Magnetic adsorption nanomaterial, preparation method and application thereof

Abstract

The application provides a magnetic adsorption nanomaterial and a preparation method and application thereof, and belongs to the technical field of nanomaterials. The preparation method is as follows: uniformly dispersing functionalized Fe3O4 nano magnetic particles in a solvent, adding a mixture of tetrabutyl titanate and acetylacetone, obtaining titanium modified Fe3O4 nano composite microspheres through reaction, then adding the titanium modified Fe3O4 nano composite microspheres into a carbon nanotube dispersion liquid, and performing ultrasonic stirring and solid-liquid separation to finally obtain the magnetic adsorption nanomaterial. The functionalized Fe3O4 nano magnetic particles are prepared by surface treatment of magnetic Fe3O4 nanoparticles with tetraethoxysilane, and then grafting amino and carboxyl active groups. The preparation method is simple in operation and green and environmentally friendly, the prepared magnetic adsorption nanomaterial can effectively adsorb impurities in a detection matrix, and has high reusability and durability. The application has great significance for solving the technical bottleneck problem of detection of illegal drug residues in animal-derived Chinese patent medicines.

Description

Technical Field

[0001] This invention belongs to the field of nanomaterials technology, specifically relating to a magnetic adsorption nanomaterial, its preparation method, and its application. Background Technology

[0002] When detecting prohibited drug residues in animal-derived traditional Chinese medicines, some endogenous contaminants can interfere with the detection matrix, increasing the difficulty of detection and affecting the accuracy of the results. Magnetic solid-phase extraction (MSE) is a novel pretreatment technique where magnetic adsorption materials can fully contact the sample in solution, and separation can be achieved simply by applying an external magnetic field.

[0003] However, existing magnetic adsorption materials generally have weak selective adsorption capacity for target pollutants in prohibited drugs, and their removal effect on strongly polar endogenous impurities (free nucleotides, small molecule peptides, etc.) is not good. Furthermore, their purification capacity decreases significantly when reused, and their durability is low. In addition, the preparation of most magnetic adsorption materials adopts complex production processes and uses a large amount of toxic organic solvents, which not only increases the preparation cost but also easily causes secondary pollution to the environment, which does not meet the needs of green development. Summary of the Invention

[0004] To address the problems existing in the background technology, the present invention provides a magnetic adsorption nanomaterial, its preparation method and application. The preparation method is simple to operate and environmentally friendly. The prepared magnetic adsorption nanomaterial can effectively adsorb impurities in the detection matrix, significantly reduce the interference of pollutants, and has high reusability and durability. It can be widely used in the pretreatment of animal-derived traditional Chinese medicine for the detection of prohibited drug residues.

[0005] To achieve the above objectives, the present invention provides the following technical solution:

[0006] A method for preparing magnetic adsorption nanomaterials includes the following steps:

[0007] S1. Functionalized Fe3O4 nanoparticles were added to anhydrous ethanol and dispersed evenly to obtain a dispersion system;

[0008] S2. Add a mixture of tetrabutyl titanate and acetylacetone to the dispersion system of step S1, stir evenly to obtain a pre-reaction solution, heat and stir to carry out the reaction, and after the reaction is completed, titanium-modified Fe3O4 nanocomposite microspheres are obtained.

[0009] S3. Add carboxylated carbon nanotubes to DMF to obtain a carbon nanotube dispersion. Add titanium-modified Fe3O4 nanocomposite microspheres obtained in step S2 to the carbon nanotube dispersion, stir ultrasonically, dilute with ethanol, apply a magnetic field for solid-liquid separation, and after washing and vacuum drying, obtain the magnetic adsorption nanomaterial.

[0010] In step S1, the functionalized Fe3O4 nanoparticles are prepared by surface treatment of magnetic Fe3O4 nanoparticles with tetraethoxysilane, followed by grafting of amino and carboxyl active groups.

[0011] Furthermore, the preparation process of functionalized Fe3O4 magnetic nanoparticles in step S1 includes the following steps:

[0012] A1. Magnetic Fe3O4 nanoparticles were added to an ethanol solution containing tetraethoxysilane, and after heating and stirring, solid-liquid separation was performed to obtain pretreated magnetic nanoparticles.

[0013] A2. Mix glycolic acid, ammonium citrate, carbon disulfide and alcohol solution evenly to obtain a premixed solution, and then add the pretreated magnetic nanoparticles obtained in step A1 to the premixed solution to obtain a suspension.

[0014] A3. Epichlorohydrin is added dropwise to the suspension obtained in step A2. After heating reaction, solid-liquid separation, washing and drying, functionalized Fe3O4 nanoparticles are obtained.

[0015] Furthermore, in step A2, the mass ratio of glycolic acid, ammonium citrate, and carbon disulfide in the premixed solution is 1:0.8-1.2:1.5-2.5, and the mass ratio of pretreated magnetic nanoparticles, glycolic acid, and alcohol solution is 1:0.2-0.3:80-120.

[0016] Furthermore, in step A2, the alcohol solution is one or a mixture of two or more of methanol, ethanol, n-propanol, isopropanol, n-butanol, and isobutanol.

[0017] Furthermore, the mass fraction of functionalized Fe3O4 nanoparticles in the dispersion system of step S1 is 0.05-0.5%.

[0018] Furthermore, in step S2, the mass ratio of tetrabutyl titanate to functionalized Fe3O4 nanoparticles is 2:0.8-1.2, and the volume ratio of tetrabutyl titanate to acetylacetone is 1:3-5.

[0019] Furthermore, in step S2, the reaction temperature is 200-260℃ and the reaction time is 2-4h.

[0020] Furthermore, in step S3, the mass fraction of carboxylated carbon nanotubes in the carbon nanotube dispersion is 0.1-0.5%.

[0021] The present invention also provides a magnetic adsorption nanomaterial, which is prepared by the preparation method described above.

[0022] This invention also provides an application of magnetic adsorption nanomaterials, in which the magnetic adsorption nanomaterials described above are used in the detection of prohibited drug residues in animal-derived traditional Chinese medicines, and the detection matrix is ​​purified and pretreated.

[0023] This application has the following beneficial effects:

[0024] 1. This invention provides a magnetic adsorption nanomaterial, its preparation method, and its application. The preparation method is simple, green, and environmentally friendly. The prepared magnetic adsorption nanomaterial can effectively adsorb impurities in the test matrix of animal-derived traditional Chinese medicine, enabling the test matrix to exhibit a relatively ideal detection recovery rate and significantly eliminating the influence of matrix effect on the test results. This is of great significance for solving the technical bottleneck problem of detecting prohibited drug residues in animal-derived traditional Chinese medicine.

[0025] 2. In the preparation of functionalized Fe3O4 nanomagnetic nanoparticles, the magnetic Fe3O4 nanoparticles are first surface-treated to improve their reactivity. Through grafting reaction, the surface of the magnetic particles is modified with amino and carboxyl active groups, which provides a basis for the uniform adhesion and efficient intercalation of nano-titanium dioxide and carboxylated carbon nanotubes. This effectively reduces and avoids the aggregation of high-concentration nano-titanium dioxide and carbon nanotubes, so that the final magnetic adsorption nanomaterial has high integrity and stability.

[0026] 3. In-situ growth of nano-titanium dioxide on the surface of functionalized Fe3O4 nanoparticles effectively improves the dispersion performance of titanium dioxide. The active groups on the surface of Fe3O4 nanoparticles can attract and combine with the polar groups (hydroxyl groups -OH) carried on the surface of nano-titanium dioxide, achieving the embellishment and modification of Fe3O4 nanoparticles by nano-titanium dioxide. This results in titanium-modified Fe3O4 nanocomposite microspheres with good binding performance and adsorption effect. At the same time, the nano-titanium dioxide embellishment layer can leave intercalation sites for carbon nanotubes. The active groups of functionalized Fe3O4 nanoparticles and the hydroxyl groups of nano-titanium dioxide can provide loading sites for carbon nanotubes, enabling carbon nanotubes to be uniformly attached and efficiently intercalated on the surface of magnetic particles. This achieves an effective combination of carbon nanotubes, magnetic particles, and nano-titanium dioxide, significantly improving the integrity and stability of magnetic nanomaterials. Ultimately, this enables magnetic adsorption nanomaterials to have a high adsorption capacity for target impurities and maintain long-term usability, achieving high purification capacity and durability. Attached Figure Description

[0027] Figure 1 Total ion chromatogram (TIC chromatogram) of samples spiked with target analytes (adamantane, adamantane methylamine, adamantane ethylamine, and memantine);

[0028] Figure 2The image shows the MRM monitoring chromatograms of adamantane-D6, where A is the ion chromatogram of quantitative ions, B is the overlay of quantitative and qualitative ions, and C is the fragmentation pattern under mass spectrometry ion source bombardment.

[0029] Figure 3 The image shows the MRM monitoring chromatograms of adamantane, where A is the ion chromatogram of quantitative ions, B is the overlay chromatogram of quantitative and qualitative ions, and C is the fragmentation chromatogram under the bombardment of the mass spectrometer ion source.

[0030] Figure 4 The image shows the MRM monitoring chromatograms of adamantane methylamine, where A is the ion chromatogram of quantitative ions, B is the overlay of quantitative and qualitative ions, and C is the fragmentation pattern under mass spectrometry ion source bombardment.

[0031] Figure 5 The image shows the MRM monitoring chromatograms of adamantane ethylamine, where A is the ion chromatogram of quantitative ions, B is the overlay chromatogram of quantitative and qualitative ions, and C is the fragmentation chromatogram under the bombardment of the mass spectrometer ion source.

[0032] Figure 6 The images show the MRM monitoring data for Amanita muscaria, where A is the ion chromatogram of quantitative ions, B is the overlay of quantitative and qualitative ions, and C is the fragmentation diagram under the bombardment of the mass spectrometer ion source. Detailed Implementation

[0033] The present application will be further described in detail below with reference to the embodiments.

[0034] Unless otherwise specified, the raw materials used in the embodiments and comparative examples of this application are all commercially available.

[0035] Example 1: A magnetic adsorption nanomaterial, prepared by the following steps:

[0036] S1. Functionalized Fe3O4 nanoparticles were added to anhydrous ethanol and dispersed evenly to obtain a dispersion system, wherein the mass fraction of functionalized Fe3O4 nanoparticles in the dispersion system was 0.2%;

[0037] S2. Add a mixture of tetrabutyl titanate and acetylacetone in a volume ratio of 1:4 to the dispersion system, wherein the mass ratio of tetrabutyl titanate to functionalized Fe3O4 nanoparticles is 2:4. Stir until homogeneous to obtain a pre-reaction solution. Heat and stir to carry out the reaction at a temperature of 230℃ for 3 hours. After the reaction is completed, titanium-modified Fe3O4 nanocomposite microspheres Ti-MFn are obtained.

[0038] S3. Carboxylated multi-walled carbon nanotubes were added to DMF and ultrasonically dispersed to obtain a carbon nanotube dispersion. The mass fraction of carboxylated multi-walled carbon nanotubes in the carbon nanotube dispersion was 0.3%. Titanium-modified Fe3O4 nanocomposite microspheres obtained in step S2 were added to the carbon nanotube dispersion, ultrasonically stirred, diluted with ethanol, and the product was separated from the solution with a magnet. After washing and vacuum drying, magnetic adsorption nanomaterial CTi-MFn was obtained.

[0039] The preparation of functionalized Fe3O4 magnetic nanoparticles in step S1 includes the following steps:

[0040] A1. Magnetic Fe3O4 nanoparticles and anhydrous ethanol were mixed at a mass ratio of 1:100, ultrasonically dispersed, and then tetraethoxysilane was added, wherein the mass ratio of the added tetraethoxysilane to the magnetic Fe3O4 nanoparticles was 1:5. The mixture was heated to 50°C, stirred rapidly, and reacted for 1.5 hours. After solid-liquid separation and drying, pretreated magnetic nanoparticles were obtained.

[0041] A2. Mix glycolic acid, ammonium citrate and carbon disulfide in a mass ratio of 1:1:2, add methanol and stir until homogeneous to obtain a premixed solution, then add the pretreated magnetic nanoparticles obtained in step A1 to obtain a suspension, wherein the mass ratio of pretreated magnetic nanoparticles, glycolic acid and methanol is 1:0.25:100.

[0042] A3. Epichlorohydrin was added dropwise to the suspension obtained in step A2. The amount of epichlorohydrin added was 50% of the mass of glycolic acid. The mixture was heated to 70°C and reacted for 3 hours. After solid-liquid separation, washing and drying, functionalized Fe3O4 nanoparticles were obtained.

[0043] Example 2: A magnetic adsorption nanomaterial, prepared by the following steps:

[0044] S1. Functionalized Fe3O4 nanoparticles were added to anhydrous ethanol and dispersed evenly to obtain a dispersion system, wherein the mass fraction of functionalized Fe3O4 nanoparticles in the dispersion system was 0.05%;

[0045] S2. Add a mixture of tetrabutyl titanate and acetylacetone in a volume ratio of 1:3 to the dispersion system, wherein the mass ratio of tetrabutyl titanate to functionalized Fe3O4 nanoparticles is 2:0.8. Stir until homogeneous to obtain a pre-reaction solution. Heat and stir to carry out the reaction at a temperature of 200℃ for 4 hours. After the reaction is completed, titanium-modified Fe3O4 nanocomposite microspheres Ti-MFn are obtained.

[0046] S3. Carboxylated multi-walled carbon nanotubes were added to DMF and ultrasonically dispersed to obtain a carbon nanotube dispersion. The mass fraction of carboxylated multi-walled carbon nanotubes in the carbon nanotube dispersion was 0.1%. Titanium-modified Fe3O4 nanocomposite microspheres obtained in step S2 were added to the carbon nanotube dispersion, ultrasonically stirred, diluted with ethanol, and the product was separated from the solution with a magnet. After washing and vacuum drying, magnetic adsorption nanomaterial CTi-MFn was obtained.

[0047] The preparation of functionalized Fe3O4 magnetic nanoparticles in step S1 includes the following steps:

[0048] A1. Magnetic Fe3O4 nanoparticles and anhydrous ethanol were mixed at a mass ratio of 1:80, ultrasonically dispersed, and then tetraethoxysilane was added, wherein the mass ratio of the added tetraethoxysilane to the magnetic Fe3O4 nanoparticles was 1:4. The mixture was heated to 40°C, stirred rapidly, and reacted for 2 hours. After solid-liquid separation and drying, pretreated magnetic nanoparticles were obtained.

[0049] A2. Mix glycolic acid, ammonium citrate and carbon disulfide in a mass ratio of 1:0.8:1.5, add to ethanol and stir evenly to obtain a premixed solution, then add the pretreated magnetic nanoparticles obtained in step A1 to obtain a suspension, wherein the mass ratio of pretreated magnetic nanoparticles, glycolic acid and ethanol is 1:0.2:80.

[0050] A3. Epichlorohydrin was added dropwise to the suspension obtained in step A2. The amount of epichlorohydrin added was 40% of the mass of glycolic acid. The mixture was heated to 60°C and reacted for 3.5 h. After solid-liquid separation, washing and drying, functionalized Fe3O4 nanoparticles were obtained.

[0051] Example 3: A magnetic adsorption nanomaterial, prepared by the following steps:

[0052] S1. Functionalized Fe3O4 nanoparticles were added to anhydrous ethanol and dispersed evenly to obtain a dispersion system, wherein the mass fraction of functionalized Fe3O4 nanoparticles in the dispersion system was 0.5%;

[0053] S2. Add a mixture of tetrabutyl titanate and acetylacetone in a volume ratio of 1:5 to the dispersion system, wherein the mass ratio of tetrabutyl titanate to functionalized Fe3O4 nanoparticles is 2:1.2. Stir until homogeneous to obtain a pre-reaction solution. Heat and stir to carry out the reaction at a temperature of 260℃ for 2 hours. After the reaction is completed, titanium-modified Fe3O4 nanocomposite microspheres Ti-MFn are obtained.

[0054] S3. Carboxylated multi-walled carbon nanotubes were added to DMF and ultrasonically dispersed to obtain a carbon nanotube dispersion. The mass fraction of carboxylated multi-walled carbon nanotubes in the carbon nanotube dispersion was 0.5%. Titanium-modified Fe3O4 nanocomposite microspheres obtained in step S2 were added to the carbon nanotube dispersion, ultrasonically stirred, diluted with ethanol, and the product was separated from the solution with a magnet. After washing and vacuum drying, magnetic adsorption nanomaterial CTi-MFn was obtained.

[0055] The preparation of functionalized Fe3O4 magnetic nanoparticles in step S1 includes the following steps:

[0056] A1. Magnetic Fe3O4 nanoparticles and anhydrous ethanol were mixed at a mass ratio of 1:120, ultrasonically dispersed, and then tetraethoxysilane was added, wherein the mass ratio of the added tetraethoxysilane to the magnetic Fe3O4 nanoparticles was 1:6. The mixture was heated to 60°C, stirred rapidly, and reacted for 1 hour. After solid-liquid separation and drying, pretreated magnetic nanoparticles were obtained.

[0057] A2. Mix glycolic acid, ammonium citrate and carbon disulfide in a mass ratio of 1:1.2:2.5, add to n-propanol and stir until homogeneous to obtain a premixed solution, then add the pretreated magnetic nanoparticles obtained in step A1 to obtain a suspension, wherein the mass ratio of pretreated magnetic nanoparticles, glycolic acid and n-propanol is 1:0.3:120;

[0058] A3. Epichlorohydrin was added dropwise to the suspension obtained in step A2. The amount of epichlorohydrin added was 60% of the mass of glycolic acid. The mixture was heated to 80°C and reacted for 2.5 h. After solid-liquid separation, washing and drying, functionalized Fe3O4 nanoparticles were obtained.

[0059] Comparative Example 1: The only difference between this comparative example and Example 1 is that in step S1, the functionalized Fe3O4 nanoparticles are replaced with magnetic Fe3O4 nanoparticles, that is, the magnetic Fe3O4 nanoparticles are not functionalized. The details are as follows:

[0060] S1. Add magnetic Fe3O4 nanoparticles to anhydrous ethanol and disperse them evenly to obtain a dispersion system, wherein the mass fraction of magnetic Fe3O4 nanoparticles in the dispersion system is 0.2%.

[0061] Comparative Example 2: The only difference between this comparative example and Example 1 is that the carboxylated multi-walled carbon nanotubes in step S3 are replaced with ordinary multi-walled carbon nanotubes, as detailed below:

[0062] S3. Ordinary multi-walled carbon nanotubes are added to DMF and ultrasonically dispersed to obtain a carbon nanotube dispersion. The mass fraction of ordinary multi-walled carbon nanotubes in the carbon nanotube dispersion is 0.3%. Titanium-modified Fe3O4 nanocomposite microspheres obtained in step S2 are added to the carbon nanotube dispersion, ultrasonically stirred, diluted with ethanol, and the product is separated from the solution with a magnet. After washing and vacuum drying, magnetic adsorption nanomaterials are obtained.

[0063] Comparative Example 3: The only difference between this comparative example and Example 1 is that in step S1, the functionalized Fe3O4 nanoparticles are replaced with magnetic Fe3O4 nanoparticles, and in step S3, the carboxylated multi-walled carbon nanotubes are replaced with ordinary multi-walled carbon nanotubes.

[0064] Comparative Example 4: The only difference between this comparative example and Example 1 is that in step S2, the functionalized Fe3O4 magnetic nanoparticles were not modified with titanium, i.e., tetrabutyl titanate and acetylacetone were not added, as detailed below:

[0065] S2. Stir the dispersion system evenly to obtain a pre-reaction solution, and then heat it to react at a temperature of 230℃ for 3 hours. After the reaction is completed, titanium-modified Fe3O4 nanocomposite microspheres are obtained.

[0066] Proof of effectiveness:

[0067] 1. Instruments and reagents:

[0068] 1.1 Instruments: Ultra-high performance liquid chromatography-tandem triple quadrupole mass spectrometry system (Agilent 1290LC-6495MS / MS, Agilent Technologies, USA); Mili-Q deionized water generator (Millipore, USA); KQ3200V ultrasonic generator (Kunshan Ultrasonic Instrument Co., Ltd.); MS3 vortex mixer (IKA, Germany); 5424R high-speed centrifuge (Eppendorf, Germany).

[0069] 1.2 Sample: Wuji Baifeng Wan (Jiuzhitang Co., Ltd., batch number: 20230808)

[0070] 1.3 Reagents: adamantane (CAS: 768-94-5), adamantane-D6 (CAS: 1219805-53-4), adamantane-methylamine (CAS: 17768-41-1), adamantane-ethylamine (CAS: 13392-28-4), and methanilide (CAS: 19982-08-2). Methanol, acetonitrile, and formic acid were all of chromatographic purity. The magnetic adsorption nanomaterials prepared in Examples 1-3 and Comparative Examples 1-4.

[0071] 2. Methods and Results:

[0072] 2.1 Preparation of reference solution: Weigh accurately 10 mg each of amantadine, amantadine-D6, adamantylmethylamine, adamantylethylamine, and memantine reference standards into a 100 mL volumetric flask, add methanol to dissolve and dilute to the mark. The mass concentration of this standard stock solution is 100 mg / L. Store it in the dark at -20 °C and dilute it to a 1 mg / L standard working solution before use to prepare a mixed standard solution.

[0073] 2.2 Sample pretreatment: Take an appropriate amount of Wuji Baifeng Pills, grind them finely and dry them for weighing; weigh accurately 2.5 g of the sample powder into a 50 mL centrifuge tube, accurately add 25 μL of 1 mg / L amantadine-D6 internal standard working solution, add 2.5 mL of distilled water and 10 mL of acetonitrile containing 1% (v / v) acetic acid, vortex and mix evenly for 5 min, extract by ultrasonic for 5 min, then centrifuge at 8000 r / min for 5 min. Take 2 mL of the supernatant and transfer it to a centrifuge tube containing 5 mg of the magnetic adsorption nanomaterial (CTi-MFn) prepared in Example 1, vortex for 30 s, place an external magnet at the bottom of the centrifuge tube to quickly separate the magnetic adsorption nanomaterial and the purification liquid, take 1 mL of the supernatant and filter it through a 0.22 μm filter membrane for UPLC-MS / MS detection.

[0074] 2.3 UPLC-MS / MS detection conditions:

[0075] Chromatographic conditions: Chromatographic column (CORTECS&UPLC&C18, 2.1*100 mm, 1.6 μm), column temperature is 30 °C, sample chamber temperature is 4 °C, injection volume is 1 μL, mobile phase A is an aqueous solution containing 0.1% formic acid, mobile phase B is methanol, flow rate is 0.3 mL / min, elution gradient: 0 - 2 min (40% B); 2.01 - 3 min (40% B - 90% B); 3.01 - 5 min (90% B); 5.01 - 7 min (40% B).

[0076] Mass spectrometry conditions: Ion source: electrospray ionization source (ESI); detection mode: positive ion detection; capillary voltage: 3.0 kV; ion source temperature: 220 °C; drying gas: nitrogen, flow rate is 11 L / min; sheath gas: nitrogen, temperature is 250 °C, flow rate is 11 L / min; nebulizing gas: nitrogen, pressure is 137895 Pa. The mass spectrometry detection parameters of amantadine, amantadine-D6 (internal standard), adamantylmethylamine, adamantylethylamine, and memantine are shown in Table 1:

[0077] Table 1

[0078] Retention time (min) Parent ion (m / z) Daughter ions (m / z) Collision energy CE (eV) Tapered hole voltage (V) Amantadine-D6 3.441 158.1 141.2* / 93.1 20 / 25 18 Amantadine 3.448 152.1 135.2* / 93.1 20 / 25 18 Amantadine Methylamine 3.805 166.1 93.1* / 149.1 18 / 24 40 adamantane ethylamine 3.893 180.2 163.1* / 81.0 16 / 22 35 Megatron 3.926 180.2 163.2* / 107.0 20 / 25 35

[0079] * is the quantitative ion

[0080] 2.4 Investigation of linearity, limit of detection, and limit of quantitation: To eliminate the influence of matrix effects on the determination results, this study added standard working solutions of four types of amantadine drugs to the Wuji Baifeng Wan sample, with concentrations of 1.0, 2.5, 5.0, 10.0, 50.0, and 100.0 μg / kg, respectively. After processing according to the method in section "2.2", the analysis was performed according to the instrument conditions in section "2.3". Linear regression was performed with the amantadine drug concentration (X, μg / kg) in the sample as the abscissa and the ratio of the peak area of ​​the quantitative ion to the internal standard correction ion (Y) as the ordinate. The results showed good linearity in the range of 1.0–100 μg / kg, with correlation coefficients greater than 0.999. The limit of detection (LOD) was determined using a signal-to-noise ratio (S / N) of 3, and the LODs for adamantane, adamantane methylamine, adamantane ethylamine, and memantine were obtained. The limit of quantitation (LOQ) was determined using a signal-to-noise ratio (S / N) of 10, and the LODs for adamantane, adamantane methylamine, adamantane ethylamine, and memantine were obtained. These results meet the sensitivity requirements for routine detection. Specific results are shown in Table 2.

[0081] Table 2

[0082] Linear equations <![CDATA[Coefficient of correlation R 2 > Limit of detection (μg / kg) Limit of quantitation (μg / kg) Amantadine Y = 0.3903X + 0.0116 0.9998 0.3 1.0 Amantadine Methylamine Y = 0.5166X + 0.0448 0.9994 0.3 1.0 adamantane ethylamine Y = 0.6338X + 0.0060 0.9997 0.3 1.0 Megatron Y = 0.7344X + 0.00016 0.9992 0.3 1.0

[0083] 2.5 MRM Mode Detection: This method uses MRM mode detection. Each analyte has two detection channels, each corresponding to one monitored ion pair. During sample detection, if peaks with retention times consistent with the reference standard appear in both channels, and the relative abundance of these two daughter ions is consistent with the reference standard, then the component can be detected in the sample. Simultaneously, based on the peak area of ​​the ion chromatogram in the quantitative monitoring ion pair, the content of amantadine drug residues in the sample is calculated using the internal standard method. Typical spiked sample detection mass spectra (total ion chromatogram and MRM monitoring chromatogram) are shown below. Figures 1-6 As shown.

[0084] As can be seen from the figure, after purification treatment using the magnetic adsorption nanomaterials prepared by the present invention, the chromatographic peaks of each monitored ion pair exhibit ideal peak shapes, symmetrical peak shapes, narrow peak widths, no tailing, stable baselines, and no flat-topped peaks, bifurcated peaks, etc., indicating that the magnetic adsorption nanomaterials are suitable for the detection of amantadine residues in Wuji Baifeng Wan (a traditional Chinese medicine).

[0085] 2.6 Comparative analysis of recovery rate and reusability: Seven groups of samples were prepared from the magnetic adsorption nanomaterials obtained in Examples 1-3 and Comparative Examples 1-4. The samples were processed according to the method in section “2.2” and then analyzed according to the instrument conditions in section “2.3”. Each group of samples was used to continuously purify the Wuji Baifeng Wan sample for 10 days. The initial recovery rate of adamantane in the purification solution was determined and the recovery retention rate was calculated. The recovery retention rate = (recovery rate on day 10 - initial recovery rate) / initial recovery rate × 100%. The specific test results are shown in Table 3.

[0086] Table 3

[0087] Initial recovery rate / % Recovery retention rate / % Example 1 98.83 97.64 Example 2 98.51 97.37 Example 3 98.66 97.23 Comparative Example 1 97.23 94.49 Comparative Example 2 98.17 91.52 Comparative Example 3 96.78 89.91 Comparative Example 4 97.52 90.35

[0088] The results showed that the initial recovery rates of Examples 1-3 were between 98.51% and 98.83%, and the recovery retention rates were between 97.23% and 97.64%. This indicates that the magnetic adsorption nanomaterials can effectively adsorb impurities in the test samples, enabling the test samples to achieve a relatively ideal spike recovery rate. Furthermore, the magnetic adsorption nanomaterials maintained a high recovery retention rate even after multiple uses, indicating that they maintain good purification performance and have high reusability and durability. Detailed analysis is as follows:

[0089] As can be seen from Example 1 and Comparative Example 1, compared with Comparative Example 1, the initial recovery rate of magnetic Fe3O4 nanoparticles was increased from 97.23% to 98.83% after functionalization treatment in Example 1, and the retention rate after the 10th recovery was increased from 94.49% to 97.64%. This shows that the functionalization treatment of magnetic Fe3O4 nanoparticles can effectively purify matrix impurities and improve the durability of magnetic adsorption nanomaterials.

[0090] As can be seen from Example 1 and Comparative Example 2, compared with Comparative Example 2, Example 1 replaced ordinary carbon nanotubes with carboxylated carbon nanotubes, and the initial recovery rate increased from 98.17% to 98.83%, while the retention rate of the 10th recovery increased from 91.52% to 97.64%. This shows that the addition of carboxylated carbon nanotubes can purify matrix impurities and improve the durability of magnetic adsorption nanomaterials.

[0091] A comprehensive analysis of Example 1 and Comparative Examples 1-3 shows that, compared to Comparative Example 3, when ordinary carbon nanotubes were replaced with carboxylated carbon nanotubes, the retention rate after the 10th recovery increased from 89.91% to 94.49%, a significantly smaller increase than the difference between Example 1 (97.64%) and Comparative Example 2 (91.52%). Similarly, compared to Comparative Example 3, the magnetic Fe3O4 nanoparticles in Comparative Example 2 underwent functionalization treatment, resulting in a retention rate after the 10th recovery increasing from 89.91% to 91.52%, a significantly smaller increase than the difference between Example 1 (97.64%) and Comparative Example 1 (94.49%). This indicates that carboxylated carbon nanotubes can synergistically interact with the functionalized magnetic Fe3O4 nanoparticles, significantly improving the retention rate after the 10th recovery and enhancing the durability of the magnetic adsorption nanomaterials.

[0092] As can be seen from Example 1 and Comparative Example 4, compared with Comparative Example 4, the titanium modification of functionalized Fe3O4 magnetic nanoparticles in Example 1 increased the initial recovery rate from 97.52% to 98.83%, and the retention rate after the 10th recovery increased from 90.35% to 97.64%. This indicates that in this system, titanium modification of functionalized Fe3O4 magnetic nanoparticles can purify matrix impurities and significantly improve the durability of magnetic adsorption nanomaterials.

[0093] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present invention will not describe the various possible combinations separately.

[0094] Furthermore, various different embodiments of the present invention can be combined in any way, as long as they do not violate the spirit of the present invention, they should also be regarded as the content disclosed by the present invention.

Claims

1. A method for preparing magnetic adsorption nanomaterials, characterized in that, Includes the following steps: S1. Functionalized Fe3O4 nanoparticles are added to a solvent and dispersed evenly to obtain a dispersion system; the functionalized Fe3O4 nanoparticles are prepared by surface treatment of magnetic Fe3O4 nanoparticles with tetraethoxysilane, followed by grafting of amino and carboxyl active groups; S2. Add a mixture of titanium source and acetylacetone to the dispersion system obtained in S1, stir evenly, heat and stir to carry out the reaction, and obtain titanium-modified Fe3O4 nanocomposite microspheres; S3. Add the titanium-modified Fe3O4 nanocomposite microspheres obtained in S2 to the carbon nanotube dispersion, stir ultrasonically, and purify and separate to obtain the magnetic adsorption nanomaterial.

2. The preparation method according to claim 1, characterized in that, The preparation process of functionalized Fe3O4 nanoparticles in step S1 includes the following steps: A1. Magnetic Fe3O4 nanoparticles were added to an ethanol solution containing tetraethoxysilane, and after heating and stirring, solid-liquid separation was performed to obtain pretreated magnetic nanoparticles. A2. Mix glycolic acid, ammonium citrate, carbon disulfide and alcohol solution evenly to obtain a premixed solution, and then add the pretreated magnetic nanoparticles obtained in step A1 to the premixed solution to obtain a suspension. A3. Epichlorohydrin is added dropwise to the suspension obtained in step A2. After heating reaction, solid-liquid separation, washing and drying, functionalized Fe3O4 nanoparticles are obtained.

3. The preparation method according to claim 2, characterized in that, In step A2, the mass ratio of glycolic acid, ammonium citrate, and carbon disulfide in the premixed solution is 1:0.8-1.2:1.5-2.5, and the mass ratio of pretreated magnetic nanoparticles, glycolic acid, and alcohol solution is 1:0.2-0.3:80-120.

4. The preparation method according to claim 2, characterized in that, In step A2, the alcohol solution is one or a mixture of two or more of methanol, ethanol, n-propanol, isopropanol, n-butanol, and isobutanol.

5. The preparation method according to claim 1, characterized in that, The mass fraction of functionalized Fe3O4 nanoparticles in the dispersion system in step S1 is 0.05-0.5%.

6. The preparation method according to claim 1, characterized in that, In step S2, the mass ratio of the titanium source to the functionalized Fe3O4 nanoparticles is 2:0.8-1.2, and the volume ratio of the titanium source to acetylacetone is 1:3-5.

7. The preparation method according to claim 1, characterized in that, In step S2, the reaction temperature is 200-260℃ and the reaction time is 2-4h.

8. The preparation method according to claim 1, characterized in that, In step S3, the mass fraction of carboxylated carbon nanotubes in the carbon nanotube dispersion is 0.1-0.5%.

9. A magnetic adsorption nanomaterial, characterized in that, The magnetic adsorption nanomaterial is prepared by the preparation method described in any one of claims 1-8.

10. An application of a magnetic adsorption nanomaterial, characterized in that, The magnetic adsorption nanomaterials described in claim 9 are used in the detection of prohibited drug residues in animal-derived traditional Chinese medicines, and the detection matrix is ​​purified and pretreated.

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