A high capacity superhydrophilic ion chromatography column packing and a method for preparing the same

Abstract

The application discloses a high-capacity super-hydrophilic ion chromatography column filler and a preparation method thereof, relates to the technical field of new materials, and solves the problem of strong hydrophobicity of the filler, which leads to serious tailing of some ion peaks. The filler is a PS-DVB base ball, a benzene ring of which is grafted with a sulfonic acid group through a covalent bond; the sulfonic acid group is combined with a long molecular chain containing a tertiary amine group through an ionic bond; the long molecular chain is generated by reaction of an amine nucleophile with a first bis-epoxy reagent; a tertiary amine group at one end of the long molecular chain forms an ionic bond with a sulfonic acid group on the surface of the base ball, and the long chain is anchored on the surface of the base ball; an epoxy group at the other end of the long molecular chain undergoes ring-opening reaction with a second bis-epoxy reagent or a hydrolysis product thereof, forming a cross-linking bond and constructing a multi-layer network structure; one epoxy group of the second bis-epoxy reagent undergoes nucleophilic reaction with the tertiary amine group in the anchored long molecular chain, generating a quaternary ammonium group; and the other epoxy group of the second bis-epoxy reagent reacts with the tertiary amine nucleophile to generate a quaternary ammonium salt functional group.

Description

Technical Field

[0001] This invention relates to the field of new materials technology, specifically to a high-capacity superhydrophilic ion chromatography column packing and its preparation method. Background Technology

[0002] Ion chromatography is widely used for the detection of ionic compounds in various types of water, such as surface water, groundwater, tap water, and bottled drinking water. Different water qualities contain a variety of ions due to differences in water source, transportation, storage, and treatment conditions, and the concentrations of these ions vary greatly. This makes it difficult to detect certain ions with extremely low concentrations, such as iodide ions and perchloric acid.

[0003] Currently, the widely used ion chromatography column packing material is mainly latex agglomeration type. The preparation of this packing material uses sulfonated polystyrene-divinylbenzene (PS-DVB) microspheres as the base spheres. The surface of the base spheres carries a large number of negative charges. Quaternized nano-latex particles are used as functional groups. The surface of the latex particles carries a large number of positive charges. After the base spheres and latex particles are mixed, the two form a whole through electrostatic adsorption. The base spheres are wrapped by the latex particles as a support, and the excess positively charged quaternary ammonium groups on the surface of the latex particles are anion exchange sites.

[0004] The disadvantages of latex-agglomerated ion chromatography column packing are obvious:

[0005] Because latex particles are tightly bonded to each other and to the substrate spheres, the number of quaternary ammonium groups on the surface of the latex particles available for anion exchange is limited, resulting in low column capacity and short lifespan, making it unsuitable for detecting low-concentration ions in complex matrix samples. Secondly, due to the hydrophobic nature of this packing material, it exhibits strong non-polar adsorption of ions such as bromine, nitric acid, iodine, and perchloric acid, leading to severe peak tailing and insufficient sensitivity, failing to meet detection requirements. Thirdly, latex synthesis typically requires the use of non-water-soluble monomers, limiting the selectivity of other available monomers and thus restricting the application range of the chromatographic column. Fourthly, the sulfonation of PS-DVB substrate spheres usually requires concentrated sulfuric acid, making operation inconvenient; latex synthesis is time-consuming, process control is difficult, and it is hard to guarantee the uniformity of latex particle size. Fifthly, to ensure that the latex particles adsorbed on the substrate sphere surface are a monolayer and do not accumulate (e.g., Figure 1 As shown in the figure, this results in excessive column pressure, requiring the base ball to be filled first, and then the latex to be slowly injected. This process often takes several days to complete the filling of the finished column, making the production process time-consuming and labor-intensive. Summary of the Invention

[0006] The present invention provides a high-capacity superhydrophilic ion chromatography column packing material and its preparation method, which solves the problem that the strong hydrophobicity of the packing material leads to severe tailing of certain ion peaks.

[0007] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0008] This invention discloses a high-capacity superhydrophilic ion chromatography column packing material, the structure of which is as follows:

[0009] Using styrene-divinylbenzene copolymer as the base sphere, sulfonic acid groups are covalently grafted onto the benzene rings on its surface to form a hydrophilic layer and ionic bonding anchors;

[0010] The sulfonic acid group is bonded to a long molecular chain containing a tertiary amine group via ionic bonds;

[0011] The long molecular chain is generated by the reaction of an amine nucleophile with a first diepoxy reagent, and the long molecular chain contains a tertiary amine group. The tertiary amine group at one end of the long molecular chain forms an ionic bond with the sulfonic acid group on the surface of the base sphere, anchoring the long chain to the surface of the base sphere. The epoxy group at the end of the long molecular chain undergoes a ring-opening reaction with a second diepoxy reagent or its hydrolysis product to form cross-linking bonds and construct a multilayer network structure.

[0012] One epoxy group of the second diepoxide reagent undergoes a nucleophilic reaction with the tertiary amine group in the anchored long molecular chain to generate a quaternary ammonium group; the other epoxy group of the second diepoxide reagent reacts with a tertiary amine nucleophile to generate a quaternary ammonium salt functional group, which is denoted by an OH group. - It exists in a form that serves as an active site for ion exchange.

[0013] As one specific implementation scheme, the amine nucleophile is methylamine, ammonia, ethylamine, ethanolamine, diethanolamine, dimethylamine, or other primary or secondary amines.

[0014] As one specific implementation, the tertiary amine nucleophile is trimethylamine, tetramethylmethyldiamine (TMMDA), tetramethylethylenediamine (TMEDA), tetramethylpropanediamine (TMPDA), tetramethylpropanoldiamine, tetramethylbutanediamine (TMBD), or 1,3-diamino-2-propanol (DAPO).

[0015] As one specific implementation scheme, the diepoxy reagent is a reagent containing a diepoxy group, such as 1,4-butanediol diglycidyl ether (BDDGE), ethylene glycol diglycidyl ether (EGDGE), glycerol diglycidyl ether (GDE), or 1,6-hexanediol diglycidyl ether (HDE).

[0016] Another aspect of the present invention discloses a method for preparing a high-capacity superhydrophilic ion chromatography column packing, which includes the following steps:

[0017] Step S100: Hydrophilic treatment of the surface of polystyrene-divinylbenzene copolymer (PS-DVB) based spheres;

[0018] In this step, PS-DVB-based spheres with a crosslinking degree of 60% were weighed and dispersed in an isopropanol aqueous solution (IPA). The mixture was then ultrasonically treated and filtered. The resulting filter cake was transferred to a beaker, and glacial acetic acid was added and stirred at low speed to disperse it evenly. Methylsulfonic acid was then added, and the mixture was stirred until homogeneous. The mixture was allowed to stand at room temperature for reaction. After the reaction was completed, the mixture was diluted with ultrapure water and filtered. The solution was then filtered with ultrapure water, 1 mol / L sodium hydroxide, methanol, and ultrapure water, respectively, to finally obtain hydrophilic spheres containing methylsulfonic acid groups.

[0019] In step S100, a mixture of acetic acid and methanesulfonic acid is used to hydrophilize the surface of the base sphere, forming a sulfonic acid-based hydrophilic layer. Acetic acid acts as a swelling agent, introducing methanesulfonic acid deeper into the surface of the base sphere, thus making the sulfonation reaction more complete. Methanesulfonic acid, as a functional reagent, serves as a functional group for the next reaction while forming the sulfonic acid hydrophilic layer.

[0020] As one specific implementation, the solid-liquid ratio of the mixture obtained by dispersing PS-DVB-based spheres in an aqueous isopropanol solution (IPA) is 1:5-10.

[0021] As one specific implementation scheme, the mass ratio of PS-DVB-based spheres to glacial acetic acid is 1:1.2-1.6.

[0022] As one specific implementation scheme, the mass ratio of PS-DVB-based spheres to methanesulfonic acid is 1:1.8-2.5.

[0023] Step S200: Synthesis of quaternary ammonium salt functional groups in multilayer network structures;

[0024] In this step, hydrophilic spheres are thoroughly stirred and dispersed with ultrapure water to form a uniform suspension. An amine nucleophile and a first diepoxy reagent are added to the suspension, and the mixture is reacted under water bath conditions to obtain a reactant. The reactant is filtered and repeatedly washed with ultrapure water until the pH of the filtrate is neutral. The washed filter cake is thoroughly stirred and dispersed with ultrapure water to obtain a uniform suspension, and a second diepoxy reagent is added to the suspension. The mixture is then reacted under water bath conditions. After the reaction is complete, the filter cake is filtered and mixed with ultrapure water and a tertiary amine nucleophile, and the mixture is stirred and reacted under water bath conditions. After the reaction is complete, the filter cake is washed with ultrapure water, 1 mol / L sodium hydroxide, and ultrapure water in sequence to obtain an OH- type high-capacity superhydrophilic ion chromatography column packing.

[0025] In step S200, a multilayer network structure quaternary ammonium salt functional group is synthesized stepwise using strong ionic bonds and nucleophilic reactions. Specifically, an amine nucleophile is selected and reacts with a first diepoxy reagent containing a diepoxy group to generate an ultralong-chain molecule containing a tertiary amine group. The tertiary amine group is ionicly bonded to the sulfonic acid group generated in step S100, forming an anchoring layer on the surface of the base spheres, providing a foundation for the subsequent construction of the multilayer network structure. The tertiary amine group also serves as the active group for the next reaction. One of the epoxy groups in the first diepoxy reagent undergoes another nucleophilic reaction with the tertiary amine group to generate a quaternary ammonium group, further strengthening the ionic bond strength between the multilayer network structure and the base sphere surface. The other epoxy group serves as the active group for the next reaction, using a tertiary amine nucleophile to generate a quaternary ammonium salt functional group, which is finally converted to OH- by washing with sodium hydroxide. - type.

[0026] As one specific implementation, the molar ratio of sulfonic acid groups to anchored tertiary amine groups on the surface of the base sphere is 1:2-4.

[0027] As one specific implementation, the molar ratio of the amine group of the amine nucleophile to the epoxy group of the first bisepoxide reagent is 1:0.8-1.2.

[0028] In one specific implementation, the molar ratio of the epoxy group of the first bisepoxy reagent to the epoxy group of the second bisepoxy reagent is 1:1.5-3.

[0029] As one specific embodiment, the molar ratio of the tertiary amine group of the tertiary amine reagent to the epoxy group of the second bisepoxide reagent is 1:2.5-3.5.

[0030] Furthermore, a method for preparing a high-capacity superhydrophilic ion chromatography column packing material for a specific practical application scenario is described below:

[0031] Step S100: Hydrophilic treatment of the surface of polystyrene-divinylbenzene copolymer (PS-DVB) based spheres;

[0032] Specifically, the implementation process of step S100 is as follows:

[0033] Weigh 15g of PS-DVB-based spheres with a crosslinking degree of 60% and a particle size of 7µm, disperse them in 100mL of 50% volume fraction isopropanol aqueous solution (IPA), sonicate for 5min, and filter.

[0034] Transfer the filter cake obtained after vacuum filtration to a beaker, add 21g of glacial acetic acid and stir to disperse; stir and disperse evenly at 200-300rpm; then add 32g of methanesulfonic acid with a mass fraction ≥99%, continue stirring for 5min to mix evenly, and let it stand at room temperature for 2 hours to react;

[0035] After the reaction was completed, the solution was diluted with 300 mL of ultrapure water and filtered. Then, the solution was washed three times with ultrapure water (300 mL each time, at room temperature), 1 mol / L sodium hydroxide (washed twice with 100 mL each time, soaking for 5-10 min each time, at room temperature), methanol (washed twice with 200 mL each time, at room temperature), and ultrapure water (washed until the pH of the filtrate was neutral, at room temperature) and filtered again. Finally, hydrophilic spheres containing methanesulfonic acid groups were obtained.

[0036] Step S200: Synthesis of quaternary ammonium salt functional groups in multilayer network structures;

[0037] Specifically, the implementation process of step S200 is as follows:

[0038] Step S201: Weigh 3g of the above hydrophilic spheres into a flask, add 16g of ultrapure water, stir thoroughly to disperse, and form a uniform suspension;

[0039] Step S202: Add 0.72g of methylamine and 0.9g of 1,4-butanediol diglycidyl ether (BDDGE) to the suspension, and react for 120min at 62℃ to obtain the reactants;

[0040] Step S203: Filter the reactants obtained in step S202 and wash them repeatedly with ultrapure water until the pH of the filtrate is neutral; transfer the washed filter cake back to the flask, add 16g of ultrapure water, stir and disperse thoroughly to obtain a uniform suspension.

[0041] Step S204: Add 1.8g BDDGE to the suspension obtained in step S203, react in a water bath at 62℃ for 30min, and filter after the reaction is complete;

[0042] Step S205: Place the filter cake obtained after filtration in step S204, 10-15g of ultrapure water, and 1.2g of 30% trimethylamine aqueous solution into a beaker and stir the mixture in a water bath at 62℃ for 30min.

[0043] Step S206: After the reaction is complete, wash the solution three times with ultrapure water at room temperature (100 mL each time), and twice with 1 mol / L sodium hydroxide at room temperature (100 mL each time, soaking for 5-10 min each time before filtration). Finally, wash the solution with ultrapure water until the pH of the filtrate is neutral to obtain OH. - High-capacity, high-capacity, superhydrophilic ion chromatography column packing material.

[0044] In step S202, methylamine (primary amine) undergoes a nucleophilic ring-opening reaction with BDDGE (diepoxy reagent) to generate a long molecular chain with epoxy groups at both ends and a tertiary amine group in the middle. The tertiary amine group at one end of the long molecular chain is ionicly bonded to the sulfonic acid group on the surface of the base sphere, anchoring the long chain to the surface of the base sphere; the end of the long molecular chain retains unreacted epoxy groups, which serve as active sites for subsequent crosslinking.

[0045] In step S204, one epoxy group of BDDGE undergoes a nucleophilic reaction with the tertiary amine group anchored inside the long molecular chain in step S202 to generate a quaternary ammonium group, thereby introducing covalent bonding on the basis of ionic bonds and enhancing the stability of the network structure. The epoxy group retained at the end of the long molecular chain undergoes a ring-opening reaction with the second portion of BDDGE (or its hydrolysis product) to form cross-linking bonds, constructing a multilayer network structure. The other epoxy group of the second portion of BDDGE is retained in this step as an active site for subsequent functionalization.

[0046] In step S205, trimethylamine (tertiary amine) undergoes a nucleophilic reaction with the epoxy groups retained in the network obtained in step S204 to generate terminal quaternary ammonium salt functional groups. Washing with sodium hydroxide converts the product to OH groups. - This type of material is convenient for direct use in anion chromatography analysis.

[0047] The chromatogram of the packing material obtained by this method is as follows: Figure 2 As shown, I - The peaks are basically consistent in their leading and trailing edges, with sharp and symmetrical peak shapes and no obvious tailing, indicating that the superhydrophilic layer formed by the multi-layer network structure completely inhibits the hydrophobic interaction between iodide ions and the filler surface. - With ClO4 - The baseline separation is achieved, with complete separation of the two peaks, obvious peak spacing, clear baseline, and no overlap, indicating that the packing material has good selectivity and separation ability, which can meet the accurate quantitative requirements of low-concentration ions in complex samples. The narrow and sharp chromatographic peaks reflect high column efficiency and low mass transfer resistance, indicating that the functional groups are uniformly distributed in the multilayer network structure, the active sites are highly accessible, the ion exchange kinetics are good, and the retention time is long, indicating that the packing material of this invention has a stronger ability to distinguish anions with different hydrophobicities.

[0048] Compared with the prior art, the present invention has the following advantages:

[0049] This invention employs a stepwise addition of diepoxy reagents to achieve a dual quaternization mechanism. Specifically, an amine nucleophile reacts with a first diepoxy reagent to generate a long molecular chain with terminal epoxy groups and a tertiary amine group in the middle. The long chain is anchored to the surface of the base sphere through ionic bonds between the tertiary amine group and the sulfonic acid group on the base sphere surface. Subsequently, a second diepoxy reagent is added, causing one of its epoxy groups to undergo a nucleophilic reaction with the tertiary amine group inside the anchored long chain to generate a quaternary ammonium group. Simultaneously, the terminal epoxy group of the long chain undergoes a ring-opening reaction with the second diepoxy reagent (or its hydrolysis product) to form a crosslinking bond. Finally, a tertiary amine reagent is added to react with the epoxy groups retained in the network to generate quaternary ammonium salt functional groups. Through this stepwise design, a dual quaternization mechanism is achieved: on the one hand, the tertiary amine group inside the long chain is converted into a quaternary ammonium group through reaction with the second diepoxy reagent; on the other hand, the epoxy groups retained in the network react with the tertiary amine reagent to generate terminal quaternary ammonium groups. Each long-chain molecule generated by an amine nucleophile can ultimately contribute more than one quaternary ammonium group (for example, each methylamine molecule can contribute approximately 1.6 quaternary ammonium groups, with tertiary amine quaternization contributing 1 and terminal quaternization contributing approximately 0.6). Furthermore, the additional polyether segments (from the bisepoxide reagent) introduced into the crosslinking network further increase the functionalization sites. Simultaneously, by controlling the molar ratio of amine to the first epoxy group, linear long chains rather than branched structures are ensured; by controlling the molar ratio of the second epoxy group to the first epoxy group, a dense multilayer crosslinking network is formed. In this invention, each anchoring point contributes multiple quaternary ammonium groups (rather than the single quaternary ammonium group of the traditional agglomeration type). The multilayer network structure ensures that the quaternary ammonium groups are distributed throughout the entire network, resulting in high accessibility of active groups, all exposed to the mobile phase, and full participation in ion exchange, thus enabling the filler of this invention to have a high capacity.

[0050] This invention, based on ionic bond anchoring, constructs a dual fixation mechanism of ionic bonds and covalent cross-linking through the addition of a second diepoxy reagent. Specifically, the tertiary amine group at one end of the long chain forms an ionic bond with the sulfonic acid group on the surface of the base sphere, anchoring the long chain to the base sphere surface. Simultaneously, one epoxy group of the second diepoxy reagent reacts with the tertiary amine group inside the long chain to generate a quaternary ammonium group (introducing a covalent bond), and the epoxy group at the end of the long chain undergoes a ring-opening reaction with the second diepoxy reagent (or its hydrolysis product) to form a cross-linking bond, connecting the discrete long chains into a continuous multilayer network. Ultimately, the multilayer network is not only attached to the base sphere by ionic bonds but also forms an integral structure through covalent cross-linking. Covalent bonds have a much higher bond energy than ionic bonds and are not easily destroyed by high-salt eluents. The cross-linked network connects the long chains into a whole, and even if some ionic bonds are broken, the network can still remain intact through covalent bonds. The polyether segments in the network (derived from bisepoxy reagents) are stable in organic solvents and are not prone to swelling or dissolution. After the epoxy groups participate in cross-linking, covalent connections are formed between the anchoring layer and the cross-linking layer, which further enhances the mechanical strength of the overall structure. Therefore, the packing material of this invention has excellent long-term stability and erosion resistance, and the column life is significantly extended.

[0051] In this invention, the sulfonic acid groups on the surface of the base sphere are strongly polar groups that form hydrogen bonds with water molecules; the ether bonds and hydroxyl groups generated after ring opening of the epoxy groups in the bisepoxide reagent are both strongly hydrophilic groups, with each bisepoxide reagent unit contributing at least two hydroxyl groups and one ether bond; the terminal quaternary ammonium salt is an ionic hydrophilic group that interacts strongly with water molecules. By adding the bisepoxide reagent stepwise to construct a multilayer network structure, these hydrophilic groups form a continuous hydration layer on the surface of the base sphere, creating a hydrophilic gradient from the inside out: sulfonic acid group-polyether chain-hydroxyl group-quaternary ammonium salt. This completely covers the original hydrophobic surface of the base sphere, forming a superhydrophilic layer and solving the problem of severe tailing of certain ion peaks (such as iodide ions and perchloric acid).

[0052] In the hydrophilic treatment of the substrate spheres, this invention uses acetic acid as a swelling agent, which also introduces methanesulfonic acid into the pores on the surface of the substrate spheres, making the sulfonation reaction more thorough, that is, more sulfonic acid groups are coated on the surface of the substrate spheres, thereby making the substrate spheres more hydrophilic. At the same time, using this method, the sulfonation reaction process is mild, does not damage the substrate sphere skeleton structure, and does not form a highly viscous substrate sphere surface that would lead to excessively high column pressure. In addition, both reagents are conventional reagents, inexpensive and readily available, and easy to operate.

[0053] The technical solution disclosed in this invention is convenient to implement, saves time and effort, does not involve large and complex equipment, uses inexpensive and readily available reagents, and is relatively environmentally and human-friendly. Attached Figure Description

[0054] Figure 1 The chromatogram is shown for the latex-agglomerated ion chromatography column packing material in Comparative Example 3.

[0055] Figure 2 This is a chromatogram of the ion chromatography column packing material used in a practical application scenario as described in this invention specification. Detailed Implementation

[0056] The following description is provided in the specific applications and requirements thereof, which will enable those skilled in the art to make and use this application. It will be apparent to those skilled in the art that various changes can be made to the disclosed embodiments, and the general principles defined herein can be applied to other embodiments and application scenarios without departing from the principles and scope of this application. Therefore, this application is not limited to the described embodiments, but should be given the broadest scope consistent with the claims.

[0057] It should be understood that the expression “one or more of…” individually includes each of the objects described after the expression, as well as various different combinations of two or more of the described objects, unless otherwise understood from the context and usage. The expression “and / or” combined with three or more described objects should be understood to have the same meaning, unless otherwise understood from the context.

[0058] The terms “including,” “having,” or “containing,” including the use of their grammatical synonyms, should generally be understood as open-ended and non-restrictive, for example, not excluding other unstated elements or steps, unless otherwise specifically stated or understood from the context.

[0059] It should be understood that the order of the steps or the order in which certain actions are performed is not important as long as the invention remains operational. Furthermore, two or more steps or actions can be performed simultaneously.

[0060] The use of any and all instances or exemplary language such as “e.g.” or “including” in this document is merely intended to better illustrate the invention and is not intended to limit the scope of the invention unless the claims are made. No language in this specification should be construed as indicating that any unclaimed element is essential to the practice of the invention.

[0061] Example

[0062] A method for preparing a high-capacity superhydrophilic ion chromatography column packing material, the specific implementation process of which is as follows:

[0063] Step S100: Hydrophilic treatment of the surface of polystyrene-divinylbenzene copolymer (PS-DVB) based spheres;

[0064] Specifically, the implementation process of step S100 is as follows:

[0065] Weigh out PS-DVB-based spheres with a crosslinking degree of 60% and a particle size of 7µm, disperse them in a 50% volume fraction of isopropanol aqueous solution (IPA), sonicate for 5 min, and filter.

[0066] Transfer the filter cake obtained after vacuum filtration to a beaker, add glacial acetic acid and stir to disperse; stir at 200-300 rpm to disperse evenly; then add methanesulfonic acid with a mass fraction ≥99%, continue stirring for 5 min to mix evenly, and let it stand at room temperature for 2 hours to react;

[0067] After the reaction was completed, the solution was diluted with 300 mL of ultrapure water and filtered. Then, the solution was washed three times with ultrapure water (300 mL each time, at room temperature), 1 mol / L sodium hydroxide (washed twice with 100 mL each time, soaking for 5-10 min each time, at room temperature), methanol (washed twice with 200 mL each time, at room temperature), and ultrapure water (washed until the pH of the filtrate was neutral, at room temperature) and filtered again. Finally, hydrophilic spheres containing methanesulfonic acid groups were obtained.

[0068] Step S200: Synthesis of quaternary ammonium salt functional groups in multilayer network structures;

[0069] Specifically, the implementation process of step S200 is as follows:

[0070] Step S201: Weigh the hydrophilic spheres into a flask, add ultrapure water, and stir thoroughly to disperse them and form a uniform suspension;

[0071] Step S202: An amine nucleophile and a first diepoxy reagent are added to the suspension, and the mixture is reacted in a water bath at 62°C for 120 min to obtain the reactants.

[0072] Step S203: Filter the reactants obtained in step S202 and wash them repeatedly with ultrapure water until the pH of the filtrate is neutral; transfer the washed filter cake back to the flask, add ultrapure water, and stir thoroughly to disperse and obtain a uniform suspension.

[0073] Step S204: Add the second bisepoxy reagent to the suspension obtained in step S203, react in a water bath at 62°C for 30 min, and filter after the reaction is complete;

[0074] Step S205: Place the filter cake obtained after filtration in step S204, ultrapure water, and a 30% trimethylamine aqueous solution into a beaker and stir the mixture in a water bath at 62°C for 30 minutes.

[0075] Step S206: After the reaction is complete, wash the solution three times with ultrapure water at room temperature (100 mL each time), and twice with 1 mol / L sodium hydroxide at room temperature (100 mL each time, soaking for 5-10 min each time before filtration). Finally, wash the solution with ultrapure water until the pH of the filtrate is neutral to obtain OH. - High-capacity, high-capacity, superhydrophilic ion chromatography column packing material.

[0076] Please refer to Tables 1 and 2 below for the specific reagent and parameter selections for Examples 1-20, respectively.

[0077] Table 1: Parameter Variables Table 1

[0078]

[0079] Table 2: Parameter Variables Table 2

[0080]

[0081] Comparative Example 1

[0082] A method for preparing ion chromatography column packing material, the specific implementation process of which is as follows:

[0083] Step S100: Hydrophilic treatment of the surface of polystyrene-divinylbenzene copolymer (PS-DVB) based spheres;

[0084] Specifically, the implementation process of step S100 is as follows:

[0085] Weigh 15g of PS-DVB-based spheres with a crosslinking degree of 60% and a particle size of 7µm, disperse them in 100mL of 50% volume fraction isopropanol aqueous solution (IPA), sonicate for 5min, and filter.

[0086] Transfer the filter cake obtained after vacuum filtration to a beaker, add 21g of glacial acetic acid and stir to disperse; stir and disperse evenly at 200-300rpm; then add 32g of methanesulfonic acid with a mass fraction ≥99%, continue stirring for 5min to mix evenly, and let it stand at room temperature for 2 hours to react;

[0087] After the reaction was completed, the solution was diluted with 300 mL of ultrapure water and filtered. Then, the solution was washed three times with ultrapure water (300 mL each time, at room temperature), 1 mol / L sodium hydroxide (washed twice with 100 mL each time, soaking for 5-10 min each time, at room temperature), methanol (washed twice with 200 mL each time, at room temperature), and ultrapure water (washed until the pH of the filtrate was neutral, at room temperature) and filtered again. Finally, hydrophilic spheres containing methanesulfonic acid groups were obtained.

[0088] Step S200: Synthesis of quaternary ammonium salt functional groups in multilayer network structures;

[0089] Specifically, the implementation process of step S200 is as follows:

[0090] Step S201: Weigh 3g of the above hydrophilic spheres into a flask, add 16g of ultrapure water, stir thoroughly to disperse, and form a uniform suspension;

[0091] Step S202: Add 0.72g of methylamine (40%) and 2.7g of 1,4-butanediol diglycidyl ether (BDDGE) to the suspension, and react for 150min at 62℃ to obtain the reactants;

[0092] Step S203: Filter the reactants obtained in step S202 and wash them repeatedly with ultrapure water until the pH of the filtrate is neutral.

[0093] Step S204: The filter cake obtained by filtration in step S203, 10-15g of ultrapure water, and 1.2g of 30% trimethylamine aqueous solution are placed in a beaker and stirred in a water bath at 62℃ for 30min.

[0094] Step S205: After the reaction is complete, the column is washed three times with ultrapure water at room temperature (100 mL each time), and twice with 1 mol / L sodium hydroxide at room temperature (100 mL each time, soaking for 5-10 min each time before filtration). Finally, it is washed with ultrapure water until the pH of the filtrate is neutral, thus obtaining the OH- type high-capacity superhydrophilic ion chromatography column packing.

[0095] In this comparative example, a sufficient amount of diepoxy reagent was added at once, and multiple competing reactions occurred simultaneously in the reaction system: (1) Chain growth and branching: After methylamine reacts with BDDGE to generate secondary amine, due to the excess of BDDGE, the secondary amine can continue to react with multiple BDDGE molecules to form a branched structure instead of the expected linear long chain; (2) Inter-chain crosslinking: The epoxy group at the end of the generated long chain reacts with the tertiary amine group (or unreacted secondary amine) inside another long chain to form a crosslink bond, and the crosslinking reaction has already started in the long chain generation stage and cannot be separated; (3) Self-polymerization reaction: BDDGE molecules undergo ring-opening self-polymerization under amine catalysis to form polyether segments, consuming a large amount of epoxy groups and reducing the effective reaction with amine groups; (4) Premature consumption of terminal epoxy groups: The epoxy groups at the end of the long chain are consumed by other amine groups or self-polymerized BDDGE in the system during the generation process and cannot be retained as active sites for subsequent crosslinking. The simultaneous occurrence of the above reactions makes the reaction process difficult to control, resulting in fillers with the following structural defects: irregular long-chain structures, disordered cross-linking networks (locally too dense or too sparse), reduced anchoring efficiency (some long chains cross-link or self-polymerize without being anchored), and low functional group density (a large number of epoxy groups are ineffectively consumed). This leads to a significant reduction in the capacity of the filler column.

[0096] Comparative Example 2

[0097] In this comparative example, step S100 is the same as in Comparative Example 1; the implementation process of step S200 is as follows:

[0098] Step S201: Weigh 3g of the above hydrophilic spheres into a flask, add 16g of ultrapure water, stir thoroughly to disperse, and form a uniform suspension;

[0099] Step S202: Add 0.72g of methylamine and 0.9g of 1,4-butanediol diglycidyl ether (BDDGE) to the suspension, and react for 120min at 62℃ to obtain the reactants;

[0100] Step S203: Filter the reactants obtained in step S202 and wash them repeatedly with ultrapure water until the pH of the filtrate is neutral.

[0101] Step S204: The filter cake obtained by filtration in step S203, 10-15g of ultrapure water, and 1.2g of 30% trimethylamine aqueous solution are placed in a beaker and stirred in a water bath at 62℃ for 30min.

[0102] Step S205: After the reaction is complete, wash the solution three times with ultrapure water at room temperature (100 mL each time), and twice with 1 mol / L sodium hydroxide at room temperature (100 mL each time, soaking for 5-10 min each time before filtration). Finally, wash the solution with ultrapure water until the pH of the filtrate is neutral to obtain OH. - High-capacity, high-capacity, superhydrophilic ion chromatography column packing material.

[0103] In this invention, methylamine reacts with BDDGE to generate long chains with terminal epoxy groups, which are anchored to the surface of the base spheres via ionic bonds. However, due to the absence of a second BDDGE addition, the tertiary amine groups inside the long chains are not converted into quaternary ammonium groups, and there is no covalent cross-linking between the long chains; they are only bonded to the base spheres by ionic bonds. The terminal quaternary ammonium salt functional groups are generated solely from the reaction of trimethylamine with the terminal epoxy groups of the long chains, with each long chain contributing only one quaternary ammonium group. This results in a loose functional layer structure, poor stability, low capacity, and insufficient hydrophilicity in the final filler.

[0104] Comparative Example 3

[0105] A method for preparing ion chromatography column packing material, the implementation process of which is as follows:

[0106] Step S100: Sulfonation treatment of polystyrene-divinylbenzene copolymer (PS-DVB) based spheres;

[0107] Specifically, the implementation process of step S100 is as follows:

[0108] Weigh 15g of PS-DVB-based spheres with a crosslinking degree of 60% and a particle size of 7µm, disperse them in 40mL of dichloroethane, and stir at room temperature for 2 hours to allow the spheres to fully swell. Then, slowly add 80g of concentrated sulfuric acid with a mass fraction of ≥98% while stirring. After the addition is complete, raise the temperature to 90℃ and react at a constant temperature for 6 hours.

[0109] After the reaction was completed, the mixture was allowed to cool naturally to room temperature. The reaction mixture was then slowly poured into 500 mL of ice water for dilution and stirred for 30 min. The mixture was then filtered and then washed with ultrapure water (300 mL each time, at room temperature), 1 mol / L sodium hydroxide (100 mL each time, soaking for 5-10 min each time, at room temperature), methanol (200 mL each time, at room temperature), and ultrapure water (washed until the pH of the filtrate was neutral, at room temperature). Finally, sulfonated spheres with sulfonic acid groups on their surface were obtained.

[0110] Step S200: Synthesis of quaternized nano-latex particles;

[0111] Specifically, the implementation process of step S200 is as follows:

[0112] Step S201: Add 150g of ultrapure water and 0.3g of sodium dodecyl sulfate (SDS) to a three-necked flask and stir to dissolve; then add 8g of styrene, 4g of divinylbenzene (DVB, 80%) and 6g of vinyl benzyl chloride (VBC) in sequence, and stir at 1000rpm at room temperature for 30min to emulsify and form a stable emulsion.

[0113] Step S202: After purging with nitrogen for 30 minutes to remove oxygen, raise the temperature to 75°C; dissolve 0.15g of potassium persulfate (KPS) in 5g of ultrapure water, add it to the reaction system, continue purging with nitrogen, and react at a constant temperature for 8 hours;

[0114] Step S203: After the reaction is complete, cool to room temperature and filter with a 200-mesh filter cloth to remove the aggregates, and obtain a chloromethyl nano-latex dispersion;

[0115] Step S204: Take 100g of the above latex dispersion (containing about 8g of latex solids), add 20g of 30% trimethylamine aqueous solution, and stir and react for 20h under a water bath at 45℃ to convert the chloromethyl group on the surface of the latex particles into quaternary ammonium group;

[0116] Step S205: After the reaction is complete, centrifuge and wash at 10,000 rpm for 20 min, discard the supernatant, add ultrapure water to redisperse, and repeat centrifugation and washing 3 times; finally, redisperse the purified quaternized nano-latex particles in ultrapure water to prepare a suspension with a solid content of 5% for later use.

[0117] Step S300: Agglomeration process;

[0118] Specifically, the implementation process of step S300 is as follows:

[0119] Step S301: Weigh 10g of the sulfonated spheres obtained in step S100, add 200g of ultrapure water, stir and disperse thoroughly to form a uniform suspension;

[0120] Step S302: Under stirring, slowly add 150g of the quaternized nano-latex suspension with a solid content of 5% prepared in step S205 (the dropping speed is controlled at 2-3mL / min). After the addition is completed, continue stirring for 3h so that the latex particles are adsorbed onto the surface of the base spheres through electrostatic attraction.

[0121] Step S303: Filter the reactants obtained in step S302 and wash them repeatedly with ultrapure water 3 times (200 mL each time) to remove unadsorbed free latex particles.

[0122] Step S304: Place the washed filter cake in a vacuum drying oven at 50℃ and dry for 6 hours to obtain latex agglomerated ion chromatography column packing.

[0123] Experimental Example 1: Determination of Ion Exchange Capacity;

[0124] Instruments and materials: Ion chromatograph (with conductivity detector); PEEK column (4.0×250 mm); Saturated solution: 50 mmol / L NaNO3; Activation solution: 1 mol / L NaOH; Eluent: Ultrapure water.

[0125] The experimental procedure is as follows:

[0126] The test packing material was packed into a 4.0×250mm PEEK column using the homogenization method, with a packing material mass of 2.0±0.1g. A 1mol / L NaOH solution was bubbled into the column at a flow rate of 1mL / min for 30 min to convert all ion exchange sites in the packing material into OH groups. - The column was flushed at a flow rate of 1 mL / min until the conductivity detector baseline stabilized (conductivity change ≤ 0.1 μS / min), at which point the initial baseline conductivity value was recorded. The eluent was then replaced with 50 mmol / L NaNO3 solution, and the flow rate was adjusted to 0.5 mL / min. The column was continuously flushed, and the conductivity change of the eluent was monitored in real time using a conductivity detector. As the NaNO3 solution was continuously introduced, NO3... - The ion exchange sites on the chromatographic column are gradually occupied. When the conductivity of the effluent first exceeds 1.01 times the initial baseline value, it indicates that the chromatographic column has begun to break through, that is, the exchange sites are approaching saturation. At this time, the injection volume accumulated from the start of the introduction of NaNO3 solution to the breakthrough point is recorded as the breakthrough volume.

[0127] According to the breakthrough volume V b Given the concentration C of the saturated solution (50 μmol / mL), calculate the column capacity Q (μmol / column) using the following formula. Perform three parallel determinations for each sample group and take the average value. Where:

[0128] Q=C*V b .

[0129] Experiment Example 2: Stability Test;

[0130] Instruments and Materials: Ion chromatograph (with conductivity detector); ion chromatography pump (programmable flow control, with pressure sensor); test column: 4.0 × 250 mm PEEK column, packed with 2.0 ± 0.1 g of the test packing material; saturated solution: 50 mmol / L NaNO3; washing buffer: 50% acetonitrile / water (v / v), 100 mmol / L Na2CO3; activation solution: 1 mol / L NaOH; eluent: ultrapure water.

[0131] The experimental method is as follows:

[0132] Column capacity determination: NaOH solution was bubbled into the column at a flow rate of 1.0 mL / min for 30 min to convert the packing material to OH⁻ type; then ultrapure water was used to flush the column at a flow rate of 1.0 mL / min for 30 min until the conductivity baseline stabilized (conductivity change ≤ 0.1 μS / min); then NaNO₃ solution was continuously bubbled into the column at a flow rate of 0.5 mL / min; the conductivity of the effluent was monitored in real time using a conductivity detector. When the conductivity first exceeded 1.01 times the initial baseline value, the cumulative volume of NaNO₃ solution bubbled in at this point was recorded as the breakthrough volume V. b0 The column capacity is Q0 = C * V b0 .

[0133] (1) Capacity retention rate test:

[0134] Solvent washing: Remove the column, after column capacity determination, from the instrument and wash it continuously with acetonitrile / water solution at a flow rate of 1.0 mL / min (using an external pump) for 100 hours; during the washing process, change the washing solution every 24 hours to ensure stable solvent concentration;

[0135] Capacity retention determination: After rinsing, the column was reinstalled in the ion chromatograph, and the column capacity determination process was repeated. The breakthrough volume was measured to calculate the remaining column capacity Q. t Capacity retention rate = Q t / Q0×100%. Each group of samples was measured in triplicate, and the average value was taken.

[0136] (2) High salt retention rate test:

[0137] Solvent washing: The column that has undergone column capacity determination was flushed with Na2CO3 solution at a flow rate of 1.0 mL / min for 50 hours; the column pressure change was recorded every 12 hours.

[0138] Determination of high salt retention: After rinsing, rinse with ultrapure water at a flow rate of 1.0 mL / min for 30 min to remove residual Na2CO3. Repeat the column capacity determination process and determine the breakthrough volume to calculate the remaining column capacity Q. t Capacity retention rate = Q t / Q0×100%. Each group of samples was measured in triplicate, and the average value was taken.

[0139] (3) Mechanical strength test:

[0140] The chromatographic column was installed in the ion chromatograph, and ultrapure water was introduced at a flow rate of 0.5 mL / min. Equilibration was allowed for 10 min until the column pressure stabilized. Starting at a flow rate of 0.5 mL / min, the stabilized column pressure P1 was recorded. The flow rate was then sequentially increased to 1.0, 1.5, 2.0, 2.5, and 3.0 mL / min, and maintained at each flow rate for 5 min, recording the stabilized column pressures P2, P3, P4, P5, and P6. The column pressure values ​​at each flow rate were recorded, and a pressure-flow rate curve was plotted with flow rate on the x-axis and column pressure on the y-axis. The linear correlation coefficient R between pressure and flow rate was calculated. 2 .

[0141] Experimental Example 3: Determination of Hydrophilicity and Separation Degree

[0142] Instruments and materials: Ion chromatograph (with conductivity detector); Test column: 4.0 × 250 mm PEEK column, packed with 2.0 ± 0.1 g of the test packing material; Eluent: 40 mmol / L KOH; Activation solution: 1 mol / L KOH; Reagents: KI (analytical grade), NaClO4·H2O (analytical grade), ultrapure water;

[0143] Weigh 0.0105 g of KI (molecular weight 166.0), dissolve it in a small amount of ultrapure water, and make up to 1 L to obtain 8 mg / L of I. ⁻ Standard solution: Weigh 0.0166 g of NaClO4·H2O (molecular weight 138.5), dissolve in a small amount of ultrapure water, and dilute to 1 L to obtain a 12 mg / L NaClO4 solution. ⁻ Standard solutions; weigh out I⁻ standard solution ClO₄ - Equal volumes of standard solutions are mixed to obtain a mixed standard solution.

[0144] Experimental methods:

[0145] Install the chromatographic column in the ion chromatograph, and pass KOH solution through it at a flow rate of 1 mL / min. Equilibrate for 30 min to convert all ion exchange sites in the packing material to the OH⁻ form.

[0146] Switch to KOH eluent and rinse the column at a flow rate of 1.0 mL / min until the conductivity detector baseline is stable (conductivity change ≤ 0.1 μS / min). Record the initial baseline conductivity value at this point.

[0147] (1) I - Symmetry factor determination:

[0148] Injection I - Inject 25 μL of a single standard solution and start the chromatographic run. Locate the I- peak on the chromatogram and read the following parameters: peak front width a (min) at 10% peak height, peak back width b (min) at 10% peak height, and retention time t. R (min), calculate the symmetry factor: As = b / a.

[0149] (2) Resolution determination:

[0150] Inject the mixed standard solution at a volume of 25 μL, start the chromatographic run, and read the following parameters from the chromatogram: I - Retention time t R1 ClO4 - Retention time t R2 I-baseline peak width W1, ClO4 - The baseline peak width W2 is used to calculate the separation degree using the following formula: Rs = 2 * (t R2 -t R1 ) / W1+W2.

[0151] Table 3: Experimental Results

[0152]

[0153] As shown in Table 3, the column capacities of Examples 1-12 are significantly higher than those of the prior art. This is because the present invention utilizes a dual quaternization mechanism, with each anchored long chain contributing multiple quaternary ammonium groups, and the crosslinking network introduces additional polyether segments to further increase functional sites. The capacity retention rates of Examples 1-12 after washing with organic solvents and high salt are all >90%, indicating that the covalent crosslinking network firmly fixes the functional layer and is resistant to erosion. In Examples 1-12, R² is ≥0.994, indicating a uniform multilayer network structure, high particle mechanical strength, and excellent pressure-flow rate linearity. In Examples 1-12, the resolution is 1.90-2.15 (all ≥1.5), and the symmetry factor is 0.97-1.04 (close to 1, with symmetrical peak shape), proving that the superhydrophilic layer completely suppresses hydrophobic interactions.

[0154] In Example 13, an excess of anchored tertiary amine groups resulted in some long chains failing to anchor due to insufficient sulfonic acid groups. These groups were lost during washing, leading to a decrease in the actual functional group density, low anchoring efficiency, fewer crosslinking points, and a loose network structure. This resulted in lower column capacity and decreased stability. In Example 14, insufficient tertiary amines resulted in fewer anchoring points for long chains, and some sulfonic acid groups remained uncovered. Subsequent crosslinking could not fully develop, leading to low coverage of the multilayer network, exposed hydrophobic sites, reduced hydrophilicity, and decreased separation.

[0155] In Example 15, when the first bisepoxy reagent is in excess, in addition to generating the target long chain, epoxy groups may undergo self-polymerization or premature cross-linking with the tertiary amine groups inside the already generated long chain, forming a locally branched structure. This hinders subsequent orderly cross-linking, resulting in an uneven network, decreased column pressure stability, and reduced hydrophilicity. In Example 16, excess amine reagent reacts with both ends of the bisepoxy reagent to generate a closed-ring structure (the two ends of the same molecule react with two amine groups to form a ring), instead of a linear long chain. The closed-ring structure cannot be effectively anchored and cross-linked, leading to a decrease in functional layer density, resulting in decreased capacity and poorer stability.

[0156] In Example 17, insufficient second bisepoxy reagent led to a lack of crosslinking agent, preventing sufficient crosslinking between long chains and resulting in a discontinuous network that relied mainly on ionic bonds for maintenance. This resulted in reduced column capacity and stability. In Example 18, when the second bisepoxy reagent was in excess, the excess epoxy groups reacted further with the already generated quaternary ammonium groups to form excessive crosslinking, blocking the network channels and reducing the accessibility of functional groups. Although the column capacity remained high, the resolution decreased.

[0157] In Example 19, the tertiary amine reagent had insufficient tertiary amine groups, resulting in incomplete formation of terminal quaternary ammonium groups, a reduction in functional sites, decreased column capacity, and decreased resolution. In Example 20, excess tertiary amine adsorbed within the network was difficult to elute completely, affecting the ion exchange environment and reducing resolution.

[0158] In Comparative Example 1, when a sufficient amount of bisepoxy reagent was added at once, the amine and the bisepoxy reagent underwent multiple reactions. Crosslinking and chain growth occurred simultaneously and were uncontrollable, forming highly branched clumps with uneven crosslinking density. These clumps were difficult to anchor uniformly on the surface of the base spheres. A large number of epoxy groups were consumed in the disordered crosslinking, reducing the effective functional groups and resulting in a decrease in column capacity, capacity retention rate, and hydrophilicity.

[0159] In Comparative Example 2, there was no cross-linking reaction, and the long chains were only anchored to the surface of the base spheres through ionic bonds. There were no covalent connections between the long chains, and the ionic bonds were easily destroyed by the high-salt eluent, resulting in a decrease in column capacity, capacity retention rate, and hydrophilicity.

[0160] Comparative Example 3 is a latex agglomeration type filler. The functional layer adheres to the substrate surface solely through electrostatic adsorption (ionic bonding), without chemical bonding. The monolayer adsorption of latex particles results in limited functional sites, and the hydrophobic surface of the substrate is not completely covered. This leads to low column capacity, poor stability, and poor hydrophilicity. Figure 1 The chromatogram shows severe tailing and insufficient separation.

[0161] The sources of the reagents used in this invention are shown in Table 4 below;

[0162] Table 4: Reagent Sources and Specifications

[0163]

[0164] The present invention can be well implemented according to the above embodiments. It is worth noting that, based on the above structural design, even if some non-substantial modifications or refinements are made to the present invention to solve the same technical problem, the essence of the technical solution adopted is still the same as that of the present invention, and therefore it should also be within the protection scope of the present invention.

Claims

1. A high-capacity, superhydrophilic ion chromatography column packing material, characterized in that, Its structure is as follows: Using styrene-divinylbenzene copolymer as the base sphere, sulfonic acid groups are covalently grafted onto the benzene rings on its surface to form a hydrophilic layer and ionic bonding anchors; The sulfonic acid group is bonded to a long molecular chain containing a tertiary amine group via ionic bonds; The long molecular chain is generated by the reaction of an amine nucleophile with a first diepoxy reagent, and the long molecular chain contains a tertiary amine group. The tertiary amine group at one end of the long molecular chain forms an ionic bond with the sulfonic acid group on the surface of the base sphere, anchoring the long chain to the surface of the base sphere. The epoxy group at the end of the long molecular chain undergoes a ring-opening reaction with a second diepoxy reagent or its hydrolysis product to form cross-linking bonds and construct a multilayer network structure. One epoxy group of the second diepoxide reagent undergoes a nucleophilic reaction with the tertiary amine group in the anchored long molecular chain to generate a quaternary ammonium group; the other epoxy group of the second diepoxide reagent reacts with a tertiary amine nucleophile to generate a quaternary ammonium salt functional group, which is denoted by an OH group. - It exists in a form that serves as an active site for ion exchange; The nucleophiles for amines are methylamine, ammonia, ethylamine, ethanolamine, diethanolamine, dimethylamine, or other primary or secondary amines.

2. The high-capacity superhydrophilic ion chromatography column packing material according to claim 1, characterized in that, Tertiary amine nucleophiles include trimethylamine, tetramethylmethyldiamine, tetramethylethylenediamine, tetramethylpropanediamine, tetramethylpropanoldiamine, tetramethylbutanediamine, or 1,3-diamino-2-propanol.

3. The high-capacity superhydrophilic ion chromatography column packing material according to claim 1, characterized in that, The bisepoxy reagent is 1,4-butanediol diglycidyl ether, ethylene glycol diglycidyl ether, glycerol diglycidyl ether, or 1,6-hexanediol diglycidyl ether.

4. A method for preparing a high-capacity superhydrophilic ion chromatography column packing material, used to prepare the packing material according to any one of claims 1-3, comprising the following steps: Step S100: Hydrophilic treatment of the surface of polystyrene-divinylbenzene copolymer-based spheres; Weigh out PS-DVB-based spheres with a crosslinking degree of 60%, disperse them in an isopropanol aqueous solution, and sonicate and filter. Transfer the filter cake obtained after filtration to a beaker, add glacial acetic acid and stir at low speed to disperse evenly. Then add methanesulfonic acid and continue stirring to mix evenly. Let the mixture stand at room temperature to react. After the reaction is complete, dilute with ultrapure water and filter. Then filter with ultrapure water, sodium hydroxide, methanol and ultrapure water respectively to finally obtain hydrophilic spheres containing methanesulfonic acid groups. Step S200: Synthesis of quaternary ammonium salt functional groups in multilayer network structures; Hydrophilic spheres were thoroughly dispersed in ultrapure water to form a homogeneous suspension. An amine nucleophile and a first diepoxy reagent were added to the suspension, and the mixture was reacted in a water bath to obtain the reactant. The reactant was filtered and repeatedly washed with ultrapure water until the pH of the filtrate was neutral. The washed filter cake was thoroughly dispersed in ultrapure water to obtain a homogeneous suspension, and a second diepoxy reagent was added. The mixture was reacted in a water bath, and after the reaction was complete, it was filtered. The resulting filter cake was mixed with ultrapure water and a tertiary amine nucleophile and stirred in a water bath. After the reaction was complete, the mixture was washed sequentially with ultrapure water, sodium hydroxide, and ultrapure water to obtain OH. - High-capacity superhydrophilic ion chromatography column packing material.

5. The method for preparing a high-capacity superhydrophilic ion chromatography column packing material according to claim 4, characterized in that, The molar ratio of sulfonic acid groups to anchored tertiary amine groups on the surface of the base sphere is 1:2-4.

6. The method for preparing a high-capacity superhydrophilic ion chromatography column packing material according to claim 4, characterized in that, The molar ratio of the amine group of the amine nucleophile to the epoxy group of the first bisepoxide reagent is 1:0.8-1.

2.

7. The method for preparing a high-capacity superhydrophilic ion chromatography column packing material according to claim 4, characterized in that, The molar ratio of the epoxy group of the first bisepoxy reagent to the epoxy group of the second bisepoxy reagent is 1:1.5-3.

8. The method for preparing a high-capacity superhydrophilic ion chromatography column packing material according to claim 4, characterized in that, The molar ratio of the tertiary amine group of the tertiary amine nucleophilic reagent to the epoxy group of the second diepoxide reagent is 1:2.5-3.

5.

9. The method for preparing a high-capacity superhydrophilic ion chromatography column packing material according to claim 4, characterized in that, The mass ratio of PS-DVB-based spheres to methanesulfonic acid is 1:1.8-2.5.

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