Magnetic fluorine and nitrogen co-doped organic polymer adsorption material and its preparation method and application

Abstract

The present invention discloses a magnetic fluorine and nitrogen co-doped organic polymer adsorption material, its preparation method, and application. The magnetic fluorine and nitrogen co-doped organic polymer adsorption material is prepared by a one-step synthesis method. The Fe3O4@SiO2-NH2 nanoparticles are used as carriers, and the nanoparticles are coated with POPs synthesized from the comonomers 1,4-bis(2,4-diamino-1,3,5-triazine)-benzene and fluoroformaldehyde benzene. The material prepared by the present invention has a high nitrogen content and can bind H under neutral and acidic conditions. + This makes its surface carry a positive charge, which can interact electrostatically with anions and effectively improve its adsorption effect; at the same time, fluorine atoms can increase the hydrogen bonding and electrostatic interactions between host and guest molecules (can produce hydrogen bonding effects with amphetamine-type stimulants), promote high selectivity of adsorption, and thus achieve high-precision quantitative detection of trace or trace amounts of amphetamine-type stimulants in samples.

Description

Technical Field

[0001] The present invention relates to the field of analysis, in particular to a magnetic fluorine and nitrogen co-doped organic polymer adsorption material, a preparation method of the magnetic fluorine and nitrogen co-doped organic polymer adsorption material, and an application of the magnetic fluorine and nitrogen co-doped organic polymer adsorption material. Background Art

[0002] Currently, the abuse of synthetic drugs, primarily methamphetamine and ecstasy, is becoming increasingly serious. The primary narcotic ingredient in methamphetamine is methamphetamine, while the primary ingredients in ecstasy are 3,4-methylenedioxymethamphetamine (MDMA), 3,4-methylenedioxyamphetamine (MDA), or 3,4-methylenedioxyethylamphetamine (MDEA). Drug abuse primarily affects the body in two ways. Drug abuse can have toxic effects on the body, manifesting as dysfunction and pathological changes in tissues, as well as severe withdrawal symptoms and the development of various complications, such as hepatitis, HIV, hallucinations, and mental disorders. Drug abuse also poses a significant threat to families, social productivity, and public security. Therefore, the rapid detection and precise quantification of amphetamine-type stimulants in biological samples is crucial for judicial assistance and human health risk assessment.

[0003] There are two main categories of detection methods for amphetamines. One is rapid screening methods, which mainly qualitatively detect whether the sample contains drug components based on the result interpretation requirements of the test kit, such as the common colloidal gold test paper method, fluorescent immunochromatography method and molecular motor method. Although these detection methods are relatively fast, they require a large amount of biological samples and can only be qualitative. They are generally used for rapid detection in actual on-site. The second category is quantitative detection methods, such as liquid chromatography-mass spectrometry and gas chromatography-mass spectrometry. They have the advantages of modern operation, accurate qualitative and quantitative analysis, and low sample volume, but they have high sample pretreatment requirements and matrix effects. Therefore, it is of great significance to develop methods to efficiently and quickly enrich amphetamines from biological samples using enrichment materials.

[0004] Currently, a variety of sample pretreatment methods have been established, including solid-phase extraction (SPE), solid-phase microextraction (SPE), magnetic solid-phase extraction (MSPE), liquid-liquid extraction (LIE), dispersive liquid-liquid microextraction (DLE), and stir-bar adsorption extraction (SPE). Among them, MSPE offers significant advantages in terms of short analysis time, analyte enrichment, matrix purification, and low organic solvent consumption, making it widely used in sample pretreatment. For MSPE, the magnetic adsorption material is a key factor affecting sample processing. Common magnetic adsorption materials include graphene-Fe₃O₄, graphene oxide-Fe₃O₄, ionic liquid-immobilized magnetic nanoparticles, zeolite-Fe₃O₄, magnetic porous organic polymers (POPs), magnetic metal-organic frameworks (MOFs), magnetic molecularly imprinted polymers (MIPs), and magnetic covalent organic frameworks (COFs). POPs have attracted research attention due to their excellent porosity and designable structure, but there have been no reports on the use of magnetic POPs in the treatment of amphetamine-type stimulant samples. Summary of the Invention

[0005] In view of this, the first object of the present invention is to provide a magnetic fluorine-nitrogen co-doped organic polymer adsorption material. The second object of the present invention is to provide a method for preparing a magnetic fluorine-nitrogen co-doped organic polymer adsorption material. The third object of the present invention is to provide applications of a magnetic fluorine-nitrogen co-doped organic polymer adsorption material.

[0006] To achieve the above object, the present invention adopts the following technical solutions:

[0007] The present invention provides a magnetic fluorine and nitrogen co-doped organic polymer adsorption material, which is prepared by a one-step synthesis method. It uses Fe3O4@SiO2-NH2 nanoparticles as a carrier, and is coated with POPs synthesized from comonomers 1,4-bis(2,4-diamino-1,3,5-triazine)-benzene and fluoroformaldehyde benzene on the Fe3O4@SiO2-NH2 nanoparticles. Wherein, the fluoroformaldehyde benzene is 3,4,5-trifluorobenzaldehyde, tetrafluoroterephthalaldehyde, or pentafluorobenzaldehyde. When the fluoroformaldehyde benzene is 3,4,5-trifluorobenzaldehyde, tetrafluoroterephthalaldehyde, or pentafluorobenzaldehyde, the structural formula of the porous organic polymer is as follows:

[0008] ; or .

[0009] The beneficial effect is that the material of the present invention has a high nitrogen content and can combine with H under neutral and acidic conditions. +The surface of the fluorine atom is positively charged, which enables electrostatic interaction with anions, effectively improving the adsorption effect. At the same time, the fluorine atoms can increase the hydrogen bonding and electrostatic interaction between the host and guest molecules, promoting high selectivity of adsorption. Among them, the adsorption material of the present invention can generate interaction forces such as π-π interaction, CH-π interaction and hydrogen bonding with amphetamine stimulants, further improving the adsorption performance of the adsorption material.

[0010] The present invention also provides a method for preparing a magnetic fluorine and nitrogen co-doped organic polymer adsorption material, the preparation method comprising the following steps:

[0011] S1, synthesis of Fe3O4 nanoparticles by solvothermal method;

[0012] S2, bonding silica on the surface of Fe3O4 nanoparticles to obtain nano-Fe3O4@SiO2;

[0013] S3, silanizing nano-Fe3O4@SiO2 to obtain Fe3O4@SiO2-NH2 nanoparticles;

[0014] S4, Fe3O4@SiO2-NH2 nanoparticles, 1,4-bis(2,4-diamino-1,3,5-triazine)-benzene and fluoroaldehyde benzene are subjected to Schiff base reaction in a nitrogen environment at 160°C-180°C, and then washed and dried in sequence to obtain the magnetic fluorine and nitrogen co-doped organic polymer adsorption material.

[0015] The present invention adopts a "top-down" strategy to synthesize fluorine-containing and nitrogen-rich porous organic compounds on the surface of Fe3O4@SiO2-NH2 nanoparticles in one step. It not only has good dispersibility but can also be reused. It has the advantages of stability and reusability. It can achieve specific identification of substances with different polarities (such as aniline stimulants and organophosphorus pesticide residues), which is of great significance for the forensic identification of amphetamine stimulants.

[0016] Preferably, the washing in S4 comprises the following: washing with DMF, methanol, acetone and ethanol alternately for several times, and then Soxhlet extraction with methanol for 24 hours; and the drying in S4 is vacuum drying at 120°C.

[0017] The present invention also provides the use of a magnetic fluorine- and nitrogen-co-doped organic polymer adsorption material for the quantitative detection of amphetamine-type stimulants. Specifically, the magnetic fluorine- and nitrogen-co-doped organic polymer adsorption material is used as a solid-phase extraction material. The sample is first enriched and extracted, then eluted and redissolved, and finally, the redissolved sample is subjected to qualitative and quantitative analysis using GC-MS / MS or HPLC-MS / MS.

[0018] The method for quantitatively detecting amphetamine-type stimulants of the present invention comprises the following specific steps:

[0019] S1, adding a magnetic fluorine and nitrogen co-doped organic polymer adsorption material to a working solution containing an amphetamine-type stimulant, and vortexing for 5-15 minutes to extract the amphetamine-type stimulant from the working solution;

[0020] S2, magnetic separation to remove the aqueous solution, ultrasonic elution with methanol, drying the eluate in a nitrogen environment, and then re-dissolving it with methanol, filtering, and obtaining the test solution;

[0021] S3, analyzing the test solution obtained in step S2 using GC-MS / MS or HPLC-MS / MS, and plotting a standard curve for each amphetamine-type stimulant using concentration as the abscissa and peak area as the ordinate;

[0022] S4, measuring the sample according to the test method of the standard working solution in steps S1-S3, qualitatively analyzing the retention time, and calculating the concentration of the amphetamine-type stimulant in the sample based on the peak area value of the target compound and the standard curve;

[0023] The present invention uses magnetic fluorine and nitrogen co-doped organic polymer adsorption material as solid phase microextraction material, establishes a kind of MSPE-GC-MS / MS analytical method of micro or trace amphetamine stimulant in measuring sample, the method is simple to operate, sample treatment is simple and can be controlled within 10min, and the recovery rate of every kind of amphetamine stimulant is all more than 84%, and RSD value is within 5.6%, and precision is high, can be used for the quantitative detection of amphetamine stimulant in actual sample.In addition, magnetic fluorine and nitrogen co-doped organic polymer adsorption material of the present invention has good repeatability, reduces cost.

[0024] In this invention, the optimal conditions for microextraction of amphetamine-type stimulants from sample solutions (or working solutions) using a magnetic fluorine- and nitrogen-codoped organic polymer adsorbent are: 6 mg of material per 50 mL of sample solution (or working solution); adsorption time of 10 minutes; 1.0 mL of methanol as the eluent; and ultrasonic elution time of 1 minute. By optimizing the MSPE process, this invention effectively ensures the reliability and reproducibility of detection results.

[0025] Preferably, the gas chromatography conditions of GC-MS / MS in step S3 are as follows: the chromatographic column is an SH-5SiL MS elastic quartz capillary column, the injection port temperature is 270°C, splitless injection is used, the carrier gas is helium, the pressure is 100 KPa, the initial temperature of the chromatographic column is 60°C, maintained for 2 min, and then heated to 220°C at a rate of 10°C / min and maintained for 1 min;

[0026] The mass spectrometry conditions of GC-MS / MS were as follows: MRM acquisition mode, interface temperature of 220°C, ion source temperature of 250°C, and solvent delay time of 2 min.

[0027] Compared with the existing technology, the present invention uses Fe3O4@SiO2-NH2 nanoparticles coated with POPs synthesized from comonomers 1,4-bis(2,4-diamino-1,3,5-triazine)-benzene and fluoroaldehyde benzene. The material has a high nitrogen content and can bind H under neutral and acidic conditions. + This makes its surface carry a positive charge, which can interact electrostatically with anions and effectively improve its adsorption effect; at the same time, fluorine atoms can increase the hydrogen bonding and electrostatic effects between host and guest molecules, promoting high selectivity of adsorption.

[0028] The present invention establishes an MSPE-GC-MS / MS method for quantitatively detecting trace or micro-amounts of amphetamine stimulants based on a magnetic fluorine and nitrogen co-doped organic polymer adsorption material. The method is simple to operate, requires simple sample processing, and has a short processing time. The recovery rate of each amphetamine stimulant is above 84%, the RSD value is within 5.6%, the precision is high, and the method has good repeatability and reliable results. The method can be used for the quantitative detection of trace or micro-amounts of amphetamine stimulants in actual samples and has good application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 These are the FT-IR graphs of Fe3O4@SiO2@3F, Fe3O4@SiO2@4F, and Fe3O4@SiO2@5F.

[0030] Figure 2 These are the SEM and elemental analysis images of Fe3O4@SiO2@3F of the present invention.

[0031] Figure 3 These are the SEM and elemental analysis images of Fe3O4@SiO2@4F of the present invention.

[0032] Figure 4 These are the SEM and elemental analysis images of Fe3O4@SiO2@5F of the present invention.

[0033] Figure 5 The XRD patterns of the present invention are shown in Figures a and b. (a) show the XRD patterns of Fe3O4@SiO2@3F and POPs (3F); (b) show the XRD patterns of Fe3O4@SiO2@4F and POPs (4F); and (c) show the XRD patterns of Fe3O4@SiO2@5F and POPs (5F).

[0034] Figure 6 This is the XPS spectrum of Fe3O4@SiO2@3F of the present invention.

[0035] Figure 7 This is the XPS spectrum of Fe3O4@SiO2@4F of the present invention.

[0036] Figure 8 This is the XPS spectrum of Fe3O4@SiO2@5F of the present invention.

[0037] Figure 9 The VSM diagram of the present invention is shown in Figure 1. In the figure, a is the hysteresis loop of Fe3O4@SiO2@3F; b is the hysteresis loop of Fe3O4@SiO2@4F; and c is the hysteresis loop of Fe3O4@SiO2@5F.

[0038] Figure 10 This is a comparison chart of the adsorption of amphetamine-type stimulants by Fe3O4@SiO2@3F, Fe3O4@SiO2@4F, and Fe3O4@SiO2@5F of the present invention.

[0039] Figure 11 This is a diagram of the adsorption performance of Fe3O4@SiO2@5F during recycling of the present invention.

[0040] Figure 12 This is a chromatogram of the spiked urine sample in Example 5 of the present invention. DETAILED DESCRIPTION

[0041] The embodiments of the present invention are described in detail below in conjunction with the accompanying drawings. This embodiment is implemented based on the technical solution of the present invention, and provides detailed implementation methods and specific operating procedures. However, the protection scope of the present invention is not limited to the following embodiments. In addition, it should be noted that, unless otherwise specified, the reagents used in the present invention are all existing commercially available reagents, and the equipment used are all conventional laboratory equipment.

[0042] 1. Preparation of magnetic fluorine and nitrogen co-doped organic polymer adsorption materials

[0043] The magnetic fluorine- and nitrogen-co-doped organic polymer adsorbent material of the present invention is prepared using a one-step synthesis method. Specifically, Fe₃O₄@SiO₂-NH₂ nanoparticles are used as a carrier, and POPs synthesized from the comonomers 1,4-bis(2,4-diamino-1,3,5-triazine)-benzene and fluoroaldehyde benzene are coated on the Fe₃O₄@SiO₂-NH₂ nanoparticles. The magnetic fluorine- and nitrogen-co-doped organic polymer adsorbent material of the present invention is described in detail below with reference to specific examples.

[0044] Example 1 Magnetic fluorine and nitrogen co-doped organic polymer adsorption material Fe3O4@SiO2@3F

[0045] S1, synthesis of Fe3O4 nanoparticles by solvothermal method

[0046] To the lining of a 100-mL reactor, add 80 mL of ethylene glycol to 2.7 g of FeCl3, sonicate to dissolve the ferric chloride, then slowly add 7.2 g of anhydrous sodium acetate and 2.0 g of polyethylene glycol with a degree of polymerization of 1000, and sonicate for 15 min until the mixture becomes silky smooth. The reactor lining is fixed in the reactor, and the mixture is slowly heated to 200 °C under nitrogen protection and reacted at 200 °C for 12 h. After the reaction, the mixture is cooled to room temperature, and the black product is washed alternately with anhydrous ethanol and water four times (using a magnet to assist separation during the washing process) to obtain Fe3O4 magnetic nanoparticles. The prepared Fe3O4 magnetic nanoparticles are stored in anhydrous ethanol for later use.

[0047] S2, bonding silica on the surface of Fe3O4 nanoparticles to prepare nano-Fe3O4@SiO2;

[0048] To 2 g of Fe3O4 nanoparticles, 200 mL of 0.1 mol / L citric acid solution was added, ultrasonically mixed, and stirred at 40°C for 12 h. After the reaction, the mixture was separated with a magnet and the solution was discarded. The mixture was then washed three times with ultrapure water and ethanol with the assistance of a magnet. After washing, 160 mL of ethanol / water (v / v = 4:1) was added and ultrasonicated for 10 min. 4 mL of ammonia solution was then added and ultrasonicated for 20 min. 2 mL of tetraethyl silicate was slowly added dropwise and stirred at 45°C for 12 h. After the reaction, the mixture was separated with a magnet and the solution was discarded. The separated product was washed three times with acetone, ultrapure water, and anhydrous ethanol, and dried in vacuo at 50 °C for 12 h to obtain Fe3O4@SiO2 nanoparticles.

[0049] S3, silanizing nano-Fe3O4@SiO2 to obtain Fe3O4@SiO2-NH2 nanoparticles;

[0050] To 1.0 g of Fe3O4@SiO2 nanoparticles, 60 mL of freshly distilled anhydrous toluene was added. After ultrasonic mixing, 2 mL of 3-aminopropyltriethoxysilane was added under stirring. After addition, the reaction temperature was raised to 120°C and the stirring speed was increased. The reaction was carried out under nitrogen protection for 8 h. After the reaction, the solid product was separated using a magnet and washed three times with toluene, acetone, ultrapure water, and ethanol. Finally, the product was vacuum dried at 40 °C for 12 h to obtain Fe3O4@SiO2-NH2 nanoparticles.

[0051] S4, bonded on Fe3O4@SiO2-NH2 nanoparticles POPs ;

[0052] 1,4-Bis(2,4-diamino-1,3,5-triazine)-benzene (592.6 mg, 2 mmol), 3,4,5-trifluorobenzaldehyde (1280.7 mg, 8 mmol) and DMSO (60 mL) were added to a two-necked round-bottom flask in sequence. After thorough mixing, Fe3O4@SiO2-NH2 (615.1 mg, 2 mmol) was added and reacted at 180°C in a nitrogen environment for 24 h. An external magnetic field was applied to collect the solid product, which was then washed alternately with DMF, methanol, acetone and ethanol several times to completely remove excess reactants. The solid product was then extracted with methanol for 24 h and dried in vacuum at 120°C overnight to obtain a magnetic fluorine and nitrogen co-doped organic polymer adsorption material, hereinafter referred to as "Fe3O4@SiO2@3F".

[0053] Among them, the reaction process and structural formula of POPs (3F) on Fe3O4@SiO2-NH2 nanoparticles are as follows:

[0054] .

[0055] Example 2 Magnetic fluorine and nitrogen co-doped organic polymer adsorption material Fe3O4@SiO2@4F

[0056] The difference between this embodiment and embodiment 1 is that the fluoroformaldehyde benzene is tetrafluoroterephthalaldehyde, and the added amount is 824.4 mg (ie, 4 mmol). The rest is the same as in embodiment 1.

[0057] The magnetic fluorine and nitrogen co-doped organic polymer adsorption material (a double-shell material) prepared in this example is denoted as Fe3O4@SiO2@4F. The reaction process of POPs (4F) on Fe3O4@SiO2-NH2 nanoparticles is as follows:

[0058] .

[0059] Example 3 Magnetic fluorine and nitrogen co-doped organic polymer adsorption material Fe3O4@SiO2@5F

[0060] The difference between this embodiment and embodiment 1 is that: in this embodiment, the fluoroaldehyde benzene is pentafluorobenzaldehyde, and the amount used is 1568.7 mg (ie, 8 mmol). The rest is the same as in embodiment 1.

[0061] The magnetic fluorine and nitrogen co-doped organic polymer adsorption material (with a double-shell structure) prepared in this example is denoted as Fe3O4@SiO2@5F. The reaction process and structural formula of POPs (5F) on Fe3O4@SiO2-NH2 nanoparticles in this example are as follows:

[0062] .

[0063] 2. Characterization of Magnetic Fluorine and Nitrogen Co-doped Organic Polymer Adsorption Materials

[0064] 1. Fe3O4@SiO2@3F, Fe3O4@SiO2@4F and Fe3O4@SiO2@5F were characterized by FT-IR. The results are shown in Figure 1 .Depend on Figure 1 It can be seen that the three materials have a -1 The sharp infrared band at 1620 cm-1 (the characteristic band of triazine ring) indicates that the polycondensation reaction has been successfully carried out; the three materials do not have the -1 The imine (-C=N-) stretching band is around 3414 cm -1 There is a very broad absorption band at 1105 cm -1 Si-O-Si and 493 cm -1 The Fe-O characteristic peak at also confirms the coating of the magnetic core, indicating the successful preparation of Fe3O4@SiO2@3F, Fe3O4@SiO2@4F, and Fe3O4@SiO2@5F.

[0065] 2. SEM and X-ray energy spectrum analysis were used to observe the microscopic morphology of Fe3O4@SiO2@3F, Fe3O4@SiO2@4F, and Fe3O4@SiO2@5F. The results are shown in Figure 2-4 .Depend on Figure 2-4 It can be seen that the three materials all present a micron-sized spherical block aggregate with relatively uniform size. At the same time, due to the magnetic properties of Fe3O4, the materials show a certain degree of agglomeration. The element distribution of the materials can be inferred from the material synthesis process: first, the synthesis of Fe3O4 magnetic nanospheres represents that the material uses Fe as the core; then a certain amount of SiO2 is introduced to obtain a Fe3O4@SiO2 single core-shell structure, indicating that Si element coats Fe element, and finally a fluorine-containing aldehyde monomer and a nitrogen-rich amino monomer are introduced in one pot to prepare a double-shell structure adsorption material, wherein the outer shell of the material is C, N, O, F elements, the middle shell is Si element, and the core is Fe element. The EDS of the three materials of the present invention shows the distribution of Fe, Si, N, O, and F elements in the three materials, proving the successful preparation of the three materials.

[0066] 3. The materials Fe3O4@SiO2@3F, Fe3O4@SiO2@4F, Fe3O4@SiO2@5F and POPs (3F), POPs (4F) and POPs (5F) were characterized by X-ray powder diffractometer (XRD).

[0067] Depend on Figure 5It can be seen that the surface polymers POPs (3F), POPs (4F) and POPs (5F) all exhibit amorphous structural characteristics. The relatively broad 2θ peak at 22.5° may be derived from the stacking between benzene rings, which indicates that the arrangement of the three surface polymers is relatively irregular.

[0068] Fe3O4@SiO2@3F, Fe3O4@SiO2@4F, and Fe3O4@SiO2@5F have obvious response peaks at 2θ of 30.1°, 35.3°, 42.9°, 53.2°, 57.1°, and 62.7°, corresponding to the characteristic peaks of 220, 311, 400, 422, 511, and 440 of Fe3O4, respectively, proving the successful preparation of the three adsorption materials of the present invention.

[0069] 4. X-ray photoelectron spectroscopy (XPS) was used to characterize Fe3O4@SiO2@3F, Fe3O4@SiO2@4F, and Fe3O4@SiO2@5F. The XPS spectra of the three materials are shown in Figure 6-8 ; The distribution of element content is shown in Table 1.

[0070] Table 1 Element contents of Fe3O4@SiO2@3F, Fe3O4@SiO2@4F, and Fe3O4@SiO2@5F

[0071]

[0072] Combine Figure 6-8 As shown in Table 1, the XPS spectra of all three materials show the presence of C1s, O1s, N1s, Fe2p, Si2p, and F1s. The high-resolution spectrum of C1s is decomposed into two peaks, assigned to C-C / C=C and CN linkages, respectively. N1s can be decomposed into two distinct peaks, corresponding to nitrogen atoms in C-NH-C and triazine N linkages, respectively. O1s corresponds to Si-O and C=O structures. The Fe2p peaks at 711.8, 725.2, and 714.9 eV correspond to the Fe3O4 structure. The Si2p peak corresponds to the Si-O structure in the material. The F1s peak fitted indicates the C-F linkage in the material. The XPS results of the three materials confirm the successful synthesis of the adsorbent materials.

[0073] 5. The magnetic properties of Fe3O4@SiO2@3F, Fe3O4@SiO2@4F and Fe3O4@SiO2@5F were characterized respectively. Figure 9 .Depend on Figure 9It can be seen that the hysteresis curves of Fe3O4@SiO2@3F, Fe3O4@SiO2@4F and Fe3O4@SiO2@5F in the present invention all show superparamagnetic properties without hysteresis phenomenon, and the magnetic saturation intensity of these three materials remains at around 18 emu / g. They can be quickly separated within 3 seconds under the attraction of an external magnetic field, which is sufficient to meet the requirements for separating magnetic nanospheres from liquid solutions.

[0074] 3. Application of magnetic fluorine and nitrogen co-doped organic polymer adsorption materials

[0075] Example 4 The present invention uses a magnetic fluorine and nitrogen co-doped organic polymer adsorption material as a solid phase microextraction material to establish a method for quantitatively detecting amphetamine-type stimulants based on MSPE-GC-MS / MS, comprising:

[0076] S1: Take 50 mL of sample solution, then add 6.0 mg of adsorption material, vortex and shake for 10 minutes to allow the adsorption material to adsorb the amphetamine-type stimulants in the sample solution;

[0077] S2, after the oscillation is completed, the aqueous solution is discarded using a magnet and an external magnetic field, and then the solution is resuspended in methanol and ultrasonically eluted for 1 min. The eluate is dried at 40°C in a nitrogen environment, re-dissolved in methanol, and finally filtered through a 0.22µm filter membrane to obtain the test solution;

[0078] S3, GC-MS / MS was used to detect the test liquid. The gas chromatography conditions were as follows: the chromatographic column was an SH-5SiL MS elastic quartz capillary column, the injection port temperature was 270°C, non-split injection was used, the carrier gas was helium, the pressure was 100 KPa, the initial temperature of the chromatographic column was 60°C, maintained for 2 min, and then heated to 220°C at a rate of 10°C / min and maintained for 1 min; the mass spectrometry conditions of GC-MS / MS were as follows: the acquisition mode was MRM, the interface temperature was 220°C, the ion source temperature was 250°C, and the solvent delay time was 2 min.

[0079] The present invention can be used for the quantitative detection of the following six amphetamine-type stimulants: 3,4-methylenedioxy-N-ethylamphetamine (MDEA); 3,4-methylenedioxymethamphetamine (MDMA); 3,4-methylenedioxyamphetamine (MDA); methamphetamine (MATM); amphetamine (AMP); and phenylethylamine (PEA). The structural formulas are as follows:

[0080]

[0081] It should be noted that for aqueous solution samples, the test can be performed directly according to steps S1-S3; for hair, urine, and blood samples, the samples need to be pre-processed first. The specific processing methods are as follows:

[0082] Cut the hair sample into small pieces and weigh a certain amount of the broken hair into a centrifuge tube. Wash it with acetone, pure water, and ethanol in sequence. Then, add 1 mL of 10% NaOH solution and heat it at 80°C in a metal bath for 10 minutes to obtain a hair extract. Use the hair extract as the test object and perform the test according to the above steps S1-S3.

[0083] Add 10% NaOH solution to the urine sample to adjust the pH to above 13, then add NaCl (solid particles) until saturated, vortex for 2 minutes, centrifuge, and collect the supernatant to obtain the urine extract. Use the urine extract as the test object and perform the test according to the above steps S1-S3;

[0084] Add 1 mL of 10% NaOH solution to the blood sample and vortex for 2 minutes to obtain a blood extract. Use the urine extract as the test object and test according to the above steps S1-S3.

[0085] The method for quantitative detection of trace amounts of amphetamine-type stimulants based on MSPE-GC-MS / MS and the magnetic fluorine and nitrogen co-doped organic polymer adsorption material established in the present invention are evaluated separately in conjunction with specific test examples.

[0086] 1. Linear range, limit of quantification, and limit of detection of amphetamine-type stimulants

[0087] Mixed standard stock solutions of six amphetamine-type stimulants were prepared using ultrapure water. The concentration of each amphetamine-type stimulant in the mixed standard stock solution was 100 mg / L. The mixed standard stock solution was diluted to different multiples to obtain mixed standard working solutions with concentrations ranging from 25 to 1000 ng / mL. The detection method established in this example was used for detection (the adsorption material used was Fe3O4@SiO2@5F). The results are shown in Table 2.

[0088] Table 2 Standard curves, limits of quantification, and limits of detection of aniline stimulants

[0089]

[0090] As shown in Table 2, the linear range of each amphetamine-type stimulant in this example is 25-1000 ng / mL, and the linear correlation coefficient is ≥0.9974, which has a very high correlation and a good linear relationship. In addition, the method for quantitative detection of amphetamine-type stimulants based on MSPE-GC-MS / MS established in the present invention also has a low detection limit and quantification limit, indicating that the method has a high detection sensitivity.

[0091] 2. Adsorption performance of Fe3O4@SiO2@3F, Fe3O4@SiO2@4F and Fe3O4@SiO2@5F

[0092] The present invention uses 3,4-methylenedioxy-N-ethylamphetamine (MDEA), 3,4-methylenedioxymethamphetamine (MDMA), 3,4-methylenedioxyamphetamine (MDA), methamphetamine (MATM); amphetamine (AMP), and phenylethylamine (PEA) with a concentration of 500 ng / mL as test samples, adds 6.0 mg of an adsorption material to 50 mL of the test sample, and performs oscillation adsorption. Three groups of each adsorption material are parallelly added, and adsorption, desorption, and redissolution are sequentially performed according to the quantitative detection method of the present invention, and finally GC-MS / MS analysis is performed.

[0093] Calculate the test concentration according to the standard curve, and then calculate the recovery rate of each adsorption material (the recovery rate is equal to the ratio of the test concentration to the standard concentration). Figure 10 .Depend on Figure 10 The recovery rates of the three materials were all between 84% and 99%, meeting the requirements for quantitative detection of amphetamine-type stimulants. Furthermore, the Fe3O4@SiO2@5F prepared by the present invention exhibited better adsorption performance.

[0094] 3. Adsorption performance of the adsorption material of the present invention

[0095] The present invention uses Fe3O4@SiO2@5F as the adsorption material and a mixed standard working solution of amphetamine-type stimulants with a concentration of 500 ng / mL as the test sample to investigate the reusability of Fe3O4@SiO2@5F:

[0096] Add 6.0 mg of adsorbent material to 50 mL of the sample to be tested and vortex for 10 minutes. When saturation is reached, apply a magnetic field to discard the aqueous solution, then resuspend in methanol for desorption for 1 minute. After drying, re-dissolve and determine the concentration of amphetamine-type stimulants. Calculate the recovery (ratio of the test concentration to the standard concentration).

[0097] The eluted adsorbent material was recovered and dried, and the above process was repeated for a second cycle, and this cycle was repeated eight times. Figure 11 .

[0098] Depend on Figure 11 It can be seen that the performance of the adsorption material Fe3O4@SiO2@5F for each amphetamine-type stimulant did not decrease significantly when it was recycled eight times, indicating that the material can meet the needs of reuse.

[0099] Example 5 Application of the method for quantitative detection of trace amounts of amphetamine-type stimulants based on MSPE-GC-MS / MS established by the present invention in actual samples of amphetamine-type stimulants

[0100] It should be noted that the urine and hair samples in this example were obtained from volunteers who had not taken amphetamine-type stimulants and had not dyed or permed their hair within one year; the serum samples of the present invention were extracted from whole blood of healthy laboratory rats (which had not taken amphetamine-type stimulants).

[0101] In the first step, the hair, urine and serum samples are processed using the processing methods of Example 4 to obtain hair extracts, urine extracts and serum extracts, respectively;

[0102] In the second step, a mixed standard working solution of six amphetamine stimulants was added to each extract to prepare spiked samples at three different concentrations: high, medium, and low. The concentration of each stimulant in the low-concentration spiked sample was 100 ng / mL; the concentration of each stimulant in the medium-concentration spiked sample was 200 ng / mL; and the concentration of each stimulant in the high-concentration spiked sample was 500 ng / mL.

[0103] In the third step, 6 mg of Fe3O4@SiO2@5F was added to 50 mL of the spiked sample, vortexed for 10 minutes, and the aqueous solution was discarded using a magnet-assisted separation. The magnetic adsorbent was placed in 1.0 mL of methanol and ultrasonically eluted for 1 minute. The eluate was dried at 40°C under nitrogen. Finally, 0.5 mL of methanol was added to redissolve the solution, and the solution was filtered through a 0.22 µm filter membrane to obtain a test solution enriched with the target analyte.

[0104] Among them, each spike concentration of each sample was tested in parallel in three groups;

[0105] In the fourth step, the enriched and eluted test solution was detected by GC-MS / MS. The chromatographic conditions were the same as those in Example 4. The recovery rate of each sample at different spiked concentrations was calculated. Recovery rate = (actual concentration of analyte in spiked sample - concentration of analyte in sample before spiked) ÷ spiked concentration. The results are shown in Tables 3 and Figure 12 .

[0106] Table 3 Standard recoveries and RSDs of aniline-type stimulants

[0107]

[0108] From the above table 3 and Figure 12 It can be seen that the recovery rate of ATS in urine samples fluctuates around 100%, the recovery rate of ATS in hair samples is about 90%, and the recovery rate of ATS in serum samples is about 84%-88%, indicating that there is basically no matrix effect in urine samples;

[0109] Hair and serum samples had certain matrix effects due to their complex composition, but their corresponding recoveries were all above 84%, and the RSD values ​​were within 5.6%, indicating high precision.

[0110] The results show that the Fe3O4@SiO2@5F of the present invention has a good enrichment ability for MATM, PEA, AMP, MDA, MDMA and MDEA, and can be used for the quantitative detection of amphetamine-type stimulants in actual samples.

[0111] In summary, the method established by the present invention not only has a wider range of linearity, but also has lower quantitative detection limit, higher sensitivity, and has higher reliability, and can be used for the quantitative detection of amphetamine-type stimulants in actual samples. In addition, the material can be recycled, reducing detection costs.

Claims

1. A magnetic fluorine and nitrogen co-doped organic polymer adsorption material, characterized by: The magnetic fluorine and nitrogen co-doped organic polymer adsorption material is prepared by a one-step synthesis method. It uses Fe3O4@SiO2-NH2 nanoparticles as a carrier, and coats the Fe3O4@SiO2-NH2 nanoparticles with a porous organic polymer synthesized from comonomers 1,4-bis(2,4-diamino-1,3,5-triazine)-benzene and fluoroaldehyde benzene; wherein the fluoroaldehyde benzene is 3,4,5-trifluorobenzaldehyde, tetrafluoroterephthalaldehyde or pentafluorobenzaldehyde, and the structural formula of 3,4,5-trifluorobenzaldehyde, tetrafluoroterephthalaldehyde or pentafluorobenzaldehyde is as follows: 、 、 。 2. A method for preparing the magnetic fluorine and nitrogen co-doped organic polymer adsorption material according to claim 1, characterized in that: The preparation method comprises the following steps: S1, synthesis of Fe3O4 nanoparticles by solvothermal method; S2, bonding silica on the surface of Fe3O4 nanoparticles to obtain nano-Fe3O4@SiO2; S3, silanizing nano-Fe3O4@SiO2 to obtain Fe3O4@SiO2-NH2 nanoparticles; S4, Fe3O4@SiO2-NH2 nanoparticles, 1,4-bis(2,4-diamino-1,3,5-triazine)-benzene and fluoroaldehyde benzene are subjected to Schiff base reaction in a nitrogen environment at 160°C-180°C, and then washed and dried in sequence to obtain the magnetic fluorine and nitrogen co-doped organic polymer adsorption material.

3. The method for preparing a magnetic fluorine and nitrogen co-doped organic polymer adsorption material according to claim 2, characterized in that: The washing in S4 includes the following: The sample was washed alternately with DMF, methanol, acetone and ethanol several times, and then extracted with methanol for 24 h; the sample was dried in a vacuum at 120 °C overnight.

4. Application of the magnetic fluorine and nitrogen co-doped organic polymer adsorption material according to claim 1 or the magnetic fluorine and nitrogen co-doped organic polymer adsorption material prepared according to any one of claims 2 to 3 in the quantitative detection of amphetamine-type stimulants.

5. The use according to claim 4, characterized in that: The quantitative detection of amphetamine-type stimulants uses a magnetic fluorine and nitrogen co-doped organic polymer adsorption material as a solid phase extraction material, first enriching and extracting the sample, then eluting and re-dissolving it, and finally using GC-MS / MS or HPLC-MS / MS to perform qualitative and quantitative analysis on the re-dissolved solution.

6. The use according to claim 5, characterized in that: The quantitative detection of amphetamine-type stimulants comprises the following specific steps: S1, adding a magnetic fluorine and nitrogen co-doped organic polymer adsorption material to a working solution containing an amphetamine-type stimulant, and vortexing for 5-15 minutes to extract the amphetamine-type stimulant from the working solution; S2, magnetic separation to remove the aqueous solution, ultrasonic elution with methanol, drying the eluate in a nitrogen environment, and then re-dissolving it with methanol, filtering, and obtaining the test solution; S3, analyzing the test solution obtained in step S2 using GC-MS / MS or HPLC-MS / MS, and plotting a standard curve for each amphetamine-type stimulant using concentration as the abscissa and peak area as the ordinate; S4. Measure the sample according to the test method of the standard working solution in steps S1-S3, perform qualitative analysis based on the retention time, and calculate the concentration of the amphetamine-type stimulant in the sample based on the peak area value of the target substance and the standard curve.

7. The use according to claim 6, characterized in that: The gas chromatography conditions of GC-MS / MS in step S3 are as follows: the chromatographic column is an SH-5SiL MS elastic quartz capillary column, the injection port temperature is 270°C, splitless injection is performed, the carrier gas is helium, the pressure is 100 KPa, the initial temperature of the chromatographic column is 60°C, maintained for 2 minutes, and then heated to 220°C at a rate of 10°C / min and maintained for 1 minute; The mass spectrometry conditions of GC-MS / MS were as follows: MRM acquisition mode, interface temperature of 220°C, ion source temperature of 250°C, and solvent delay time of 2 min.

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