Molecularly imprinted passive sampling diaphragm for cinnamic acid organic ultraviolet sun-screening agent as well as preparation method and application of molecularly imprinted passive sampling diaphragm

Abstract

The invention provides a cinnamic acid organic ultraviolet sun-screening agent molecularly imprinted passive sampling diaphragm as well as a preparation method and application thereof, and the preparation method comprises the following steps: polymerizing template molecule 2-cyano-3, 3-diphenyl isooctyl acrylate, functional monomer methacrylic acid and cross-linking agent tetrahydrofuran according to a molar ratio of 1: 4: 30 to form a cinnamic acid organic ultraviolet sun-screening agent molecularly imprinted polymer; the cinnamic acid organic ultraviolet sun-screening agent molecular imprinting passive sampling diaphragm is prepared by taking polydimethylsiloxane as a substrate and adopting a solution composite film forming method. Compared with the prior art, the molecular imprinting passive sampling membrane for the cinnamic acid organic ultraviolet sun-screening agent synthesized by the invention has the advantages that the adsorption performance on octocrylene in the air is improved by 120% compared with that of a common membrane, the specificity is better, and the molecular imprinting passive sampling membrane can be applied to high-selectivity adsorption and enrichment of the cinnamic acid organic ultraviolet sun-screening agent in the air.

Description

Technical Field

[0001] The invention relates to trace collection in detection technology, and in particular to a cinnamic acid organic ultraviolet sunscreen agent molecular imprinting passive sampling membrane and a preparation method and application thereof. Background Art

[0002] The ecotoxicity of emerging contaminants is a hot topic in the current environmental research field. Addressing climate change and managing emerging contaminants are key areas of basic research and technological innovation. Organic ultraviolet filters (UVFs), as a new type of contaminant, enter the water environment through sewage discharge, direct human use, and the release of industrial materials, and produce ecotoxicity.

[0003] Cinnamic acid UVFs have become widely used organic UVFs due to their high absorption capacity in the ultraviolet region. However, with the improvement of public awareness of UV protection and personal care, as well as the intensification of ozone layer depletion and global warming, the environmental and health risks of cinnamic acid UVFs have gradually received attention. Among cinnamic acid UVFs, the distribution of octocrylene (OC) in the environment and its risk issues under single exposure and mixed exposure are becoming more prominent. Due to the high boiling point and low environmental concentration of cinnamic acid UVFs, the effective collection of cinnamic acid UVFs in environmental media remains a challenge.

[0004] Molecular imprinting technology simulates the interaction between enzymes and substrates, and achieves specific recognition and enrichment of target substances in complex sample matrices by preparing high molecular weight compounds that are selective for target molecules - molecularly imprinted polymers (MIPs). At present, in the field of new pollutants, the more mature application is to apply MIPs materials to solid-phase extraction (SPE), membrane separation technology, and sensors to assist in the separation, purification, and enrichment of environmental analysis. The selectivity of MIPs can better compensate for the non-selectivity of SPE adsorbents. New pollutants such as organic UVFs have the characteristics of long-term, colorless, odorless, hidden, and trace levels in the environment. MIPs that can preset structure-activity and specific recognition have the advantages of good stability, high mechanical strength, and good selectivity. Therefore, the introduction of molecular imprinting technology will help promote the identification and detection analysis capabilities of trace organic UVFs in complex matrices or materials. Existing collection technologies have problems such as poor selectivity, low efficiency and low accuracy. The development of a quick and effective collection material is of great significance for identifying the distribution of cinnamic acid UVFs and scientific understanding of exposure risks. Summary of the invention

[0005] The purpose of the present invention is to solve the above technical problems and to provide a cinnamic acid organic ultraviolet sunscreen agent molecular imprinting passive sampling membrane and a preparation method and application thereof. The synthesized cinnamic acid organic ultraviolet sunscreen agent molecular imprinting passive sampling membrane has an adsorption performance of octocrylene in the air that is 120% higher than that of ordinary membranes, has better specificity, and can be used for highly selective adsorption and enrichment of cinnamic acid organic ultraviolet sunscreen agents in the air.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions:

[0007] The first object of the present invention is to provide a cinnamic acid organic ultraviolet sunscreen agent molecular imprinting passive sampling membrane, which comprises polymerizing a template molecule, a functional monomer and a cross-linking agent into a cinnamic acid organic ultraviolet sunscreen agent molecular imprinting polymer, and using polydimethylsiloxane as a substrate to prepare the cinnamic acid organic ultraviolet sunscreen agent molecular imprinting passive sampling membrane by a solution composite film forming method.

[0008] Furthermore, the template molecule is 2-cyano-3,3-diphenylacrylate isooctyl ester.

[0009] Furthermore, the functional monomer is a combination of one or more of methacrylic acid, methyl methacrylate, 4-vinylpyridine and acrylamide.

[0010] More preferably, the functional monomer is methacrylic acid.

[0011] Furthermore, the cross-linking agent is tetrahydrofuran.

[0012] The second object of the present invention is to provide a method for preparing a cinnamic acid organic ultraviolet sunscreen agent molecular imprinted passive sampling membrane, comprising the following steps:

[0013] (1) Aggregation

[0014] At room temperature, a template molecule (2-cyano-3,3-diphenylacrylate isooctyl ester) was placed in a 250 mL conical flask, a porogen (tetrahydrofuran) was added to dissolve, and after mixing, a functional monomer (methacrylic acid) was added and ultrasonicated for 30 minutes for prepolymerization, and then oscillated at room temperature for 12 hours overnight, and a crosslinker and an initiator were added to the conical flask again, and ultrasonicated for 30 minutes to disperse evenly and observe complete dissolution, and then the reaction solution was transferred to a flask, and nitrogen was passed for 10-15 minutes for deoxygenation and sealed, and reacted at 60°C for 10 hours under magnetic stirring, and centrifuged at 4000 r / min to obtain a crude white solid cinnamic acid organic UV sunscreen molecular imprinting polymer;

[0015] (2) Elution

[0016] The obtained crude product of cinnamic acid organic UV sunscreen molecularly imprinted polymer was dried at 60°C to constant weight, ground into powder, and the powder was placed in a 100 mL conical flask and eluted with a methanol / acetic acid (9:1, v / v) mixture, ultrasonicated for 30 min, and centrifuged at 4000 r / min. After centrifugation, the supernatant was taken to remove the template molecule and unreacted compounds, dried at 60°C, and sieved to obtain the cinnamic acid organic UV sunscreen molecularly imprinted polymer;

[0017] (3) Film formation

[0018] Cinnamic acid organic UV sunscreen agent molecular imprinting polymer and polydimethylsiloxane are taken and the solution composite film-forming method is used to synthesize the cinnamic acid organic UV sunscreen agent molecular imprinting passive sampling membrane.

[0019] Furthermore, the molar ratio of the template molecule 2-cyano-3,3-diphenylacrylate, the functional monomer methacrylic acid, and the cross-linking agent tetrahydrofuran is (0.5-2):4:30.

[0020] More preferably, the molar ratio of the template molecule 2-cyano-3,3-diphenylacrylate, the functional monomer methacrylic acid, and the cross-linking agent tetrahydrofuran is 1:4:30.

[0021] More preferably, the template molecule 2-cyano-3,3-diphenylacrylate isooctyl ester is used in an amount of 0.2 mmol, the functional monomer methacrylic acid is used in an amount of 0.8 mmol, and the cross-linking agent tetrahydrofuran is used in an amount of 6 mmol.

[0022] Furthermore, the porogen is tetrahydrofuran; the ratio of the template molecule 2-cyano-3,3-diphenylacrylate isooctyl ester to the porogen is 1 mol: (100-300) L.

[0023] Further preferably, the porogen is tetrahydrofuran; and the ratio of the template molecule 2-cyano-3,3-diphenylacrylate to the porogen is 1 mol:250L.

[0024] More preferably, the porogen is tetrahydrofuran, and the dosage is 50 mL.

[0025] Furthermore, the initiator is azobisisobutyronitrile, and the ratio of the initiator to the template molecule 3-isooctyl diphenylacrylate is 1 mol: (50-200) g.

[0026] Further preferably, the initiator is azobisisobutyronitrile, and the ratio of the initiator to the template molecule 3-isooctyl diphenylacrylate is 1 mol:100 g.

[0027] More preferably, the initiator is azobisisobutyronitrile, and the dosage is 20 mg.

[0028] Furthermore, the solution composite film forming method of step (3) includes the following process:

[0029] Take cinnamic acid organic UV sunscreen molecular imprinting polymer and polydimethylsiloxane in a beaker, add n-hexane and turn on magnetic stirring, stir until a uniform and transparent solution is formed, then add curing agent, place in a clean fume hood to evaporate the solvent, put in a refrigerator to cool for 24 hours, take out and pour into a mold, put the mold into a precision blast drying oven at 80°C for 4 hours to cure, and demold after curing to form the product cinnamic acid organic UV sunscreen molecular imprinting passive sampling membrane.

[0030] Furthermore, the curing agent is BSTFA-TMCS; the mass ratio of the cinnamic acid organic UV sunscreen molecular imprinting polymer, polydimethylsiloxane, and curing agent is 1:20:2; the amount ratio of the cinnamic acid organic UV sunscreen molecular imprinting polymer and n-hexane is 1g:50L.

[0031] Further preferably, the curing agent is BSTFA-TMCS, the masses of the cinnamic acid organic UV sunscreen molecular imprinted polymer and polydimethylsiloxane are 0.3 g and 6 g respectively, and the amount of n-hexane is 15 mL.

[0032] More preferably, the curing agent is BSTFA-TMCS, and the amount used is 0.6 g.

[0033] The third object of the present invention is to provide the application of the molecular imprinting passive sampling membrane of the cinnamic acid organic UV sunscreen agent, the adsorption performance of octocrylene in the air is improved by 120% compared with ordinary membranes, and it is used for selective adsorption of trace organic UV sunscreen agents in environmental media.

[0034] Furthermore, the adsorption performance of the cinnamic acid organic UV sunscreen molecular imprinting passive sampling membrane for octocrylene in the air is improved by 120% compared with ordinary membranes, and the specificity is better, and it can be used for highly selective adsorption and enrichment of cinnamic acid organic UV sunscreen in the air.

[0035] Compared with the prior art, the present invention has the following advantages:

[0036] 1) The synthesized cinnamic acid organic ultraviolet sunscreen agent molecularly imprinted polymer of the present invention is a white powder polymer, which has a "memory" function for the three-dimensional structure of the cinnamic acid organic ultraviolet sunscreen agent molecule, can selectively adsorb the cinnamic acid organic ultraviolet sunscreen agent, and has a strong adsorption capacity.

[0037] 2) The molecular imprinting passive sampling membrane for cinnamic acid organic ultraviolet sunscreens synthesized by the present invention can be used for highly selective adsorption and enrichment of cinnamic acid organic ultraviolet sunscreens in the air. The adsorption amount of octocrylene by the molecular imprinting passive sampling membrane in the air is 2.178 times that of ordinary membranes. Compared with ordinary membranes, it has better specificity and better detection effect on cinnamic acid organic ultraviolet sunscreens.

[0038] 3) The present invention provides a method for preparing a cinnamic acid organic ultraviolet sunscreen agent molecular imprinting passive sampling membrane, wherein a template molecule, a functional monomer, and a cross-linking agent are polymerized into a cinnamic acid organic ultraviolet sunscreen agent molecular imprinting polymer, and a solution composite film-forming method is adopted to prepare the cinnamic acid organic ultraviolet sunscreen agent molecular imprinting passive sampling membrane. The preparation method is simple and efficient. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 This is a scanning electron microscope image of an ordinary membrane.

[0040] Figure 2 This is a scanning electron microscope image of the passive molecular imprinting film of the cinnamic acid organic ultraviolet sunscreen agent of Example 1 of the present invention.

[0041] Figure 3 is the binding energy of octocrylene (OC) and four functional monomers.

[0042] Figure 4 The adsorption curves of the cinnamic acid organic UV sunscreen molecular imprinting passive sampling membrane of Example 1 at different times.

[0043] Figure 5 This is the cinnamic acid organic ultraviolet sunscreen agent molecular imprinting passive sampling membrane of Example 1 of the present invention and the saturated adsorption amount of different organic ultraviolet sunscreen agents.

[0044] Figure 6 This is a graph showing the adsorption capacity of the cinnamic acid organic UV sunscreen molecular imprinting passive sampling membrane of Example 1 for octocrylene in the air. DETAILED DESCRIPTION

[0045] The following is a detailed description of an embodiment of the present invention: This embodiment is implemented on the premise of the technical solution of the present invention, and a detailed implementation method and a specific operation process are given, but the protection scope of the present invention is not limited to the following embodiments.

[0046] The present invention is described in detail below in conjunction with specific embodiments, but is by no means intended to limit the present invention. Features such as preparation methods, materials, structures or composition ratios not explicitly described in this technical solution are considered to be common technical features disclosed in the prior art.

[0047] The following examples will help those skilled in the art to further understand the present invention, but are not intended to limit the present invention in any form. It should be noted that, for those of ordinary skill in the art, several modifications and improvements may be made without departing from the concept of the present invention. These all fall within the scope of protection of the present invention.

[0048] The practice of the present invention may employ conventional techniques of chemistry within the skill of the art. In the following examples, efforts have been made to ensure accuracy with respect to the numbers used (including amounts, temperatures, reaction times, etc.), but some experimental errors and deviations should be taken into account.

[0049] In the following examples, the preparation process of the common membrane is as follows: 6 g of polydimethylsiloxane is added to a beaker, 15 mL of n-hexane is added, and magnetic stirring is turned on. After stirring until a uniform and transparent solution is formed, a curing agent is added, and the solution is placed in a clean fume hood to volatilize the solvent, placed in a refrigerator and allowed to stand for cooling for 24 hours, and then poured into a mold. The mold is placed in a precision blast drying oven at 80°C for 4 hours to cure, and after curing, the mold is removed to form a product common membrane (NIPs membrane), such as Figure 1 The figure shows a scanning electron microscope image of an ordinary membrane.

[0050] In the following examples, polydimethylsiloxane (Sylgard 184PDM) was purchased from Dow Corning Corporation, USA.

[0051] Example 1.

[0052] This embodiment provides a method for preparing a cinnamic acid organic ultraviolet sunscreen agent molecular imprinting passive sampling membrane, comprising the following steps:

[0053] At room temperature, 0.2 mmol of the template molecule 2-cyano-3,3-diphenylacrylate isooctyl ester was placed in a 250 mL conical flask, 50 ml of tetrahydrofuran was added to dissolve the porogen, 0.8 mmol of the functional monomer methacrylic acid (MAA) was added after mixing, and prepolymerization was carried out by ultrasonication for 30 min. Then, the mixture was shaken at room temperature for 12 h overnight. 6 mmol of the crosslinking agent tetrahydrofuran and 20 mg of the initiator azobisisobutyronitrile were added to the conical flask again, and the mixture was dispersed evenly by ultrasonication for 30 min. After the mixture was completely dissolved, the reaction solution was transferred to a flask, deoxygenated with nitrogen for 10-15 min, and sealed. The mixture was reacted at 60° C. for 10 h under magnetic stirring, and centrifuged at 4000 r / min to obtain a crude white solid cinnamic acid organic UV sunscreen molecular imprinting polymer. The obtained crude product of cinnamic acid organic UV sunscreen molecular imprinting polymer was dried at 60°C to constant weight, ground into powder, and the powder was placed in a 100 mL conical flask and eluted with a methanol / acetic acid (9:1, v / v) mixture, ultrasonicated for 30 min, and centrifuged at 4000 r / min. After centrifugation, the supernatant was taken to remove the template molecules and unreacted compounds, dried at 60°C, and passed through a 300 mesh sieve to obtain cinnamic acid organic UV sunscreen molecular imprinting polymer. Take 0.3g of cinnamic acid organic UV sunscreen molecular imprinting polymer and 6g of polydimethylsiloxane and use the solution composite film forming method to synthesize the product cinnamic acid organic UV sunscreen molecular imprinting passive sampling membrane. The solution composite film forming method is specifically to add 15mL of n-hexane to 0.3g of cinnamic acid organic UV sunscreen molecular imprinting polymer and 6g of polydimethylsiloxane in a beaker and turn on the magnetic stirring. After stirring until a uniform and transparent solution is formed, a curing agent is added, and the solution is placed in a clean fume hood to evaporate the solvent. The solution is placed in a refrigerator and allowed to cool for 24 hours, then taken out and poured into a mold. The mold is placed in a precision blast drying oven at 80°C for 4 hours to cure. After curing, the film is demolded to form the product cinnamic acid organic UV sunscreen molecular imprinting passive sampling membrane (MIPs membrane).

[0054] like Figure 2 This is a scanning electron microscope image of the passive molecular imprinting film of the cinnamic acid organic ultraviolet sunscreen agent of Example 1 of the present invention.

[0055] Example 2.

[0056] The difference from Example 1 is that the porogen tetrahydrofuran in Example 2 is 20 mL.

[0057] Example 3.

[0058] The difference from Example 1 is that the porogen tetrahydrofuran in Example 3 is 30 mL.

[0059] Example 4.

[0060] The difference from Example 1 is that the porogen tetrahydrofuran in Example 4 is 40 mL.

[0061] Example 5.

[0062] The difference from Example 1 is that the porogen tetrahydrofuran in Example 5 is 60 mL.

[0063] Example 6.

[0064] The difference from Example 1 is that the template molecule 2-cyano-3,3-diphenylacrylate isooctyl ester in Example 6 is 0.1 mmol.

[0065] Example 7.

[0066] The difference from Example 1 is that the template molecule 2-cyano-3,3-diphenylacrylate isooctyl ester in Example 7 is 0.3 mmol.

[0067] Example 8.

[0068] The difference from Example 1 is that the template molecule 2-cyano-3,3-diphenylacrylate isooctyl ester in Example 8 is 0.4 mmol.

[0069] Example 9.

[0070] The difference from Example 1 is that the functional monomer of Example 9 is methyl methacrylate (MMA).

[0071] Example 10.

[0072] The difference from Example 1 is that the functional monomer of Example 10 is 4-vinylpyridine (4-vp).

[0073] Example 11.

[0074] The difference from Example 1 is that the functional monomer of Example 11 is acrylamide (AM).

[0075] Example 12.

[0076] The difference from Example 1 is that the initiator azobisisobutyronitrile (AIBN) in Example 12 is 10 mg.

[0077] Example 13.

[0078] The difference from Example 1 is that the initiator azobisisobutyronitrile (AIBN) in Example 13 is 30 mg.

[0079] Example 14.

[0080] The difference from Example 1 is that the initiator azobisisobutyronitrile (AIBN) in Example 14 is 40 mg.

[0081] Morphological characterization of polymers:

[0082] According to Examples 1, 6, 7, and 8, 2-cyano-3,3-diphenylacrylate (OC) is used as a template molecule. When the molar ratio of the template molecule to the functional monomer is 1:4, adhesion occurs to the particles after elution. At the same time, obvious holes appear after the template molecules are washed away. The surface has many pores and presents a highly cross-linked porous structure. After complete elution, the imprinted holes are exposed, which is beneficial to the generation of adsorption sites and the improvement of adsorption capacity.

[0083] The influence of functional monomer types:

[0084] According to Examples 1, 9, 10, and 11, compared with other functional monomers, AM has a significant advantage in binding energy, indicating that it is the most ideal functional monomer in theory. However, AM clearly has neurotoxicity, immunotoxicity, carcinogenicity and other toxicities. Considering the expected subsequent application of MIPs membranes, it is not recommended to select AM as the raw material for MIPs membranes. The binding energy ΔE increases in the order of OC-MAA, OC-4-VP, and OC-MMA. Therefore, among the functional monomers except AM, MAA and OC have a stronger binding force and better stability. The binding energy is 0.066 Hartree, or 173.598 kJ / mol. The binding effect of MMA is the worst, which is consistent with the explanation that OC, as a Lewis base, is easier to combine with neutral and acidic monomers. Figure 3 is the binding energy of OC and four functional monomers.

[0085] Adsorption capacity:

[0086] According to Example 1, the adsorption kinetics of the MIPs membrane is mainly to study the changes in the adsorption amount of the analyte by the MIPs membrane over a period of time. Figure 4 It can be seen that the adsorption capacity of the MIPs membrane in Example 1 increases rapidly in the first 20 minutes, and can reach more than 95% of the adsorption capacity after 60 minutes, and reaches adsorption equilibrium at about 90 minutes, at which time the saturated adsorption capacity is 0.9803 mg / g. The adsorption capacity of the NIPs membrane (ordinary membrane) also increases sharply in the early stage, and then tends to increase slowly, and the final saturated adsorption capacity is 0.7894 mg / g. The saturated adsorption capacity of the MIPs membrane is 1.24 times that of the NIPs membrane.

[0087] Effect of porogen dosage:

[0088] The present invention uses tetrahydrofuran as solvent, and tetrahydrofuran also serves as a porogen. By increasing the amount of the porogen, other components are in a relatively dilute concentration, so that the particles that are polymerized can be prevented from agglomerating into a block. Generally, the precipitation polymerization method can obtain more uniform microparticles, or even monodisperse microspherical polymers. According to Example 1 and Example 2, 3, 4, and 5, by comparing different amounts of tetrahydrofuran, it is found that the polymer particles obtained by 50 mL of tetrahydrofuran (porogen) have a larger particle size and a large output, and there is almost no solvent residue in the system; the particles obtained by 20, 30, 40, and 60 mL of tetrahydrofuran (porogen) do not show much difference in appearance; the polymer particles obtained by 30 mL of tetrahydrofuran (porogen) are smaller, the output is also less, and there are more solvents remaining in the system.

[0089] Adsorption levels of different pollutants:

[0090] like Figure 5 As shown, under the same other conditions, the MIPs membrane of Example 1 still has a greater adsorption capacity for the four types of organic UVFs in the experiment than the NIPs membrane. It is worth noting that compared with the NIPs membrane, the MIPs membrane has a significantly higher adsorption capacity for IMC (isoamyl p-methoxycinnamate) and EHMC (ethylhexyl methoxycinnamate) with similar structures than BP-3 (2-hydroxy-4-methoxybenzophenone) and BMDBM (methoxydibenzoylmethane) with different structures, which indicates that the MIPs membrane also has a certain broad spectrum of adsorption for OC structural analogs, that is, cinnamic acid organic UVFs. When using the MIPs membrane of the present application, the adsorption effect of such substances will also be improved.

[0091] Effect of initiator dosage:

[0092] According to Examples 1, 12, 13, and 14, the equilibrium adsorption capacity of molecular imprinting polymers with 2-cyano-3,3-diphenylacrylate as the template molecule and AIBN dosage of 10 mg, 20 mg, 30 mg, and 40 mg were compared. As the dosage of the initiator AIBN increased, the stability of the polymer decreased. When the dosage of the initiator was 40 mg, it was impossible to fit it with a single F model, and the correlation was too low, indicating that the uniformity of the binding sites was poor, and the MIPs membrane prepared with 20 mg of the initiator had the best adsorption performance.

[0093] Embodiment 15

[0094] The cinnamic acid organic ultraviolet sunscreen agent molecular imprinting passive sampling membrane (MIPs membrane) of the present invention and a common membrane (NIPs membrane) were tested and compared.

[0095] The specific SPE process is as follows:

[0096] (1) Activation: Add 3 mL of methanol to the SPE column, and then add 2 mL of 0.1 mol / L hydrochloric acid to pass through the column.

[0097] (2) Loading: Add 1 mL of 1 mg / L organic UV screener solution to pass through the column, and take the effluent to determine the residual concentration of organic UV screener by HPLC.

[0098] (3) Elution: Add 1 mL of 0.4% formic acid aqueous solution to the column and drain the SPE column.

[0099] (4) Elution: Add 1 mL of methanol / acetic acid (9:1, v / v) to pass through the column, blow dry the effluent with nitrogen, add water to make up to 1 mL, and detect by HPLC. Add 1 mL of methanol / acetic acid (9:1, v / v) and repeat the above steps, using a total of 2 mL of eluent.

[0100] (5) SPE column regeneration: add 5 mL of 50% methanol aqueous solution (containing 0.1 M NaOH) to wash away the excess acid and possible residual organic UV sunscreen in the SPE column, then add 5 mL of water, 1 mL of 0.1 M HCl, and 6 mL of methanol to pass through the column, vacuum dry, and set aside.

[0101] Gas chromatography-mass spectrometry GC-MS / MS detection process:

[0102] A. Thermal Desorption Conditions

[0103] a) Carrier gas: high purity (99.999%) nitrogen

[0104] b) Flow rate: 30mL / min

[0105] c) Pre-purge: 1min

[0106] d) Adsorption tube temperature: 300℃

[0107] e) Desorption time: 10min

[0108] f) Cold trap temperature: -10℃

[0109] g) Desorption temperature: 280℃

[0110] h) Cold trap desorption time: 5min

[0111] i) Transmission line temperature: 200°C

[0112] B. Gas Chromatography Instrument Conditions

[0113] a) Inlet temperature: 280℃

[0114] b) Heating program: Initial column temperature was maintained at 35°C for 4 min, then increased to 150°C at 5°C / min, maintained for 7.0 min, then increased to 200°C at 10°C / min, maintained for 4.0 min

[0115] c) Carrier gas: Helium, purity ≥ 99.999%

[0116] d) Column flow rate: 1.0ml / min

[0117] e) Injection mode: splitless injection

[0118] f) Solvent delay time: 5min

[0119] C. Mass Spectrometry Conditions

[0120] a) Ionization method: EI

[0121] b) Ion source temperature: 230°C

[0122] c) Ionization energy: 70Ev

[0123] d) Transmission line temperature: 250°C

[0124] e) Determination method: Selected ion scanning mode (SIM)

[0125] f) Full scanning range: 35u~300u

[0126] The injection method was split flow injection, and the injection volume was 1 μL.

[0127] The experimental results are as follows Figure 6 The results show that both the NIPs and MIPs membranes recovered after being placed for a period of time have eluted a certain amount of OC, indicating that they also have the ability to adsorb OC volatilized into the air. Moreover, the MIPs membrane exhibits better adsorption performance, and the amount of OC adsorbed by the MIPs membrane in the air is 2.178 times that of the NIPs membrane. It has better specificity and better detection effect on trace organic UV sunscreens.

[0128] The above description of the embodiments is to facilitate the understanding and use of the invention by those skilled in the art. It is obvious that those skilled in the art can easily make various modifications to these embodiments and apply the general principles described herein to other embodiments without creative work. Therefore, the present invention is not limited to the above embodiments, and 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 within the scope of protection of the present invention.

Claims

1. A cinnamic acid organic ultraviolet sunscreen agent molecular imprinting passive sampling membrane, characterized in that: The template molecule 2-cyano-3,3-diphenylacrylate isooctyl ester, the functional monomer methacrylic acid and the cross-linking agent tetrahydrofuran are polymerized into a cinnamic acid organic ultraviolet sunscreen agent molecular imprinting polymer, and the cinnamic acid organic ultraviolet sunscreen agent molecular imprinting passive sampling membrane is prepared by a solution composite film-forming method using polydimethylsiloxane as a substrate.

2. A method for preparing a cinnamic acid organic ultraviolet sunscreen molecularly imprinted passive sampling membrane as claimed in claim 1, characterized in that: The preparation method comprises the following steps: (1) Polymerization: Take the template molecule 2-cyano-3,3-diphenylacrylate isooctyl ester at room temperature, add a porogen to dissolve it, mix it well, add the functional monomer methacrylic acid to perform ultrasonic prepolymerization, then shake it at room temperature, add the crosslinking agent tetrahydrofuran and the initiator again, and after ultrasonic dispersion, pass nitrogen gas to deoxygenate the reaction solution and seal it, heat and stir to react, and centrifuge to obtain a crude product of cinnamic acid organic UV sunscreen molecular imprinting polymer; (2) eluting: eluting the obtained crude product of the cinnamic acid organic ultraviolet sunscreen agent molecularly imprinted polymer with a mixture of methanol and ethanol to obtain the cinnamic acid organic ultraviolet sunscreen agent molecularly imprinted polymer; (3) Film formation: Cinnamic acid organic UV sunscreen agent molecular imprinting polymer and polydimethylsiloxane are taken, and a cinnamic acid organic UV sunscreen agent molecular imprinting passive sampling membrane is synthesized by a solution composite film forming method.

3. The method for preparing the cinnamic acid organic ultraviolet sunscreen molecular imprinted passive sampling membrane according to claim 2, characterized in that: Step (1) includes the following process: Take the template molecule 2-cyano-3,3-diphenylacrylate isooctyl ester at room temperature, add the porogen to dissolve it, mix well, add the functional monomer methacrylic acid and perform ultrasonic prepolymerization for 30 minutes, then oscillate at room temperature for 12 hours overnight, add the cross-linking agent and initiator again, disperse by ultrasonic for 30 minutes, deoxygenate the reaction solution with nitrogen for 10-15 minutes and seal it, react at 60°C for 10 hours under magnetic stirring, and centrifuge at 4000r / min to obtain the crude product of cinnamic acid organic UV sunscreen molecular imprinting polymer.

4. The method for preparing the cinnamic acid organic ultraviolet sunscreen molecular imprinted passive sampling membrane according to claim 2, characterized in that: Step (2) includes the following process: The obtained crude product of cinnamic acid organic UV sunscreen molecularly imprinted polymer was dried at 60°C to constant weight, ground into powder, and the powder was eluted with a mixture of methanol and ethanol in a volume ratio of 9:1, ultrasonicated for 30 minutes, and centrifuged at 4000r / min. The supernatant was taken after centrifugation to remove the template molecules and unreacted compounds, dried at 60°C, and sieved to obtain cinnamic acid organic UV sunscreen molecularly imprinted polymer.

5. The method for preparing the cinnamic acid organic ultraviolet sunscreen molecular imprinted passive sampling membrane according to claim 2, characterized in that: The molar ratio of the template molecule 2-cyano-3,3-diphenylacrylate isooctyl ester, the functional monomer methacrylic acid and the crosslinking agent tetrahydrofuran is (0.5-2):4:

30.

6. The method for preparing the cinnamic acid organic ultraviolet sunscreen molecular imprinted passive sampling membrane according to claim 2, characterized in that: The porogen is tetrahydrofuran; The dosage ratio of the template molecule 2-cyano-3,3-diphenylacrylate isooctyl ester to the porogen is 1 mol: (100-300) L.

7. The method for preparing the cinnamic acid organic ultraviolet sunscreen molecularly imprinted passive sampling membrane according to claim 2, characterized in that: The initiator is azobisisobutyronitrile, and the dosage ratio of the initiator to the template molecule 3-isooctyl diphenylacrylate is 1 mol: (50-200) g.

8. The method for preparing the cinnamic acid organic ultraviolet sunscreen molecular imprinted passive sampling membrane according to claim 2, characterized in that: The process of the solution composite film forming method comprises the following steps: Take cinnamic acid organic UV sunscreen molecular imprinting polymer and polydimethylsiloxane, add n-hexane and stir, then add curing agent, evaporate the solvent, let it stand and cool, then pour it into a mold, dry and solidify, and demold after solidification to form a product cinnamic acid organic UV sunscreen molecular imprinting passive sampling membrane.

9. The method for preparing the cinnamic acid organic ultraviolet sunscreen molecularly imprinted passive sampling membrane according to claim 8, characterized in that: The curing agent is BSTFA-TMCS; The mass ratio of the cinnamic acid organic UV sunscreen molecular imprinting polymer, polydimethylsiloxane and curing agent is 1:20:2; The usage ratio of the cinnamic acid organic ultraviolet sunscreen molecular imprinting polymer to n-hexane is 1 g:50 L.

10. An application of the cinnamic acid organic ultraviolet sunscreen molecular imprinting passive sampling membrane as claimed in claim 1, characterized in that: The cinnamic acid organic ultraviolet sunscreen agent molecular imprinting passive sampling membrane is used for selective adsorption of trace organic ultraviolet sunscreen agents in environmental media.

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