sp 2 C-covalent organic framework functionalized silicon-based chromatographic stationary phases, their preparation methods and applications
sp2C-COF materials were prepared by Schiff base-mediated aldehyde-alcohol condensation reaction initiated by self-assembled monolayer auxiliary surfaces, which solved the problem of poor stability of imine bond-linked COF materials and achieved efficient separation of geometric isomers.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- NINGXIA UNIVERSITY
- Filing Date
- 2024-06-11
- Publication Date
- 2026-07-24
AI Technical Summary
Existing imine-linked COFs materials have poor stability when used as HPLC stationary phases, are prone to hydrolysis, and cannot adequately separate geometric isomers on traditional C18 columns.
A Schiff base-mediated aldehyde-alcohol condensation reaction initiated by a self-assembled monolayer auxiliary surface was used to form an sp2C covalent organic framework functionalized silicon-based chromatographic stationary phase, which was then loaded onto a silica matrix via C=N bonds to prepare sp2C-COF materials.
It improves the stability of the material and enhances the selective separation capability of geometric isomers, enabling efficient separation of various complex samples in RPLC and HILIC modes.
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Figure CN118491495B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of chromatographic stationary phase technology, specifically to a sp... 2 C covalent organic framework functionalized silicon-based chromatographic stationary phase. Background Technology
[0002] Geometric isomers are a class of chemical isomers formed by the different orientations of the π electron plane within a molecule. They often possess similar polarity, differing only in molecular shape. Because these isomers exhibit significant differences in chemical properties and biological activities, their separation is one of the most challenging problems currently facing us, and solving this task is crucial in fields such as environmental, clinical, and food science.
[0003] High-performance liquid chromatography (HPLC) is one of the most effective techniques for separating isomers, and the quality of the stationary phase with high molecular shape selectivity is crucial for separating geometric isomers. However, long-chain geometric isomer solutes, such as carotenoids and tocopherols, are not always adequately separated on traditional octadecylsilane-based silica gel phases (ODS or C18). Researching and developing novel silica gel-based stationary phases to enhance molecular shape selectivity for geometric isomers has long been a goal for researchers.
[0004] The development of porous materials has provided an opportunity for separation. Currently, common porous materials, such as covalent organic frameworks (COFs), have attracted widespread attention in separation science due to their unique properties, including large specific surface area, regular structure, tunable pore size, ease of functionalization, and good thermal and chemical stability. However, common imine-linked COFs exhibit poor stability as stationary phases in high-performance liquid chromatography (HPLC) and are prone to hydrolysis. Therefore, developing novel COFs materials with higher stability and hydrolysis resistance in HPLC is of great significance for separating geometric isomers. Summary of the Invention
[0005] The technical problem to be solved by the present invention is to provide a sp 2 C18 covalent organic framework functionalized silicon-based chromatographic stationary phases overcome the shortcomings of common imine-linked COFs materials as HPLC stationary phases, such as poor stability and easy hydrolysis; and enhance the selectivity of geometric isomers that cannot be fully separated on traditional C18 columns, thereby achieving the purpose of geometric isomer separation.
[0006] This invention discloses a sp 2 C covalent organic framework functionalized silicon-based chromatographic stationary phase, the sp 2The C-covalent organic framework functionalized silica-based chromatographic stationary phase uses silica gel as a matrix and 2,4,6-trimethyl-1,3,5-triazine and 1,3,5-tris(4-formylphenyl)triazine as raw materials. A Schiff base-mediated aldehyde-alcohol condensation reaction initiated by a self-assembled monolayer auxiliary surface forms the covalent organic framework, which is then supported on the silica gel matrix via C=N bonds. 2 The structure of the C-covalent organic framework functionalized silicon-based chromatographic stationary phase is as follows:
[0007] .
[0008] Preferably, the silica matrix is spherical with a particle size of 5–7 μm, a pore size of 8–15 nm, and a specific surface area of 300 m². 2 g -1 .
[0009] Preferably, the amount of covalent organic framework contained on each gram of the silica matrix is 0.1 to 2.0 g.
[0010] Preferably, the covalent organic framework material contains sp 2 Hybridized C=C groups, sp 2 C-COF material forms a dense micelle-like load layer on the surface of a silica matrix.
[0011] This invention also discloses an sp 2 The method for preparing C-covalent organic framework functionalized silicon-based chromatographic stationary phases includes the following steps:
[0012] (1) Preparation of amino silica gel: Activated spherical silica gel particles are dispersed in anhydrous toluene according to a certain ratio, and then an amino-containing silane coupling agent is added. After stirring under nitrogen protection for 8 to 24 hours, the mixture is cooled to room temperature and filtered. It is then washed three times each with toluene, ethanol and acetone, and dried in a vacuum drying oven to obtain amino silica gel SiO2-NH2.
[0013] (2) sp 2 Synthesis of C-covalent organic framework functionalized silicon-based chromatographic stationary phase: Equal volumes of trimethylbenzene and 1,4-dioxane were mixed to obtain a mixture. 2,4,6-trimethyl-1,3,5-triazine and 1,3,5-tris(4-formylphenyl)triazine were dispersed in the mixed solution to obtain a further mixture. The mixture was then placed in a heat-resistant glass tube equipped with a vacuum valve. Trifluoroacetic acid, acetonitrile, and aminosilicone were subsequently added, and the mixture was sonicated to obtain a homogeneous suspension. The reaction tube was then heated to 150°C under a N2 atmosphere and reacted for 12–72 h. After the reaction, the mixture was cooled to room temperature, washed three times each with tetrahydrofuran and acetone by centrifugation, and dried at room temperature to obtain sp. 2C covalent organic framework functionalized silicon-based chromatographic stationary phase SiO2@sp 2 C-COF.
[0014] Preferably, in step (1):
[0015] The amino-containing silanizing coupling agent is (3-aminopropyl)-triethoxysilane;
[0016] Spherical silica gel particles: anhydrous toluene: silane coupling agent = 1g: (15-25)mL: (1-2)mL;
[0017] The drying process is carried out at a temperature of 60–100℃ for 8–24 hours.
[0018] Preferably, in step (2):
[0019] 2,4,6-Trimethyl-1,3,5-triazine: 1,3,5-tris(4-formylphenyl)triazine: mixture = 1 mol: 1 mol: (18-54) mL;
[0020] Trifluoroacetic acid:acetonitrile:aminosilica gel = (4.0~8.0) mL : (0.5~2.0) mL : (25.0~50.0) mg;
[0021] The mass ratio of the mixture to amino silicone is 2:1;
[0022] The drying time at room temperature is 12–24 hours;
[0023] The heat-resistant glass tube is in a vacuum environment.
[0024] Preferably, the activation treatment in step (1) includes the following steps: dispersing silica particles in HCl solution, heating and refluxing at 120°C for 7 hours, centrifuging and washing with deionized water until neutral pH value, and then drying to obtain activated SiO2.
[0025] Preferably, the concentration of the HCl solution is 3 mol / L, the ratio of silica gel particles to HCl solution is 3 g to 60 mL, the drying temperature is 100 °C, and the drying time is 12 h.
[0026] This invention also discloses an sp 2 The application of C covalent organic framework functionalized silicon-based chromatographic stationary phases, the sp 2 C-covalent organic framework functionalized silicon-based chromatographic stationary phases can be used for high-performance liquid chromatography (HPLC) in reversed-phase chromatography (RPLC) to separate geometric isomers, including tocopherols, carotenoids, diethylstilbestrol, and 1,4-cyclohexanediol; the sp... 2C covalent organic framework functionalized silicon-based chromatographic stationary phases can also separate nucleosides and nucleobases in hydrophilic chromatography (HILIC) mode.
[0027] The reaction principle of this invention: the sp of this invention 2 The preparation method of C covalent organic framework functionalized silicon-based chromatographic stationary phase, step (2) is a two-step reaction. First, the 1,3,5-tris(4-formylphenyl)triazine (TFPT) monomer reacts with amino silica gel (SiO2-NH2) to form a uniform SiO2-NH2-TFPT layer through Schiff base condensation. Then, the monolayer aldehyde groups of the SiO2-NH2-TFPT layer react with 2,4,6-trimethyl-1,3,5-triazine (TMT) through aldol condensation under the catalysis of trifluoroacetic acid to generate sp. 2 C covalent organic framework functionalized silicon-based chromatographic stationary phase, in this step using trifluoroacetic acid as a catalyst, can catalyze both Schiff base condensation and alcohol-aldehyde condensation reactions.
[0028] The beneficial effects of this invention are:
[0029] 1. The synthesized stationary phase, as a chromatographic column, has both RPLC and HILIC chromatographic modes during the separation process, which can make up for the defects and deficiencies of a single chromatographic mode when separating complex samples.
[0030] 2.sp 2 C=C can overcome the problems of instability and poor hydrolysis resistance of common imine-linked COFs materials in HPLC.
[0031] 3.sp 2 C-COF possesses an in-plane π-conjugated, highly ordered, and robust framework structure. Furthermore, it contains hydrophilic covalent triazine groups, hydrophobic benzene rings, and other groups, which can provide various interactions such as hydrophobicity, π-π stacking, hydrogen bonding, and hydrophilicity. This results in the preparation of fixed-relative shape-restricted isomers and geometric isomers exhibiting high selectivity and separation capabilities.
[0032] 4. Compared with other methods of bonding COF to the surface of SiO2 particles, the Schiff base-mediated aldehyde-alcohol polycondensation reaction initiated by the self-assembled monolayer auxiliary surface can control the morphology and thickness of COF particles grown on silica gel. Attached Figure Description
[0033] Figure 1 For the present invention sp 2 Schematic diagram of the structure of a C covalent organic framework functionalized silicon-based chromatographic stationary phase.
[0034] Figure 2 For the present invention sp 2Schematic diagram of the reaction process for preparing C covalent organic framework functionalized silicon-based chromatographic stationary phases.
[0035] Figure 3 For sp 2 XRD pattern of C covalent organic framework functionalized silicon-based chromatographic stationary phase.
[0036] Figure 4 For sp 2 C is the SEM characterization image of the covalent organic framework functionalized silicon-based chromatographic stationary phase.
[0037] Figure 5 For sp 2 C is the thermogravimetric characterization diagram of the covalent organic framework functionalized silicon-based chromatographic stationary phase.
[0038] Figure 6 The chromatogram is for Application Example 1.
[0039] Figure 7 The chromatogram is for application example 2.
[0040] Figure 8 The chromatogram is for application example 3.
[0041] Figure 9 The chromatogram is for application example 4. Detailed Implementation
[0042] To make the technical solution of the present invention easier to understand, the technical solution of the present invention will now be clearly and completely described in conjunction with the accompanying drawings and specific embodiments.
[0043] Example 1:
[0044] sp in this embodiment 2 The method for preparing C-covalent organic framework functionalized silicon-based chromatographic stationary phases includes the following steps:
[0045] (1) Activation treatment of silica particles: According to the ratio of silica particles: HCl solution = 3g: 60mL, the silica particles are dispersed in HCl solution with a concentration of 3mol / L. After heating and refluxing at 120℃ for 7h, the silica particles are washed with deionized water by centrifugation until the pH value is neutral. Then, the silica particles are dried at 100℃ for 12h to obtain activated spherical silica particles SiO2.
[0046] (2) Preparation of amino silica gel: The spherical silica gel particles were dispersed in anhydrous toluene according to the ratio of spherical silica gel particles: anhydrous toluene: silane coupling agent = 1g: 15mL: 2mL. Then (3-aminopropyl)-triethoxysilane was added. After stirring under nitrogen protection for 8 hours, the mixture was cooled to room temperature and filtered. The mixture was washed three times each with toluene, ethanol and acetone. Finally, it was dried in a vacuum drying oven at 60℃ for 24 hours to obtain amino silica gel SiO2-NH2.
[0047] (3) sp 2 Synthesis of C-covalent organic framework functionalized silicon-based chromatographic stationary phase: Equal volumes of trimethylbenzene and 1,4-dioxane were mixed to obtain a solution, followed by the synthesis of 2,4,6-trimethyl-1,3,5-triazine. A mixture of 2,4,6-trimethyl-1,3,5-triazine and 1,3,5-tris(4-formylphenyl)triazine was prepared by dispersing 1,3,5-triazine in a mixed solution at a ratio of 1 mol: 1 mol: 18 mL. The mixture was then placed in a heat-resistant glass tube equipped with a vacuum valve. Trifluoroacetic acid, acetonitrile, and aminosilicone were added at a ratio of 4.0 mL: 2.0 mL: 25.0 mg (the mass ratio of the mixture to aminosilicone was 2:1), and the mixture was sonicated to obtain a homogeneous suspension. The reaction tube was then heated to 150 °C under a nitrogen atmosphere for 12 h. After the reaction, the mixture was cooled to room temperature, washed three times each with tetrahydrofuran and acetone by centrifugation, and dried at room temperature for 12 h to obtain the sp. 2 C covalent organic framework functionalized silicon-based chromatographic stationary phase SiO2@sp 2 C-COF, i.e., sample 1.
[0048] Example 2:
[0049] sp in this embodiment 2 The method for preparing C-covalent organic framework functionalized silicon-based chromatographic stationary phases includes the following steps:
[0050] (1) Activation treatment of silica particles: According to the ratio of silica particles: HCl solution = 3g: 60mL, the silica particles are dispersed in HCl solution with a concentration of 3mol / L. After heating and refluxing at 120℃ for 7h, the silica particles are washed with deionized water by centrifugation until the pH value is neutral. Then, the silica particles are dried at 100℃ for 12h to obtain activated spherical silica particles SiO2.
[0051] (2) Preparation of amino silica gel: The activated spherical silica gel particles were dispersed in anhydrous toluene according to the ratio of spherical silica gel particles: anhydrous toluene: silane coupling agent = 1g: 20mL: 1.5mL. Then (3-aminopropyl)-triethoxysilane was added. After stirring under nitrogen protection for 15h, the mixture was cooled to room temperature and filtered. The mixture was washed three times each with toluene, ethanol and acetone. Finally, it was dried in a vacuum drying oven at 80℃ for 15h to obtain amino silica gel SiO2-NH2.
[0052] (3) sp 2Synthesis of C-covalent organic framework functionalized silicon-based chromatographic stationary phase: Equal volumes of trimethylbenzene and 1,4-dioxane were mixed to obtain a solution, followed by the synthesis of 2,4,6-trimethyl-1,3,5-triazine. 1,3,5-Tris(4-formylphenyl)triazine:mixture = 1 mol:1 mol:35 mL was used to disperse 2,4,6-trimethyl-1,3,5-triazine and 1,3,5-tris(4-formylphenyl)triazine in a mixed solution to obtain a mixture. The mixture was then placed in a heat-resistant glass tube equipped with a vacuum valve. Trifluoroacetic acid, acetonitrile, and aminosilicone were then added at a ratio of 6.0 mL:1.0 mL:35.0 mg, with a mass ratio of the mixture to aminosilicone of 2:1. The mixture was then sonicated to obtain a homogeneous suspension. The reaction tube was then heated to 150 °C under a N2 atmosphere and reacted for 40 h. After the reaction, the mixture was cooled to room temperature, washed three times each with tetrahydrofuran and acetone by centrifugation, and dried at room temperature for 15 h to obtain sp. 2 C covalent organic framework functionalized silicon-based chromatographic stationary phase SiO2@sp 2 C-COF, i.e., sample 2.
[0053] Example 3:
[0054] sp in this embodiment 2 The method for preparing C-covalent organic framework functionalized silicon-based chromatographic stationary phases includes the following steps:
[0055] (1) Activation treatment of silica particles: The silica particles were dispersed in HCl solution with a concentration of 3 mol / L according to the ratio of silica particles: HCl solution = 3 g: 60 mL. After heating and refluxing at 120 °C for 7 h, the silica particles were washed with deionized water by centrifugation until the pH value was neutral. Then, the silica particles were dried at 100 °C for 12 h to obtain activated spherical silica particles SiO2.
[0056] (2) Preparation of amino silica gel: The spherical silica gel particles were dispersed in anhydrous toluene according to the ratio of spherical silica gel particles: anhydrous toluene: silane coupling agent = 1g: 25mL: 1mL. Then (3-aminopropyl)-triethoxysilane was added. After stirring under nitrogen protection for 24h, the mixture was cooled to room temperature and filtered. The mixture was washed three times each with toluene, ethanol and acetone. Finally, it was dried in a vacuum drying oven at 100℃ for 8h to obtain amino silica gel SiO2-NH2.
[0057] (3) sp 2Synthesis of C-covalent organic framework functionalized silicon-based chromatographic stationary phase: Equal volumes of trimethylbenzene and 1,4-dioxane were mixed to obtain a solution, followed by the synthesis of 2,4,6-trimethyl-1,3,5-triazine. 1,3,5-Tris(4-formylphenyl)triazine:mixture = 1 mol:1 mol:54 mL was used to disperse 2,4,6-trimethyl-1,3,5-triazine and 1,3,5-tris(4-formylphenyl)triazine in a mixed solution to obtain a mixture. The mixture was then placed in a heat-resistant glass tube equipped with a vacuum valve. Trifluoroacetic acid, acetonitrile, and aminosilicone were then added at a ratio of 8.0 mL:0.5 mL:50.0 mg (trifluoroacetic acid:acetonitrile:aminosilicone), with a mass ratio of the mixture to aminosilicone of 2:1. The mixture was then sonicated to obtain a homogeneous suspension. The reaction tube was then heated to 150 °C under a N2 atmosphere and reacted for 72 h. After the reaction, the mixture was cooled to room temperature, washed three times each with tetrahydrofuran and acetone by centrifugation, and dried at room temperature for 24 h to obtain sp. 2 C covalent organic framework functionalized silicon-based chromatographic stationary phase SiO2@sp 2 C-COF, i.e., sample 3.
[0058] Table 1 sp 2 Elemental analysis table of C covalent organic framework functionalized silicon-based chromatographic stationary phases
[0059] <![CDATA[SiO2-NH2]]> 1.56 4.61 1.63 <![CDATA[SiO2@sp 2 C-COF]]> 4.13 10.01 2.61
[0060] Application Example 1:
[0061] Using Sample 2 obtained in Example 2, a chromatographic column was prepared, and several polycyclic aromatic hydrocarbon shape-restricted isomers were separated in RPLC mode. Figure 6 The chromatographic separation results were as follows: 1-naphthalene; 2-biphenyl; 3-fluorene; 4-diphenylmethane; 5-phenanthrene; 6-fluoranthene; 7-pyrene; 8-acenaphthene. The results indicate that the chromatographic column prepared using Sample 2 from Example 2 has good separation performance for polycyclic aromatic hydrocarbons. Chromatographic conditions: mobile phase: acetonitrile:water (20:80, v / v); flow rate: 1.0 mL / min; temperature: 30℃; detection wavelength: 254 nm.
[0062] Application Example 2:
[0063] A chromatographic column was prepared using sample 2 obtained in Example 2, and the tocopherol isomers were separated in RPLC mode. Figure 7 The chromatographic separation results showed that the chromatographic column prepared using Sample 2 from Example 2 had a good separation effect on the tocopherol isomers; chromatographic conditions: mobile phase: acetonitrile:water (40:60, v / v); flow rate: 1.0 mL / min; temperature: 20℃; detection wavelength: 254 nm.
[0064] Application Example 3:
[0065] A chromatographic column was prepared using sample 2 obtained in Example 2, and several sulfonamide compounds were separated in RPLC mode. Figure 8 The chromatographic separation results were as follows: 1-sulfadimethylpyrimidine; 2-sulfamethylpyrimidine; 3-sulfathiazole; 4-sulfacetamide; 5-sulfisoxazole; 6-sulfabenzoyl. The results showed that the chromatographic column prepared using Sample 2 from Example 2 had good separation performance for sulfonamide compounds. Chromatographic conditions: mobile phase: acetonitrile:water (40:60, v / v); flow rate: 1.0 mL / min; temperature: 30℃; detection wavelength: 254 nm.
[0066] Application Example 4:
[0067] A chromatographic column was prepared using Sample 2 obtained in Example 2, and several nucleosides and nucleobase compounds were separated in HILIC mode. Figure 9 The chromatographic separation results were as follows: 1-thiourea; 2-cytosine; 3-thymine; 4-inosine; 5-adenosine; 6-guanosine; 7-adenine. The results showed that the chromatographic column prepared using Sample 2 from Example 2 had good separation performance for nucleosides and nucleobase compounds. Chromatographic conditions: mobile phase: acetonitrile:water (80:20, v / v); flow rate: 1.0 mL / min; temperature: 30℃; detection wavelength: 254 nm.
[0068] It should be noted that the embodiments described herein are only some embodiments of the present invention, and not all implementations of the present invention. These embodiments are merely illustrative and are intended only to provide a more intuitive and clear way to understand the content of the present invention, not to limit the technical solutions described herein. All other implementation methods that can be conceived by those skilled in the art without creative effort, as well as other simple substitutions and variations of the technical solutions of the present invention, without departing from the concept of the present invention, are within the protection scope of the present invention.
Claims
1. A kind of sp 2 C covalent organic framework functionalized silicon-based chromatographic stationary phase, characterized in that... The sp 2 The C-covalent organic framework functionalized silica-based chromatographic stationary phase uses silica gel as a matrix and 2,4,6-trimethyl-1,3,5-triazine and 1,3,5-tris(4-formylphenyl)triazine as raw materials. A Schiff base-mediated aldehyde-alcohol condensation reaction initiated by a self-assembled monolayer auxiliary surface forms the covalent organic framework, which is then supported on the silica gel matrix via C=N bonds. 2 The structure of the C-covalent organic framework functionalized silicon-based chromatographic stationary phase is as follows: 。 2. The sp as described in claim 1 2 C covalent organic framework functionalized silicon-based chromatographic stationary phase, characterized in that... The silica matrix is spherical with a particle size of 5–7 μm, a pore size of 8–15 nm, and a specific surface area of 300 m². 2 g -1 .
3. The sp as described in claim 1 2 C covalent organic framework functionalized silicon-based chromatographic stationary phase, characterized in that... The dosage of the covalent organic framework on each gram of the silica matrix is 0.1 to 2.0 g.
4. The sp as described in claim 1 2 C covalent organic framework functionalized silicon-based chromatographic stationary phase, characterized in that... The covalent organic framework contains sp 2 Hybridized C=C groups, sp 2 C-COF material forms a dense micelle-like load layer on the surface of a silica matrix.
5. The sp as described in claim 1 2 A method for preparing C-covalent organic framework functionalized silicon-based chromatographic stationary phases, characterized in that... Includes the following steps: (1) Preparation of amino silica gel: Activated spherical silica gel particles are dispersed in anhydrous toluene according to a certain ratio, and then an amino-containing silane coupling agent is added. After stirring under nitrogen protection for 8 to 24 hours, the mixture is cooled to room temperature and filtered. After washing with toluene, ethanol and acetone three times each, the mixture is dried in a vacuum drying oven to obtain amino silica gel SiO2-NH2. (2) sp 2 Synthesis of C-covalent organic framework functionalized silicon-based chromatographic stationary phase: Equal volumes of trimethylbenzene and 1,4-dioxane were mixed to obtain a mixture. 2,4,6-trimethyl-1,3,5-triazine and 1,3,5-tris(4-formylphenyl)triazine were dispersed in the mixed solution to obtain a further mixture. The mixture was then placed in a heat-resistant glass tube equipped with a vacuum valve. Trifluoroacetic acid, acetonitrile, and aminosilicone were subsequently added, and the mixture was sonicated to obtain a homogeneous suspension. The reaction tube was then heated to 150°C under a N2 atmosphere and reacted for 12–72 h. After the reaction, the mixture was cooled to room temperature, washed three times each with tetrahydrofuran and acetone by centrifugation, and dried at room temperature to obtain sp. 2 C covalent organic framework functionalized silicon-based chromatographic stationary phase SiO2@sp 2 C-COF.
6. A sp as described in claim 5 2 A method for preparing C-covalent organic framework functionalized silicon-based chromatographic stationary phases, characterized in that... In step (1): The amino-containing silanizing coupling agent is (3-aminopropyl)-triethoxysilane; Spherical silica gel particles: anhydrous toluene: silane coupling agent = 1g: (15-25)mL: (1-2)mL; The drying process is carried out at a temperature of 60–100℃ for 8–24 hours.
7. The sp as described in claim 5 2 A method for preparing C-covalent organic framework functionalized silicon-based chromatographic stationary phases, characterized in that... In step (2): 2,4,6-Trimethyl-1,3,5-triazine: 1,3,5-tris(4-formylphenyl)triazine: mixture = 1 mol: 1 mol: (18-54) mL; Trifluoroacetic acid:acetonitrile:aminosilica gel = (4.0~8.0) mL : (0.5~2.0) mL : (25.0~50.0) mg; The mass ratio of the mixture to amino silicone is 2:1; The drying time at room temperature is 12–24 hours; The heat-resistant glass tube is in a vacuum environment.
8. The sp as described in claim 5 2 A method for preparing C-covalent organic framework functionalized silicon-based chromatographic stationary phases, characterized in that... The activation process in step (1) includes the following steps: dispersing silica particles in HCl solution, heating and refluxing at 120°C for 7 hours, centrifuging and washing with deionized water until neutral pH value, and then drying to obtain activated SiO2.
9. The sp as described in claim 8 2 A method for preparing C-covalent organic framework functionalized silicon-based chromatographic stationary phases, characterized in that... The concentration of the HCl solution was 3 mol / L, the ratio of silica gel particles to HCl solution was 3 g to 60 mL, the drying temperature was 100℃, and the drying time was 12 h.
10. A sp as described in claim 1 2 The application of C-covalent organic framework functionalized silicon-based chromatographic stationary phases is characterized by... The sp 2 C-covalent organic framework functionalized silicon-based chromatographic stationary phases can be used for high-performance liquid chromatography (HPLC) in reversed-phase mode to separate geometric isomers, including tocopherols, carotenoids, diethylstilbestrol, and 1,4-cyclohexanediol; the sp... 2 C-covalent organic framework functionalized silicon-based chromatographic stationary phases can also separate nucleosides and nucleobases in hydrophilic chromatographic mode.