A hydrophilic anion chromatographic column based on mixed mode separation, its preparation method and application in detection field

Abstract

The application belongs to the field of environmental functional materials and detection technology, and discloses a hydrophilic anion chromatographic column based on mixed mode separation and a preparation method and application in the field of detection thereof. The application takes styrene-divinylbenzene microspheres as a chromatographic column matrix, adopts sulfonation and amination to endow the microspheres with hydrophilic properties, and controls the ion selectivity of the stationary phase through hyperbranched reaction. The application adopts microwave heating to alternately modify the epoxy bond and the polyamine bond of the sulfonated microspheres, and terminates with methylamine to prepare a hydrophilic anion chromatographic stationary phase, and press the hydrophilic anion chromatographic stationary phase into a chromatographic column, and apply the chromatographic column to common ions in a detection sample. Due to the introduction of rich hydroxyl groups by hyperbranched modification and the formation of regular dendritic structures by alternating reaction, under the mixed modes of hydrophilic interaction, network structure and charge exchange, the ion chromatographic column of the application has a shorter retention time of high-valence state ions such as SO4 2‑ , PO4 3‑ than that of low-valence state ions when detecting common anions.

Description

Technical Field

[0001] This invention belongs to the field of environmental functional materials and detection technology, and specifically relates to a hydrophilic anion chromatography column based on mixed-mode separation, its preparation method, and its application in the detection field. Background Technology

[0002] Chromatography is a common separation and analysis method. Based on the different interactions between the stationary phase and the target analyte, a suitable chromatographic column is selected to separate and detect the target analyte in the sample. From the early 20th century to the present, chromatographic technology has undergone more than a century of development, giving rise to various techniques such as gas chromatography, liquid chromatography, ion chromatography, and coupled chromatography, playing a crucial role in the analytical field. Ion chromatography is an important branch of chromatographic technology. In recent years, advancements in ion chromatography columns, delivery pumps, suppressors, detectors, and other accessories have significantly improved the performance of ion chromatographs, leading to their widespread application in environmental monitoring, food analysis, biopharmaceuticals, and other industries.

[0003] With the continuous development of ion chromatography, ion chromatography columns have also become mature commercial products. They can detect and separate various matrices, including anions / cations, small organic molecules, and large biological proteins. Anion chromatography columns are among the most widely used, and the preparation technology of column packing materials involves multiple patents. For example, patent CN201811285091 proposes an ion exchange resin used as the stationary phase of an ion chromatography column, namely a sulfonamide-based anion exchange resin. This resin uses negatively charged substrate particles bonded to a positively charged polymer layer, connecting sulfonamide and amino exchange groups. The retention time of phosphate in the column is controlled by adjusting the pH of the mobile phase. Patent CN201910217754 proposes an anion stationary phase based on a cross-linked hydroxyalkylamine layer and glycidyl ether. It utilizes quaternary ammonium, ether, and hydroxyl-based condensation polymer layers attached to a negatively charged matrix material to prepare the anion stationary phase. The separation performance of this anion stationary phase was verified using haloacetic acid and inorganic anions as separation targets. Patent CN202010229551 discloses a hydrophilic anion exchange chromatographic medium. This anion exchange stationary phase is formed by reacting polyethylene glycol diglycidyl ether with a primary amine on negatively charged matrix particles to form a basic condensation layer. Subsequently, through one or more reaction cycles, one or more alkylamine polymer condensation layers are formed on the basic condensation layer. This anion exchange stationary phase can be used for the detection of fluoride ions, chloride ions, bromide ions, iodide ions, sulfate ions, polysulfide ions, polarizable ions, and perchlorate. Patent CN 200710009869 discloses a formulation and preparation method for a chromatographic column that combines both hydrophilic and reversed-phase ion exchange separation modes. The synthesis method involves polymerizing raw materials in a capillary tube, followed by hydrolyzing the epoxy bonds on the stationary phase surface with an acid or alkali solution to obtain a hydrophilic and reversed-phase ion exchange chromatographic column. This column stationary phase can be used for the detection of aniline compounds, alkaloids, and narcotic drugs.

[0004] Although various types of commercial anion chromatography columns and related patented inventions exist, numerous scholars and institutions continue to conduct in-depth research, hoping to broaden their application areas and reduce manufacturing and detection costs to meet the increasingly complex analytical needs of various industries. Therefore, providing an inexpensive, stable anion chromatography column that meets routine separation requirements remains essential for the development of the ion chromatography industry. Summary of the Invention

[0005] In order to overcome the shortcomings and deficiencies of the existing technology, the primary objective of this invention is to provide a method for preparing hydrophilic anion chromatography column packing material based on mixed-mode separation; the method uses a hyperbranched anion chromatography stationary phase obtained rapidly by microwave-assisted heating.

[0006] Another object of the present invention is to provide a hydrophilic anion chromatography column based on mixed-mode separation prepared by the above preparation method.

[0007] Another object of the present invention is to provide the application of the above-mentioned hydrophilic anion chromatography column based on mixed-mode separation in the field of detection.

[0008] This invention utilizes microwave-assisted heating to perform alternating dendritic modification of sulfonated PS-DVB microspheres (styrene-divinylbenzene microspheres) with epoxy and polyamine bonds, followed by methylamine end-capping, to prepare a hyperbranched anion chromatography stationary phase. The prepared stationary phase is then pressed into a chromatographic column for the detection of common anions in samples. Due to the introduction of abundant hydroxyl groups and the formation of a regular dendritic structure through alternating hyperbranching modification, the ion chromatography column provided by this invention exhibits excellent performance in detecting common anions, particularly SO42-. 2- PO4 3- The retention time of ions with higher valence states is shorter than that of NO2. - ,Br - NO3 - Low-valence ions, etc.

[0009] The objective of this invention is achieved through the following technical solution:

[0010] A method for preparing a hydrophilic anion chromatography column based on mixed-mode separation comprises the following steps: Sulfonated PS-DVB microspheres with an electron-withdrawing layer are dendritic-modified with alternating diepoxy groups and polyamine groups using microwave-assisted heating to obtain initially modified microspheres; the initially modified microspheres are then capped with diepoxy groups and primary amines to finally obtain a hydrophilic stationary phase incorporating a large number of hydroxyl and quaternary ammonium functional groups; the obtained hydrophilic stationary phase is packed into ion chromatography columns of different specifications using ultrasonic homogenization and multiple continuous pressurization methods, thus obtaining the hydrophilic anion chromatography column based on mixed-mode separation.

[0011] The microwave-assisted heating technology uses a microwave power of 100W to 1500W and a heating temperature of 50℃ to 80℃; the microwave-assisted heating uses a stirring speed of 200rpm / min to 800rpm / min and a stirring reaction time of 10min to 60min.

[0012] The sulfonated PS-DVB microspheres with an electron-withdrawing layer are prepared according to the following steps: sulfonating the PS-DVB microspheres with concentrated sulfuric acid of 70% to 99.7% by mass, so that sulfonic acid groups are grafted onto the benzene rings of the microsphere skeleton, forming a hydrophilic negatively charged thin layer on the surface of the microspheres; after centrifugation and washing, sulfonated PS-DVB microspheres with an electron-withdrawing layer are obtained; the ratio of concentrated sulfuric acid to PS-DVB microspheres is 1 mL:1 g to 15 mL:1 g.

[0013] The sulfonation conditions are as follows: at a temperature of 60℃~80℃, with a stirring speed of 200rpm / min~400rpm / min, the sulfonation reaction is carried out for 10min~120min; the centrifugation speed is 5000rpm / min~9000rpm / min; the washing is performed by washing with pure water until the pH value is neutral, followed by washing with ethanol, acetone and ethanol 2~3 times respectively.

[0014] The diepoxy group is provided by 1,4-butanediol diglycidyl ether; the polyamine group is tetraethylenepentamine; the primary amine is methylamine, ethylenediamine or hexamethylenediamine, preferably methylamine, and is prepared as an aqueous solution with a mass percentage concentration of 30% to 40% before use.

[0015] The ultrasonic homogenization is to obtain a stationary phase homogenous slurry by ultrasonic degassing, with an ultrasonic power of 100W to 500W and an ultrasonic time of 10min to 60min; the multiple continuous pressurization method refers to first loading the chromatographic column with pressures of 10MPa, 20MPa, and 25MPa in sequence, and then releasing the pressure with pressures of 25MPa, 20MPa, and 10MPa in sequence.

[0016] A hydrophilic anion chromatography column based on mixed-mode separation, prepared by the above-described method.

[0017] The above-mentioned hydrophilic anion chromatography column based on mixed-mode separation is used in the detection of anions.

[0018] This invention uses 1,4-butanediol diglycidyl ether as a diepoxy intermediate that can be used for ring opening, and tetraethylenepentamine as a long-chain, multi-active-site mediator of amine groups. Under alkaline conditions, the epoxy bonds open and bond with the amine groups to generate a large number of hydrophilic hydroxyl groups, while secondary and tertiary amine groups are also generated.

[0019] The primary amine reagent used in this invention has the characteristics of high basicity and high activity, which enables rapid ring-opening reaction of epoxy bonds, and the capacity of short-chain quaternary amine groups can be flexibly controlled.

[0020] The hydrophilic anion exchange column prepared in this invention exhibits a multi-mode mixed retention mechanism during application, including ion exchange, hydrophobic interactions, and hydration. This is particularly useful for separating conventional anions, such as fluoride ions (F...). - ), chloride ions (Cl) - ), bromide ions (Br) - ), nitrite ions (NO2) - ), nitrate ions (NO3) - ), sulfate ions (SO4) 2- ), phosphate ions (PO4) 3-), bromate ions (BrO3) - ), iodide ions (I) - Sulfate ions (SO4) 2- ), phosphate ions (PO4) 3- The retention time of high-valence ions such as nitrite ions (NO2) is shorter than that of high-valence ions. - ), bromide ions (Br) - ), nitrate ions (NO3) - Low-valence ions such as )

[0021] The principle of this invention:

[0022] This invention first sulfonates the matrix microspheres, then uses microwave radiation as a heating method. Utilizing the principle that polar molecules rotate with microwave vibration in a microwave field due to the molecular dipole moment, and the heat generated by friction is absorbed by the molecules, thus raising their temperature, this accelerates the reaction of amine compounds such as tetraethylenepentamine with the sulfonated microspheres to form polyamine active chains. Taking advantage of the basicity of amine groups, double epoxy bonds are grafted onto the reaction sites, and hydroxyl groups are further introduced after the ring-opening reaction. Ultrasonic dispersion and microwave-assisted heating are used to shorten the synthesis time of the stationary phase, rapidly obtaining a stable ion chromatography stationary phase, thereby shortening the preparation time of the chromatographic column.

[0023] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0024] (1) The anion chromatography column rapidly prepared by the present invention can be effectively applied to the detection of ions.

[0025] (2) The present invention uses ultrasonic dispersion and microwave-assisted heating to improve the reaction rate and quickly prepare anionic stationary phase with regular dendritic branched structure.

[0026] (4) The anion chromatography column provided by this invention, when simultaneously separating common anions, also separates sulfate ions (SO42-). 2- ), phosphate ions (PO4) 3- The retention time of high-valence ions such as nitrite ions (NO2) is shorter than that of high-valence ions. - ), bromide ions (Br) - ), nitrate ions (NO3) - Low-valence ions such as ) Attached Figure Description

[0027] Figure 1 Scanning electron microscope (SEM) images of PS-DVB microspheres (a), sulfonated PS-DVB microspheres (b), and hyperbranched modified stationary phase (c) from Example 1.

[0028] Figure 2 Chromatograms of four ions separated by the ion chromatography column provided in Example 1 under different eluents.

[0029] Figure 3 Chromatograms of seven ions separated by the ion chromatography column provided in Example 1 under different eluents.

[0030] Figure 4 Chromatograms of seven anions at different column temperatures provided in Example 1 using the ion chromatography column.

[0031] Figure 5 The ion chromatography column provided in Example 2 provides chromatograms of separation of 4 and 7 anions.

[0032] Figure 6 The chromatogram of the ion chromatography column provided in Example 3 for detecting seven anions in an actual sample. Detailed Implementation

[0033] The present invention will be further described in detail below with reference to the embodiments and accompanying drawings, but the embodiments of the present invention are not limited thereto.

[0034] Example 1

[0035] The preparation process of a hydrophilic anionic stationary phase specifically includes the following steps:

[0036] (1) First, PS microspheres were prepared: 95% ethanol-water solution was placed in a 250 mL four-necked flask, and PVP dispersant was added; the reaction system under conventional heating was heated to 70 °C to completely dissolve the dispersant; 18 g of styrene (ST) monomer containing the initiator azobisisobutyronitrile (ANBN) was added to it; the system was stirred at 70 °C (250 rpm / min) for 24 h; after the reaction was completed, it was centrifuged (6000 rpm / min, 3 min), and the collected product was dried at 60 °C for 12 h to obtain PS microspheres for later use.

[0037] (2) Preparation of PS-DVB (styrene-divinylbenzene) microspheres: Using the PS microspheres from step (1) as templates, toluene and dibutyl phthalate (DBP) as swelling agents, and sodium dodecyl sulfate (SDS) as surfactants; during the PS activation process, benzoyl peroxide (BPO) initiator was added; in a 250 mL beaker, SDS was added to 100 mL of H2O to form a 0.15 wt% dispersion solution, which served as an emulsifier. The mixture of BPO, DBP, and toluene was added to the above dispersion solution, and the resulting mixture was ultrasonically dispersed (power 500 W, 30 °C, 30 min) to obtain an emulsion. Then, a 500 mL flask was taken, the PS microsphere solution was added, and the obtained emulsion was added. Under conventional heating mode, the mixture was stirred at 30 °C (300 rpm / min) for 10 h; after the reaction was completed, 13.3 mL of ST monomer and an equal volume of DVB crosslinking monomer, as well as 35 mL of 4.28 wt% PVP aqueous solution, were added, and the mixture was allowed to swell for 10 h. The temperature was raised to 70℃ and the reaction was carried out for 4 hours. After the reaction was completed, the product was centrifuged (9000 rpm / min, 5 min), ultrasonically cleaned, and dried in a vacuum drying oven at 80℃ for 12 hours to obtain PS-DVB microspheres.

[0038] (3) Preparation of sulfonated PS-DVB microspheres: Weigh 5g of the PS-DVB microspheres obtained in step (2) and add 20mL of concentrated sulfuric acid (99.7% by mass). Stir at 80℃ for 1h. After the reaction is complete, centrifuge (9000rpm / min, 3min), wash with pure water until the pH value is neutral, and then wash with ethanol, acetone, and ethanol 2-3 times respectively to obtain sulfonated PS-DVB microspheres for later use.

[0039] (4) Preparation of hydrophilic anionic stationary phase: ① Weigh 5.0 g of sulfonated PS-DVB microspheres and place them in a 100 mL four-necked flask. Add 15 mL of 1,4-butanediol diglycidyl ether (BDDGE) and 15 mL of tetraethylenepentamine (TEPA), respectively. ② Place the four-necked flask in a microwave reactor and stir magnetically at 70 °C (500 W) for 30 min. ③ After the reaction is complete, wash the product three times with pure water by centrifugation (9000 rpm / min, 5 min). ④ Then add 10 mL of BDDGE and stir magnetically at 70 °C (500 W) for 15 min. Repeat step ③ by centrifugation and washing. ⑤ Add 10 mL of TEPA and stir magnetically at 70 °C (500 W) for 15 min. Repeat step ③ by centrifugation and washing. ⑥ Repeat steps ④ to ⑤ once. ⑦ Add 10 mL of TEPA. BDDGE was reacted at 70℃ under microwave for 15 min (500W power, magnetic stirring); ⑧ Step ③ was repeated by centrifugation and washing; ⑨ 10 mL of methylamine solution was added to continue the reaction; ⑩ After the reaction was completed, step ③ was repeated by centrifugation and washing to obtain a hydrophilic anionic stationary phase.

[0040] (5) Pressing of anion chromatography column: Prepare an empty column of 4.6 mm × 250 mm. Weigh 4.5 g of the hydrophilic anion stationary phase obtained in step (4). Use pure water (25 mL) as the dispersant. After ultrasonically dispersing and degassing for 20 min, pour it into a homogenizing tank. Use pure water as the eluent and pressurize with N2 program (0→10 MPa→20 MPa→25 MPa). After the eluent exceeds 500 mL, depressurize program (25 MPa→20 MPa→10 MPa→0 MPa) to obtain an ion chromatography column of model 4.6 mm × 250 mm.

[0041] (6) Ion Chromatography Equipment: The ion chromatograph used in this embodiment is a Qingdao Shenghan CIC-D120 ion chromatograph, equipped with a SHY-A-6 suppressor, a conductivity detector, and a SHA-17 autosampler. The scanning electron microscope image of the hydrophilic anion stationary phase prepared in this embodiment is shown below. Figure 1 As shown.

[0042] Results and Discussion: Figure 1 Images a-c in the figures are scanning electron microscope (SEM) images of PS-DVB microspheres, sulfonated PS-DVB microspheres, and a hydrophilic anionic stationary phase, respectively. The results show that the microspheres in this embodiment have uniform diameters and maintain intact surface morphology after a series of chemical reactions.

[0043] The surface elemental analysis (XPS) of the hydrophilic anionic stationary phase prepared in this embodiment is shown in Table 1. As shown in Table 1, compared with PS-DVB microspheres, the S and O elements on the surface of the sulfonated PS-DVB microspheres increased, indicating that the sulfonation reaction successfully introduced sulfonic acid groups. After the hyperbranching reaction, the S element on the surface of the obtained hydrophilic anionic stationary phase decreased and the N element increased, indicating that the hyperbranching reaction introduced N-containing groups. The results show that the expected functional groups were grafted into the hydrophilic anionic stationary phase microspheres.

[0044] Table 1. Surface element content of PS-DVB microspheres, sulfonated PS-DVB microspheres, and stationary phase in Example 1.

[0045]

[0046]

[0047] The ion chromatography column provided in this embodiment was used to investigate the effect on fluoride ions (F⁻) under different eluent, column temperature, and flow rate conditions. - ), chloride ions (Cl) - ), sulfate ions (SO4) 2- ), nitrate ions (NO3) - ) 4 anions and bromide ion (Br) - ), nitrite ions (NO2) - ), phosphate ions (PO4) 3- The separation capabilities of the seven anions are shown in Table 2, and the experimental conditions are as follows: chromatograms are shown in Table 2. Figures 2-4 As shown.

[0048] Table 2 Chromatographic conditions of Example 1

[0049]

[0050] Depend on Figure 2 It can be seen that under different eluent conditions, all four anions were completely separated. With increasing eluent concentration, the retention time of the target analytes decreased, and the retention order of each target analyte was consistent under different eluent systems. Under different concentrations of Na₂CO₃ eluent, the high-valence ions (SO₄²⁻) were... 2- PO4 3- The retention times of all of them are less than those of monovalent ions. Figure 4 At different column temperatures, the chromatographic behavior of the seven ions showed that the retention time decreased overall with increasing temperature, but the elution retention order remained the same, and temperature did not affect the selectivity of the chromatographic column.

[0051] Figure 3 and Figure 4 The results show that, under different column temperatures and eluent conditions, the chromatographic column provided in this embodiment can completely separate seven anions, and SO42-2- PO4 3- The retention time of NO2 is always shorter than that of NO2. - ,Br - NO3 - .

[0052] Example 2

[0053] A rapid preparation process for anionic stationary phases specifically includes the following steps:

[0054] (1) The preparation operations of PS microspheres, PS-DVB microspheres and sulfonated PS-DVB microspheres and hydrophilic anionic stationary phase in the early stage of this embodiment are the same as those in Example 1.

[0055] (2) Pressurization of the anion chromatography column: Prepare a 4.6 mm × 150 mm empty column. Weigh 3.0 g of the hydrophilic anion stationary phase obtained above, use 25 mL of pure water as the dispersant, ultrasonically disperse and degas for 15 min, then pour into a homogenizing tank, use pure water as the eluent, and pressurize using a N2 program (0→10 MPa→20 MPa→25 MPa). After the eluent exceeds 500 mL, depressurize using a program (25 MPa→20 MPa→10 MPa→0 MPa) to obtain a 4.6 mm × 150 mm ion chromatography column.

[0056] (3) Ion chromatograph conditions. The ion chromatograph used in this embodiment is the Qingdao Shenghan Ion CIC-D120 ion chromatograph, equipped with a SHY-A-6 suppressor, a conductivity detector and a SHA-17 autosampler.

[0057] (4) Na2CO3 or Na2CO3-NaHCO3 was used as the eluent during the experiment. The column temperature was 35℃ and the flow rate was 0.7mL / min. The experimental conditions are shown in Table 3.

[0058] Table 3 Chromatographic conditions of Example 2

[0059]

[0060]

[0061] The 150mm chromatographic column provided in this embodiment can completely separate 4 and 7 anions within 18 minutes, as shown in the chromatogram. Figure 5 As shown, compared with the 250 mm column in Example 1, the retention time is shortened, thus improving the detection efficiency. However, the retention order of the target ions is consistent, indicating that the column length does not affect the selectivity for the target ions.

[0062] Example 3

[0063] This embodiment uses the ion chromatography column provided in Example 1 to detect fluoride ions (F) in tap water, surface water, and industrial wastewater. - ), chloride ions (Cl) - ), bromide ions (Br) - ), nitrite ions (NO2) - ), nitrate ions (NO3) - ), sulfate ions (SO4) 2- ), phosphate ions (PO4) 3- The concentration of ) specifically includes the following steps:

[0064] (1) Instrument and method conditions: The ion chromatograph used in this embodiment was a Qingdao Shenghan CIC-D120 ion chromatograph equipped with a SHY-A-6 suppressor, a conductivity detector, and a SHA-17 autosampler. The column temperature was 40℃, the flow rate was 1.0 mL / min, the eluent was 3.6 mmol / L Na2CO3, the injection volume was 25 μL, the column size was 4.6 mm × 250 mm, and the data acquisition time was 30 min. Three parallel samples were prepared for each sample, and the arithmetic mean was taken.

[0065] (2) Sample pretreatment method: Take 10 mL of sample and remove particulate matter with a 0.22 μm aqueous filter membrane. Then take 2.0 mL of the filtered sample and detect the concentration of each ion with an ion chromatograph.

[0066] (3) Detection Results: The experimental chromatograms of the hydrophilic anion immobilizer relative to different samples (surface water, tap water, industrial wastewater) in this embodiment are shown below. Figure 6 As shown in Table 4. The standard curve is shown in Table 5, and the test results are shown in Table 5. After calculation with the standard curve, the F in surface water... - Cl - SO4 2- and NO3 - The concentrations were 0.09 mg / L, 3.12 mg / L, 4.66 mg / L, and 5.16 mg / L, respectively. Tap water contained 0.13 mg / L, 14.11 mg / L, 25.46 mg / L, and 7.70 mg / L of F. - Cl - SO4 2- and NO3 - Ions. Cl- concentrations of 183.07 mg / L, 17.44 mg / L, and 223.77 mg / L were detected in industrial wastewater. - SO4 2- and NO3 - ion.

[0067] Table 4 Standard Curve in Example 3

[0068]

[0069] Table 5. Detection results of surface water, tap water, and industrial wastewater in Example 3 (n=3)

[0070]

[0071] 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, modifications, substitutions, combinations, or simplifications made without departing from the spirit and principle of the present invention shall be considered equivalent substitutions and shall be included within the protection scope of the present invention.

Claims

1. A method for preparing a hydrophilic anion chromatography column based on mixed-mode separation, characterized in that... The following steps are followed: Sulfonated PS-DVB microspheres with an electron-withdrawing layer are modified with alternating diepoxy groups and polyamine groups in a dendritic pattern using microwave-assisted heating technology to obtain initially modified microspheres; then, the initially modified microspheres are capped with diepoxy groups and primary amines to finally obtain a hydrophilic stationary phase with a large number of hydroxyl and quaternary ammonium functional groups. This hydrophilic stationary phase is a hyperbranched anion chromatography stationary phase, which introduces hydroxyl groups and forms a regular dendritic structure through alternating hyperbranching modification; the obtained hydrophilic stationary phase is then packed into ion chromatography columns of different specifications using ultrasonic homogenization and multiple continuous pressurization methods to obtain a hydrophilic anion chromatography column based on mixed-mode separation. The diepoxy group is provided by 1,4-butanediol diglycidyl ether; the polyamine group is tetraethylenepentamine. Anion chromatography column for separating F - Cl - ,Br - NO2 - NO3 - SO4 2- PO4 3- BrO3 - and I - At that time, the high-valence ion SO4 2- and PO4 3- The retention time is shorter than that of low-valence ions NO2. - ,Br - and NO3 - .

2. The preparation method according to claim 1, characterized in that: The microwave-assisted heating technology uses a microwave power of 100 W to 1500 W and a heating temperature of 50℃ to 80℃; the microwave-assisted heating uses a stirring speed of 200 rpm / min to 800 rpm / min and a stirring reaction time of 10 min to 60 min.

3. The preparation method according to claim 1, characterized in that: The sulfonated PS-DVB microspheres with an electron-withdrawing layer are prepared according to the following steps: sulfonating the PS-DVB microspheres with concentrated sulfuric acid of 70%~99.7% by mass, so that sulfonic acid groups are grafted onto the benzene rings of the microsphere skeleton, forming a hydrophilic negatively charged thin layer on the surface of the microspheres; after centrifugation and washing, sulfonated PS-DVB microspheres with an electron-withdrawing layer are obtained; the ratio of concentrated sulfuric acid to PS-DVB microspheres is 1 mL:1 g to 15 mL:1 g.

4. The preparation method according to claim 3, characterized in that: The sulfonation conditions are as follows: at a temperature of 60℃ to 80℃, with a stirring speed of 200 rpm / min to 400 rpm / min, the sulfonation reaction is carried out for 10 min to 120 min; the centrifugation speed is 5000 rpm / min to 9000 rpm / min; the washing is performed by washing with pure water until the pH value is neutral, followed by washing with ethanol, acetone, and ethanol 2 to 3 times respectively.

5. The preparation method according to claim 1, characterized in that: The primary amine is methylamine, ethylenediamine, or hexamethylenediamine, and is prepared as an aqueous solution with a mass percentage concentration of 30% to 40% before use.

6. The preparation method according to claim 1, characterized in that: The primary amine is methylamine.

7. The preparation method according to claim 1, characterized in that: The ultrasonic homogenization is to obtain a stationary phase homogenous slurry by ultrasonic degassing, with an ultrasonic power of 100 W to 500 W and an ultrasonic time of 10 min to 60 min; the multiple continuous pressurization method refers to first packing the chromatographic column with pressures of 10 MPa, 20 MPa, and 25 MPa in sequence, and then depressurizing it with pressures of 25 MPa, 20 MPa, and 10 MPa in sequence.

8. A hydrophilic anion chromatography column based on mixed-mode separation, prepared by the preparation method according to any one of claims 1 to 7.

9. The application of the hydrophilic anion chromatography column based on mixed-mode separation as described in claim 8 in the detection of anions.

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