Nano magnetic adsorption material as well as preparation method and application thereof

Abstract

The invention belongs to the technical field of adsorption materials, and particularly relates to a nano magnetic adsorption material as well as a preparation method and application thereof. The nano magnetic adsorption material comprises biochar, nano magnetic particles and hydroxyl, the nano magnetic adsorption material is of a nano cluster structure, and the nano magnetic particles are loaded on the biochar and connected with the hydroxyl; wherein the biochar is prepared from shrimp shells. The nanometer magnetic adsorption material can effectively adsorb psychoactive substances, and especially the adsorption efficiency of morphine can reach 98%.

Description

Technical Field

[0001] The present invention belongs to the technical field of adsorption materials, and in particular relates to a nano magnetic adsorption material and a preparation method and application thereof. Background Art

[0002] Psychoactive substances (such as antidepressants, sedatives or stimulants) continue to enter the aquatic environment through medical discharge, domestic sewage and other channels. Due to their high biological activity, persistence and accumulation, they pose a serious threat to aquatic ecosystems. Studies have shown that such substances can interfere with the endocrine system of aquatic organisms even at trace concentrations, inducing behavioral abnormalities, reproductive disorders and population decline. Traditional water treatment processes (such as activated carbon adsorption and ozone oxidation) are difficult to efficiently and targetedly remove low-concentration, highly polar psychoactive compounds, and there are problems such as high operating costs and the easy production of toxic byproducts.

[0003] Although current magnetic adsorption materials (such as Fe3O4-based composite materials) can achieve solid-liquid separation through an external magnetic field, they still face three major bottlenecks: poor selectivity: insufficient design of functional groups on the surface of the material makes it difficult to specifically identify structurally diverse psychotropic substances in complex water bodies; low adsorption capacity: nanoparticles are prone to agglomeration, resulting in a decrease in specific surface area and insufficient adsorption efficiency for trace pollutants; and difficulty in regeneration: after adsorption, the material requires strong acid / organic solvent for desorption, causing secondary pollution and attenuation of magnetic stability.

[0004] There is an urgent need to develop new adsorption materials that have high selectivity, strong magnetic responsiveness and environmental friendliness. Summary of the Invention

[0005] The present invention uses shrimp shells as biomass materials to react with nano-magnetic materials, and uses a low eutectic solvent for modification to obtain a nano-magnetic adsorption material. The nano-magnetic adsorption material has strong adsorption energy for psychoactive substances, especially for morphine, and the adsorption efficiency can reach 98% or above.

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

[0007] On one hand, the present invention provides a nanomagnetic adsorption material, which comprises biochar and nanomagnetic particles. The nanomagnetic adsorption material is a nanocluster structure, and the nanomagnetic particles are loaded on the biochar and connected with hydroxyl groups; wherein the biochar is prepared from shrimp shells.

[0008] Preferably, the nanomagnetic particles are ferrosoferric oxide nanoparticles.

[0009] Another aspect of the present invention provides a method for preparing a nanomagnetic adsorption material, the preparation method comprising:

[0010] (1) mixing shrimp shell powder with iron hydroxide to react and separating to obtain a solid product;

[0011] (2) pyrolyzing the solid product to obtain magnetic nanomaterials;

[0012] (3) Mixing the magnetic nanomaterial with a low eutectic solvent to react and separating the nanomagnetic adsorption material.

[0013] Preferably, in the above preparation method,

[0014] In step (1), the iron-containing hydroxide is a divalent iron salt and a trivalent iron salt, and the pH is adjusted to form a precipitate; and / or

[0015] In step (3), the deep eutectic solvent is selected from a choline chloride-propylene glycol deep eutectic solvent, a choline chloride-phenylethanol deep eutectic solvent or a choline chloride-lactic acid deep eutectic solvent; and / or

[0016] In step (3), the mass volume ratio of the magnetic nanomaterial to the low eutectic solvent is (10-100) g:1 L.

[0017] Preferably, in the above preparation method, in step (2), the pyrolysis temperature is 500°C-800°C.

[0018] In another aspect, the present invention provides a use of the above-mentioned nanomagnetic adsorption material in adsorbing and / or detecting psychoactive substances.

[0019] Preferably, in the above application, the psychoactive substance is selected from morphine, codeine, 6 - One or more of monoacetylmorphine, 3,4-methylenedioxymethamphetamine, or 4-methylmethcathinone.

[0020] On the other hand, the present invention provides a method for adsorbing psychoactive substances in an aqueous environment, the adsorption method comprising: using the above-mentioned nanomagnetic adsorption material for adsorption.

[0021] Preferably, in the above adsorption method, the psychoactive substance is selected from morphine, codeine, 6 - One or more of monoacetylmorphine, 3,4-methylenedioxymethamphetamine, or 4-methylmethcathinone.

[0022] Preferably, in the above adsorption method, the pH value of the water sample to be adsorbed is adjusted to 4 to 10, and then the above nano-magnetic adsorption material is used for adsorption.

[0023] The beneficial effects of the present invention include:

[0024] (1) The nanomagnetic adsorption material prepared by the present invention can effectively adsorb psychoactive substances (for example, one or more of morphine, codeine, O6-monoacetylmorphine, 3,4-methylenedioxymethamphetamine or 4-methylmethcathinone), especially the adsorption efficiency of morphine can reach 98%.

[0025] (2) The nanomagnetic adsorption material prepared by the present invention has a strong anti-interference ability when adsorbing psychoactive substances (especially morphine) in an environment (such as a water environment), and the adsorption efficiency does not change significantly in the presence of interfering substances such as humic acid, urea, and salt ions. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 Scanning electron micrographs of BC, Fe3O4@BC, and Fe3O4@BC-DES prepared in Example 1;

[0027] Figure 2 IR spectra of BC, Fe3O4@BC, and Fe3O4@BC-DES prepared in Example 1;

[0028] Figure 3 This is the hysteresis regression curve of Fe3O4@BC-DES prepared in Example 1;

[0029] Figure 4 The adsorption capacity of Fe3O4@BC-DES for morphine at different pH values;

[0030] Figure 5 The adsorption efficiency of morphine by BC prepared at different pyrolysis temperatures in a tube furnace is shown;

[0031] Figure 6 The adsorption efficiency of morphine by Fe3O4@BC-DES prepared with different deep eutectic solvents;

[0032] Figure 7 The adsorption efficiency of morphine by Fe3O4@BC-DES prepared by adding different volumes of deep eutectic solvents;

[0033] Figure 8 The adsorption efficiency of Fe3O4@BC-DES prepared in Example 1 for different psychoactive substances;

[0034] Figure 9 This is a graph showing the selective adsorption capacity of morphine by the Fe3O4@BC-DES nano-adsorption material prepared in Example 1 in the presence of various interfering factors. DETAILED DESCRIPTION

[0035] The examples are used to better illustrate the present application, but are not intended to limit the present application to only the examples. Therefore, those skilled in the art can make non-essential improvements and modifications to the embodiments according to the above description, which still belong to the protection scope of the present application.

[0036] The terms used herein are used only to describe particular embodiments and are not intended to limit the present disclosure. Unless otherwise apparent in context, expressions in singular form include expressions in plural form. As used herein, it should be understood that terms such as "include", "have", "contain", etc. are intended to indicate the presence of features, numbers, operations, components, parts, elements, materials, or combinations thereof. The terms of the present application are disclosed in the specification, and are not intended to exclude the possibility that one or more other features, numbers, operations, components, parts, elements, materials, or combinations thereof can exist or can be added. As used herein, " / " can be interpreted as "and" or "or" depending on the circumstances.

[0037] As described above, the mental active substances in the environment, especially in the water environment, face the problems of low adsorption selectivity and low adsorption efficiency. In particular, the mental active drug-morphine has the defects of poor adsorbent selectivity in the water environment, which is difficult to accurately identify and efficiently adsorb. At present, the removal of morphine in the environment mainly covers three types of technologies: physical adsorption, chemical decomposition and biological treatment. In the physical adsorption method, activated carbon relies on its large specific surface area and rich pore structure to fill in the adsorption column, allowing wastewater or air containing morphine to pass through to achieve adsorption of morphine. Moreover, the existing adsorbents have weak anti-interference ability, and the adsorption efficiency is greatly reduced in the presence of interference substances such as humic acid, urea and salt ions; the adsorbent is difficult to recover, which easily causes secondary pollution and has low reusability; the adsorption efficiency is greatly affected by environmental factors (such as pH value), and the stability is poor.

[0038] The adsorbent material prepared by compounding shrimp shell biomass with nano-magnetic material and eutectic solvent has rich functional groups and specific adsorption sites, strong selective adsorption capacity for morphine, and adsorption efficiency of 97%; at the same time, it has excellent anti-interference ability and can still stably adsorb morphine in a complex water environment; its magnetic structure enables it to be quickly separated and recovered under the action of an external magnetic field, avoiding secondary pollution and improving reusability; and it has good adsorption performance in a wide pH value range (pH 4-10), and the adsorption efficiency can reach 98% at pH 9. Therefore, the adsorbent of the present application can effectively solve the many problems existing in the prior art, and provides an efficient, stable and easy-to-recover solution for removing morphine in the water environment

[0039] In order to achieve the above purpose, the present application can adopt the following technical scheme:

[0040] In a first aspect, an embodiment of the present invention provides a nanomagnetic adsorption material, which comprises biochar and nanomagnetic particles. The nanomagnetic adsorption material is a nanocluster structure, and the nanomagnetic particles are loaded on the biochar and connected with hydroxyl groups; wherein the biochar is prepared from shrimp shells.

[0041] It should be noted that the biochar prepared from shrimp shells presents a porous honeycomb structure with an extremely rich network of pores and holes. After being loaded with nanomagnetic particles, it turns into nanoneedles. After adding a low eutectic solvent, the nanoneedle structure gradually disintegrates and turns into loose nanoclusters. Moreover, after adding a low eutectic solvent, the nanomagnetic adsorption material adds more hydroxyl groups, thereby improving the adsorption efficiency of psychoactive substances.

[0042] In some specific examples, the nanomagnetic particles are ferroferric oxide nanoparticles.

[0043] It should be noted that the nanomagnetic particles in the present invention are all nanomagnetic particles known in the art, preferably ferrosoferric oxide nanoparticles. Ferrosoferric oxide nanoparticles have excellent magnetic properties, good biocompatibility and low biotoxicity, and can reduce the impact on the environment.

[0044] In a second aspect, an embodiment of the present invention provides a method for preparing a nanomagnetic adsorption material, the preparation method comprising:

[0045] (1) mixing shrimp shell powder with iron hydroxide to react and separating to obtain a solid product;

[0046] (2) pyrolyzing the solid product to obtain magnetic nanomaterials;

[0047] (3) Mixing the magnetic nanomaterial with a low eutectic solvent to react and separating the nanomagnetic adsorption material.

[0048] It should be noted that the operational terms "mixing reaction," "separation," and "pyrolysis" in the present invention are conventional operational terms in the art and have no special meanings. Furthermore, it should be understood that the shrimp shells are shells of shrimp species known in the art, such as Neopenaeus scabra (Penaeus scutellariae); Furthermore, the shrimp shell powder is preferably dried and activated before the reaction, and can be sieved through a 100-mesh sieve. Furthermore, the solid product can be washed and dried before pyrolysis to increase the yield of the magnetic nanomaterial.

[0049] In some specific embodiments, before the shrimp shell powder is mixed with the iron hydroxide for reaction, the shrimp shell powder is activated, specifically as follows: the shrimp shells of the Neopenaeus lanceolatus (Penaeus striata) are washed and dried; the shells are crushed with a grinder and passed through a 100-mesh sieve to obtain shrimp shell powder; the shrimp shell powder is then mixed with 20 mL of a 1 mol / L HCl aqueous solution, stirred evenly, and allowed to stand for 4 hours to obtain the activated shrimp shell powder.

[0050] In some specific examples, in the above preparation method,

[0051] In step (1), the iron-containing hydroxide is a divalent iron salt and a trivalent iron salt, and the pH is adjusted to form a precipitate; and / or

[0052] In step (3), the deep eutectic solvent is selected from a choline chloride-propylene glycol deep eutectic solvent, a choline chloride-phenylethanol deep eutectic solvent or a choline chloride-lactic acid deep eutectic solvent; and / or

[0053] In step (3), the mass volume ratio of the magnetic nanomaterial to the deep eutectic solvent is (10-100) mg:1 mL.

[0054] It should be noted that in the above step (1), during the preparation of the iron hydroxide, the pH of the ferrous salt and the ferric salt is adjusted to form a precipitate, which can be adjusted by adding alkali solution, preferably ammonia water. The temperature of the adjustment process can be set at 20°C-90°C, generally 80°C, which will react quickly without affecting the quality of the precipitate. The above preparation process may include: weighing the ferrous salt and the ferric salt according to a certain molar ratio, adding the ferrous salt and the ferric salt to a three-necked flask containing 100mL-120mL of deionized water heated in a water bath and kept at 55°C-65°C under nitrogen protection, stirring for 25min-35min, and then rapidly adding 8mL-12mL of a concentrated ammonia solution with a mass concentration of 28%-30% under stirring, and keeping the temperature for 30min-35min after the addition to obtain the ferrous oxide nanomagnetic material; wherein the molar ratio of the ferrous salt to the ferric salt can be 1:(1-3).

[0055] In addition, in step (3), the deep eutectic solvent can be selected from a choline chloride propane-propylene glycol deep eutectic solvent, a choline chloride-phenylethanol deep eutectic solvent or a choline chloride-lactic acid deep eutectic solvent. In the present invention, the choline chloride propane-propylene glycol deep eutectic solvent can be preferred. The magnetic nanomaterial prepared after modification of the deep eutectic solvent has an adsorption efficiency of morphine of 98% or more, which is better than choline chloride-phenylethanol (71%) and choline chloride-lactic acid (53%).

[0056] In addition, in step (3), the mass volume ratio of the magnetic nanomaterial to the deep eutectic solvent also affects the adsorption capacity of the prepared nanomagnetic adsorption material. The mass volume ratio in the present invention can be (10-100) g:1L, for example, 15g:1L, 20g:1L, 25g:1L, 30g:1L, 40g:1L, 50g:1L, 70m:1L, 90g:1L, etc., among which 50g:1L is preferred. The adsorption capacity of the nanomagnetic adsorption material prepared at this ratio is stronger than that of other ratios, and the adsorption efficiency of morphine can reach 99%.

[0057] It should also be noted that the preparation method of the above-mentioned deep eutectic solvent is known in the art, for example, comprising heating a hydrogen bond donor (propylene glycol, phenylethanol, and lactic acid) and a hydrogen bond acceptor (choline chloride) at a specific molar ratio, maintaining the reaction at 80°C, turning on a magnetic stirrer, and continuously stirring until a homogeneous, transparent solution is formed, for about 30 minutes. In addition, the molar ratio of the hydrogen bond donor to the hydrogen bond acceptor can be 1:2.

[0058] It should also be noted that the purpose of using a low eutectic solvent to modify the magnetic nanomaterial in step (3) is to give the adsorption material rich multifunctional functional groups (such as N and O atoms and corresponding groups), so that there are a large number of chemical sites in the adsorption material that can serve as adsorption sites for psychoactive substances, thereby overcoming the problems of poor adsorption capacity and poor interaction between existing adsorption materials and the psychoactive substance morphine.

[0059] In some specific examples, in the above preparation method, in step (2), the pyrolysis temperature is 500°C-800°C.

[0060] It should be noted that in step (2) of the present invention, the pyrolysis temperature can be 500°C-800°C, such as 550°C, 600°C, 650°C, 700°C or 750°C; the shrimp shell biochar prepared at different pyrolysis temperatures has different adsorption efficiency for morphine. When the pyrolysis temperature is lower than 500°C, the biomass pyrolysis reaction is insufficient, resulting in a relatively small specific surface area of ​​the prepared biochar and poor pore development. The limited specific surface area and pore structure seriously limit the biochar's ability to capture and accommodate pollutants, greatly reducing the adsorption efficiency and being unfavorable for the effective adsorption of pollutants. When the pyrolysis temperature exceeds 800°C, the microstructure inside the biochar will change significantly, and its pore structure will collapse seriously under the continuous action of high temperature. This phenomenon is mainly due to the excessive destruction of the molecular bonds inside the biochar, the deformation and fracture of the skeleton that originally supported the pore structure, and the collapse of the pores over a large area. Therefore, taking all factors into consideration, the pyrolysis temperature in the present invention can be 500°C-800°C, among which 700°C is more preferred. The adsorption efficiency of morphine by the magnetic nanomaterial prepared by pyrolysis at 700°C can reach 73%, which is much higher than the adsorption efficiency at 500°C (32%), 600°C (63%) and 800°C (67%).

[0061] In some specific embodiments, the method for preparing the shrimp shell powder may include: washing the shrimp shell powder alternately with anhydrous ethanol and deionized water 4-5 times, drying at 60°C, placing the dried black product in a tube furnace, heating it to a specific temperature at a heating rate of 5°C / min, controlling the temperature for 2 hours, and cooling it to room temperature; grinding the black product, soaking it in a beaker containing 1 mol / L hydrochloric acid, washing it multiple times until the pH of the filtrate is neutral, and centrifuging to separate the sediment to obtain BC.

[0062] In a third aspect, an embodiment of the present invention provides an application of the above-mentioned nanomagnetic adsorption material in the adsorption and / or detection of psychoactive substances.

[0063] It should be noted that the nanomagnetic adsorption material of the present invention is effective for psychoactive substances (psychoactive substances are selected from morphine, codeine, 6 -monoacetylmorphine, 3,4-methylenedioxymethamphetamine or 4-methylmethcathinone) has a strong adsorption capacity and can be applied to the adsorption of psychoactive substances. Based on this, when detecting psychoactive substances in an environment (such as a water environment), the nanomagnetic adsorption material of the present invention can be used first for adsorption and then for detection.

[0064] In a fourth aspect, an embodiment of the present invention provides a method for adsorbing psychoactive substances in an aqueous environment, the adsorption method comprising: using the above-mentioned nanomagnetic adsorption material for adsorption.

[0065] It should be noted that, generally, the water environment composition is complex, various types of anions and cations, organic matter and microorganisms and other impurities will interfere with the adsorption process. However, the adsorbent of the present application can effectively resist these interference factors, accurately identify and efficiently adsorb morphine molecules due to its unique microstructure and surface active sites. In view of the outstanding performance of the adsorbent in treating water environment containing morphine, as well as its stable and efficient adsorption performance in different complex water bodies, it can be widely used in various scenes involving adsorption of psychoactive substances in water environment.

[0066] In some specific examples, in the above adsorption method, the psychoactive substance is selected from one or more of morphine (MOR), codeine, O6-monoacetylmorphine (O 6 -MAM), 3,4-methylenedioxymethamphetamine (MDMA) or 4-methylmethcathinone (4-MCC).

[0067] It should be noted that the nano-magnetic adsorbent in the present application has high selectivity for morphine adsorption. Under the same adsorption conditions, the adsorption efficiency of the nano-magnetic adsorbent in the present application for morphine can reach 98% or more, which is better than O6-monoacetylmorphine (O 6 -MAM) (95%), codeine (90%), 3,4-methylenedioxymethamphetamine (MDMA) (78%) and 4-methylmethcathinone (4-MCC) (69%).

[0068] In some specific examples, in the above adsorption method, after adjusting the pH value of the water sample to be adsorbed to 4 to 10, the above nano-magnetic adsorbent is used for adsorption.

[0069] It should be noted that when adsorbing psychoactive substances in water environment, the pH value of the water environment can be adjusted first, and the pH value is preferably 4 to 10. The adsorption efficiency of morphine at this pH value is more than 88%, and more preferably the pH value is 9. The adsorption efficiency of morphine at this pH value is 98% or more.

[0070] In order to better understand the present application, the content of the present application will be further illustrated below in combination with specific examples, but the content of the present application is not limited to the following examples.

[0071] Preparation Example

[0072] Example 1

[0073] (1) Preparation of shrimp shell biomass

[0074] 1) First, wash the shrimp shell of Neoliimaeus vannmami (Jiwei shrimp) to remove surface impurities, dry at 60°C, crush with a crusher, and then sieve with a 100-mesh sieve to obtain shrimp shell powder;

[0075] 2) Accurately weigh 10 g of shrimp shell powder and transfer it to a suitable container. Measure 20 mL of 1 mol / L HCl solution and slowly pour it into the container containing the shrimp shell powder.

[0076] 3) Using a glass rod, stir thoroughly to evenly mix the shrimp shell powder and the HCl solution; after stirring, let the mixture stand at room temperature for 4 hours and then dry it at 60° C. to obtain activated shrimp shell biomass BC.

[0077] (2) Preparation of magnetic nanomaterials Fe3O4@BC

[0078] 1) Accurately weigh ferrous chloride and ferric chloride in a 1:2 molar ratio. Add 100 mL of deionized water to a three-necked flask, place it in a water bath, and turn on the nitrogen protection device to create an oxygen-free reaction environment.

[0079] 2) After the water bath temperature stabilizes at 80°C, slowly add the weighed iron salt to the three-necked flask and stir at an appropriate speed for 30 minutes to ensure that the iron salt is fully dissolved and mixed;

[0080] 3) Then, while stirring continuously, quickly add 20 mL of a 28% concentrated ammonia solution to the three-necked flask. Maintain stirring at 80°C for 30 minutes to allow the iron ions to react fully with the ammonia solution to form an iron hydroxide precipitate.

[0081] 4) slowly adding the shrimp shell biomass activated by standing for 4 hours in step (1) to the above system, stirring continuously for 6 hours to allow the shrimp shell biomass to fully contact with the precipitate to achieve a composite of the two;

[0082] 5) After the reaction is completed, solid-liquid separation is performed using an external magnetic field, and the black product is collected and washed alternately with anhydrous ethanol and deionized water five times to remove impurities on the product surface;

[0083] 6) The cleaned product was placed in a drying oven at 60°C and then transferred to a tube furnace for reaction at 700°C for 2 hours. After the reaction was completed, the product was cooled to room temperature and ground and passed through a No. 6 sieve to obtain the magnetic nanomaterial Fe3O4@BC.

[0084] (3) Preparation of Fe3O4@BC-DES by post-modification method

[0085] 1) Weigh choline chloride and propylene glycol in a 1:2 molar ratio, transfer to a reaction vessel, place in an 80°C constant temperature water bath, turn on a magnetic stirrer, and continue stirring until a uniform, transparent choline chloride-propylene glycol deep eutectic solvent is formed;

[0086] 2) 0.5 g of Fe3O4@BC and 10 mL of a deep eutectic solvent (the mass volume ratio of Fe3O4@BC to the deep eutectic solvent was 50:1 (g / L)) were mixed and dispersed in 50 mL of methanol solution; the mixture was then stirred using a magnetic stirrer for 6 hours.

[0087] 3) The mixture was washed with ethanol and water for three cycles, separated by an external magnet, and then dried at 60°C to obtain the psychoactive substance adsorption material Fe3O4@BC-DES.

[0088] Example 2 to Example 4

[0089] Examples 2 to 4 provide Fe3O4@BC prepared at different pyrolysis temperatures, as follows:

[0090] Examples 2 to 4 are substantially the same as steps (1) and (2) in Example 1, except that the temperature in step (6) in step (2) in Examples 2 to 4 is different from that in Example 1. The temperatures in step (6) in step (2) in Examples 2, 3, and 4 are 500°C, 600°C, and 800°C, respectively, to prepare different Fe3O4@BC.

[0091] Example 5 to Example 6

[0092] Examples 5 and 6 provide adsorption materials prepared using different deep eutectic solvents, as follows:

[0093] Example 5 and Example 6 are substantially the same as Example 1. The difference between Example 5 and Example 6 and Example 1 is that the low eutectic solvents in step (3) in step 1) are different; the low eutectic solvents in Example 5 and Example 6 are choline chloride-phenylethanol and choline chloride-lactic acid, respectively, and different adsorption materials Fe3O4@BC-DES (choline chloride-phenylethanol) and Fe3O4@BC-DES (choline chloride-lactic acid) are prepared, respectively;

[0094] In addition, the preparation method of the deep eutectic solvent choline chloride-phenylethanol in Example 5 is the same as that in Example 1 (just replace the raw materials);

[0095] The preparation method of the deep eutectic solvent choline chloride-lactic acid in Example 6 is the same as that in Example 1 (just replace the raw materials).

[0096] Example 7 to Example 8

[0097] Examples 7 and 8 provide Fe3O4@BC-DES prepared with different amounts of deep eutectic solvent added, as follows:

[0098] Example 7 and Example 8 are substantially the same as Example 1, except that the amount of Fe3O4@BC added in step 2) in Example 7 and Example 8 is different from that in step (3) in Example 1, and the amount of Fe3O4@BC added in Example 7 and Example 8 is 0.1 g and 1 g, respectively; that is, in Example 7, the mass volume ratio of Fe3O4@BC and the low eutectic solvent is 10:1 (g / L), and in Example 8, the mass volume ratio of Fe3O4@BC and the low eutectic solvent is 100:1 (g / L); and Fe3O4@BC-DES is prepared.

[0099] Characterization:

[0100] (1) Scanning electron microscope observation

[0101] The biochar (BC), ferroferric oxide-loaded biochar (Fe3O4@BC), and ferroferric oxide-loaded biochar treated with a deep eutectic solvent (Fe3O4@BC-DES) prepared in Example 1 were observed using a scanning electron microscope (SEM). Figure 1 shown.

[0102] Figure 1 a shows the SEM image of BC, which presents a porous honeycomb structure with a very rich pore and hole network, laying a solid foundation for the subsequent adsorption of morphine molecules; when loaded with Fe3O4, Figure 1 From the SEM image of Fe3O4@BC in b, it can be seen that the material morphology changes to nano-needle; after further addition of the deep eutectic solvent, the nano-needle structure gradually disintegrates and changes into loose nano-clusters in Fe3O4@BC-DES ( Figure 1 c).

[0103] (2) Infrared spectrum test

[0104] The BC, Fe3O4@BC and Fe3O4@BC-DES prepared in Example 1 were subjected to infrared spectroscopy tests respectively. The test results are as follows: Figure 2 shown.

[0105] in, Figure 2 A is the infrared spectrum of BC. As shown in the figure, 1652cm -1 is the stretching vibration absorption peak of C=C, 3410 cm -1 is the stretching vibration absorption peak of CC;

[0106] Figure 2 C is the infrared spectrum of Fe3O4@BC, 574cm -1 is the stretching vibration absorption peak of Fe-O in magnetic materials, 3266 cm -1 is the stretching vibration absorption peak of OH;

[0107] Figure 2 B is the infrared spectrum of Fe3O4@BC@PDES, 3433 cm -1 is the stretching vibration absorption peak of OH, 1043 cm -1 and 1095cm -1 They are the stretching vibration absorption peaks of CN and CO in the deep eutectic solvent, 567 cm -1 is the stretching vibration absorption peak of Fe-O; in addition, the peak at 3433cm in Fe3O4@BC-PDES -1 The width and intensity of the hydroxyl peak at indicate that more hydroxyl groups were added due to the introduction of the deep eutectic solvent during the post-modification process.

[0108] The above infrared spectrum results show that the synthesis of Fe3O4 and low eutectic solvent were successful.

[0109] (3) Plotting the hysteresis regression curve

[0110] The hysteresis regression curve of Fe3O4@BC-DES prepared in Example 1 was plotted. The results are as follows: Figure 3 As shown, the results show that Fe3O4@BC-DES nanoparticles exhibit a closed magnetization curve with hysteresis phenomenon, and the saturation magnetization intensity of Fe3O4@BC@PDES is about 21.17emu / g.

[0111] Application Examples

[0112] In the following examples, UPLC-MS / MS was mainly composed of an LC-40 ultra-high performance liquid chromatography system, a QTRAP 5500+ triple quadrupole linear ion trap mass spectrometer, and a Waters ACQUITY BEH C18 chromatographic column (100 mm × 2.1 mm, 1.7 μm); chromatographic conditions: mobile phase A (0.1% formic acid 2 mmol·L -1 ammonium acetate solution) and mobile phase B (acetonitrile); the flow rate was 0.3 mL min -1 ; The column temperature was set at 40°C; the injection volume was 2 μL; the gradient elution program is shown in Table 1;

[0113] Table 1 Gradient elution program

[0114]

[0115]

[0116] In addition, the mass spectrometry conditions were as follows: an electrospray ionization source (ESI) was used, the multiple reaction monitoring mode (MRM) of positive ion (ESI+), the ion source temperature was 550°C, and the mass spectrometry parameters are shown in Table 2.

[0117] Table 2 Retention time, selected ion pairs, DP and CE parameters of morphine

[0118] substance Retention time (min) daughter / parent ion (m / z) CE(V) DP(V) morphine 4.13 165.3 / 201.2*，286.1 33，40 80

[0119] Example 9 to Example 19

[0120] Examples 9 to 19 tested the adsorption of morphine in a morphine aqueous solution by the adsorption material Fe3O4@BC-DES prepared in Example 1 at different pH values, as follows:

[0121] (1) 1 mg of the Fe3O4@BC-DES adsorbent material prepared in Example 1 was weighed and placed in a 5 mL glass bottle, 4 mL of a morphine aqueous solution with an initial concentration of 200 μg / L was added thereto, and the pH value of the morphine aqueous solution was adjusted to 2 (Example 9), 3 (Example 10), 4 (Example 11), 5 (Example 12), 6 (Example 13), 7 (Example 14), 8 (Example 15), 9 (Example 16), 10 (Example 17), 11 (Example 18), and 12 (Example 19), respectively;

[0122] (2) Place the glass bottle containing the adsorbent material and the morphine aqueous solution in a constant temperature oscillator at 25°C and a speed of 180 r / min for 60 minutes to ensure that the adsorption reaction proceeds fully;

[0123] (3) After the oscillation is completed, the adsorbent material is separated from the solution using an external magnetic field, the supernatant is collected, and the supernatant is filtered using a 0.22 μm filter membrane;

[0124] (4) The filtered supernatant was analyzed by ultra-high performance liquid chromatography-tandem mass spectrometry (UPLC-MS / MS) to determine the residual amount of the sample to be adsorbed, and the adsorption rate (%) of the adsorbent to be tested was calculated according to equation (1).

[0125]

[0126] Where C0 (ng / mL) and V (mL) represent the initial concentration and solution volume, respectively. e (ng / mL) is the concentration of the adsorbed sample remaining in the supernatant after adsorption.

[0127] Test results such as Figure 4As shown, at pH 2, the Fe3O4@BC-DES adsorbent exhibited the lowest recovery rate of morphine in aqueous solution, at only 44%. However, the recovery rate remained relatively stable as the pH varied from 4 to 10, demonstrating the good applicability of Fe3O4@BC-DES over a wide pH range. Of particular note, the recovery rate reached its highest value, 98%, at pH 9 (Example 17).

[0128] Performance Verification

[0129] In the following examples, the adsorption rate (%) is tested and calculated according to the following method:

[0130] Accurately weigh 1 mg of the adsorbent sample to be tested and place it in a 5 mL glass vial. Simultaneously prepare a reference substance. Subsequently, add the sample solution to be adsorbed to each glass vial. Place the vial in a constant temperature oscillating device and oscillate at 25°C and 180 rpm for 60 min to allow the sample and adsorbent to fully react. After the oscillation is completed, solid-liquid separation is achieved with the aid of an external magnetic field. The supernatant is filtered through a 0.22 μm filter membrane and the filtrate is analyzed by ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS / MS). The residual amount of the sample to be adsorbed is determined, and the adsorption rate (%) of the adsorbent to be tested is calculated according to equation (1).

[0131]

[0132] Where C0 (ng / mL) and V (mL) represent the initial concentration and solution volume, respectively. e (ng / mL) is the concentration of the adsorbed sample remaining in the supernatant after adsorption.

[0133] First, the adsorption rates of Fe3O4@BC (500℃, 600℃ and 800℃) prepared in Examples 2 to 4 were tested respectively according to the above-mentioned adsorption rate test method (the adsorbent sample to be tested was 3mL of morphine aqueous solution with an initial concentration of 200μg / L and a pH of 6). The results are as follows: Figure 5 As shown, the Fe₃O₄@BC prepared at a tube furnace pyrolysis temperature of 700°C has the highest adsorption efficiency (approximately 73%), far exceeding the adsorption rates at 500°C (32%), 600°C (63%), and 800°C (67%). This means that the tube furnace pyrolysis temperature for shrimp shell powder in the present invention can be set between 500°C and 800°C, with a preferred temperature of 700°C.

[0134] In addition, according to the above-mentioned adsorption rate test method (the adsorbent sample to be tested is 4 mL of an aqueous solution of morphine with an initial concentration of 200 μg / L and a pH of 6), the adsorption rates of the adsorbent materials prepared in Examples 1 and 5 to 9 were tested, as follows:

[0135] First, the adsorption efficiency of morphine by Fe3O4@BC-DES (choline chloride-propylene glycol) prepared in Example 1, Fe3O4@BC-DES (choline chloride-phenylethanol) and Fe3O4@BC-DES (choline chloride-lactic acid) prepared in Example 5 and Example 6 was tested (tested according to the above method). The results are as follows: Figure 6 As shown, the results show that there are obvious differences in the adsorption efficiency of morphine among the adsorption material samples prepared by reacting different deep eutectic solvents with Fe3O4@BC. The adsorption efficiency of morphine prepared by reacting choline chloride-propylene glycol deep eutectic solvent with Fe3O4@BC can be as high as 98%, which is higher than the adsorption efficiency of morphine prepared by reacting other deep eutectic solvents with Fe3O4@BC.

[0136] Secondly, the adsorption efficiency of morphine by Fe3O4@BC-DES prepared in Example 1 (the mass volume ratio of Fe3O4@BC to the deep eutectic solvent was 50:1 (g / L)), Fe3O4@BC-DES prepared in Examples 8 and 9 (the mass volume ratio of Fe3O4@BC to the deep eutectic solvent was 10:1 (g / L)), and Fe3O4@BC-DES (the mass volume ratio of Fe3O4@BC to the deep eutectic solvent was 100:1 (g / L)) were tested respectively. The results are shown in FIG. Figure 7 The results showed that the adsorption efficiency of morphine by the prepared Fe3O4@BC-DES (tested according to the above method) varied depending on the mass ratio of DES to Fe3O4@BC. Fe3O4@BC@PDES (50:1) had the best adsorption efficiency (approximately 99%), followed by Fe3O4@BC-DES (100:1), and finally Fe3O4@BC-DES (10:1).

[0137] In addition, the present invention also tested the adsorption capacity of Fe3O4@BC-DES (choline chloride-propylene glycol) prepared in Example 1 for different adsorption targets (morphine (MOR), codeine (Codeine), O6-monoacetylmorphine (O6-MAM), 3,4-methylenedioxymethamphetamine (MDMA) and 4-methylmethcathinone (4-MMC)) according to the above-mentioned adsorption rate test method (the adsorbent sample to be tested is 4mL of morphine aqueous solution with an initial concentration of 200ug / L and a pH of 6). The results are as follows. Figure 8 As shown, the results show that the Fe3O4@BC-DES adsorption material has good adsorption performance for opioid psychoactive substances such as morphine, especially the morphine adsorption efficiency is as high as 98%, indicating that the adsorption material has specific adsorption capacity for opioids, especially morphine.

[0138] In addition, the ability of Fe3O4@BC-DES prepared in Example 1 to adsorb morphine in different concentrations of urea, humic acid and sodium chloride was tested to verify the anti-interference ability of Fe3O4@BC-DES. The specific steps were as follows: 1 mg of adsorbent Fe3O4@BC-DES (choline chloride-propylene glycol system) was accurately weighed and placed in a glass bottle, and humic acid concentrations of 0, 5 mg / L, 10 mg / L, 20 mg / L, 50 mg / L, 100 mg / L, 200 mg / L were prepared respectively. A series of solutions with 50 mL of urea, 0, 0.1, 0.2, 0.3, 0.4, and 0.5 mol / L, and 0, 50, 50, 100, 150, and 200 mol / L of NaCl were prepared. A morphine standard solution was added to each solution to a morphine concentration of 300 μg / L. Four mL of each solution was then transferred to a vial containing the adsorbent in triplicate. The mixture was shaken at 25°C and 170 rpm for 1 hour, followed by separation using an external magnet. The filtered supernatant was analyzed by ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS / MS) to determine the residual morphine in the adsorbed sample.

[0139] The results of the test are as follows Figure 9 As shown, the results show:

[0140] Figure 9 A reveals the influence of humic acid on the adsorption of morphine. As the concentration of humic acid gradually increases, its adsorption performance for morphine shows a trend of first increasing and then decreasing. When the concentration of humic acid reaches 50 mg·L -1 When the adsorption performance reaches the optimal level, the adsorption amount reaches the peak. From the overall trend, the presence of humic acid has a relatively limited effect on the adsorption amount, and the change in the adsorption amount is small.

[0141] Figure 9 Figure B shows the effect of urea on morphine adsorption. Increasing urea concentration negatively correlates with morphine adsorption, a decrease attributed to competitive adsorption. However, despite this competitive adsorption, the overall effect of urea on morphine adsorption remains relatively small, with the decrease in adsorption limited. This indicates that under the experimental conditions, urea's interference with morphine adsorption by Fe3O4@BC-DES is relatively mild, and the adsorption system retains a certain degree of stability.

[0142] Figure 9 C Sodium chloride was used to study the effect of ions on the adsorption of morphine by Fe3O4@BC-DES. With the increase of sodium chloride concentration, the adsorption capacity decreased slightly, but the decrease was limited.

[0143] In general, the adsorption material showed excellent anti-interference ability in the environments of humic acid, urea and salt ions, indicating that its adsorption effect on morphine has strong specificity and stability.

[0144] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not limiting. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the purpose and scope of the technical solutions of the present invention, which should all be covered by the scope of the claims of the present invention.

Claims

1. A nano magnetic adsorption material, characterized in that: It contains biochar and nanomagnetic particles. The nanomagnetic adsorption material is a nanocluster structure. The nanomagnetic particles are loaded on the biochar and connected with hydroxyl groups. The biochar is prepared from shrimp shells.

2. The nanomagnetic adsorption material according to claim 1, characterized in that: The nano magnetic particles are ferroferric oxide nano particles.

3. The method for preparing the nanomagnetic adsorption material according to claim 1 or 2, characterized in that: The preparation method comprises: (1) mixing shrimp shell powder with iron hydroxide to react and separating to obtain a solid product; (2) pyrolyzing the solid product to obtain magnetic nanomaterials; (3) Mixing the magnetic nanomaterial with a low eutectic solvent to react and separating the nanomagnetic adsorption material.

4. The preparation method according to claim 3, characterized in that In step (1), the iron-containing hydroxide is a divalent iron salt and a trivalent iron salt, and the pH is adjusted to form a precipitate; and / or In step (3), the deep eutectic solvent is selected from a choline chloride-propylene glycol deep eutectic solvent, a choline chloride-phenylethanol deep eutectic solvent or a choline chloride-lactic acid deep eutectic solvent; and / or In step (3), the mass volume ratio of the magnetic nanomaterial to the low eutectic solvent is (10-100) g:1 L.

5. The preparation method according to claim 3 or 4, characterized in that In step (2), the pyrolysis temperature is 500°C-800°C.

6. Use of the nanomagnetic adsorption material according to claim 1 or 2 in the adsorption and / or detection of psychoactive substances.

7. The use according to claim 6, characterized in that Psychoactive substances are selected from morphine, codeine, 6 - One or more of monoacetylmorphine, 3,4-methylenedioxymethamphetamine, or 4-methylmethcathinone.

8. A method for adsorbing psychoactive substances in an aqueous environment, characterized in that: The adsorption method comprises: using the nanomagnetic adsorption material according to claim 1 or 2 for adsorption.

9. The adsorption method according to claim 8, characterized in that Psychoactive substances are selected from morphine, codeine, 6 - One or more of monoacetylmorphine, 3,4-methylenedioxymethamphetamine, or 4-methylmethcathinone.

10. The adsorption method according to claim 8 or 9, characterized in that: After the pH value of the water sample to be adsorbed is adjusted to 4 to 10, the nanomagnetic adsorption material according to claim 1 or 2 is used for adsorption.

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