Sulfonic strong cation exchange chromatography stationary phase, its preparation method and application

Abstract

The application relates to a sulfonic strong cation exchange chromatography stationary phase and a preparation method and application thereof, the preparation method comprising the following steps: (1) reacting silica gel with a surface modifier in a solvent to obtain alkenyl functionalized silica gel; (2) performing a sulfonation reaction on the alkenyl functionalized silica gel in step (1) with pyrosulfite solution to obtain the sulfonic strong cation exchange chromatography stationary phase; and the surface modifier comprises an epoxy group and an alkenyl group. The sulfonic strong cation exchange chromatography stationary phase obtained by the application has excellent separation selectivity for 16 kinds of rare earth elements and Fe, U and Th elements, and can be used for macro-preparation of high-purity rare earth and U and Th.

Description

Technical Field

[0001] This invention relates to the field of ion exchange chromatography technology, and in particular to a sulfonic acid-based strong cation exchange chromatography stationary phase, its preparation method, and its application. Background Technology

[0002] Rare earth elements include scandium, yttrium, and fifteen lanthanides. High-purity rare earth compounds are indispensable key raw materials in semiconductors, new energy, and high-end manufacturing. Therefore, developing efficient rare earth separation and purification technologies is of great significance. Among various separation techniques, ion exchange chromatography is considered the preferred method for achieving high-purity single rare earth preparation due to its high resolution and low pollution. It utilizes the difference in affinity between sample ions and exchangeable ions on the chromatographic stationary phase surface to achieve separation. This method plays an irreplaceable role in the separation and purification of charged substances such as metal ions, proteins, and nucleic acids due to its high efficiency and environmental friendliness. The key to this technology depends on the structure and properties of the stationary phase. Among them, sulfonic acid-functionalized silica gel has become a research focus in this field because it combines the excellent mechanical stability of the silica matrix with the strong cation exchange capacity of sulfonic acid groups.

[0003] However, due to the selectivity of existing ion exchange chromatography packing materials, it still faces severe challenges in handling the separation of rare earth elements from all components.

[0004] Currently available sulfonate-based functionalized silica gel packings generally exhibit insufficient selectivity when continuously separating more than ten rare earth elements, resulting in poor separation and failing to meet the requirements for high-purity preparation. Furthermore, some packings suffer from low loading and rapid decline in column efficiency during separation, which severely restricts the practical application of this technology in the precise removal of rare earth impurities.

[0005] In summary, developing a chromatographic packing material capable of efficiently separating multiple rare earth elements is an urgent need in this field. Summary of the Invention

[0006] To address the aforementioned technical problems, this invention provides a sulfonic acid-based strong cation exchange chromatography stationary phase, its preparation method, and its application. The sulfonic acid-based strong cation exchange chromatography stationary phase provided by this invention has a high degree of sulfonic acid modification and exhibits excellent separation selectivity for 16 rare earth elements, as well as Fe, U, and Th elements. It can be used for the large-scale preparation of high-purity rare earth elements, as well as U and Th.

[0007] To achieve this objective, the present invention adopts the following technical solution: In a first aspect, the present invention provides a method for preparing a sulfonic acid-based strong cation exchange chromatography stationary phase, the method comprising the following steps: (1) Reacting silica gel with a surface modifier in a solvent to obtain alkenyl functionalized silica gel; (2) The alkenyl functionalized silica gel described in step (1) is subjected to a sulfonation reaction with a metabisulfite solution to obtain a sulfonic acid-based strong cation exchange chromatography stationary phase; The surface modifier in step (1) includes epoxy groups and alkenyl groups.

[0008] In this invention, alkenyl-functionalized silica gel is first prepared by introducing alkenyl groups onto the silica gel surface through ring-opening of the epoxy groups using a surface modifier containing epoxy and alkenyl groups in a solvent. The alkenyl-functionalized silica gel then undergoes a sulfonation reaction with a metabisulfite solution to prepare a sulfonic acid-based strong cation exchange chromatography stationary phase. The obtained sulfonic acid-based strong cation exchange chromatography stationary phase exhibits excellent separation selectivity for 16 rare earth elements and Fe, U, and Th elements, and can be used for the large-scale preparation of high-purity rare earth elements and U and Th.

[0009] As a preferred technical solution of the present invention, the surface modifier in step (1) has the structural formula shown in Formula 1: Formula 1 R includes alkyl chains with 0-10 carbon atoms, alkyl chains with 1-10 carbon atoms containing ether bonds, alkyl chains with 1-10 carbon atoms containing benzene rings, or alkyl chains with 1-10 carbon atoms containing both benzene rings and ether bonds.

[0010] In this invention, the alkyl chains containing benzene rings with 1-10 carbon atoms and the alkyl chains containing benzene rings and ether bonds with 1-10 carbon atoms do not include the 6 carbon atoms of the benzene ring with 1-10 carbon atoms.

[0011] Preferably, the surface modifier in step (1) includes any one of allyl glycidyl ether, 3,4-epoxy-1-butene, 1,2-epoxy-5-hexene, or 1,2-epoxy-7-octene.

[0012] As a preferred embodiment of the present invention, the metabisulfite includes sodium metabisulfite.

[0013] Preferably, the solvent in step (1) includes anhydrous toluene or anhydrous xylene.

[0014] Preferably, in step (1), triethylamine is added to the solvent at a volume ratio of 0.1%-5%, for example, it can be 0.1%, 0.5%, 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5% or 5%, but it is not limited to the listed values. Other unlisted values ​​within the above range are also applicable.

[0015] Preferably, the solvent of the metabisulfite solution includes water or a water-alcohol mixture.

[0016] Preferably, the volume ratio of water to alcohol in the water-alcohol mixture is (3-5):(1-2), for example, it can be 3:1, 3:2, 4:1, 4:2, 5:1 or 5:2, but it is not limited to the listed values. Other unlisted values ​​within the above range are also applicable.

[0017] Preferably, the alcohol in the water-alcohol mixture includes methanol and / or ethanol.

[0018] As a preferred technical solution of the present invention, the amount of surface modifier used in step (1) is 0.002-0.03 mol / g silica gel, for example, it can be 0.002 mol / g silica gel, 0.003 mol / g silica gel, 0.005 mol / g silica gel, 0.008 mol / g silica gel, 0.01 mol / g silica gel, 0.015 mol / g silica gel, 0.02 mol / g silica gel, 0.025 mol / g silica gel or 0.03 mol / g silica gel, but is not limited to the listed values. Other unlisted values ​​within the above range are also applicable.

[0019] Preferably, the reaction temperature in step (1) is 60-120℃, for example, it can be 60℃, 65℃, 70℃, 75℃, 80℃, 85℃, 90℃, 95℃, 100℃, 105℃, 110℃, 115℃ or 120℃, and the reaction time is 12-48h, for example, it can be 12h, 14h, 16h, 18h, 20h, 22h, 24h, 26h, 28h, 30h, 32h, 34h, 36h, 38h, 40h, 42h, 44h, 46h or 48h, but it is not limited to the listed values, and other unlisted values ​​within the above range are also applicable.

[0020] Preferably, the liquid-to-solid ratio of the alkenyl functionalized silica gel to the metabisulfite solution in step (2) is 1g:(5-20)mL, for example, it can be 1g:5mL, 1g:7mL, 1g:10mL, 1g:12mL, 1g:15mL, 1g:17mL or 1g:20mL, but is not limited to the listed values. Other unlisted values ​​within the above range are also applicable. Preferably, the concentration of the metabisulfite solution in step (2) is 0.1-3mol / L, for example, it can be 0.1mol / L, 0.5mol / L, 1.0mol / L, 1.5mol / L, 2.0mol / L, 2.5mol / L or 3.0mol / L, but is not limited to the listed values. Other unlisted values ​​within the above range are also applicable.

[0021] Preferably, the sulfonation reaction temperature in step (2) is 50-100℃, for example, it can be 50℃, 55℃, 60℃, 65℃, 70℃, 75℃, 80℃, 85℃, 90℃, 95℃, or 100℃, and the sulfonation reaction time is 12-48h, for example, it can be 12h, 14h, 16h, 18h, 20h, 22h, 24h, 26h, 28h, 30h, 32h, 34h, 36h, 38h, 40h, 42h, 44h, 46h, or 48h, but it is not limited to the listed values. Other unlisted values ​​within the above range are also applicable.

[0022] As a preferred technical solution of the present invention, step (1) further includes a pretreatment step before the reaction, the pretreatment step including: activating the silica gel with acid to obtain activated silica gel.

[0023] Preferably, the acid includes hydrochloric acid.

[0024] Preferably, the pore size of the silicone is 70-200 Å, for example, it can be 70 Å, 80 Å, 90 Å, 100 Å, 120 Å, 140 Å, 160 Å, 180 Å or 200 Å, but is not limited to the listed values. Other unlisted values ​​within the above range are also applicable.

[0025] Preferably, the particle size of the silica gel is 1-20 μm, for example, it can be 1 μm, 1.5 μm, 1.8 μm, 2 μm, 3 μm, 4 μm, 5 μm, 6 μm, 7 μm, 8 μm, 9 μm, 10 μm, 11 μm, 12 μm, 13 μm, 14 μm, 15 μm, 16 μm, 17 μm, 18 μm, 19 μm or 20 μm, but is not limited to the listed values, other unlisted values ​​within the above range are also applicable.

[0026] As a preferred technical solution of the present invention, step (1) further includes a first washing and drying step after the reaction.

[0027] Preferably, the solvent used for the first washing includes any one of toluene, ethanol, or methanol.

[0028] Preferably, step (2) further includes a second washing and drying step after the sulfonation reaction.

[0029] Preferably, the solvent used for the second washing includes any one of water, methanol, or ethanol.

[0030] Secondly, the present invention provides a sulfonic acid-based strong cation exchange chromatography stationary phase prepared by the preparation method described in the first aspect.

[0031] The sulfonic acid-based strong cation exchange chromatography stationary phase provided by this invention contains sulfonic acid groups, has a strong negative surface charge, and plays a charge exchange role. At the same time, it also contains hydroxyl groups, which have good hydrophilicity and inhibit hydrophobic adsorption, making it very suitable as a cation exchange chromatography stationary phase.

[0032] Thirdly, the present invention provides an application of the sulfonic acid-based strong cation exchange chromatography stationary phase described in the second aspect, wherein the sulfonic acid-based strong cation exchange chromatography stationary phase is used for the separation of rare earth elements, Fe, U or Th.

[0033] Preferably, the sulfonic acid-based strong cation exchange chromatography stationary phase is also used for the preparation of high-purity rare earth elements, U, or Th.

[0034] As a preferred embodiment of the present invention, the method for separating rare earth elements, Fe, U, or Th includes: Ion exchange chromatography is used to separate and analyze rare earth elements, Fe, U or Th, and the sulfonic acid-based strong cation exchange chromatography stationary phase is used in the chromatographic separation process.

[0035] As a preferred embodiment of the present invention, the mobile phase of the ion exchange chromatography includes phase A and phase B, wherein phase A includes... α An aqueous solution of hydroxyisobutyric acid, wherein phase B comprises water.

[0036] Preferably, the ion exchange chromatography employs gradient elution.

[0037] Compared with the prior art, the present invention has at least the following beneficial effects: This invention introduces alkenyl groups onto the surface of silica gel through ring-opening of epoxy groups to obtain alkenyl functionalized silica gel. The sulfonated strong cation exchange chromatography stationary phase obtained by subsequent sulfonation reaction has a high degree of sulfonyl group modification and exhibits excellent separation selectivity for 16 rare earth elements as well as Fe, U, and Th elements. It can be used for the large-scale preparation of high-purity rare earth elements and U and Th. Attached Figure Description

[0038] Figure 1 This is a schematic diagram of the structure of the sulfonic acid-based strong cation exchange chromatography stationary phase prepared in this invention; Figure 2 This is a schematic diagram of the structure of the sulfonic acid-based strong cation exchange chromatography stationary phase prepared in Example 1 of the present invention; Figure 3 This is a chromatographic separation diagram of 16 rare earth elements in the product prepared in Example 1 of this invention; Figure 4 This is a chromatographic separation diagram of 15 rare earth elements in the product prepared in Example 4 of this invention; Figure 5 This is a chromatographic separation diagram of 16 rare earth elements in the product prepared in Example 5 of the present invention; Figure 6 This is a chromatographic separation diagram of 16 rare earth elements in the product prepared in Example 6 of the present invention; Figure 7 This is a chromatographic separation diagram of rare earth elements Sc and Fe, U, and Th elements in the product prepared in Example 5 of this invention. Detailed Implementation

[0039] The technical solution of the present invention will be further described below with reference to the accompanying drawings and specific embodiments. However, the following examples are merely simplified examples of the present invention and do not represent or limit the scope of protection of the present invention. The scope of protection of the present invention is determined by the claims.

[0040] This invention provides a method for preparing a sulfonic acid-based strong cation exchange chromatography stationary phase, the method comprising the following steps: (1) Reacting silica gel with a surface modifier in a solvent to obtain alkenyl functionalized silica gel; (2) The alkenyl functionalized silica gel obtained in step (1) is subjected to a sulfonation reaction with a metabisulfite solution to obtain a sulfonic acid-based strong cation exchange chromatography stationary phase, as shown in the figure. Figure 1 As shown; The surface modifier in step (1) includes epoxy groups and alkenyl groups.

[0041] Example 1 This embodiment provides a method for preparing a sulfonic acid-based strong cation exchange chromatography stationary phase, the preparation method comprising the following steps: 5 g of hydrochloric acid-activated silica gel (pore size 100 Å, particle size 10 μm) and 50 mL of anhydrous toluene were added to a three-necked flask. After mechanical stirring and dispersion, 5 mL of allyl glycidyl ether was slowly added. The mixture was stirred at 60 °C for 24 h. The product was washed successively with toluene and ethanol, and then dried under vacuum at 70 °C to obtain alkenyl-functionalized silica gel. The alkenyl-functionalized silica gel was added to 50 mL of a 0.5 mol / L Na₂S₂O₅ aqueous-ethanol mixed solution (water:ethanol volume ratio = 3:2). The mixture was stirred at 60 °C for 24 h. The product was washed with water and ethanol, and then dried under vacuum at 70 °C to obtain a sulfonic acid-based strong cation exchange chromatography stationary phase, the structure of which is shown below. Figure 2 As shown in the figure, Sil represents silicone.

[0042] Example 2 This embodiment provides a method for preparing a sulfonic acid-based strong cation exchange chromatography stationary phase, the preparation method comprising the following steps: 5 g of hydrochloric acid-activated silica gel (pore size 100 Å, particle size 10 μm) and 50 mL of anhydrous xylene were added to a three-necked flask. After mechanical stirring and dispersion, 10 mL of allyl glycidyl ether was slowly added. The mixture was mechanically stirred at 60 °C for 24 h. The product was washed successively with toluene and ethanol, and then dried under vacuum at 80 °C to obtain alkenyl functionalized silica gel. The alkenyl functionalized silica gel was added to 70 mL of a 1 mol / L Na₂S₂O₅ aqueous-ethanol mixed solution (water:ethanol volume ratio = 5:2). The mixture was mechanically stirred at 50 °C for 24 h. The product was washed with water and ethanol, and then dried under vacuum at 80 °C to obtain a sulfonic acid-based strong cation exchange chromatography stationary phase.

[0043] Example 3 This embodiment provides a method for preparing a sulfonic acid-based strong cation exchange chromatography stationary phase, the preparation method comprising the following steps: 5 g of hydrochloric acid-activated silica gel (pore size 100 Å, particle size 10 μm) and 60 mL of anhydrous toluene were added to a three-necked flask. After mechanical stirring and dispersion, 15 mL of allyl glycidyl ether was slowly added. The mixture was mechanically stirred at 60 °C for 24 h. The product was washed with toluene and ethanol sequentially, and then dried under vacuum at 80 °C to obtain alkenyl-functionalized silica gel. The alkenyl-functionalized silica gel was added to 70 mL of a 2 mol / L Na₂S₂O₅ aqueous-ethanol mixed solution (water:ethanol volume ratio = 5:1). The mixture was mechanically stirred at 60 °C for 24 h. The product was washed with water and ethanol, and then dried under vacuum at 70 °C to obtain a sulfonic acid-based strong cation exchange chromatography stationary phase.

[0044] Example 4 This embodiment provides a method for preparing a sulfonic acid-based strong cation exchange chromatography stationary phase. The only difference from Example 1 is that the silica gel has a pore size of 120 Å and a particle size of 5 μm. All other aspects are the same as in Example 1.

[0045] Example 5 This embodiment provides a method for preparing a sulfonic acid-based strong cation exchange chromatography stationary phase. The only difference from Example 1 is that the silica gel has a pore size of 120 Å and a particle size of 3 μm. All other aspects are the same as in Example 1.

[0046] Example 6 This embodiment provides a method for preparing a sulfonic acid-based strong cation exchange chromatography stationary phase. The only difference from Example 1 is that the silica gel has a pore size of 120 Å and a particle size of 1.8 μm. All other aspects are the same as in Example 1.

[0047] Comparative Example 1 This comparative example provides a method for preparing sulfonic acid functionalized silica ion exchange chromatography packing material, wherein the sulfonating agent used is 1,3-propanesulfonyl lactone. The specific preparation method is carried out in accordance with Example 2 of the specific implementation of CN118454662A (A sulfonic acid functionalized ion exchange chromatography packing material and its application in the separation of rare earth elements), and the sulfonic acid functionalized silica ion exchange chromatography packing material Sil-SCX is obtained.

[0048] Application Examples 1-3 The sulfonic acid-based strong cation exchange chromatographic stationary phases prepared in Examples 1-3 were used as ion exchange chromatographic packing materials and packed into a 4.6 × 250 mm column. The ion exchange chromatography employed gradient elution for the separation and analysis of rare earth mixed samples. Data was acquired at a wavelength of 658 nm using a UV-Vis detector. The results of rare earth element separation and testing in Example 1 are as follows: Figure 3 As shown, Application Examples 2 and 3 also exhibit excellent separation performance; The chromatographic conditions are as follows: Rare earth mixed sample: 16 rare earth elements mixed standard (except Pm), single rare earth concentration 100mg / L; Injection volume: 5 μL; Mobile phases: Phase A: aqueous solution of α-hydroxyisobutyric acid (concentration: 400 mmol / L, pH=3.70); Phase B: water. Elution flow rate: 1.0 mL / min; Post-column derivatization solution: azoarsine III concentration 1.5 × 10⁻⁶ -4 An aqueous solution with a concentration of 0.01 mol / L urea and 0.1 mol / L acetic acid; Post-column derivatization flow rate: 0.6 mL / min; Column temperature: 25℃.

[0049] The gradient elution procedure is shown in Table 1: Table 1 Application Example 4 The sulfonic acid-based strong cation exchange chromatographic stationary phase prepared in Example 4 was used as the packing material in a 4.6 × 250 mm chromatographic column. Gradient elution was employed in the ion exchange chromatography for the separation and analysis of rare earth mixed samples. Data was acquired at a wavelength of 658 nm using a UV-Vis detector. The results of the rare earth element separation test are as follows: Figure 4 As shown; The chromatographic conditions are as follows: Rare earth mixed sample: 15 rare earth elements mixed standard (except Sc and Pm), single rare earth concentration 100 mg / L; all other conditions are the same as in application example 1.

[0050] The gradient elution procedure is shown in Table 2: Table 2 Application Example 5 The sulfonic acid-based strong cation exchange chromatographic stationary phase prepared in Example 5 was packed into a 4.6 × 250 mm chromatographic column as the ion exchange chromatographic packing material. Gradient elution was used for the separation and analysis of rare earth mixed samples. Data was acquired at a wavelength of 658 nm using a UV-Vis detector. The results of the rare earth element separation test are as follows: Figure 5 As shown.

[0051] Except for the gradient elution program, all other chromatographic conditions were the same as in Application Example 1. The gradient elution program is shown in Table 3. Table 3 Application Example 6 The sulfonic acid-based strong cation exchange chromatographic stationary phase prepared in Example 6 was used as the packing material in a 2.1 × 100 mm chromatographic column. Gradient elution was employed in the ion exchange chromatography for the separation and analysis of rare earth mixed samples. Data was acquired at a wavelength of 658 nm using a UV-Vis detector. The results of the rare earth element separation test are as follows: Figure 6 As shown; Except for the chromatographic conditions listed below, all other chromatographic conditions are the same as in Application Example 1, and the gradient elution program is shown in Table 4: Sample: A mixed standard of 16 rare earth elements (excluding Pm), with a single rare earth element concentration of 20 mg / L; Elution flow rate: 0.5 mL / min; Post-column derivatization flow rate: 0.4 mL / min.

[0052] Table 4 Application Example 7 The sulfonic acid-based strong cation exchange chromatographic stationary phase prepared in Example 5 was used for the chromatographic separation of rare earth elements and Fe, U, and Th elements. The chromatographic column used was the same as in Application Example 5; the chromatographic conditions were the same as in Application Example 5; the sample was a mixture of Fe, Sc, U, and Th elements, with a single element concentration of 100 ppm. The results of the rare earth element separation test are as follows: Figure 7 As shown.

[0053] Application Comparative Example 1 The sulfonic acid-functionalized silica gel ion exchange chromatography packing material Sil-SCX prepared in Comparative Example 1 was used for the chromatographic separation of 15 rare earth elements, and the chromatographic conditions were the same as those in Application Example 5.

[0054] Test Example 1 Carbon and sulfur elemental analysis Carbon and sulfur elements were analyzed in the samples prepared in Example 5 and Comparative Example 1, where S% is the percentage of sulfur by mass and C% is the percentage of carbon by mass. The test results are shown in Table 5.

[0055] Table 5 Experimental results show that, compared with Comparative Example 1, the sulfonic acid-based strong cation exchange chromatography stationary phase provided in Example 5 has a higher C and S content, i.e., a higher sulfonic acid content.

[0056] like Figure 3 As shown, when the sulfonic acid-based strong cation exchange chromatography stationary phase provided in Example 1 is used as the ion exchange chromatography stationary phase, the elution order of the 16 rare earth elements is: lutetium (Lu), ytterbium (Yb), thulium (Tm), erbium (Er), holmium (Ho), yttrium (Y), dysprosium (Dy), terbium (Tb), scandium (Sc), gadolinium (Gd), europium (Eu), samarium (Sm), neodymium (Nd), praseodymium (Pr), cerium (Ce), and lanthanum (La). This can achieve the separation of the 16 rare earth elements, and all chromatographic peaks show almost no tailing phenomenon.

[0057] like Figure 4 As shown, when the sulfonic acid-based strong cation exchange chromatography stationary phase provided in Example 4 is used as the ion exchange chromatography stationary phase, the elution order of the 16 rare earth elements is: lutetium (Lu), ytterbium (Yb), thulium (Tm), erbium (Er), holmium (Ho), yttrium (Y), dysprosium (Dy), terbium (Tb), gadolinium (Gd), europium (Eu), samarium (Sm), neodymium (Nd), praseodymium (Pr), cerium (Ce), and lanthanum (La). This can achieve the separation of 15 rare earth elements, and all chromatographic peaks show almost no tailing phenomenon.

[0058] like Figure 5 As shown, when the sulfonic acid-based strong cation exchange chromatography stationary phase provided in Example 5 is used as the ion exchange chromatography stationary phase, the elution order of the 16 rare earth elements is: lutetium (Lu), ytterbium (Yb), thulium (Tm), erbium (Er), scandium (Sc), holmium (Ho), yttrium (Y), dysprosium (Dy), terbium (Tb), gadolinium (Gd), europium (Eu), samarium (Sm), neodymium (Nd), praseodymium (Pr), cerium (Ce), and lanthanum (La). This can achieve the separation of the 16 rare earth elements, and all chromatographic peaks show almost no tailing phenomenon.

[0059] like Figure 6As shown, when the sulfonic acid-based strong cation exchange chromatography stationary phase provided in Example 6 is used as the ion exchange chromatography stationary phase, the elution order of the 16 rare earth elements is: lutetium (Lu), ytterbium (Yb), thulium (Tm), erbium (Er), holmium (Ho), yttrium (Y), dysprosium (Dy), scandium (Sc), terbium (Tb), gadolinium (Gd), europium (Eu), samarium (Sm), neodymium (Nd), praseodymium (Pr), cerium (Ce), and lanthanum (La). This can achieve the separation of the 16 rare earth elements, and all chromatographic peaks show almost no tailing phenomenon.

[0060] like Figure 7 As shown, when the sulfonic acid-based strong cation exchange chromatography stationary phase provided in Example 5 is used as an ion exchange chromatography stationary phase, the elution order of rare earth elements Sc and Fe, Th, and U is: iron (Fe), scandium (Sc), thorium (Th), and uranium (U), which can achieve the separation of rare earth elements Sc and Fe, Th, and U, and all chromatographic peaks show almost no tailing phenomenon.

[0061] When the sulfonic acid functionalized silica gel ion exchange chromatography packing material Sil-SCX prepared in Comparative Example 1 was used for the chromatographic separation of 15 rare earth elements, it failed to achieve baseline separation of most rare earth elements, and its separation effect was far worse than that of the sulfonic acid-based strong cation exchange chromatography stationary phase prepared in Example 5 of this application.

[0062] In summary, the sulfonic acid-based strong cation exchange chromatography stationary phase prepared by this invention has a high degree of sulfonic acid group modification. When used as an ion exchange chromatography stationary phase, it can achieve efficient separation of 16 rare earth elements, as well as the efficient separation of rare earth elements and Fe, U, and Th elements, and can also be used for the large-scale preparation of high-purity rare earth elements and U and Th.

[0063] The applicant declares that the above description is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention fall within the protection and disclosure scope of the present invention.

Claims

1. A method for preparing a sulfonic acid-based strong cation exchange chromatographic stationary phase, characterized in that, The preparation method includes the following steps: (1) Reacting silica gel with a surface modifier in a solvent to obtain alkenyl functionalized silica gel; (2) The alkenyl functionalized silica gel described in step (1) is subjected to a sulfonation reaction with a metabisulfite solution to obtain a sulfonic acid-based strong cation exchange chromatography stationary phase; The surface modifier in step (1) includes epoxy groups and alkenyl groups.

2. The preparation method according to claim 1, characterized in that, The structural formula of the surface modifier mentioned in step (1) is shown in Formula 1: Formula 1 R includes alkyl chains with 0-10 carbon atoms, alkyl chains with 1-10 carbon atoms containing ether bonds, alkyl chains with 1-10 carbon atoms containing benzene rings, or alkyl chains with 1-10 carbon atoms containing both benzene rings and ether bonds. Preferably, the surface modifier in step (1) includes any one of allyl glycidyl ether, 3,4-epoxy-1-butene, 1,2-epoxy-5-hexene, or 1,2-epoxy-7-octene.

3. The preparation method according to claim 1 or 2, characterized in that, The metabisulfite mentioned in step (1) includes sodium metabisulfite; Preferably, the solvent in step (1) includes anhydrous toluene or anhydrous xylene; Preferably, the solvent of the metabisulfite solution in step (1) includes water or a water-alcohol mixture; Preferably, the volume ratio of water to alcohol in the water-alcohol mixture is (3-5):(1-2); Preferably, the alcohol in the water-alcohol mixture includes methanol and / or ethanol.

4. The preparation method according to any one of claims 1-3, characterized in that, The amount of surface modifier used in step (1) is 0.002-0.03 mol / g silica gel; Preferably, the temperature of the reaction in step (1) is 60-120°C, and the reaction time is 12-48 h; Preferably, the liquid-to-solid ratio of the alkenyl functionalized silica gel to the metabisulfite solution in step (2) is 1 g:(5-20) mL; Preferably, the concentration of the metabisulfite solution in step (2) is 0.1-3 mol / L; Preferably, the sulfonation reaction in step (2) is carried out at a temperature of 50-100°C and for a time of 12-48 hours.

5. The preparation method according to any one of claims 1-4, characterized in that, Step (1) further includes a pretreatment step before the reaction, which includes: activating the silica gel with acid to obtain activated silica gel; Preferably, the acid includes hydrochloric acid; Preferably, the pore size of the silicone is 70-200 Å; Preferably, the particle size of the silica gel is 1-20 μm.

6. The preparation method according to any one of claims 1-5, characterized in that, The reaction described in step (1) is followed by a first washing and drying step; Preferably, the solvent used for the first washing includes any one of toluene, ethanol, or methanol; Preferably, step (2) further includes a second washing and drying step after the sulfonation reaction; Preferably, the solvent used for the second washing includes any one of water, methanol, or ethanol.

7. A sulfonic acid-based strong cation exchange chromatographic stationary phase, characterized in that, The sulfonic acid-based strong cation exchange chromatography stationary phase is prepared by the preparation method according to any one of claims 1-6.

8. An application of the sulfonic acid-based strong cation exchange chromatographic stationary phase according to claim 7, characterized in that, The sulfonic acid-based strong cation exchange chromatographic stationary phase is used for the separation of rare earth elements, Fe, U, or Th. Preferably, the sulfonic acid-based strong cation exchange chromatography stationary phase is also used for the preparation of high-purity rare earth elements, U, or Th.

9. The application according to claim 8, characterized in that, The methods for separating rare earth elements, Fe, U, or Th include: Ion exchange chromatography is used to separate and analyze rare earth elements, Fe, U or Th, and the sulfonic acid-based strong cation exchange chromatography stationary phase is used in the chromatographic separation process.

10. The application according to claim 9, characterized in that, The mobile phase of the ion exchange chromatography includes phase A and phase B, wherein phase A includes... α An aqueous solution of hydroxyisobutyric acid, wherein phase B comprises water; Preferably, the ion exchange chromatography employs gradient elution.

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