A magnetic diatomite-based adsorbent capable of adsorbing various glucocorticoids, a preparation method and application thereof

Abstract

The application discloses a kind of preparation methods of magnetic diatomite-based adsorbent capable of adsorbing various glucocorticoids, and belongs to the field of advanced inorganic non-metallic materials, comprising the following steps: (1) first, diatomite composite multi-ligand metal organic framework is prepared by solvothermal method; (2) then, magnetic diatomite composite multi-ligand metal organic framework is prepared by solvothermal method, and the application is obtained.The magnetic diatomite-based adsorbent / aiding filter can be used to simultaneously adsorb and remove various glucocorticoid pollutants in environmental water, and simultaneously and efficiently extract various glucocorticoid residues in animal-derived food, has good adsorption effect, and can be repeatedly used multiple times, and has great market competitiveness.

Description

Technical Field

[0001] This invention belongs to the field of advanced inorganic non-metallic materials, specifically relating to a magnetic diatomaceous earth-based adsorbent capable of adsorbing various types of glucocorticoids, its preparation method, and its application. Background Technology

[0002] Glucocorticoids are a class of endocrine disruptors that primarily act on corticosteroid signaling pathways in animals and humans. They exert their effects mainly by binding to glucocorticoid receptors, regulating the biosynthesis and metabolism of carbohydrates, fats, and proteins, inhibiting immune responses, and exhibiting anti-inflammatory, antitoxic, and anti-shock effects. They are among the most widely used prescription drug categories globally for treating allergies, autoimmune diseases, and inflammatory conditions. Incompletely metabolized glucocorticoids enter environmental water bodies primarily through animal excrement in livestock farms, industrial wastewater, and medical wastewater, causing water pollution. Furthermore, glucocorticoids are widely used in livestock and poultry farming, accumulating in animal bodies and entering the human body through the food chain, directly impacting human health. Therefore, the adsorption and removal of glucocorticoids from environmental water and the analysis and monitoring of glucocorticoid residues in animal-derived foods are particularly important.

[0003] Although glucocorticoids are included in routine monitoring of animal-derived foods, a method capable of detecting multiple types of glucocorticoids in various matrices in a single test is still lacking. While glucocorticoids are not currently included in routine monitoring of environmental water, some researchers have attempted to develop solid adsorbents for the adsorption and removal of glucocorticoids from environmental water, but these methods are still only applicable to the adsorption and removal of certain types of glucocorticoids. In summary, given the large number of environmental water and animal-derived food samples and the diverse range of glucocorticoids requiring monitoring, effectively improving work efficiency is the main challenge for the adsorption and removal of glucocorticoids from environmental water samples and the analysis and monitoring of glucocorticoid residues in animal-derived food samples.

[0004] The reason why there is currently no universally applicable method for simultaneously adsorbing multiple types of glucocorticoids is that glucocorticoids are diverse in type and have significantly different physicochemical properties, while existing adsorption materials offer limited adsorption sites and mechanisms. This makes the simultaneous adsorption of these glucocorticoids with such diverse properties extremely challenging and urgently requires technological breakthroughs. Furthermore, the complex matrices of environmental water bodies and animal-derived foods necessitate adsorbent materials that can rapidly enrich target substances and purify the matrix to ensure the timeliness, sensitivity, and accuracy of the entire monitoring process. Therefore, there is an urgent need to develop adsorption / filtration aid materials capable of simultaneously adsorbing multiple types of glucocorticoids, and to develop a new, rapid, simple, universal, and high-throughput method for the adsorption and removal of glucocorticoids from environmental water and the analysis and monitoring of glucocorticoid residues in animal-derived foods based on this material. Summary of the Invention

[0005] To address the aforementioned problems, this invention provides a magnetic diatomaceous earth-based adsorbent / filter aid capable of simultaneously adsorbing multiple types of glucocorticoids, enabling it to be used for the simultaneous adsorption and removal of multiple types of glucocorticoid pollution in environmental water, as well as the efficient extraction of multiple glucocorticoid residues from animal-derived foods.

[0006] A method for preparing a magnetic diatomaceous earth-based adsorbent capable of adsorbing various types of glucocorticoids includes the following steps:

[0007] (1) First, prepare diatomaceous earth composite multiligand metal-organic frameworks using a solvothermal method;

[0008] (2) Then, magnetic diatomite composite multiligand metal-organic framework is prepared by solvothermal method.

[0009] Furthermore, the step of preparing diatomaceous earth composite multi-ligand metal-organic frameworks by solvothermal method described in step (1) includes:

[0010] 1) Dissolve 0.1–1.0 mmol of a metal salt in 5–50 mL of N,N-dimethylformamide to obtain mixed solution A;

[0011] 2) Dissolve 0.01–0.50 mmol of organic ligand A and 0.01–0.50 mmol of organic ligand B in 5–50 mL of N,N-dimethylformamide to obtain solution B;

[0012] 3) Slowly add solution B to solution A and stir until homogeneous to obtain the metal-organic framework precursor solution;

[0013] 4) Add 50-100 mg of diatomaceous earth to the metal-organic framework precursor solution, and disperse it evenly by ultrasonication to obtain a diatomaceous earth suspension;

[0014] 5) The diatomaceous earth suspension was transferred to a stainless steel reactor and reacted at 100-150°C for 12-36 h. After centrifugation to separate the precipitate, the residual solvent was washed off and the diatomaceous earth composite multiligand metal-organic framework was obtained after vacuum drying.

[0015] Furthermore, the metal salt mentioned in step 1) is any one of the hydrochloride, nitrate, or acetate salts of copper, iron, zinc, aluminum, chromium, zirconium, nickel, or cobalt.

[0016] Furthermore, in step 2), organic ligand A and organic ligand B are any one of terephthalic acid, 4,4'-biphenyldicarboxylic acid, 1,3,5-benzenetricarboxylic acid, 2,6-pyridinedicarboxylic acid, 2-aminoterephthalic acid, nitroterephthalic acid, and tetrafluoroterephthalic acid.

[0017] Furthermore, the step of preparing the magnetic diatomite composite multi-ligand metal-organic framework by solvothermal method in step (2) includes:

[0018] S1. Add 0.1 to 1.0 g of the diatomaceous earth composite multiligand metal-organic framework obtained in step (1) to 20 to 80 mL of ethylene glycol and disperse by ultrasonication to obtain a uniform suspension A.

[0019] 2) Add 0.1–1.0 g of ferric chloride hexahydrate and 0.3–3.0 g of sodium acetate trihydrate to suspension A, and stir until homogeneous to obtain suspension B;

[0020] 3) Transfer suspension B to a stainless steel reactor and react at 120-220℃ for 8-20 h. After separating the precipitate by magnetic centrifugation, washing off the residual solvent, and vacuum drying, a magnetic diatomaceous earth composite multiligand metal-organic framework is obtained.

[0021] A magnetic diatomaceous earth-based adsorbent capable of adsorbing various types of glucocorticoids, prepared by the method described in any one of the above-mentioned methods.

[0022] Application of a magnetic diatomaceous earth-based adsorbent capable of adsorbing various types of glucocorticoids: used as an adsorbent / filter aid to adsorb glucocorticoids in environmental water or as an adsorbent to adsorb and extract residual glucocorticoids in animal-derived foods.

[0023] Furthermore, the environmental water includes groundwater, surface water, tap water, domestic sewage, industrial wastewater, agricultural wastewater, or medical wastewater.

[0024] Furthermore, the animal-derived foods include livestock and poultry muscle, edible viscera, aquatic products, eggs, honey, milk, and their processed products.

[0025] Furthermore, the glucocorticoids include aclomethasone, ancinonide, beclomethasone, betamethasone, budesonide, cortisone, cicotinide, clobetasol, clobetasol, clocotropin, deficotinide, dexamethasone, difluralasone, diflucolone, fludrocortisone, fluocinolone, fluocinolone, fluticasone, flunicasone, flunisolone, fluprednisolone, halcinonide, halometasone, hydrocortisone, clotepone, methylprednisolone, methylprednisolone, mometasone, peramisone, prednisone, prednisolone, limesole, tecortisone, triamcinolone, ubetasol, prednisolone, and flucolone.

[0026] The present invention has the following advantages over the prior art:

[0027] (1) The adsorbent of this invention achieves the effect of simultaneously and efficiently adsorbing multiple types of glucocorticoids by providing multiple adsorption mechanisms. The magnetic diatomaceous earth composite multi-ligand metal-organic framework can form an adsorption effect with glucocorticoids through various forms of forces such as hydrogen bonding, electrostatic interaction, π-π interaction, and hydrophobic interaction by means of multiple components, multiple functional groups, and multiple adsorption sites. At the same time, as a widely used filter aid and adsorbent carrier, the porous structure of diatomaceous earth can complement the porous structure of the multi-ligand metal-organic framework, forming a composite porous structure adsorbent material with multiple pore sizes and multiple pore volumes. This structure is conducive to the binding of multiple target substances with multiple molecular sizes to the surface or pores of the adsorbent through size exclusion effect. Through the above-mentioned effects, the adsorption efficiency of the magnetic diatomaceous earth composite multi-ligand metal-organic framework for multiple types of glucocorticoids can reach more than 90%. That is, the multi-ligand metal-organic framework enriches the adsorption mechanism of diatomaceous earth for glucocorticoids, increases the adsorption sites, and thus achieves efficient co-adsorption of multiple types of glucocorticoids.

[0028] (2) The magnetic diatomite composite multi-ligand metal-organic framework has excellent application performance: it can adsorb a wide variety of glucocorticoids, is suitable for a wide range of sample matrices, and is flexible and easy to operate when adsorbing. It can also be reused multiple times, which effectively reduces the application cost. The magnetic diatomaceous earth composite multiligand metal-organic framework prepared in this invention can simultaneously adsorb glucocorticoids including aclomethasone, ancinonide, beclomethasone, betamethasone, budesonide, cortisone, cyclosonepine, clobetasol, clobetasol, clocotropin, deficosine, dexamethasone, difluralasone, diflucortisone, fluocinolone, fluocinolone, fluticasone, fluticasone, flunicasone, flunitrothion, fluprednisolone, halcinonide, halometasone, hydrocortisone, clotepone, methylprednisolone, methylprednisolone, mometasone, peramisone, prednisone, prednisolone, limesole, tecortisone, triamcinolone, urobetasol, prednisolone, and flucortisone.

[0029] (3) Magnetic diatomaceous earth composite multi-ligand metal-organic framework is a magnetic material that can be directly added to environmental water samples for adsorption and removal of glucocorticoids. After adsorption, the two phases can be separated by an external magnetic field without additional separation steps such as secondary centrifugation and filtration. Recovery is simple and convenient, avoiding secondary pollution of environmental water bodies. It can be directly added to the sample extract for magnetic solid phase extraction. Unlike traditional solid phase extraction columns, it does not require multiple steps such as activation, rinsing, washing, and elution. It also does not require granular adsorbents to be packed into columns or encapsulated in a mesh membrane before use. It is not only convenient to operate, but also fundamentally avoids the "channeling effect" caused by uneven packing. The stability and reproducibility of the extracted target are better.

[0030] (4) When the material of this invention is used as an adsorbent / filter aid, it is suitable for various environmental waters such as groundwater, surface water, tap water, domestic sewage, industrial wastewater, agricultural wastewater, or medical wastewater. It only needs to be directly added to the environmental water sample, and the total removal rate of various glucocorticoids can reach more than 90% within 5 minutes. After the adsorption and removal are completed, the two-phase separation between the adsorbent and the water sample can be achieved by using an external magnetic field, without the need for secondary operations such as centrifugation and filtration. The magnetic diatomaceous earth-based adsorbent can be reused after simple regeneration, and it can be reused at least 20 times. When used as a magnetic solid-phase extraction adsorbent, it is suitable for the extraction of glucocorticoid drug residues in animal-derived foods, including livestock and poultry muscle, edible offal tissue, aquatic products, eggs, honey, milk and their processed products. Only a few milligrams of adsorbent are needed to efficiently extract glucocorticoids from animal-derived food samples, while effectively reducing the interference of impurities in the sample (matrix effect less than 20%). There is no need for conventional operations such as rinsing and nitrogen blowing redissolution. The magnetic diatomaceous earth composite multi-ligand metal-organic framework can be directly reused after use, and it can be reused at least 20 times. Detailed Implementation

[0031] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions in the embodiments of this invention will be clearly and completely described below in conjunction with the embodiments of this invention. Obviously, the described embodiments are only a part of the embodiments of this invention, and not all of the embodiments. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0032] In the embodiments, it should be noted that any processes not specifically described below are those that can be implemented or understood by those skilled in the art by referring to existing technology. Reagents or instruments whose manufacturers are not specified are considered to be conventional products that can be purchased commercially.

[0033] Example 1

[0034] A method for preparing a magnetic diatomaceous earth-based adsorbent capable of adsorbing various types of glucocorticoids includes the following steps:

[0035] (1) Preparation of diatomaceous earth composite multi-ligand metal-organic frameworks by solvothermal method:

[0036] 1) Dissolve 0.4 mmol of zirconium chloride in 10 mL of N,N-dimethylformamide, and add 1.2 mmol of benzoic acid to obtain solution A;

[0037] 2) Dissolve 0.25 mmol of 2-aminoterephthalic acid and 0.25 mmol of 4,4'-biphenylcarboxylic acid in 10 mL of N,N-dimethylformamide to obtain solution B;

[0038] 3) Slowly add solution B to solution A, add 50 mg of diatomaceous earth, and after ultrasonic dispersion, transfer it to a stainless steel reactor and react at 120℃ for 24 h. After centrifugation to separate the precipitate, wash off the residual solvent, and vacuum dry, obtain the diatomaceous earth composite multiligand metal-organic framework.

[0039] (2) Preparation of magnetic diatomite composite multi-ligand metal-organic frameworks by solvothermal method:

[0040] 1) 0.4 g of diatomaceous earth composite multiligand metal-organic framework was added to 60 mL of ethylene glycol and ultrasonically dispersed to obtain a homogeneous suspension: A;

[0041] 2) Add 0.4 g of ferric chloride hexahydrate and 1.0 g of sodium acetate trihydrate to suspension A, stir until uniform to obtain suspension B. Transfer suspension B to a stainless steel reactor and react at 200℃ for 12 h. Separate the precipitate by magnetic centrifugation, wash off the residual solvent, and vacuum dry to obtain a magnetic diatomaceous earth composite multiligand metal-organic framework.

[0042] S3: Magnetic diatomaceous earth composite multi-ligand metal-organic frameworks are used as adsorbents (filter aids) to adsorb and remove glucocorticoids from lake water. Specifically, this is applied to the adsorption and removal of glucocorticoids such as aclomethasone, ansilonide, beclomethasone, betamethasone, budesonide, cortisone, ciroxonide, clobetasol, clobetasol, clotocinone, diffluxol, dexamethasone, difluralasone, diflucolone, fluocinolone, fluocinolone, fluticasone, fluticasone, flunicasone, flunitrothion, fluprednisolone, halcinonide, halometasone, hydrocortisone, clotiprednisolone, methylprednisolone, methylprednisolone, mometasone, peramisone, prednisone, prednisolone, limesolone, tecortisone, triamcinolone, urobetasol, prednisolone, and fluocinolone from lake water samples. The specific steps are as follows:

[0043] 200 mg of magnetic diatomite-based multi-ligand metal-organic framework was added to each liter of lake water sample. After adsorption, the magnetic diatomite-based multi-ligand metal-organic framework was separated using a magnet. Each milligram of diatomite-based multi-ligand metal-organic framework was regenerated by soaking in 0.5 mL of methanol for 2 min. The regenerated magnetic diatomite-based multi-ligand metal-organic framework could be reused as a solid-phase adsorbent, and could be reused up to 20 times without a significant decrease in adsorption efficiency.

[0044] Example 2

[0045] A method for preparing a magnetic diatomaceous earth-based adsorbent capable of adsorbing various types of glucocorticoids includes the following steps:

[0046] (1) Preparation of diatomaceous earth composite multi-ligand metal-organic frameworks by solvothermal method:

[0047] 1) Dissolve 0.8 mmol of ferric nitrate in 20 mL of N,N-dimethylformamide, and add 3.0 mmol of formic acid to obtain solution A;

[0048] 2) Dissolve 0.15 mmol of 2,6-pyridinedicarboxylic acid and 0.30 mmol of nitroterephthalic acid in 30 mL of N,N-dimethylformamide to obtain solution B;

[0049] 3) Slowly add solution B to solution A, add 80 mg of diatomaceous earth, and after ultrasonic dispersion, transfer it to a stainless steel reactor and react at 150℃ for 36 h. After centrifugation to separate the precipitate, wash off the residual solvent, and vacuum dry, obtain the diatomaceous earth composite multiligand metal-organic framework.

[0050] (2) Preparation of magnetic diatomite composite multi-ligand metal-organic frameworks by solvothermal method:

[0051] 1) Add 0.8 g of multi-ligand metal-organic framework to 40 mL of ethylene glycol and disperse by ultrasonication to obtain a homogeneous suspension A;

[0052] 2) Add 0.2 g of ferric chloride hexahydrate and 2.4 g of sodium acetate trihydrate to suspension A, stir until uniform to obtain suspension B. Transfer suspension B to a stainless steel reactor and react at 150°C for 20 h. Separate the precipitate by magnetic centrifugation, wash off the residual solvent, and vacuum dry to obtain a magnetic diatomaceous earth composite multiligand metal-organic framework.

[0053] Magnetic diatomaceous earth composite multi-ligand metal-organic frameworks were used as adsorbents to remove glucocorticoids from medical wastewater. Specifically, this application was used to remove glucocorticoids such as aclomethasone, ansilonide, beclomethasone, betamethasone, budesonide, cortisone, cicotinide, clobetasol, clobetasol, clocotropin, dexamethasone, difluralasone, diflucolone, fluocinolone, fluocinolone, fluticasone, fluticasone, flunicasone, flunicolone, halcinonide, halometasone, hydrocortisone, clotepone, methylprednisolone, methylprednisolone, mometasone, peramisone, prednisone, prednisolone, limesole, tecortisone, triamcinolone, urobetasol, prednisolone, and fluocinolone from medical wastewater samples.

[0054] 300 mg of magnetic diatomaceous earth composite multi-ligand metal-organic framework was added to each liter of medical wastewater sample. After adsorption, the magnetic diatomaceous earth composite multi-ligand metal-organic framework was separated using a magnet. Each milligram of magnetic diatomaceous earth composite multi-ligand metal-organic framework was regenerated by soaking in 1.0 mL of methanol for 5 min. The regenerated magnetic diatomaceous earth composite multi-ligand metal-organic framework can be reused as a solid-phase adsorbent and can be reused up to 30 times without a significant decrease in adsorption efficiency.

[0055] Example 3

[0056] A method for preparing a magnetic diatomaceous earth-based adsorbent capable of adsorbing various types of glucocorticoids includes the following steps:

[0057] (1) Preparation of diatomaceous earth composite multi-ligand metal-organic frameworks by solvothermal method:

[0058] 1) Dissolve 0.6 mmol of copper acetate in 50 mL of N,N-dimethylformamide, and add 0.5 mmol of trifluoroacetic acid to obtain solution A;

[0059] 2) Dissolve 0.5 mmol of 1,3,5-benzenetricarboxylic acid in 20 mL of N,N-dimethylformamide to obtain solution B;

[0060] 3) Slowly add solution B to solution A, add 100 mg of diatomaceous earth, and after ultrasonic dispersion, transfer it to a stainless steel reactor and react at 100℃ for 36 h. After centrifugation to separate the precipitate, wash off the residual solvent, and vacuum dry, obtain the diatomaceous earth composite multiligand metal-organic framework.

[0061] (2) Preparation of magnetic diatomite composite multi-ligand metal-organic frameworks by solvothermal method:

[0062] 1) 0.2 g of multi-ligand metal-organic framework was added to 20 mL of ethylene glycol and ultrasonically dispersed to obtain a homogeneous suspension 1;

[0063] 2) Add 0.1 g of ferric chloride hexahydrate and 0.3 g of sodium acetate trihydrate to suspension A, stir until uniform to obtain suspension B. Transfer suspension B to a stainless steel reactor and react at 220℃ for 8 h. Separate the precipitate by magnetic centrifugation, wash off the residual solvent, and vacuum dry to obtain a magnetic diatomaceous earth composite multiligand metal-organic framework.

[0064] Magnetic diatomaceous earth composite multi-ligand metal-organic frameworks were used as adsorbents to remove glucocorticoids from tap water. Specifically, this was applied to the adsorption and removal of glucocorticoids such as aclomethasone, ansilonide, beclomethasone, betamethasone, budesonide, cortisone, cicotinide, clobetasol, clobetasol, clocotropin, dexamethasone, difluralasone, diflucolone, fluocinolone, fluocinolone, fluticasone, fluticasone, flunicasone, flunitrothion, fluprednisolone, halcinonide, halometasone, hydrocortisone, clotiprednisolone, methylprednisolone, methylprednisolone, mometasone, peramisone, prednisone, prednisolone, limesole, tecortisone, triamcinolone, urobetasol, prednisolone, and flucotropin from tap water samples.

[0065] 150 mg of magnetic diatomaceous earth complex multi-ligand metal-organic framework was added to each liter of tap water sample. After adsorption, the magnetic diatomaceous earth complex multi-ligand metal-organic framework was separated using a magnet. Each milligram of magnetic diatomaceous earth complex multi-ligand metal-organic framework was regenerated by soaking in 0.2 mL of methanol for 5 min. The regenerated magnetic diatomaceous earth complex multi-ligand metal-organic framework can be reused as a solid-phase adsorbent and can be reused up to 25 times without a significant decrease in adsorption efficiency.

[0066] Example 4

[0067] A method for preparing a magnetic diatomaceous earth-based adsorbent capable of adsorbing various types of glucocorticoids includes the following steps:

[0068] (1) Preparation of diatomaceous earth composite multi-ligand metal-organic frameworks by solvothermal method:

[0069] 1) Dissolve 0.3 mmol of aluminum chloride in 10 mL of N,N-dimethylformamide, and then add 0.3 mmol of acetic acid to obtain solution A;

[0070] 2) Dissolve 0.1 mmol tetrafluoroterephthalic acid and 0.5 mmol terephthalic acid in 30 mL N,N-dimethylformamide to obtain solution B;

[0071] 3) Slowly add solution B to solution A, add 75 mg of diatomaceous earth, and after ultrasonic dispersion, transfer it to a stainless steel reactor and react at 150℃ for 12 h. After centrifugation to separate the precipitate, wash off the residual solvent, and vacuum dry, obtain the diatomaceous earth composite multiligand metal-organic framework.

[0072] (2) Preparation of magnetic diatomite composite multi-ligand metal-organic frameworks by solvothermal method:

[0073] 1) 0.5 g of diatomaceous earth composite multiligand metal-organic framework was added to 80 mL of ethylene glycol and ultrasonically dispersed to obtain a homogeneous suspension A;

[0074] 2) Add 0.3 g of ferric chloride hexahydrate and 2.7 g of sodium acetate trihydrate to suspension A, stir until uniform to obtain suspension B. Transfer suspension B to a stainless steel reactor and react at 180℃ for 12 h. Separate the precipitate by magnetic centrifugation, wash off the residual solvent, and vacuum dry to obtain a magnetic diatomaceous earth composite multiligand metal-organic framework.

[0075] Magnetic diatomaceous earth composite multi-ligand metal-organic frameworks were used as magnetic solid-phase extraction adsorbents for the extraction of glucocorticoid residues from beef. Specifically, this method was applied to the extraction of glucocorticoids from beef samples, including aclomethasone, ansilonide, beclomethasone, betamethasone, budesonide, cortisone, cicotinide, clobetasol, clobetasol, clocotropin, dexamethasone, difluralasone, diflucolone, fluocinolone, fluocinolone, fluticasone, fluticasone, flunicasone, flunitrothion, fluprednisolone, halcinonide, halometasone, hydrocortisone, clotiprednisolone, methylprednisolone, methylprednisolone, mometasone, peramisone, prednisone, prednisolone, limesolone, tecortisone, triamcinolone, urobetasol, prednisolone, and flucotropin.

[0076] The beef sample was initially processed into a sample solution using a grinding method. Then, a magnetic diatomaceous earth-based multi-ligand metal-organic framework was placed in the sample solution and vortexed continuously for 5 min. The glucocorticoids in the sample were adsorbed by the magnetic diatomaceous earth-based multi-ligand metal-organic framework. The glucocorticoids were eluted from the magnetic diatomaceous earth-based multi-ligand metal-organic framework using 0.8 mL of methanol. The eluent was collected for subsequent detection. The eluted magnetic diatomaceous earth-based multi-ligand metal-organic framework could be reused for the next extraction and could be reused up to 20 times without a significant decrease in adsorption efficiency.

[0077] Example 5

[0078] A method for preparing a magnetic diatomaceous earth-based adsorbent capable of adsorbing various types of glucocorticoids includes the following steps:

[0079] This embodiment is applied to the extraction of various glucocorticoid residues from fish samples.

[0080] The specific steps for preparing the material according to the present invention are as follows:

[0081] (1) Preparation of diatomaceous earth composite multi-ligand metal-organic frameworks by solvothermal method:

[0082] 1) Dissolve 1.0 mmol of cobalt nitrate in 25 mL of N,N-dimethylformamide, and add 2.5 mmol of stearic acid to obtain solution A;

[0083] 2) Dissolve 0.4 mmol tetrafluoroterephthalic acid and 0.5 mmol 4,4'-biphenyl dicarboxylic acid in 40 mL N,N-dimethylformamide to obtain solution B;

[0084] 3) Slowly add solution B to solution A, add 60 mg of diatomaceous earth, and after ultrasonic dispersion, transfer it to a stainless steel reactor and react at 100℃ for 30 h. After centrifugation to separate the precipitate, wash off the residual solvent, and vacuum dry, obtain the diatomaceous earth composite multiligand metal-organic framework.

[0085] (2) Preparation of magnetic diatomite composite multi-ligand metal-organic frameworks by solvothermal method:

[0086] 1) Add 1.0 g of multi-ligand metal-organic framework to 50 mL of ethylene glycol and disperse by ultrasonication to obtain a homogeneous suspension A;

[0087] 2) Add 0.6 g of ferric chloride hexahydrate and 2.0 g of sodium acetate trihydrate to suspension A, stir until homogeneous to obtain suspension B. Transfer suspension B to a stainless steel reactor and react at 160℃ for 18 h. Separate the precipitate by magnetic centrifugation, wash off the residual solvent, and vacuum dry to obtain a magnetic diatomaceous earth composite multiligand metal-organic framework.

[0088] Magnetic diatomaceous earth composite multi-ligand metal-organic frameworks were used as magnetic solid-phase extraction adsorbents for the extraction of glucocorticoid residues from fish meat. Specifically, this method was applied to the extraction of glucocorticoids from fish meat samples, including aclomethasone, ancinonide, beclomethasone, betamethasone, budesonide, cortisone, cyclosporine, clobetasol, clobetasol, clocotropin, dexamethasone, difluralasone, diflucolone, fluocinolone, fluocinolone, fluticasone, fluticasone, flunicasone, flunitrothion, fluprednisolone, halcinonide, halometasone, hydrocortisone, clotiprednisolone, methylprednisolone, methylprednisolone, mometasone, peramisone, prednisone, prednisolone, limesolone, tecortisone, triamcinolone, urobetasol, prednisolone, and flucotropin.

[0089] The fish meat sample was initially processed into a sample solution using ultrasonic extraction. Then, a magnetic diatomaceous earth-based multi-ligand metal-organic framework was placed in the sample solution and vortexed continuously for 10 min. The glucocorticoids in the sample were adsorbed by the magnetic diatomaceous earth-based multi-ligand metal-organic framework. The glucocorticoids were eluted from the magnetic diatomaceous earth-based multi-ligand metal-organic framework using 1.0 mL of methanol, and the eluent was collected for subsequent detection. The eluted magnetic diatomaceous earth-based multi-ligand metal-organic framework could be reused for the next extraction and could be reused up to 20 times without a significant decrease in adsorption efficiency.

[0090] Example 6

[0091] A method for preparing a magnetic diatomaceous earth-based adsorbent capable of adsorbing various types of glucocorticoids includes the following steps:

[0092] (1) Preparation of diatomaceous earth composite multi-ligand metal-organic frameworks by solvothermal method:

[0093] 1) Dissolve 0.7 mmol of nickel chloride in 35 mL of N,N-dimethylformamide, and add 1.8 mmol of benzoic acid to obtain solution A;

[0094] 2) Dissolve 0.3 mmol of nitroterephthalic acid and 0.3 mmol of 2-aminoterephthalic acid in 15 mL of N,N-dimethylformamide to obtain solution B;

[0095] 3) Slowly add solution B to solution A, add 90 mg of diatomaceous earth, and after ultrasonic dispersion, transfer it to a stainless steel reactor and react at 125℃ for 15 h. After centrifugation to separate the precipitate, wash off the residual solvent, and vacuum dry, obtain the diatomaceous earth composite multiligand metal-organic framework.

[0096] (2) Preparation of magnetic diatomite composite multi-ligand metal-organic frameworks by solvothermal method:

[0097] 1) 0.3 g of diatomaceous earth composite multiligand metal-organic framework was added to 25 mL of ethylene glycol and ultrasonically dispersed to obtain a homogeneous suspension A;

[0098] 2) Add 0.7 g of ferric chloride hexahydrate and 2.5 g of sodium acetate trihydrate to suspension A, stir until uniform to obtain suspension B. Transfer suspension B to a stainless steel reactor and react at 175℃ for 15 h. Separate the precipitate by magnetic centrifugation, wash off the residual solvent, and vacuum dry to obtain a magnetic diatomaceous earth composite multiligand metal-organic framework.

[0099] Magnetic diatomaceous earth composite multi-ligand metal-organic frameworks were used as magnetic solid-phase extraction adsorbents for the extraction of glucocorticoid residues from eggs. Specifically, this method was applied to the extraction of glucocorticoids from egg samples, including aclomethasone, ansilonide, beclomethasone, betamethasone, budesonide, cortisone, cyclosporine, clobetasol, clobetasol, clocotropin, dexamethasone, difluralasone, diflucolone, fluocinolone, fluocinolone, fluticasone, fluticasone, flunicasone, flunitrothion, fluprednisolone, halcinonide, halometasone, hydrocortisone, clotenophenone, methylprednisolone, methylprednisolone, mometasone, peramisone, prednisone, prednisolone, limesolone, tecortisone, triamcinolone, urobetasol, prednisolone, and flucolone.

[0100] Egg samples were initially processed into a sample solution using a homogenization and centrifugation method. Then, a magnetic diatomaceous earth-based multi-ligand metal-organic framework (MOF) was placed in the sample solution and vortexed continuously for 8 minutes. The glucocorticoids in the sample were adsorbed by the MOF. The glucocorticoids were eluted from the MOF using 0.5 mL of methanol, and the eluent was collected for subsequent analysis. The eluted MOF could be reused for the next extraction, up to 50 times, without a significant decrease in adsorption efficiency.

[0101] The above embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above embodiments. Any changes, substitutions, combinations, simplifications, etc. made based on the principles or spirit of the present invention should be equivalent and are included within the protection scope of the present invention.

Claims

1. A method for preparing a magnetic diatomaceous earth-based adsorbent capable of adsorbing various types of glucocorticoids, characterized in that, Includes the following steps: (1) First, prepare diatomaceous earth composite multiligand metal-organic frameworks using a solvothermal method; (2) Then, magnetic diatomite composite multiligand metal-organic framework is prepared by solvothermal method.

2. The method for preparing a magnetic diatomaceous earth-based adsorbent capable of adsorbing multiple types of glucocorticoids according to claim 1, characterized in that, The steps for preparing diatomaceous earth composite multi-ligand metal-organic frameworks by solvothermal method described in step (1) include: 1) Dissolve 0.1–1.0 mmol of a metal salt in 5–50 mL of N,N-dimethylformamide to obtain solution A; 2) Dissolve 0.01–0.50 mmol of organic ligand A and 0.01–0.50 mmol of organic ligand B in 5–50 mL of N,N-dimethylformamide to obtain solution B; 3) Slowly add solution B to solution A and stir until homogeneous to obtain the metal-organic framework precursor solution; 4) Add 50-100 mg of diatomaceous earth to the metal-organic framework precursor solution, and disperse it evenly by ultrasonication to obtain a diatomaceous earth suspension; 5) The diatomaceous earth suspension was transferred to a stainless steel reactor and reacted at 100-150°C for 12-36 h. After centrifugation to separate the precipitate, the residual solvent was washed off and the diatomaceous earth composite multiligand metal-organic framework was obtained after vacuum drying.

3. The method for preparing a magnetic diatomaceous earth-based adsorbent capable of adsorbing multiple types of glucocorticoids according to claim 2, characterized in that, The metal salt mentioned in step 1) is any one of the hydrochloride, nitrate, or acetate salts of copper, iron, zinc, aluminum, chromium, zirconium, nickel, or cobalt.

4. The method for preparing a magnetic diatomaceous earth-based adsorbent capable of adsorbing multiple types of glucocorticoids according to claim 2, characterized in that, In step 2), organic ligand A and organic ligand B are any one of terephthalic acid, 4,4'-biphenyldicarboxylic acid, 1,3,5-benzenetricarboxylic acid, 2,6-pyridinedicarboxylic acid, 2-aminoterephthalic acid, nitroterephthalic acid, and tetrafluoroterephthalic acid.

5. The method for preparing a magnetic diatomaceous earth-based adsorbent capable of adsorbing multiple types of glucocorticoids according to claim 1, characterized in that, The steps in step (2) for preparing magnetic diatomite composite multi-ligand metal-organic frameworks using the solvothermal method include: S1. Add 0.1 to 1.0 g of the diatomaceous earth composite multiligand metal-organic framework obtained in step (1) to 20 to 80 mL of ethylene glycol and disperse by ultrasonication to obtain a uniform suspension A. 2) Add 0.1–1.0 g of ferric chloride hexahydrate and 0.3–3.0 g of sodium acetate trihydrate to suspension A, and stir until homogeneous to obtain suspension B; 3) Transfer suspension B to a stainless steel reactor and react at 120-220℃ for 8-20 h. After separating the precipitate by magnetic centrifugation, washing off the residual solvent, and vacuum drying, a magnetic diatomaceous earth composite multiligand metal-organic framework is obtained.

6. A magnetic diatomaceous earth-based adsorbent capable of adsorbing various types of glucocorticoids, characterized in that, Made by the method described in any one of claims 1-5 above.

7. The application of a magnetic diatomaceous earth-based adsorbent capable of adsorbing multiple types of glucocorticoids as described in claim 6, characterized in that, It can be used as an adsorbent to adsorb glucocorticoids in environmental water or as an adsorbent to adsorb and extract residual glucocorticoids in animal-derived foods.

8. The application of the magnetic diatomaceous earth-based adsorbent capable of adsorbing various types of glucocorticoids according to claim 7, characterized in that, The environmental water includes groundwater, surface water, tap water, domestic sewage, industrial wastewater, agricultural wastewater, or medical wastewater.

9. The application of the magnetic diatomaceous earth-based adsorbent capable of adsorbing various types of glucocorticoids according to claim 7, characterized in that, Animal-derived foods include livestock and poultry muscle, edible viscera, aquatic products, eggs, honey, milk, and their processed products.

10. The application of the magnetic diatomaceous earth-based adsorbent capable of adsorbing multiple types of glucocorticoids according to claim 7, characterized in that, The glucocorticoids mentioned include aclomethasone, ancinonide, beclomethasone, betamethasone, budesonide, cortisone, cicosone, clobetasol, clobetasol, clocotropin, deficosone, dexamethasone, difluralasone, diflucolone, fludrocortisone, fluocinolone, flumicolone, fluticasone, flunicasone, flunisolone, fluprednisolone, halcinonide, halometasone, hydrocortisone, clotepone, methylprednisolone, methylprednisolone, mometasone, peramisone, prednisone, prednisolone, limesole, tecortisone, triamcinolone, urobetasol, prednisolone, and flucolone.