A multi-dimensional layered material, and a method of preparing and using the same

Abstract

The present application belongs to the technical field of analytical chemistry, and particularly relates to a kind of multi-dimensional layered material and its preparation method and application.The preparation method of the multi-dimensional layered material of the present application comprises: (1) lithium fluoride and titanium carbon aluminum are dissolved in hydrochloric acid-water solution respectively, and the two are mixed to react, Ti3C2 is obtained; (2) polyvinylpyrrolidone, sodium hydroxide and hydrazine hydrate are mixed, then added to the mixed solution of Ti3C2 and cobalt salt, reacted, Ti3C2-Co is obtained; (3) then Ti3C2-Co aqueous solution is reacted with chitosan aqueous solution, Ti3C2-Co@chitosan is obtained; (4) finally, Ti3C2-Co@chitosan and pyrrole monomer are reacted, and the multi-dimensional layered material is obtained. When the multi-dimensional layered material prepared by the present application is used to extract samples, the whole adsorption extraction and enrichment resolution process can be completed in only 2 min, and it is a kind of magnetic solid phase adsorbent with good magnetic separation effect, high recycling efficiency and great potential.

Description

Technical Field

[0001] This invention belongs to the field of analytical chemistry technology, specifically relating to a multidimensional layered material, its preparation method, and its application. Background Technology

[0002] Triazine herbicides are a class of highly effective, broad-spectrum, and low-toxicity herbicides with a stable triazine structure, widely used internationally. They effectively control some stubborn weeds and improve crop yield and quality. However, under the influence of the plant microenvironment, triazine herbicides can also generate highly toxic triazine metabolites, such as deethylatrazine, deisopropylatrazine, and deethyltert-butylazine, which have significant impacts on the environment and crops. Due to the complex composition of traditional Chinese medicinal materials, efficient enrichment and precise extraction of target components are crucial steps to ensure accurate and reliable results. Various sample pretreatment methods have been reported.

[0003] Chinese invention patent CN104316620A discloses a method for detecting trace amounts of triazine herbicides. The method involves using a diluted test sample as the test solution. 1-Hexyl-3-methylimidazolium ferric chloride is added to the test solution and ultrasonically dispersed. Carbonyl iron powder is then added to the test solution, shaken, and magnetically separated to obtain adsorbed iron powder. Double-distilled water and a weakly polar organic reagent are added to the adsorbed iron powder, and the mixture is shaken to separate the layers. The upper reagent layer is transferred to a test tube, dried with nitrogen, and acetonitrile is added and shaken to obtain the injection solution. The chromatogram of the injection solution is determined using an ultra-fast liquid chromatograph. The concentration of triazine herbicides in the test sample is quantitatively analyzed based on the regression equation between the peak area A and the triazine herbicide concentration c.

[0004] Another Chinese invention patent, CN112946128A, discloses a pretreatment method and quantitative detection method for triazine herbicides. The pretreatment method for triazine herbicides involves: adding an appropriate amount of hydrochloric acid to the sample to be tested and mixing it to obtain a sample solution; adding the sample solution to an activated spin-integrated column solid-phase microextraction device and centrifuging at 2500 r / min for 1 min; discarding the solution in the sleeve; adding 2 mL of an acetonitrile / acetic acid solution with a volume ratio of 30:70 to the above device and centrifuging at 1000 r / min for 1 min; collecting the eluent in the sleeve and filtering it through a 0.22 μm microporous membrane.

[0005] However, almost all of the above methods use commercially available solid-phase extraction (SPE) and solid-phase microextraction (SPE) instruments or modified commercially available dispersion solid-phase extraction materials. When using SPE pretreatment methods, the sample processing involves activation, loading, rinsing, drying, and elution, resulting in significant organic solvent consumption, cumbersome operation, time-consuming and labor-intensive procedures, and failing to meet environmental protection requirements. Furthermore, commercially available dispersion solid-phase extraction materials are traditional C1... 18Carbon materials such as graphite and carbon black, adsorbents such as neutral alumina or PSA powder, and functionalized iron-based materials with simple oxygen-containing functional groups such as carbonyl iron powder, although they have fast pretreatment speeds, have low selectivity, poor specificity, and few detectable components. They cannot be fully recycled after one-time consumption and pose a risk of environmental pollution.

[0006] Therefore, combining rapid dispersion solid-phase extraction technology with novel nano-adsorbents that are highly specific, have a high enrichment rate, and are recyclable can provide new methods and ideas for laboratories and testing institutions in the analysis of triazine herbicides and their metabolite residues. It is of great significance to establish a rapid, efficient, multi-component, high-throughput online screening and quantitative detection technology for the analysis of triazine herbicides and their metabolite residues in Chinese medicinal materials. Summary of the Invention

[0007] This invention addresses the problems existing in the prior art by providing a multidimensional layered material, its preparation method, and its applications. This invention synthesizes a novel layered magnetic nanomaterial with excellent adsorption properties, capable of forming strong intermolecular forces and π-π bonds with triazine organic compounds with a triazine structure, which can be used for rapid analysis of triazine herbicides and their metabolite residues in traditional Chinese medicinal materials.

[0008] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0009] A multidimensional layered material, wherein the raw materials of the multidimensional layered material include lithium fluoride, cobalt salt, titanium aluminum carbide, polyvinylpyrrolidone and chitosan.

[0010] Preferably, the particle size of the multidimensional layered material is 50-80 nm.

[0011] Preferably, the cobalt salt is selected from one or more of cobalt nitrate hexahydrate, cobalt chloride hexahydrate, and cobalt hexaaminochloride.

[0012] Preferably, the molar ratio of lithium fluoride, cobalt salt, titanium aluminum carbide, polyvinylpyrrolidone and chitosan is 58-77:4.4-5.4:5.1-6.2:0.56-1.4:4.5-5.4.

[0013] The present invention also provides a method for preparing the above-mentioned multidimensional layered material, comprising the following steps:

[0014] (1) Lithium fluoride and titanium aluminum carbide were dissolved separately in hydrochloric acid-water solution, and the two were mixed and reacted to obtain Ti3C2;

[0015] (2) Mix polyvinylpyrrolidone, sodium hydroxide and hydrazine hydrate, and then add them to a mixed solution of Ti3C2 and cobalt salt. React to obtain Ti3C2-Co.

[0016] (3) The Ti3C2-Co aqueous solution is then reacted with the chitosan aqueous solution to obtain Ti3C2-Co@chitosan;

[0017] (4) Finally, Ti3C2-Co@chitosan and pyrrole monomer are reacted to obtain the multidimensional layered material.

[0018] Preferably, in step (1), the mass-to-volume ratio of lithium fluoride to hydrochloric acid-water solution is 1.5-2g:15-20mL. When the lithium fluoride is dissolved in hydrochloric acid-water solution, it needs to be stirred. The stirring speed is 100-400r / min and the stirring time is 10-60min.

[0019] Preferably, the mass-to-volume ratio of titanium aluminum carbide to hydrochloric acid-water solution in step (1) is 1-1.2 g: 5 mL. When titanium aluminum carbide is dissolved in hydrochloric acid-water solution, it needs to be sonicated. The power of the sonication is 60-200 W and the sonication time is 8-15 min.

[0020] Preferably, in step (1), the volume ratio of hydrochloric acid to water in the hydrochloric acid-water solution is 3-5:1, the reaction temperature is 25-35℃, the reaction is stirred, and after the reaction, the solution is washed with water until pH=7, filtered, and freeze-dried under an ice bath and nitrogen atmosphere.

[0021] Preferably, the stirring speed is 100-400 r / min, the stirring time is 24-30 h, the freeze-drying temperature is -18-4℃, and the freeze-drying time is 0.5-120 min.

[0022] Preferably, the mass-to-volume ratio of polyvinylpyrrolidone, sodium hydroxide and hydrazine hydrate in step (2) is 0.1-0.25g:0.12-0.4g:30-40mL, and the mixture is stirred and sonicated during mixing.

[0023] Preferably, the stirring speed is 100-400 r / min, the stirring time is 30-120 min, the ultrasonic power is 60-200 W, and the ultrasonic time is 10-30 min.

[0024] Preferably, the cobalt salt in step (2) needs to be dissolved in ethylene glycol, and the mass-volume ratio of the cobalt salt to ethylene glycol is 1-2g:15-20mL.

[0025] Preferably, the Ti3C2 needs to be dissolved in water and ultrasonicated, the mass-to-volume ratio of Ti3C2 to water is 1-1.5g:20-50mL, the ultrasonic power is 60-200W, and the ultrasonic time is 90-120min.

[0026] Preferably, the dropping rate in step (2) is 2-5 drops / 10 seconds, the reaction temperature is 25-35°C, the reaction is performed using ultrasound, and the reaction is followed by filtration, washing, and drying.

[0027] Preferably, the ultrasonic power is 60-200W, the ultrasonic time is 10-20min, the washing solution includes water and ethanol, the washing is performed 3-6 times, the drying temperature is 60-80℃, and the drying time is 22-24h.

[0028] Preferably, in step (3), the mass fraction of the Ti3C2-Co aqueous solution is 1-2%, the mass fraction of the chitosan aqueous solution is 0.5-1%, and the volume ratio of the Ti3C2-Co aqueous solution to the chitosan aqueous solution is 1:1-2.

[0029] Preferably, the reaction temperature in step (3) is 25-35°C, the reaction is stirred, and the reaction is washed with water, centrifuged and dried after the reaction.

[0030] Preferably, the stirring speed is 100-400 r / min, the stirring time is 30-90 min, the number of water washing and centrifugation is 3-5 times, the drying temperature is 60-80℃, and the drying time is 22-24 h.

[0031] Preferably, the reaction temperature in step (4) is 25-35°C and the reaction time is 24-30h.

[0032] Preferably, in step (4), Ti3C2-Co@chitosan and pyrrole monomers need to be mixed with hydrochloric acid aqueous solution and sonicated before the reaction, and ammonium persulfate solution needs to be added during the reaction. After the reaction, the mixture is filtered, washed, dried and ground.

[0033] Preferably, the volume ratio of hydrochloric acid to water in the hydrochloric acid-water solution is 1:4-1:5, the concentration of the ammonium persulfate solution is 0.04-0.05 mol / L, and the mass-volume ratio of Ti3C2-Co@chitosan, pyrrole monomer, hydrochloric acid-water solution and ammonium persulfate solution is 1-1.2 g: 8-14 mL: 100-150 mL: 20 mL.

[0034] Preferably, the ultrasonic power is 60-200W, the ultrasonic time is 10-20min, the washing solution includes water and ethanol, the drying temperature is 60-80℃, and the drying time is 22-24h.

[0035] This invention also provides the application of the above-mentioned multidimensional layered material in the analysis and detection of triazine herbicides and their metabolites in traditional Chinese medicine.

[0036] Compared with the prior art, the present invention has the following advantages:

[0037] (1) When using the multidimensional layered material prepared by the present invention to extract samples, the extraction time is greatly shortened because the layered magnetic material has a short diffusion distance. The entire adsorption extraction and enrichment analysis process can be completed in just 2 minutes. It is a magnetic solid phase adsorbent with good magnetic separation effect and high recycling efficiency.

[0038] (2) The multidimensional layered material prepared by the present invention can be used for rapid and efficient extraction and enrichment of triazine herbicides. It can be coupled with high performance liquid chromatography. This detection method is green, environmentally friendly, efficient, with high recovery rate, good precision and low detection limit.

[0039] (3) It can perform high-throughput multi-component simultaneous online rapid screening and quantitative determination of 22 kinds of triazine herbicides and their metabolites, which is extremely suitable for the residual analysis of triazine herbicides and their metabolites in Chinese medicinal materials, and is of great significance for the quality and safety detection and control of Chinese medicinal materials.

[0040] (4) The multidimensional layered material prepared by the present invention at room temperature contains Co and chitosan, which gives the material excellent ferromagnetism and further enhances its adsorption performance. Attached Figure Description

[0041] Figure 1 The image shows a scanning electron microscope (SEM) image of Ti3C2-Co@chitosan@PPy prepared in Example 1.

[0042] Figure 2 The image shows a scanning electron microscope (SEM) image of Ti3C2-Co prepared in Comparative Example 2.

[0043] Figure 3 High-performance liquid chromatograms of 22 triazine herbicides and their metabolites are shown (where 1-22 represent: 1. deisopropyl atrazine, 2. benzoxazine, 3. deethyl atrazine, 4. simazine, 5. cycloazine, 6. simazine, 7. deethyl terbutaline, 8. atrazine, 9. methamidophos, 10. cypermethrin, 11. atrazine, 12. sec-butylmethrin, 13. pyridaben, 14. terbutaline, 15. atrazine, 16. pyridaben, 17. terbutaline, 18. pyridaben, 19. terbutaline, 20. cypermethrin, 21. isopentylethylmethazine, 22. isopropylmethazine).

[0044] Figure 4 High-performance liquid chromatograms of *Euphorbia humifusa* samples, a whole-herb medicinal material, obtained using different pretreatment methods.

[0045] Figure 5 High-performance liquid chromatography (HPLC) chromatograms of deethylated atrazine, a component detected by five methods, when processing samples of Euphorbia humifusa.

[0046] Figure 6The HPLC chromatograms of the chrysanthemum, a flower-class Chinese medicinal material sample, under different pretreatment methods.

[0047] Figure 7 The HPLC chromatograms of prometryn, the component detected by five methods for the chrysanthemum sample.

[0048] Figure 8 The HPLC chromatograms of the astragalus membranaceus, a root and rhizome-class Chinese medicinal material sample, under different pretreatment methods.

[0049] Figure 9 The HPLC chromatograms of metribuzin and prometryn, the components detected by five methods for the astragalus membranaceus sample.

[0050] Figure 10 The HPLC chromatograms of the ganoderma lucidum, a fungus-class Chinese medicinal material sample, under different pretreatment methods.

[0051] Figure 11 The HPLC chromatograms of the ganoderma lucidum sample when no components are detected by five methods.

[0052] Figure 12 The HPLC chromatograms of the euryale ferox, a fruit and seed-class Chinese medicinal material sample, under different pretreatment methods.

[0053] Figure 13 The HPLC chromatograms of the euryale ferox sample when no components are detected by five methods.

[0054] ( Figure 4-13 In Figure 4-13 , numbers 1 - 5 respectively represent: 1. Direct extraction method; 2. PSA + 18 Dispersive solid-phase extraction; 3. Ti3C2-Co magnetic solid-phase extraction; 4. Ti3C2-Co@chitosan magnetic solid-phase extraction; 5. The present method (Ti3C2-Co@chitosan@PPy). Specific implementation manner

[0055] It should be noted that the raw materials used in the present invention are all ordinary commercially available products. Among them, polyvinylpyrrolidone (molecular weight 8000), product number P110608, and chitosan (molecular weight about 1 million), product number C434553, are both purchased from Aladdin Reagent Company; anhydrous ethanol, ethylene glycol, hydrochloric acid, sodium hydroxide, pyrrole, hydrazine hydrate, and ammonium persulfate (APS) are all of analytical grade and are all purchased from Sinopharm Chemical Reagent Company; C 18(40-63μm), graphite carbon black (200-400 mesh), neutral alumina (Al-N, 100-300 mesh), and PSA (ethylenediamino-N-propyl, 40-63μm, 60A) were all purchased from Shanghai Anpu Reagent Co., Ltd.; simazine, atrazine, cypermethrin ...

[0056] Example 1

[0057] A multidimensional layered material (Ti3C2-Co@chitosan@PPy) is prepared by the following steps:

[0058] (1) Preparation of Ti3C2:

[0059] First, dissolve 1.5g of LiF in 15mL of hydrochloric acid-water solution with a volume ratio of 5:1, place the solution in a round-bottom flask, and stir continuously at 100r / min for 60min until homogeneous. The resulting solution is named Liquid No. 1.

[0060] Weigh out 1.0 g of Ti3AlC2 powder and dissolve it in 5.0 mL of hydrochloric acid-water solution with a volume ratio of 5:1. Disperse the solution using ultrasonication at 60 W for 15 min until a uniform dispersion is achieved. Name this liquid No. 2. Immediately pour all of liquid No. 2 into liquid No. 1 and stir continuously at 100 r / min for 60 min at 25 °C. Allow the mixture to react completely for 24 h.

[0061] Finally, after the reaction is complete, the suspension is washed with pure water to remove excess acid. The precipitate is collected by filtration and centrifugation. The product is washed with pure water until neutral pH=7. It is then freeze-dried at -18℃ for 0.5 min under ice bath and nitrogen purging to obtain Ti3C2 powder.

[0062] (2) Preparation of Ti3C2-Co:

[0063] First, weigh 0.10g of polyvinylpyrrolidone and 0.12g of sodium hydroxide and dissolve them in 30mL of hydrazine hydrate. Stir continuously at 400r / min for 30min until homogeneous, and then sonicate at 200W for 10min to prepare a homogeneous solution, which is denoted as solution A. Next, weigh 1.29g of cobalt nitrate hexahydrate and dissolve it in 15mL of ethylene glycol to prepare a cobalt ion-containing alcohol solution, which is denoted as solution B. Then, weigh 1.0g of Ti3C2 powder in 20mL of aqueous solution and sonicate at 200W for 90min to obtain a homogeneous dispersion, which is denoted as solution C.

[0064] Mix solution B and solution C thoroughly and denote the mixture as solution M.

[0065] At 25℃, mixed solution M was added to solution A at a rate of 2 drops / 10 seconds, followed by continuous stirring at 400 rpm for 30 min, and then ultrasonic treatment at 200 W for 10 min to ensure complete reaction. After the reaction was complete, the precipitate was removed, washed three times with pure water and ethanol respectively, and then vacuum dried at 60℃ for 24 h to obtain magnetic Ti3C2-Co powder.

[0066] (3) Preparation of Ti3C2-Co@chitosan:

[0067] At 25℃, 20 mL of 0.5% chitosan aqueous solution and 20 mL of 1.0% Ti3C2-Co aqueous solution were continuously stirred at 100 rpm for 90 min until homogeneous. After washing with deionized water and centrifuging three times, the mixture was dried at 60℃ for 24 h to obtain Ti3C2-Co@chitosan.

[0068] (4) Preparation of Ti3C2-Co@chitosan@PPy:

[0069] At 25℃, 1.0 g of magnetic Ti3C2-Co@chitosan powder and 8 mL of pyrrole monomer were weighed and dissolved in 100 mL of 1.0 mol / L hydrochloric acid aqueous solution (volume ratio 1:4), and then ultrasonicated at 60 W for 20 min.

[0070] To ensure uniform dispersion, 20 mL of 0.04 mol / L ammonium persulfate solution was slowly added dropwise to a round-bottom flask under acidic conditions while stirring. The reaction was allowed to proceed for 24 hours. The sample was then separated by filtration and washed three times with pure water and ethanol. After drying at 60°C for 24 hours, the sample was ground to obtain magnetic Ti3C2-Co@chitosan@PPy.

[0071] Example 2

[0072] A multidimensional layered material (Ti3C2-Co@chitosan@PPy) is prepared by the following steps:

[0073] (1) Preparation of Ti3C2:

[0074] First, dissolve 2.0 g of LiF in 20 mL of a 3:1 hydrochloric acid-water solution and place it in a round-bottom flask. Stir continuously at 400 rpm for 10 min until homogeneous. The resulting solution is named Liquid No. 1.

[0075] Weigh out 1.2g of Ti3AlC2 powder and dissolve it in 5.0mL of hydrochloric acid-water solution with a volume ratio of 3:1. Disperse the solution using ultrasonication at 200W for 10min until a uniform dispersion is achieved. Name this liquid No. 2. Immediately pour all of liquid No. 2 into liquid No. 1 and stir continuously at 400rpm for 10min at 35℃. Allow the mixture to react completely for 30h.

[0076] Finally, after the reaction is complete, the suspension is washed with pure water to remove excess acid. The precipitate is collected by filtration and centrifugation. The product is washed with pure water until neutral pH=7. It is then freeze-dried at 4°C for 120 min under ice bath and nitrogen purging to obtain Ti3C2 powder.

[0077] (2) Preparation of Ti3C2-Co:

[0078] First, weigh 0.25g of polyvinylpyrrolidone and 0.40g of sodium hydroxide and dissolve them in 40mL of hydrazine hydrate. Stir continuously at 100r / min for 120min until homogeneous, and then sonicate at 60W for 30min to prepare a homogeneous solution, which is denoted as solution A. Next, weigh 1.29g of cobalt hexaaminochloride and dissolve it in 20mL of ethylene glycol to prepare a cobalt ion-containing alcohol solution, which is denoted as solution B. Then, weigh 1.5g of Ti3C2 powder in 50mL of aqueous solution and sonicate at 60W for 120min to obtain a homogeneous dispersion, which is denoted as solution C.

[0079] Mix solution B and solution C thoroughly and denote the mixture as solution M.

[0080] At 35℃, mixed solution M was added to solution A at a rate of 5 drops / 10 seconds, followed by continuous stirring at 100 rpm for 120 min, and then ultrasonic treatment at 60 W for 20 min to ensure complete reaction. After the reaction was complete, the precipitate was removed, washed 6 times with pure water and ethanol respectively, and then vacuum dried at 70℃ for 22 h to obtain magnetic Ti3C2-Co powder.

[0081] (3) Preparation of Ti3C2-Co@chitosan:

[0082] At 35℃, 40 mL of 1.0% chitosan aqueous solution and 20 mL of 2.0% Ti3C2-Co aqueous solution were continuously stirred at 400 rpm for 30 min until homogeneous. After washing with deionized water and centrifuging 5 times, Ti3C2-Co@chitosan was obtained by drying at 70℃ for 22 h.

[0083] (4) Preparation of Ti3C2-Co@chitosan@PPy:

[0084] At 35℃, 1.2g of magnetic Ti3C2-Co@chitosan powder and 14mL of pyrrole monomer were weighed and dissolved in 150mL of 1.25mol / L hydrochloric acid aqueous solution (volume ratio 1:5). The mixture was ultrasonically treated at 200W for 10min to disperse it evenly. Under acidic conditions, 20mL of 0.05mol / L ammonium persulfate solution was slowly added dropwise to a round-bottom flask while stirring. The reaction was carried out for 30h. The sample was separated by filtration and washed repeatedly with pure water and ethanol 5 times. The sample was dried at 70℃ for 22h and then ground to obtain magnetic Ti3C2-Co@chitosan@PPy.

[0085] Comparative Example 1

[0086] The material is PSA+C. 18 .

[0087] Comparative Example 2

[0088] A multidimensional layered material (Ti3C2-Co) is prepared by the following steps:

[0089] (1) Preparation of Ti3C2:

[0090] First, dissolve 1.5g of LiF in 15mL of hydrochloric acid-water solution with a volume ratio of 5:1, place the solution in a round-bottom flask, and stir continuously at 100r / min for 60min until homogeneous. The resulting solution is named Liquid No. 1.

[0091] Weigh out 1.0 g of Ti3AlC2 powder and dissolve it in 5.0 mL of hydrochloric acid-water solution with a volume ratio of 5:1. Disperse the solution using ultrasonication at 60 W for 15 min until a uniform dispersion is achieved. Name this liquid No. 2. Immediately pour all of liquid No. 2 into liquid No. 1 and stir continuously at 100 r / min for 60 min at 25 °C. Allow the mixture to react completely for 24 h.

[0092] Finally, after the reaction is complete, the suspension is washed with pure water to remove excess acid. The precipitate is collected by filtration and centrifugation. The product is washed with pure water until neutral pH=7. It is then freeze-dried at -18℃ for 0.5 min under ice bath and nitrogen purging to obtain Ti3C2 powder.

[0093] (2) Preparation of Ti3C2-Co:

[0094] First, weigh 0.10g of polyvinylpyrrolidone and 0.12g of sodium hydroxide and dissolve them in 30mL of hydrazine hydrate. Stir continuously at 400r / min for 30min until homogeneous, and then sonicate at 200W for 10min to prepare a homogeneous solution, which is denoted as solution A. Next, weigh 1.29g of cobalt nitrate hexahydrate and dissolve it in 15mL of ethylene glycol to prepare a cobalt ion-containing alcohol solution, which is denoted as solution B. Then, weigh 1.0g of Ti3C2 powder in 20mL of aqueous solution and sonicate at 200W for 90min to obtain a homogeneous dispersion, which is denoted as solution C.

[0095] Mix solution B and solution C thoroughly and denote the mixture as solution M.

[0096] At 25℃, mixed solution M was added to solution A at a rate of 2 drops / 10 seconds, followed by continuous stirring at 400 rpm for 30 min, and then ultrasonic treatment at 200 W for 10 min to ensure complete reaction. After the reaction was complete, the precipitate was removed, washed three times with pure water and ethanol respectively, and then vacuum dried at 60℃ for 24 h to obtain magnetic Ti3C2-Co powder.

[0097] Comparative Example 3

[0098] A multidimensional layered material (Ti3C2-Co@chitosan) is prepared by the following steps:

[0099] (1) Preparation of Ti3C2:

[0100] First, dissolve 1.5g of LiF in 15mL of hydrochloric acid-water solution with a volume ratio of 5:1, place the solution in a round-bottom flask, and stir continuously at 100r / min for 60min until homogeneous. The resulting solution is named Liquid No. 1.

[0101] Weigh out 1.0 g of Ti3AlC2 powder and dissolve it in 5.0 mL of hydrochloric acid-water solution with a volume ratio of 5:1. Disperse the solution using ultrasonication at 60 W for 15 min until a uniform dispersion is achieved. Name this liquid No. 2. Immediately pour all of liquid No. 2 into liquid No. 1 and stir continuously at 100 r / min for 60 min at 25 °C. Allow the mixture to react completely for 24 h.

[0102] Finally, after the reaction is complete, the suspension is washed with pure water to remove excess acid. The precipitate is collected by filtration and centrifugation. The product is washed with pure water until neutral pH=7. It is then freeze-dried at -18℃ for 0.5 min under ice bath and nitrogen purging to obtain Ti3C2 powder.

[0103] (2) Preparation of Ti3C2-Co:

[0104] First, weigh 0.10g of polyvinylpyrrolidone and 0.12g of sodium hydroxide and dissolve them in 30mL of hydrazine hydrate. Stir continuously at 400r / min for 30min until homogeneous, and then sonicate at 200W for 10min to prepare a homogeneous solution, which is denoted as solution A. Next, weigh 1.29g of cobalt nitrate hexahydrate and dissolve it in 15mL of ethylene glycol to prepare a cobalt ion-containing alcohol solution, which is denoted as solution B. Then, weigh 1.0g of Ti3C2 powder in 20mL of aqueous solution and sonicate at 200W for 90min to obtain a homogeneous dispersion, which is denoted as solution C.

[0105] Mix solution B and solution C thoroughly and denote the mixture as solution M.

[0106] At 25℃, mixed solution M was added to solution A at a rate of 2 drops / 10 seconds, followed by continuous stirring at 400 rpm for 30 min, and then ultrasonic treatment at 200 W for 10 min to ensure complete reaction. After the reaction was complete, the precipitate was removed, washed three times with pure water and ethanol respectively, and then vacuum dried at 60℃ for 24 h to obtain magnetic Ti3C2-Co powder.

[0107] (3) Preparation of Ti3C2-Co@chitosan:

[0108] At 25°C, a 0.5% chitosan aqueous solution (molecular weight approximately 1 million) and a 1.0% Ti3C2-Co aqueous solution were continuously stirred at 100 rpm for 90 min until homogeneous. The mixture was then washed with deionized water and centrifuged three times. Finally, it was dried at 60°C for 24 h to obtain Ti3C2-Co@chitosan.

[0109] The multidimensional layered material (magnetic Ti3C2-Co@chitosan@PPy) prepared in Example 1 was examined by scanning electron microscopy as follows: Figure 1 As shown, Figure 1 It can be seen that the Ti3C2-Co@chitosan@PPy nanoparticles coated with chitosan and polypyrrole have a small particle size, only 50-80nm.

[0110] The scanning electron microscope image of the Ti3C2-Co material prepared in Comparative Example 2 is shown below. Figure 2 As shown, Figure 2 It can be seen that Ti3C2-Co nanomaterials exhibit a distinct lamellar structure under a scanning electron microscope, and the addition of cobalt gives the material excellent magnetic properties.

[0111] Application example: quantitative determination

[0112] The above-mentioned multidimensional layered materials were applied to the determination of 22 triazine compounds and their metabolites in 109 kinds of Chinese medicinal materials in 4 major categories.

[0113] (1) 20 kinds of whole herbs: Euphorbia humifusa, Lysimachia christinae, Sedum sarmentosum, Leonurus japonicus, Eleusine indica, Plantago asiatica, Juncus effusus, Solanum nigrum, Pteris vittata, Houttuynia cordata, Prunella vulgaris, Lysimachia christinae, Scutellaria barbata, Artemisia annua, Euphorbia helioscopia, Amaranthus chinensis, Andrographis paniculata, Lonicera japonica, Gynostemma pentaphyllum, Epimedium brevicornu;

[0114] (2) 14 types of flowers: chrysanthemum, rose, honeysuckle, cockscomb, peony, coltsfoot, lily, mimosa, locust flower, safflower, kudzu flower, magnolia flower, corn silk, lotus stamen;

[0115] (3) 48 kinds of roots and rhizomes: Astragalus membranaceus, Fritillaria cirrhosa, Angelica sinensis, Panax notoginseng, Ginseng, Dioscorea opposita, Curcuma longa, Bupleurum chinense, Gentiana macrophylla, Cynanchum paniculatum, Salvia miltiorrhiza, Codonopsis pilosula, Aucklandia lappa, Scutellaria baicalensis, Sparganium stoloniferum, Rehmannia glutinosa, Coptis chinensis, Morinda officinalis, Rubia cordifolia, Platycodon grandiflorus, Dipsacus asper, Atractylodes lancea, Atractylodes macrocephala, Rheum palmatum, Polygonum cuspidatum, Polygonum multiflorum, Achyranthes bidentata, Aconitum carmichaelii, Paeonia lactiflora, Stephania tetrandra, Corydalis yanhusuo, Isatis indigotica, Pueraria lobata, Glycyrrhiza uralensis, Ephedra sinica, Ophiopogon japonicus, Asparagus cochinchinensis, Ligusticum chuanxiong, Asarum heterotropoides, Polygala tenuifolia, Cyperus rotundus, Kaempferia galanga, Pinellia ternata, Ramie root, Polygonum cuspidatum, Ilex pubescens, Paris polyphylla, Achyranthes bidentata;

[0116] (4) Five types of fungi: Ganoderma lucidum, Poria cocos, Tremella fuciformis, Perilla frutescens, and Smilax glabra.

[0117] (5) 22 kinds of fruits and seeds: Euryale ferox, lotus seeds, wolfberry, peach kernel, hawthorn, gardenia, Quisqualis indica, white cardamom, dodder seed, raspberry, plantain seed, mulberry, castor bean, apricot kernel, Vaccaria segetalis, jujube seed, soapberry, monk fruit, cypress seed, citron, long pepper, malt.

[0118] The determination method includes the following steps:

[0119] (1) Sample preparation: The dried sample was crushed by a pulverizer, passed through a 40-mesh sieve, and stored in a sealed container at room temperature;

[0120] (2) Extraction: Weigh 10.0g (accurate to 0.001g) of Chinese herbal medicine powder into a 50mL centrifuge tube, add 20mL of acetonitrile solution, mix and shake at 5000rpm for 20min, incubate in a 30℃ water bath, sonicate at 70W for 10min, and centrifuge at 4000r / min for 5min. Repeat the extraction twice, combine the two supernatants, concentrate to near dryness by nitrogen blowing at 35℃, dissolve the residue with acetone, and make up to 10mL.

[0121] (3) Purification: Transfer 1.0 mL of the above-mentioned purified solution to a centrifuge tube, add 10 mg of the multidimensional layered material prepared in Example 1 and Comparative Examples 1-3 to the centrifuge tube, sonicate for 1 min, vortex for 2 min, and perform solid-liquid two-phase magnetic separation. Remove the supernatant and retain the magnetic nanoparticles containing the target component. Accurately transfer 2 mL of acetone, vortex for 2 min to completely elute the target component from the nanoparticles, collect the eluent, filter it through a 0.22 μm filter membrane, and use the filtrate for further instrumental analysis. A reagent blank test was performed simultaneously during the experiment.

[0122] The multidimensional layered material prepared in Example 1 can be reused 15-20 times without reducing its specific adsorption effect after repeated washing with acetone and pure water.

[0123] 1. Preparation of standard solutions

[0124] 1.1 Prepare standard solutions (1000 μg / mL) of 22 triazine herbicides and their metabolites: simazine, simazine, atraz ...

[0125] 1.2 Preparation of mixed standard stock solution (40 μg / mL): 40 μL of each of the 22 triazine herbicides and their metabolites standard solutions were transferred into brown sample bottles and diluted to 1.0 mL with acetonitrile to prepare a mixed standard stock solution of triazine herbicides and their metabolites with a mass concentration of 40 μg / mL.

[0126] 1.3 Preparation of mixed standard working solutions: The 40 μg / mL mixed standard stock solution was serially diluted to prepare a series of mixed standard working solutions with mass concentrations of 0.1, 0.2, 0.4, 0.5, 1.0, 2.0, 4.0, 5.0, 10.0 and 20 μg / mL. Before each dilution or preparation, the stock solution was brought to room temperature and vortexed to mix.

[0127] 2. Plotting the standard curve

[0128] The standard solutions were injected into the liquid chromatograph in sequence from low to high concentration. Linear regression analysis was performed with the peak area of ​​each compound component as the ordinate and the labeled concentration of each component as the abscissa to obtain the standard curve regression equation.

[0129] The liquid chromatography detection conditions are as follows:

[0130] Column: Athena C 18Hydrophobic column (250mm×4.6mm, 5μm).

[0131] Column temperature: 35℃.

[0132] Detection wavelength: 222nm.

[0133] Injection volume: 5.0 μL.

[0134] Flow rate: 1.0 mL / min.

[0135] Mobile phase: Linear gradient elution was performed using water (phase A) and acetonitrile (phase B) as the mobile phase.

[0136] Gradient elution program: 0-5 min, 0% B → 30% B; 5-15 min, 30% B → 35% B; 15-25 min, 35% B → 45% B; 25-35 min, 45% B → 55% B; 35-40 min, 55% B → 25% B.

[0137] High-performance liquid chromatograms of 22 triazine herbicides and their metabolites are shown below. Figure 3 As shown, Figure 3 The numbers 1-22 represent: 1. deisopropyl atrazine, 2. benzoxazine, 3. deethyl atrazine, 4. simazine, 5. cycloazine, 6. simazine, 7. deethyl terbutaline, 8. atrazine, 9. benzoxazine, 10. simazine, 11. atrazine, 12. sec-butyl atrazine, 13. pyridaben, 14. terbutaline, 15. atrazine, 16. pyridaben, 17. terbutaline, 18. pyridaben, 19. terbutaline, 20. methazine, 21. isopentylethyl atrazine, 22. isopropyl atrazine.

[0138] Table 1 shows the peak times, standard curves, linear ranges, and correlation coefficients of 22 triazine herbicides and their metabolites. Table 2 shows the limits of detection, limits of quantitation, recoveries, and relative standard deviations of the 22 triazine herbicides and their metabolites.

[0139] The results in Table 1-2 show that the linear range of this method is 0.1-20 μg / mL, the limit of detection range is 0.2-1.0 μg / kg, the limit of quantitation range is 0.7-3.3 μg / kg, the recovery rate range is 92.8-99.6%, the relative standard deviation range is 1.2-3.8%, and the correlation coefficient R0 is [missing value]. 2 The value was 0.9999, indicating that the method has high recovery rate, good precision, low detection limit, and good linearity.

[0140] Table 1. Peak times, standard curves, and linear ranges of 22 triazine herbicides and their metabolites.

[0141]

[0142] Table 2. Limits of detection, limits of quantitation, recoveries, and relative standard deviations of 22 triazine herbicides and their metabolites.

[0143]

[0144]

[0145] 3. Determination of representative sample solutions

[0146] 3.1 Application of this method (Ti3C2-Co@chitosan@PPy magnetic solid phase extraction prepared in Example 1) and other pretreatment methods (direct extraction; PSA+C prepared in Comparative Example 1) 18 Dispersive solid-phase extraction was performed; magnetic solid-phase extraction was performed on Ti3C2-Co prepared in Comparative Example 2; magnetic solid-phase extraction was performed on Ti3C2-Co@chitosan prepared in Comparative Example 3. The contents of 22 triazine herbicides and their metabolites in the whole herb sample of Euphorbia humifusa were detected by high performance liquid chromatography. The direct extraction method refers to the method without pretreatment steps such as extraction, enrichment, analysis and concentration of the sample.

[0147] The results of the high performance liquid chromatography overlay are as follows: Figure 4 As shown, Figure 4 From top to bottom: 1. Direct extraction method; 2. PSA+C prepared in Comparative Example 1 18 3. Perform dispersion solid-phase extraction; 4. Perform magnetic solid-phase extraction on Ti3C2-Co prepared in Comparative Example 2; 5. Perform magnetic solid-phase extraction on Ti3C2-Co@chitosan prepared in Comparative Example 3; 6. Perform magnetic solid-phase extraction on Ti3C2-Co@chitosan@PPy prepared in Example 1.

[0148] Among the components, deethylated atrazine was detected, such as... Figure 5 As shown, the mass concentrations obtained by methods 1-5 are 5.02 μg / kg, 5.12 μg / kg, 5.20 μg / kg, 5.17 μg / kg, and 5.25 μg / kg, respectively.

[0149] 3.2 Using this method and other pretreatment methods, the contents of 22 triazine herbicides and their metabolites in chrysanthemum, a type of floral medicinal material, were detected by high performance liquid chromatography.

[0150] The results of the high performance liquid chromatography overlay are as follows: Figure 6 As shown, Figure 6 From top to bottom: 1. Direct extraction method; 2. PSA+C prepared in Comparative Example 1 18 3. Perform dispersion solid-phase extraction; 4. Perform magnetic solid-phase extraction on Ti3C2-Co prepared in Comparative Example 2; 5. Perform magnetic solid-phase extraction on Ti3C2-Co@chitosan prepared in Comparative Example 3; 6. Perform magnetic solid-phase extraction on Ti3C2-Co@chitosan@PPy prepared in Example 1.

[0151] The component promethazine was detected, such as... Figure 7 As shown, the mass concentrations obtained by methods 1-5 are 7.90 μg / kg, 7.96 μg / kg, 7.04 μg / kg, 7.23 μg / kg, and 8.02 μg / kg, respectively.

[0152] 3.3 Using this method and other pretreatment methods, the contents of 22 triazine herbicides and their metabolites in Astragalus membranaceus root and rhizome samples were detected by high performance liquid chromatography.

[0153] The results of the high performance liquid chromatography overlay are as follows: Figure 8 As shown, Figure 8 From top to bottom: 1. Direct extraction method; 2. PSA+C prepared in Comparative Example 1 18 3. Perform dispersion solid-phase extraction; 4. Perform magnetic solid-phase extraction on Ti3C2-Co prepared in Comparative Example 2; 5. Perform magnetic solid-phase extraction on Ti3C2-Co@chitosan prepared in Comparative Example 3; 6. Perform magnetic solid-phase extraction on Ti3C2-Co@chitosan@PPy prepared in Example 1.

[0154] The components metribuzin and pyrazosulfan were detected, such as Figure 9 As shown, the mass concentrations of metribuzin obtained by methods 1-5 were 9.93 μg / kg, 10.37 μg / kg, 10.70 μg / kg, 7.76 μg / kg, and 11.22 μg / kg, respectively. The mass concentrations of propargite obtained by methods 1-5 were 2.83 μg / kg, 2.47 μg / kg, 3.34 μg / kg, 3.37 μg / kg, and 4.79 μg / kg, respectively.

[0155] 3.4 Using this method and other pretreatment methods, the contents of 22 triazine herbicides and their metabolites in Ganoderma lucidum samples were detected by high performance liquid chromatography.

[0156] The results of the high performance liquid chromatography overlay are as follows: Figure 10 As shown, Figure 10 From top to bottom: 1. Direct extraction method; 2. PSA+C prepared in Comparative Example 1 18 3. Perform dispersion solid-phase extraction; 4. Perform magnetic solid-phase extraction on Ti3C2-Co prepared in Comparative Example 2; 5. Perform magnetic solid-phase extraction on Ti3C2-Co@chitosan prepared in Comparative Example 3; 6. Perform magnetic solid-phase extraction on Ti3C2-Co@chitosan@PPy prepared in Example 1.

[0157] No target component was detected, and the sample detection rate was 0%. Figure 11 As shown.

[0158] 3.5 Using this method and other pretreatment methods, the contents of 22 triazine herbicides and their metabolites in the fruit and seed samples of Euryale ferox were detected by high performance liquid chromatography.

[0159] The results of the high performance liquid chromatography overlay are as follows: Figure 12 As shown, Figure 12 From top to bottom: 1. Direct extraction method; 2. PSA+C prepared in Comparative Example 1 18 3. Perform dispersion solid-phase extraction; 4. Perform magnetic solid-phase extraction on Ti3C2-Co prepared in Comparative Example 2; 5. Perform magnetic solid-phase extraction on Ti3C2-Co@chitosan prepared in Comparative Example 3; 6. Perform magnetic solid-phase extraction on Ti3C2-Co@chitosan@PPy prepared in Example 1.

[0160] No target component was detected, and the sample detection rate was 0%. Figure 13 As shown.

[0161] Depend on Figure 4-13 It can be seen that the multidimensional layered material prepared in this invention has a significantly better detection effect than the direct extraction method and comparative examples 1-3 in detecting the content of 22 triazine herbicides and their metabolites.

[0162] 4. Recovery rate and precision testing

[0163] Recovery test: Three different spiking concentrations (low, medium, and high) were added to the sample extract, namely 2.0 μg / kg, 5.0 μg / kg, and 20 μg / kg. The samples were processed and tested according to the extraction procedure. Each sample was measured in parallel 7 times (n=7). The actual mass concentration was calculated. The average recovery rate at each mass concentration should be 90-110%, and the relative standard deviation (RSD) of the 7 recovery rate data should be <10%.

[0164] The recovery rate (%) is calculated using the following formula:

[0165] Recovery rate % = (Actual mass concentration - Mass concentration of the analyte in the sample) / Theoretical mass concentration × 100%

[0166] Precision testing: The relative standard deviation is commonly used to represent the relative value of the standard deviation of a single measurement to the average value of the measurement. The actual mass concentration obtained from the parallel measurements of each sample is substituted into the formula for calculation.

[0167] The formulas for calculating standard deviation (SD) and relative standard deviation (RSD) are as follows:

[0168]

[0169] Relative standard deviation (RSD) = Standard deviation (SD) / Arithmetic mean of measurement results

[0170] Each sample was measured in parallel for 7 consecutive times. The average recovery rate and relative standard deviation (RSD) were calculated. The test results of the spiked recovery range and relative standard deviation of the samples for the 5 methods are summarized in Table 3.

[0171] Table 3. Spike Recovery Range and Relative Standard Deviation of Samples

[0172]

[0173]

[0174] As shown in Table 3, the average recovery rate and relative standard deviation (RSD) of the Ti3C2-Co@chitosan@PPy prepared in Example 1 of this invention were better than those of the direct extraction method and Comparative Examples 1-3 after pretreatment and detection of the contents of 22 triazine herbicides and their metabolites by high performance liquid chromatography.

[0175] Finally, it should be noted that the above content is only used to illustrate the technical solution of the present invention, and is not intended to limit the scope of protection of the present invention. Simple modifications or equivalent substitutions made by those skilled in the art to the technical solution of the present invention do not depart from the essence and scope of the technical solution of the present invention.

Claims

1. A multi-dimensional layered material, characterized in that, The raw materials of the multi-dimensional layered material include lithium fluoride, cobalt salt, titanium carbon aluminum, polyvinyl pyrrolidone and chitosan, The preparation method of the multi-dimensional layered material comprises the following steps: (1) lithium fluoride and titanium carbon aluminum are respectively dissolved in hydrochloric acid-water solution, and the two are mixed and reacted to obtain Ti3C2; (2) polyvinyl pyrrolidone, sodium hydroxide and hydrazine hydrate are mixed, and then added to the mixed solution of Ti3C2 and cobalt salt, and reacted to obtain Ti3C2-Co; (3) then the Ti3C2-Co aqueous solution is reacted with the chitosan aqueous solution to obtain Ti3C2-Co @ chitosan; (4) finally, Ti3C2-Co @ chitosan and pyrrole are reacted to obtain the multi-dimensional layered material; The temperature of the reaction in step (3) is 25-35℃, the reaction is stirred, and after the reaction, water washing, centrifugation and drying are performed; In step (4), before the reaction, Ti3C2-Co @ chitosan and pyrrole are mixed with hydrochloric acid aqueous solution and ultrasonic, ammonium persulfate solution is added during the reaction, and after the reaction, filtration, washing, drying and grinding are performed.

2. The multi-dimensional layered material of claim 1, wherein, The particle size of the multi-dimensional layered material is 50-80 nm.

3. The multi-dimensional layered material of claim 1, wherein, The cobalt salt is selected from one or more of cobalt nitrate hexahydrate, cobalt chloride hexahydrate and hexamino cobalt chloride.

4. The multi-dimensional layered material of claim 1, wherein, The molar ratio of lithium fluoride, cobalt salt, titanium carbon aluminum, polyvinyl pyrrolidone and chitosan is 58-77:4.4-5.4:5.1-6.2:0.56-1.4:4.5-5.

4.

5. A method of producing a multi-dimensional layered material as claimed in any one of claims 1 to 4, characterized by, Comprise the following steps: (1) lithium fluoride and titanium carbon aluminum are respectively dissolved in hydrochloric acid-water solution, and the two are mixed and reacted to obtain Ti3C2; (2) polyvinyl pyrrolidone, sodium hydroxide and hydrazine hydrate are mixed, and then added to the mixed solution of Ti3C2 and cobalt salt, and reacted to obtain Ti3C2-Co; (3) then the Ti3C2-Co aqueous solution is reacted with the chitosan aqueous solution to obtain Ti3C2-Co @ chitosan; (4) finally, Ti3C2-Co @ chitosan and pyrrole are reacted to obtain the multi-dimensional layered material; The temperature of the reaction in step (3) is 25-35℃, the reaction is stirred, and after the reaction, water washing, centrifugation and drying are performed; In step (4), before the reaction, Ti3C2-Co @ chitosan and pyrrole are mixed with hydrochloric acid aqueous solution and ultrasonic, ammonium persulfate solution is added during the reaction, and after the reaction, filtration, washing, drying and grinding are performed.

6. The production method according to claim 5, wherein The mass-volume ratio of the lithium fluoride and the hydrochloric acid-water solution in step (1) is 1.5-2 g:15-20 mL, the lithium fluoride needs to be stirred when dissolved in the hydrochloric acid-water solution, the stirring speed is 100-400 r / min, and the stirring time is 10-60 min; the mass-volume ratio of the titanium aluminum carbide and the hydrochloric acid-water solution in step (1) is 1-1.2 g:5 mL, the titanium aluminum carbide needs to be ultrasonic when dissolved in the hydrochloric acid-water solution, the ultrasonic power is 60-200 W, and the ultrasonic time is 8-15 min; the volume ratio of hydrochloric acid to water in the hydrochloric acid-water solution in step (1) is 3-5:1, the reaction temperature is 25-35℃, the reaction is stirred, after the reaction, water washing is performed until pH=7, filtration, ice bath and freeze drying under nitrogen, the stirring speed is 100-400 r / min, the stirring time is 24-30 h, the freeze drying temperature is-18-4℃, and the freeze drying time is 0.5-120 min.

7. The preparation method according to claim 5, characterized in that, The mass-volume ratio of the polyvinylpyrrolidone, sodium hydroxide and hydrazine hydrate in step (2) is 0.1-0.25 g:0.12-0.4 g:30-40 mL, the mixing is stirred and ultrasonic, the stirring speed is 100-400 r / min, the stirring time is 30-120 min, the ultrasonic power is 60-200 W, and the ultrasonic time is 10-30 min; the cobalt salt needs to be dissolved in ethylene glycol in step (2), the mass-volume ratio of the cobalt salt to ethylene glycol is 1-2 g:15-20 mL, the Ti3C2 needs to be dissolved in water and ultrasonic, the mass-volume ratio of the Ti3C2 to water is 1-1.5 g:20-50 mL, the ultrasonic power is 60-200 W, and the ultrasonic time is 90-120 min; the drop speed of the added in step (2) is 2-5 drops / 10 seconds, the reaction temperature is 25-35℃, the reaction is ultrasonic, after the reaction, filtration, washing and drying are performed, the ultrasonic power is 60-200 W, the ultrasonic time is 10-20 min, the washing solution includes water and ethanol, the washing times are 3-6 times, the drying temperature is 60-80℃, and the drying time is 22-24 h.

8. The preparation method according to claim 5, characterized in that, The mass fraction of the Ti3C2-Co aqueous solution in step (3) is 1-2%, the mass fraction of the chitosan aqueous solution is 0.5-1%, and the volume ratio of the Ti3C2-Co aqueous solution to the chitosan aqueous solution is 1:1-2; the stirring speed in step (3) is 100-400 r / min, the stirring time is 30-90 min, the washing and centrifugation times are 3-5 times, the drying temperature is 60-80℃, and the drying time is 22-24 h.

9. The preparation method according to claim 5, characterized in that, The temperature of the reaction in step (4) is 25-35℃, and the reaction time is 24-30 h; in step (4), the volume ratio of hydrochloric acid to water in the hydrochloric acid-water solution is 1:4-5, the concentration of the ammonium persulfate solution is 0.04-0.05 mol / L, the mass-volume ratio of the Ti3C2-Co@chitosan, pyrrole, hydrochloric acid aqueous solution and ammonium persulfate solution is 1-1.2 g:8-14 mL:100-150 mL:20 mL, the power of the ultrasonic is 60-200 W, the ultrasonic time is 10-20 min, the washing solution comprises water and ethanol, the drying temperature is 60-80℃, and the drying time is 22-24 h.

10. Use of the multi-dimensional layered material according to any one of claims 1-4 or the multi-dimensional layered material obtained by the preparation method according to any one of claims 5-9 in the analysis and detection of Chinese medicinal materials triazine herbicides and metabolites thereof.

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