Selective removal and detection method for zearalenone in complex matrix

Abstract

The invention provides a preparation method of a poly eutectic solvent MOF-based polymer Poly (DES) (at) MIL-101-NH2 (Cr), which is characterized by comprising the following steps: (1) preparing a eutectic solvent (DES) from betaine and acrylic acid under a stirring condition; (2) Cr (NO3) 3.9 H2O, terephthalic acid and alkali metal are subjected to a reaction, and a metal organic framework MIL-101-NH2 (Cr) is prepared; (3) dissolving a metal organic framework MIL-101-NH2 (Cr) and curcumin in an organic solvent, and then carrying out prepolymerization with the eutectic solvent; and (4) adding a cross-linking agent and an initiator, degassing, and reacting to obtain the MOF-based polymer Poly (DES) (at) MIL-101-NH2 (Cr). The invention provides a green, safe, simple, effective, accurate and sensitive analysis strategy, provides a simple and efficient scheme for specific detection and removal of ZEN in a complex matrix, and also provides a new reference for effective enrichment and sensitive detection of other mycotoxins and trace pollutants.

Description

Technical Field

[0001] The present application belongs to the field of detection technology, and in particular relates to a method for selectively removing and detecting zearalenone in a complex matrix. Background Art

[0002] Zearalenone (ZEN) is a fungal toxin produced by Fusarium during its growth and reproduction. As one of the most widespread mycotoxins in the world, it is widely present in cereal feed and agricultural by-products such as corn, coix seed, wheat and sorghum.

[0003] ZEN has genotoxic, cytotoxic, immunotoxic, hepatotoxic, carcinogenic and mutagenic properties, and can affect the normal synthesis of tissue cell DNA, leading to cell mutations; it has estrogen-like effects, mainly acting on the reproductive system, causing female infertility, miscarriage during pregnancy and fetal malformations; it can also cause liver and kidney toxicity, cause organ damage, and induce cancer. It is classified as a Class III carcinogen by the International Agency for Research on Cancer. Moreover, ZEN is stable in nature and highly heat-resistant. It can remain active for a long time in grain storage, food processing and animal feed production, posing a great threat to food safety and animal health.

[0004] At present, the commonly used detection methods of ZEN mainly include thin layer chromatography (TLC), high performance liquid chromatography (HPLC), enzyme-linked immunosorbent assay (ELISA), colloidal gold immunochromatography (GICT) and liquid chromatography-mass spectrometry (LC-MS). These methods can be used for the determination of ZEN, but they still have limitations such as time-consuming, complex operation, low selectivity and detection sensitivity. Strong toxicity, low content and complex matrix interference effects are key issues for the accurate determination of ZEN. The analytical method combining chromatographic analysis technology with sample pretreatment techniques such as solid phase extraction (SPE) can reduce matrix interference effects and improve the sensitivity and accuracy of the analytical method. Molecularly imprinted polymers (MIPs) are used as selective adsorbents in solid phase extraction due to their unique advantages in specific recognition ability. They can also specifically recognize target molecules in the presence of other molecules, overcome the interference effects of complex matrices, and effectively enrich trace amounts of ZEN. Summary of the invention

[0005] The technical problem to be solved by the present application is to overcome the limitations of the commonly used detection methods of ZEN in the prior art, such as time-consuming, complicated operation, low selectivity and detection sensitivity, and the fact that ZEN is highly toxic, has a low content, and has a complex matrix interference effect, making it difficult to achieve safe and simple rapid removal and detection, and to provide a method for the selective removal and detection of zearalenone in a complex matrix. The present application establishes an environmentally friendly and efficient detection system based on computer-aided design for the selective removal and detection of zearalenone in coix seeds.

[0006] This application adopts the following technical solutions to solve the above technical problems:

[0007] First aspect:

[0008] The present application provides a method for preparing a poly-low eutectic solvent MOF-based polymer Poly(DES)@MIL-101-NH2(Cr), characterized in that it comprises the following steps:

[0009] (1) preparing a deep eutectic solvent (DES) by mixing betaine and acrylic acid under stirring conditions;

[0010] (2) Synthesis of the metal organic framework MIL-101-NH2(Cr) by reacting Cr(NO3)3·9H2O, terephthalic acid and alkali metal;

[0011] (3) first dissolving the metal organic framework MIL-101-NH2(Cr) and curcumin in an organic solvent, and then prepolymerizing with the low eutectic solvent;

[0012] (4) adding a crosslinking agent and an initiator, and reacting after degassing to obtain the MOF-based polymer Poly(DES)@MIL-101-NH2(Cr).

[0013] Preferably, the preparation method of the poly-low eutectic solvent MOF-based polymer Poly(DES)@MIL-101-NH2(Cr) satisfies at least one of the following conditions:

[0014] In step (1), the molar ratio of the betaine to the acrylic acid is 1:(2-4);

[0015] In step (1), betaine and acrylic acid are mixed in a molar ratio of 1:2, 1:3 and 1:4 respectively, and heated and stirred continuously at 85°C.

[0016] In step (1), the heating temperature is 80-90°C.

[0017] Preferably, the preparation method of the poly-low eutectic solvent MOF-based polymer Poly(DES)@MIL-101-NH2(Cr) satisfies at least one of the following conditions:

[0018] In step (2), the mass ratio of the Cr(NO3)3·9H2O to the terephthalic acid to the alkali metal is 1:1:(1-4), for example 1:1:2;

[0019] In step (2), the terephthalic acid includes 2-aminoterephthalic acid;

[0020] In step (2), the alkali metal includes sodium hydroxide;

[0021] In step (2), the Cr(NO3)3·9H2O, terephthalic acid and alkali metal further include an ultrasonic dispersion operation before the synthesis reaction;

[0022] In step (2), the synthesis reaction time is 8 to 14 hours, for example 12 hours;

[0023] In step (2), the synthesis reaction further includes an ultrasonic dispersion operation;

[0024] In step (2), after the synthesis reaction, the process further includes washing and drying operations.

[0025] Preferably, the preparation method of the poly-low eutectic solvent MOF-based polymer Poly(DES)@MIL-101-NH2(Cr) satisfies at least one of the following conditions:

[0026] At least one of the following conditions is met:

[0027] The ultrasonic dispersion time is 20 to 45 minutes, for example 30 minutes;

[0028] The ultrasonic dispersion is performed in water;

[0029] The washing comprises washing once with DMF and then washing twice with an alcohol solution;

[0030] The time of one washing is 5 to 20 minutes, for example 5 minutes.

[0031] The secondary washing time is 18 to 36 hours, for example 24 hours;

[0032] The solvent for the secondary washing is ethanol.

[0033] The temperature of the secondary washing is 80-100°C, for example 100°C;

[0034] The drying comprises vacuum drying;

[0035] The vacuum drying time is 10 to 16 hours, for example 12 hours;

[0036] The vacuum drying temperature is 75-90°C, for example 80°C.

[0037] Preferably, the preparation method of the poly-low eutectic solvent MOF-based polymer Poly(DES)@MIL-101-NH2(Cr) satisfies at least one of the following conditions:

[0038] In step (3), the mass ratio of the DES to the curcumin is 1 to 6:(1), for example, 3:1;

[0039] In step (3), the organic solvent is a methanol-acetonitrile mixed solvent;

[0040] In step (3), the prepolymerization further includes an ultrasonic dispersion operation;

[0041] In step (3), the mass of the MIL-101-NH2 is 100 to 400 mg, for example, 200 mg;

[0042] In step (3), the prepolymerization time is 1 to 24 hours, for example 2 hours.

[0043] Preferably, the preparation method of the poly-low eutectic solvent MOF-based polymer Poly(DES)@MIL-101-NH2(Cr) satisfies at least one of the following conditions:

[0044] At least one of the following conditions is met:

[0045] The volume ratio of methanol to acetonitrile is 1:1;

[0046] The ultrasound duration is 20 to 40 minutes, for example 30 minutes.

[0047] Preferably, the preparation method of the poly-low eutectic solvent MOF-based polymer Poly(DES)@MIL-101-NH2(Cr) satisfies at least one of the following conditions:

[0048] At least one of the following conditions is met:

[0049] In step (4), the cross-linking agent includes EGDMA;

[0050] In step (4), the initiator includes AIBN;

[0051] In step (4), the mass ratio of the curcumin to the cross-linking agent is 1:(15-25), for example 1:20.

[0052] In step (4), the mass ratio of the DES to the cross-linking agent is 1:4 to 8, for example 1:6.

[0053] In step (4), the mass ratio of the curcumin to the DES and the cross-linking agent is 1:1-6:15-25, for example 1:3:20.

[0054] In step (4), the mass of the initiator is 40 to 100 mg, for example 75 mg;

[0055] In step (4), the degassing is ultrasonic degassing of the mixed liquid;

[0056] In step (4), the degassing time is 20 min;

[0057] In step (4), the degassing further includes nitrogen blowing

[0058] In step (4), the reaction temperature is 50-70°C, for example 60°C;

[0059] In step (4), the reaction time is 18 to 28 hours, for example 24 hours;

[0060] In step (4), the reaction further includes elution and drying operations;

[0061] Preferably, the preparation method of the poly-low eutectic solvent MOF-based polymer Poly(DES)@MIL-101-NH2(Cr) satisfies at least one of the following conditions:

[0062] At least one of the following conditions is met:

[0063] The nitrogen blowing time is 15min;

[0064] The elution is performed using a methanol / acetic acid solution, wherein the volume ratio of the methanol to the acetic acid is 9:1;

[0065] The elution time is 24 to 44 hours, for example 36 hours;

[0066] The drying time is 12h;

[0067] The drying temperature is 50-70°C, for example 60°C.

[0068] The present application also provides a poly-low eutectic solvent MOF-based polymer Poly(DES)@MIL-101-NH2(Cr), which is prepared by the above-mentioned poly-low eutectic solvent MOF-based polymer Poly(DES)@MIL-101-NH2(Cr) preparation method.

[0069] The present application also provides the application of the MOF-based polymer Poly(DES)@MIL-101-NH2(Cr) in the poly-low eutectic solvent, characterized in that it is used for the removal and detection of ZEN in coix seed samples.

[0070] Second aspect:

[0071] This application conducted a spike recovery experiment on coix seed samples, and the specific operations are as follows:

[0072] The ZEN spike levels in coix seed samples were 0.1, 0.5, and 1 mg / L;

[0073] 100 mg of PDES-MIP material was accurately weighed and placed in a simple solid phase extraction syringe. 1 ml of coix seed sample solution containing different concentrations of ZEN was added thereto. The spiked coix seed solution was allowed to slowly flow out through the adsorbent in the simple solid phase extraction syringe. The entire outflow process lasted for about 5 minutes.

[0074] Elution was performed using 5 ml of methanol:acetic acid (v / v, 8:2). The eluate was filtered through a 0.22 μm microporous filter membrane and the concentration of ZEN was determined. The above experimental process was repeated three times in parallel, and the recovery rate and relative standard deviation (RSD) of ZEN at different spike levels were calculated.

[0075] On the basis of conforming to the common sense in the art, the above-mentioned preferred conditions can be arbitrarily combined to obtain the preferred embodiments of the present application.

[0076] The reagents and raw materials used in this application are commercially available.

[0077] The positive effects of this application are:

[0078] (1) This application and the present invention establish an environmentally friendly and efficient enrichment strategy based on computer-aided design for the selective removal and detection of ZEN in coix seed. Using the functionalized MIL-101-NH2(Cr) metal organic framework as a carrier, curcumin as an alternative template, and (acrylic acid-betaine) low eutectic solvent system as a functional monomer, the synthesis scheme and process were optimized, and a new type of green poly-low eutectic solvent MOF-based polymer Poly(DES)@MIL-101-NH2(Cr) was synthesized through a green and safe preparation process. Finally, using Poly(DES)@MIL-101-NH2(Cr) as an adsorbent for solid phase extraction, the SPE simple syringe was combined with high performance liquid chromatography (HPLC) technology to achieve accurate and sensitive detection and effective removal of ZEN in coix seed. The DFT-assisted MIT combined with SPE-HPLC analysis strategy constructed in this study not only provides an effective solution for the effective removal of fungal toxins by poly-low eutectic solvent MOF-based molecular imprinting composites, but also has positive significance in the removal of trace pollutants and the safety monitoring of crop and Chinese medicinal materials cultivation.

[0079] (2) The isothermal adsorption and kinetic adsorption experiments of this application show that the actual adsorption capacity of the prepared poly-low eutectic solvent MOF-based molecular imprinting composite material for ZEN is 9.59 mg / g, the imprinting factor IF is 2.59, and the selectivity factor is 3.41. Based on the SPE simple syringe and HPLC detection system constructed in this study, ZEN in the coix seed sample was specifically removed and accurately detected, and a good recovery rate of 93.99% was obtained, and the maximum RSD value was only 3.24%. After 7 adsorption-desorption cycles, the removal rate of ZEN remained above 90%, and the detection limit and quantification limit of ZEN were 0.05 mg / L and 0.167 mg / L, respectively. This application establishes a green, safe, simple, effective, accurate and sensitive analytical strategy, which provides a simple and efficient solution for the specific detection and removal of ZEN in complex matrices, and also provides a new reference for the effective enrichment and sensitive detection of other mycotoxins and trace pollutants. BRIEF DESCRIPTION OF THE DRAWINGS

[0080] The present application can be better understood by referring to the description given below in conjunction with the accompanying drawings. The accompanying drawings, together with the following detailed description, are included in this specification and form a part of this specification, and are used to further illustrate the preferred embodiments of the present application and explain the principles and advantages of the present application.

[0081] in:

[0082] Figure 1 is a flow chart;

[0083] Figure 2is the isothermal adsorption curve;

[0084] Figure 3 It is the kinetic adsorption curve diagram;

[0085] Figure 4 It is the flow chart of polymer preparation and ZEN adsorption and detection;

[0086] Figure 5 for the selectivity of PDES-MIP;

[0087] Figure 6 For the reusability of PDES-MIP;

[0088] Figure 7 This is the removal chromatogram of ZEN in the real sample Coix seeds.

[0089] Table 1 shows the recovery of ZEN in coix seed after spiked. DETAILED DESCRIPTION

[0090] The present application is further described below by way of examples, but the present application is not limited to the scope of the examples. The experimental methods without specific conditions in the following examples are selected according to conventional methods and conditions, or according to the product instructions.

[0091] Unless otherwise specified, the experimental methods used in the following examples are conventional methods.

[0092] The raw materials in the following examples are all commercially available.

[0093] Example 1

[0094] (1) Preparation of deep eutectic solvent (DES)

[0095] Betaine and acrylic acid were mixed in a molar ratio of 1:2, and heated and stirred continuously at 85°C until a uniform and stable liquid was formed.

[0096] (2) Synthesis of the metal-organic framework MIL-101-NH2(Cr)

[0097] 3.2 g Cr(NO3)3·9H2O, 1.44 g 2-aminoterephthalic acid and 0.64 g sodium hydroxide were dispersed in 60 mL deionized water and ultrasonicated for 30 min. The reaction solution was then transferred to a polytetrafluoroethylene-lined stainless steel autoclave and reacted at 150 °C for 12 h. The autoclave was cooled to room temperature, the green precipitate was collected by centrifugation and washed with DMF at room temperature to remove the unreacted 2-aminoterephthalic acid, and then the product was further washed with hot alcohol at 100 °C for 24 h in the autoclave to remove the unreacted 2-aminoterephthalic acid in the pores of the product. Finally, the product was vacuum dried at 80 °C for 12 h, and green MIL-101-NH2 particles were subsequently obtained.

[0098] (3) Poly(DES)@MIL-101-NH 2( Synthesis of Cr)

[0099] 0.200g MIL-101-NH2 and 0.5mmol curcumin were dissolved in 50mL methanol: acetonitrile = 1:1 (V / V) solvent, 1.5mmol DES was added and ultrasonicated for 30min, mixed evenly, then sealed, and stirred at room temperature for 2h for prepolymerization. After prepolymerization, 10mmol crosslinker EGDMA and 0.075g initiator AIBN were added thereto, the mixed solution was ultrasonically degassed for 20min, then nitrogen was blown for 15min to exhaust the oxygen therein, sealed and reacted at 60℃ for 24h. The obtained solid precipitate was eluted in a Soxhlet extractor with methanol / acetic acid (9:1, v / v) extract for 36h until the template molecule was completely eluted, and then the residual acetic acid was eluted with methanol, and then dried in an oven at 60℃ for 12h.

[0100] Effect Example 1

[0101] In order to evaluate the practicality of Poly(DES)@MIL-101-NH2(Cr) material, a spiked recovery experiment was carried out on coix seed samples.

[0102] The ZEN spike levels in coix seed samples were 0.1, 0.5 and 1 mg / L, respectively. 100 mg of PDES-MIP material was accurately weighed and placed in a simple solid phase extraction syringe, and 1 ml of coix seed sample solution containing different concentrations of ZEN was added thereto, so that the spiked coix seed solution slowly flowed out through the adsorbent in the simple solid phase extraction syringe, and the entire outflow process lasted about 5 minutes. 5 ml of methanol: acetic acid (v / v, 8:2) was used for elution, and the eluate was filtered through a 0.22 μm microporous filter membrane to determine the concentration of ZEN. The above experimental process was repeated 3 times in parallel, and the recovery rate and relative standard deviation (RSD) of ZEN at different spike levels were calculated. The results are shown in Table 1.

[0103] Table 1 Recovery of ZEN in coix seed after spiked (n=3)

[0104]

[0105] Table 1 shows the recoveries and relative standard deviations (RSDs) of coix seed samples at different spike levels. The spike recovery was calculated to be 90.39%-91.99% according to the spike level of ZEN in coix seed samples; the coix seed samples were repeated three times in parallel for each spike level, and the RSD was calculated to be 2.13%-3.24%, which proves that the prepared Poly(DES)@MIL-101-NH2(Cr) has good selectivity and adsorption performance for ZEN in coix seed.

[0106] Finally, it should be noted that in this application, the terms "comprises", "includes" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or apparatus that includes a series of elements includes not only those elements, but also other elements that are not explicitly listed, or also includes elements that are inherent to such process, method, article or apparatus.

[0107] Although the present application has been disclosed above through the description of the specific embodiments of the present application, it should be understood that those skilled in the art can design various modifications, improvements or equivalents to the present application within the spirit and scope of the attached scheme. These modifications, improvements or equivalents should also be considered to be included in the scope of protection claimed in the present application.

Claims

1. A method for preparing a poly(DES)@MIL-101-NH2(Cr)-based polymer of a poly(deep eutectic solvent) MOF, characterized in that: The steps include: (1) preparing a deep eutectic solvent (DES) by mixing betaine and acrylic acid under stirring conditions; (2) Synthesis of the metal organic framework MIL-101-NH2(Cr) by reacting Cr(NO3)3·9H2O, terephthalic acid and alkali metal; (3) first dissolving the metal organic framework MIL-101-NH2(Cr) and (a structural analogue of zearalenone) in an organic solvent, and then prepolymerizing with the low eutectic solvent; (4) adding a crosslinking agent and an initiator, and reacting after degassing to obtain the MOF-based polymer Poly(DES)@MIL-101-NH2(Cr).

2. The method for preparing the poly(DES)@MIL-101-NH2(Cr) based polymer of the poly(deep eutectic solvent) MOF according to claim 1, characterized in that: At least one of the following conditions is met: In step (1), the molar ratio of the betaine to the acrylic acid is 1:(2-4); In step (1), betaine and acrylic acid are mixed in a molar ratio of 1:(2-4), and heated and stirred continuously at 85°C; In step (1), the heating temperature is 80-90°C.

3. The method for preparing the poly(DES)@MIL-101-NH2(Cr) based polymer of the poly(deep eutectic solvent) MOF according to claim 1, characterized in that: At least one of the following conditions is met: In step (2), the mass ratio of the Cr(NO3)3·9H2O to the terephthalic acid to the alkali metal is 1:1:(1-4), for example 1:1:2; In step (2), the terephthalic acid includes 2-aminoterephthalic acid; In step (2), the alkali metal includes sodium hydroxide; In step (2), the Cr(NO3)3·9H2O, terephthalic acid and alkali metal further include an ultrasonic dispersion operation before the synthesis reaction; In step (2), the synthesis reaction time is 8 to 14 hours, for example 12 hours; In step (2), the synthesis reaction further includes an ultrasonic dispersion operation; In step (2), after the synthesis reaction, the process further includes washing and drying operations.

4. The method for preparing the poly(DES)@MIL-101-NH2(Cr) based polymer of the poly(deep eutectic solvent) MOF according to claim 3, characterized in that: At least one of the following conditions is met: The ultrasonic dispersion time is 20 to 45 minutes, for example 30 minutes; The ultrasonic dispersion is performed in water; The washing comprises washing once with DMF and then washing twice with an alcohol solution; The time of one washing is 5 to 20 minutes, for example 5 minutes; The secondary washing time is 18 to 36 hours, for example 24 hours; The solvent for the secondary washing is ethanol; The temperature of the secondary washing is 80-100°C, for example 100°C; The drying comprises vacuum drying; The vacuum drying time is 10 to 16 hours, for example 12 hours; The vacuum drying temperature is 75-90°C, for example 80°C.

5. The method for preparing the poly(DES)@MIL-101-NH2(Cr) based polymer of the poly(deep eutectic solvent) MOF according to claim 1, characterized in that: At least one of the following conditions is met: In step (3), the mass ratio of the DES to the curcumin is 1 to 6:(1), for example, 3:1; In step (3), the organic solvent is a methanol-acetonitrile mixed solvent; In step (3), the prepolymerization further includes an ultrasonic dispersion operation; In step (3), the mass of the MIL-101-NH2 is 100 to 500 mg, for example, 200 mg; In step (3), the prepolymerization time is 1 to 24 hours, for example 2 hours; In step (3), the (zearalenone structural analogue) also includes quercetin, coumarin-3-carboxylic acid, warfarin, puerarin, chrysin, and myricetin.

6. The method for preparing the poly(DES)@MIL-101-NH2(Cr) based polymer of the poly(deep eutectic solvent) MOF according to claim 5, characterized in that: At least one of the following conditions is met: The volume ratio of methanol to acetonitrile is 1:1; The ultrasound duration is 20 to 40 minutes, for example 30 minutes.

7. The method for preparing the poly(DES)@MIL-101-NH2(Cr) based polymer of the poly(deep eutectic solvent) MOF according to claim 1, characterized in that: At least one of the following conditions is met: In step (4), the cross-linking agent includes EGDMA; In step (4), the initiator includes AIBN; In step (4), the mass ratio of the curcumin to the cross-linking agent is 1:(15-25), for example 1:20; In step (4), the mass ratio of the DES to the cross-linking agent is 1:4 to 8, for example 1:6; In step (4), the mass ratio of the curcumin to the DES and the cross-linking agent is 1:1-6:15-25, for example, 1:3:20; In step (4), the mass of the initiator is 40-100 mg, for example, 75 mg. In step (4), the degassing is ultrasonic degassing of the mixed liquid; In step (4), the degassing time is 20 min; In step (4), the degassing further includes nitrogen blowing; In step (4), the reaction temperature is 50-70°C, for example 60°C; In step (4), the reaction time is 18 to 28 hours, for example 24 hours; In step (4), the reaction further includes elution and drying operations.

8. The method for preparing the poly(DES)@MIL-101-NH2(Cr) based polymer of the poly(deuteroeutectic solvent) MOF according to claim 7, characterized in that: At least one of the following conditions is met: The nitrogen blowing time is 15min; The elution is performed using a methanol / acetic acid solution, wherein the volume ratio of the methanol to the acetic acid is 9:1; The elution time is 24 to 44 hours, for example 36 hours; The drying time is 12h; The drying temperature is 50-70°C, for example 60°C.

9. A poly-low eutectic solvent MOF-based polymer Poly(DES)@MIL-101-NH2(Cr), which is prepared by the preparation method of the poly-low eutectic solvent MOF-based polymer Poly(DES)@MIL-101-NH2(Cr) according to any one of claims 1 to 8.

10. A use of the poly(DES)@MIL-101-NH2(Cr) based polymer of the poly(deuteroeutectic solvent) MOF as claimed in claim 9, characterized in that: Used for the removal and detection of ZEN in coix seed samples.

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