymerization for 12h at room temperature;

step three, adding 25mmol of EGDMA and 0.5mmol of AIBN in sequence, carrying out ultrasonic treatment for 5min, continuously introducing nitrogen for 10min, sealing, carrying out magnetic stirring for 24h at the temperature of 60 ℃, and taking out the prepared white polymer to a Soxhlet extractor;

step four, extracting with 60mL of absolute ethyl alcohol-acetic acid with the volume ratio of 8: 2 for 6h, and repeatedly performing ultrasonic elution with methanol-water with the volume ratio of 1: 1 for multiple times until the eluent is neutral;

step five, eluting with methanol until diflufenican molecules cannot be detected by LC-MS/MS;

sixthly, drying the polymer in a 60 ℃ drying oven to obtain the diflufenican molecularly imprinted polymer, and placing the diflufenican molecularly imprinted polymer in a dryer for later use.

Further, in the second step, the mass ratio of diflufenican to TFMAA is 1: 3.

further, in the second step, the amount of TFMAA added was 3 mmol.

In a second aspect, the invention provides a performance characterization method of the diflufenican molecularly imprinted polymer prepared by the preparation method of the diflufenican molecularly imprinted polymer, which comprises the following steps:

respectively preparing a D-MIP substance and a D-NIP substance by using diflufenican and thiram according to the same method;

weighing 7 parts of 20mg of D-MIP and 20mg of D-NIP respectively, and placing the two parts in 10mL plastic centrifuge tubes respectively;

5mL of 10mg/L diflufenican solution is added into a plastic centrifuge tube, and the mixture is oscillated in a constant temperature water bath at the temperature of 30 ℃;

simultaneously taking out 1 part of D-MIP and D-NIP at 10min, 20min, 30 min, 40 min, 50min, 60 min and 80min respectively, centrifuging, and putting 100 mu L of supernatant into a 100mL volumetric flask;

fixing the volume to the scale with distilled water, and filtering 1mL of the solution through a 0.22-micron filter membrane for LC-MS/MS measurement;

the adsorption capacity Q at 10,20,30,40,50,60 and 80min was plotted against the adsorption time t, and an adsorption kinetics curve was plotted, and the adsorption capacity was calculated as follows:

in the formula: q represents the adsorption amount in μ g/g; v represents the volume of the diflufenican solution in mL; c0 represents the initial concentration of diflufenican in ng/mL; c1 represents diflufenican concentration after adsorption in ng/mL; w represents the mass of D-MIP or D-NIP in mg.

Further, the method further comprises:

weighing 6 parts of 20mg of D-MIP and 20mg of D-NIP respectively, and placing the D-MIP and the 20mg of D-NIP in a 10mL plastic centrifuge tube;

respectively adding 5mL of diflufenican standard solutions with the concentrations of 2,4,6,8,10 and 12 mu g/mL into a plastic centrifuge tube, and oscillating for 50min at constant temperature of 30 ℃;

centrifuging, and placing 100 mu L of supernatant into a 100mL volumetric flask;

fixing the volume to the scale with distilled water, and filtering 1mL of the solution through a 0.22-micron filter membrane for LC-MS/MS measurement;

and (5) plotting the adsorption quantity Q and the diflufenican concentration C to draw an isothermal adsorption curve.

Further, the method further comprises:

2 parts of 20mg D-MIP are put into a 10mL plastic centrifuge tube;

respectively adding 5mL of diflufenican and thiram aqueous solution with the concentration of 10 mu g/mL, and oscillating for 50min at constant temperature for LC-MS/MS determination;

the adsorption performance of D-MIP on diflufenican and thiram is compared.

In a third aspect, the invention also provides the diflufenican molecularly imprinted polymer prepared by the preparation method of the diflufenican molecularly imprinted polymer, and the application of the diflufenican molecularly imprinted polymer in purification of diflufenican and research on trace diflufenican residues in complex matrixes of foods and environments.

The invention has the beneficial effects that: the diflufenican molecularly imprinted polymer is successfully prepared by using diflufenican as a template molecule, TFMAA as a functional monomer, EGDMA as a cross-linking agent and AIBN as an initiator, and has good adsorbability and strong selectivity. The diflufenican molecularly imprinted polymer performance characterization method provided by the invention can accurately test the adsorption performance of the diflufenican molecularly imprinted polymer.

Drawings

FIG. 1 is a flow chart of a preparation method of diflufenican molecularly imprinted polymers of the present invention;

FIG. 2 is SEM pictures of template molecules and functional monomer polymers in different proportions;

FIG. 3 is a graph showing the adsorption kinetics of diflufenican by D-MIP and D-NIP;

FIG. 4 is SEM pictures of D-NIP and D-MIP at different resolutions;

FIG. 5 is a graph showing the static adsorption curves of D-NIP and D-MIP.

Detailed Description

The principles and features of this invention are described below in conjunction with the following drawings, which are set forth by way of illustration only and are not intended to limit the scope of the invention. The present invention provides the following preferred embodiments.

As shown in fig. 1, an embodiment of the present invention provides a preparation method of a diflufenican molecularly imprinted polymer, including:

step one, weighing 0.394g diflufenican into a 250mL triangular flask.

In particular, diflufenican is used as a template molecule, and the electronic balance BS244S of Sadolis scientific instruments ltd is adopted to realize accurate weighing. Diflufenican is 95% diflufenican, which is adopted by Shenyang chemical research institute.

And step two, adding 100mL of acetonitrile into the triangular flask until diflufenican in the triangular flask is completely dissolved, adding TFMAA (2- (trifluoromethyl) acrylic acid), and carrying out prepolymerization for 12h at room temperature.

Specifically, acetonitrile was used as a porogen and chromatographically purified, Fisher corporation, usa. TFMAA is used as a functional monomer, and 98 percent of TFMAA of the alatin is adopted. The template molecule diflufenican and a functional monomer (TFMAA) form a hydrogen bond, and more active sites are generated in the polymer after polymerization and elution. 3mmol TFMAA may be added.

Preferably, the mass ratio of diflufenican to TFMAA is 1: 3. the inventors changed the amount of template molecule added while keeping the above polymerization conditions unchanged to obtain the SEM image of D-MIP shown in FIG. 2, wherein (a) NIP in FIG. 2; (b) D-MIP (1: 1); (c) D-MIP (1: 2); (d) D-MIP (1: 3); (e) D-MIP (1: 4); (f) D-MIP (1: 5). As can be seen from FIG. 2, when the mass ratio of diflufenican to TFMAA is 1: 5, the prepared diflufenican molecularly imprinted polymer is agglomerated together, and does not form a mesh structure with uniform spatial dispersion, which is not beneficial to elution of diflufenican and affects the adsorption capacity of the diflufenican molecularly imprinted polymer. The particle size of the diflufenican molecularly imprinted polymer is gradually reduced with the increase of diflufenican amount to present a spatial network structure, when the amount ratio of the diflufenican to TFMAA substances reaches 1: 3, the diflufenican molecularly imprinted polymer is in a loose spatial network structure, the particle surface is rough, a large number of pores are formed among particles, it is presumed that the diflufenican with a proper ratio props up larger pores among the diflufenican molecularly imprinted polymer particles through electrostatic adsorption, hydrogen bonding and the like to form a large number of spatial binding sites, and binding sites with specific adsorbability are left among the pores after the diflufenican is eluted. However, as the amount of diflufenican continues to increase, the surface of diflufenican molecularly imprinted polymer particles becomes smooth, the particle size increases, and pores are obviously reduced, presumably due to diflufenican interaction, which reduces the probability of forming holes in the diflufenican molecularly imprinted polymer. Therefore, the mass ratio of diflufenican to TFMAA was selected from 1: 3, the diflufenican molecularly imprinted polymer can obtain the best adsorption performance.

And step three, sequentially adding 25mmol of EGDMA (ethylene glycol dimethacrylate) and 0.5mmol of AIBN (azobisisobutyronitrile), carrying out ultrasonic treatment for 5min, continuously introducing nitrogen for 10min, sealing, carrying out magnetic stirring for 24h at 60 ℃, and taking out the prepared white polymer in a Soxhlet extractor.

Specifically, EGDMA is used as a cross-linking agent, and 98% of EGDMA is adopted. AIBN was used as initiator, Maxin 98% AIBN was used. The yields of the polymers obtained from the above-mentioned materials in the above proportions, amounts and reaction conditions were the highest, and the polymers were white granular powders, and the polymers were clearly seen to have a spatial network structure in FIG. 2 (a). The invention adopts a heat-collecting constant-temperature heating magnetic stirrer DF-101S for magnetic stirring in the empyrexia instruments manufacturing factory.

And step four, extracting the mixture for 6 hours by using 60mL of absolute ethyl alcohol-acetic acid with the volume ratio of 8: 2, and repeatedly performing ultrasonic elution by using methanol-water with the volume ratio of 1: 1 for many times until the eluent is neutral.

Specifically, the ultrasonic elution method adopts a numerical control ultrasonic cleaner KQ5200DE of ultrasonic instruments Limited in Kunshan to carry out ultrasonic elution. The absolute ethanol is analytically pure, and is obtained by a Daoyang chemical reagent factory in Tianjin. Glacial acetic acid was prepared by analytical pure, Tianjin, Daozhi chemical reagent plant. Methanol-water was used to elute residual template molecules and acetic acid residues.

And step five, eluting with methanol until diflufenican molecules cannot be detected by LC-MS/MS.

Specifically, the present invention employs a tandem mass spectrometer API 4000, manufactured by applied biosystems, usa, and a liquid chromatograph LC 20A, manufactured by shimadzu corporation, japan. The methanol was chromatographically pure, Fisher company, USA.

Sixthly, drying the polymer in a 60 ℃ drying oven to obtain the diflufenican molecularly imprinted polymer, and placing the diflufenican molecularly imprinted polymer in a dryer for later use.

Specifically, the invention adopts the electrothermal blowing drying oven 101-2 of the far east numerical control instrument factory in Yuyao City as the oven.

The invention also provides a performance characterization method of the diflufenican molecularly imprinted polymer prepared by the preparation method of the diflufenican molecularly imprinted polymer, and the performance characterization method proves that the diflufenican molecularly imprinted polymer prepared by the method has better adsorbability and stronger selectivity through an adsorption kinetics test, a static equilibrium adsorption test and a selective adsorption test.

Wherein, the LC-MS/MS detection conditions are as follows:

symmetry C18 column (150 mm. times.2.1 mm,3.5 μm); the mobile phase A is water, the mobile phase B is methanol, and 0.1% of formic acid is respectively added; linear gradient elution procedure: 20% B in 0-1.5min, 95% B in 1.5-3min from 20% B, 95% B in 3-4.5min, 20% B in 4.5-5min from 95% B, and 20% B in 5-7 min. The flow rate is 0.35mL/min, the column temperature is 35 ℃, and the injection volume is 10 mu L.

Electrospray ionization (ESI), positive ion scanning; multiple Reaction Monitoring (MRM); electrospray voltage Ionspray voltage, IS) 5500V; atomizing gas pressure 65psi (1psi 6894.76 Pa); air curtain pressure 15 psi; auxiliary gas pressure 65 psi; the ion source temperature is 550 ℃; the qualitative ion pair, the quantitative ion pair, the collisional gas energy (CE) and the Declustering Potential (DP) are shown in table 1.

TABLE 1 Mass Spectrometry parameters of diflufenican and thiram

The adsorption kinetics test comprises the following steps: D-MIP (diflufenican molecularly imprinted polymer) and D-NIP (non-molecularly imprinted polymer) were prepared in the same manner using diflufenican and thiram, respectively. 20mg of D-MIP and 20mg of D-NIP were weighed out in 7 portions and placed in 10mL plastic centrifuge tubes, respectively. 5mL of 10mg/L diflufenican solution is added into a plastic centrifuge tube, and the mixture is shaken in a constant temperature water bath at 30 ℃. At 10,20,30,40,50,60 and 80min, 1 part of D-MIP and D-NIP were taken out simultaneously, and 100. mu.L of supernatant after centrifugation was taken out and placed in a 100mL volumetric flask. The volume is fixed to the scale by distilled water, and 1mL of solution is filtered through a 0.22 mu m filter membrane for LC-MS/MS measurement. The adsorption capacity Q at 10,20,30,40,50,60 and 80min was plotted against the adsorption time t, and an adsorption kinetics curve was plotted, and the adsorption capacity was calculated as follows:

in the formula: q represents the adsorption amount in μ g/g; v represents the volume of the diflufenican solution in mL; c0 represents the initial concentration of diflufenican in ng/mL; c1 represents diflufenican concentration after adsorption in ng/mL; w represents the mass of D-MIP or D-NIP in mg.

In particular, other pesticidal compounds than thiram may be chosen for comparison, but this compound must be able to behave similarly to the diflufenican compound in chromatography for chromatographic quantification. The invention adopts a constant temperature water bath oscillator SHA-B of the Guo Hua enterprise to carry out constant temperature water bath oscillation. The invention adopts a desktop centrifuge 800-1 of a Xinrui instrument factory in the western city of the gold altar area for centrifugation.

The amount of diflufenican molecules adsorbed on the surface and among pores of the polymer is increased along with the increase of the adsorption time of the polymer. As shown in fig. 3, the adsorption time is 10-20min, and the adsorption rate is fastest; between 20-50min, the adsorption capacity continuously increases at a relatively slow rate; when the adsorption time is increased to 50min, the adsorption capacity reaches a saturated state; the adsorption amount also shows a slight decrease tendency as the adsorption time is further extended. In the early stage of adsorption, diflufenican molecules are rapidly attached to the surfaces of polymer particles, occupy binding sites on the surfaces, slowly enter pores among the particles along with the oscillation action along with the increase of time, and find suitable positions through the binding sites with a memory function. And (4) when the time is continuously prolonged to 50min, the surface of the polymer and the sites among the particles are all occupied, the maximum adsorption capacity of the polymer is reached, the maximum adsorption capacity of the D-MIP is 1350mg/kg, and the maximum adsorption capacity of the D-NIP is 320 mg/kg. Because of the lack of binding sites for this "memory function" on the D-NIP surface and between particles, the adsorption capacity is significantly lower than for D-MIP.

As shown in FIG. 4, (a) and (d) in the figure represent 20 μm; (b) and (e) represents 5 μm; (c) and (f) represents 2 μm. Under the condition that the magnification of the D-NIP and the D-MIP is gradually increased, the particle size of the D-NIP particles is more clearly found to be obviously larger than that of the D-MIP particles, and in a figure 4(f), the surface of the D-MIP particles is uneven, and a large number of pores are uniformly distributed among the particles, and due to the uneven structure and the pores on the surface of the D-MIP particles, the D-NIP and the D-MIP are endowed with good adsorption performance and specific selectivity. The structural distribution of the polymer particles further proves that the adsorption quantity of the D-MIP is obviously larger than that of the D-NIP.

The static equilibrium adsorption test comprises: 20mg of D-MIP and 20mg of D-NIP were weighed in 6 portions each and placed in a 10mL plastic centrifuge tube. 5mL of diflufenican standard solutions with the concentrations of 2,4,6,8,10 and 12 mu g/mL are respectively added into a plastic centrifuge tube, and the mixture is shaken for 50min at constant temperature of 30 ℃. Centrifuge, and place 100. mu.L of the supernatant into a 100mL volumetric flask. The volume is fixed to the scale by distilled water, and 1mL of solution is filtered through a 0.22 mu m filter membrane for LC-MS/MS measurement. And (5) plotting the adsorption quantity Q and the diflufenican concentration C to draw an isothermal adsorption curve.

Keeping the adsorption time for 50min, and verifying the change of the adsorption capacity of the polymer in diflufenican standard solutions with different concentrations. As shown in FIG. 5, both D-MIP and D-NIP showed a tendency to increase the amount of adsorption as the concentration of adsorbed diflufenican increased. The adsorption curve of the D-NIP is relatively stable, the phenomenon of sudden adsorption does not occur, the imprinting pores and the recognition sites with specific adsorbability in the D-MIP structure are matched with the concentration of diflufenican, diflufenican molecules occupy the space on the surface and in the pores of the D-MIP particles quickly, the adsorption behavior reaches the end point when the mass concentration reaches 8 mu g/mL, and the maximum adsorption quantity is 1350 mg/kg. The X-NIP also has certain adsorption behavior depending on the self gap and loose structure, and the saturated adsorption quantity is 320 mg/kg.

The selective adsorption test comprises: 2 portions of 20mg D-MIP were placed in 10mL plastic centrifuge tubes. Respectively adding 5mL of diflufenican and thiram aqueous solution with the concentration of 10 mu g/mL, and oscillating for 50min at constant temperature for LC-MS/MS determination. The adsorption performance rates of D-MIP on diflufenican and thiram are compared.

The adsorption capacity of D-MIP on diflufenican and thiram molecules was compared under the same experimental conditions. The results show that: the adsorption capacity of the D-MIP to the diflufenican is obviously higher than that of the thiram and is 1350 mg/kg; the adsorption quantity of the carrier on the thiram is 350 mg/kg. It is proved again that the 'memory' pores and recognition sites formed in the D-MIP structure are only matched with diflufenican molecules, and have no recognition function with the molecular structure of thiram.

In conclusion, the molecularly imprinted polymer of diflufenican is prepared by adopting a bulk polymerization method, acetonitrile is taken as a pore-forming agent, TFMAA is taken as a functional monomer, EGDMA is taken as a cross-linking agent, AIBN is taken as an initiator, the maximum adsorption quantity of D-MIP is 1350mg/kg, which is obviously higher than that of D-NIP, and the molecularly imprinted polymer has better adsorbability and stronger selectivity. Scanning electron microscope photographs show that the polymer is in a loose space network structure, the surfaces of particles are rough, and a large number of pores are formed among the particles, thereby proving the reason that the prepared D-MIP has good adsorbability. The invention also provides the diflufenican molecularly imprinted polymer prepared by the preparation method, and the application of the diflufenican molecularly imprinted polymer in purification of diflufenican and research on trace diflufenican residue in complex matrixes of foods and environments can be used for further researching the extraction, purification, residual quantity and the like of diflufenican in complex matrixes of foods, environments and the like by utilizing the good adsorption property and selectivity of D-MIP.

The present invention is not limited to the above preferred embodiments, and any modifications, equivalent replacements, improvements, etc. within the spirit and principle of the present invention should be included in the protection scope of the present invention.