Strong-hydrophobicity chromatographic stationary phase modified by octyl-chain-containing covalent triazine skeleton as well as preparation method and application of strong-hydrophobicity chromatographic stationary phase

Abstract

The invention discloses a strong-hydrophobicity chromatographic stationary phase modified by a covalent triazine skeleton containing an octyl chain as well as a preparation method and application of the strong-hydrophobicity chromatographic stationary phase. Activated silica gel is modified by utilizing a silane coupling agent, so that gamma-glycidyl ether oxypropyl trimethoxy is introduced into the surface of the silica gel; and performing in-situ growth of a covalent triazine skeleton layer containing an octyl chain through a Schiff base condensation reaction to prepare the strong-hydrophobicity chromatographic stationary phase. A covalent triazine skeleton containing a hydrophobic octyl chain in the structure is used for modifying the surface of silica gel, and a bonding phase contains a triazine ring, a benzene ring, an octyl chain and an amino group. According to the stationary phase, a hydrophobic long octyl chain is introduced into a bonding unit of CTF, so that the structure, morphology and performance of the CTF are changed, a'flower-on-sphere 'morphology is formed, and the stationary phase has a rigid porous structure, adjustable hydrophilicity / hydrophobicity, a rich pi electron system, strong hydrophobicity and good separation selectivity for non-polar compounds, and can be widely applied to separation of various samples.

Description

Technical Field

[0001] The present invention relates to the technical field of liquid chromatography stationary phases, and in particular, to a strongly hydrophobic chromatographic stationary phase modified with octyl chain covalently bonded triazine framework. Background Art

[0002] In the field of chromatographic separation, hydrophobic stationary phases are particularly important in RPLC and are widely used in the separation and analysis of strongly hydrophobic compounds (such as polycyclic aromatic hydrocarbons, tocopherols, carotenoids). However, traditional hydrophobic stationary phases (such as C 18 bonded silica gels) have problems such as poor chemical stability, complex surface modification, and limited hydrophobic performance. In addition, C 18 has too strong retention for strongly hydrophobic compounds, often requiring high proportions of organic phase for elution, increasing the analysis cost and restricting the application of green chemistry. In recent years, porous organic polymers (such as metal-organic frameworks MOFs, covalent organic frameworks COFs) have attracted attention due to their high specific surface area and tunable pore structures, but problems such as insufficient hydrophobicity, poor hydrothermal stability (especially MOFs are prone to hydrolysis), and harsh synthesis conditions have limited their application in the chromatographic field.

[0003] Covalently bonded triazine frameworks (CTFs) are composed of triazine rings covalently linked to aromatic units, possessing excellent chemical stability, high hydrophobicity, and rich π-electron systems. In theory, they can achieve efficient adsorption and selective separation of hydrophobic substances. However, pure CTF materials have low mechanical strength and non-uniform particle morphology, which easily lead to column bed collapse and increased mass transfer resistance when directly used as stationary phases. Existing technologies have attempted to composite CTF with inorganic carriers (such as silica) to improve its processability, but often face problems such as weak interfacial bonding, non-uniform CTF layers, and easy fragmentation of core-shell structures, and the preparation processes mostly involve high temperature and high pressure or toxic solvents.

[0004] Therefore, it is of great significance to develop a composite stationary phase with high hydrophobicity, high stability, and a green preparation process. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a strongly hydrophobic chromatographic stationary phase modified with octyl chain covalently bonded triazine framework, its preparation method and application. By using SiO2 as a rigid core to provide mechanical support, a dense CTF layer containing octyl chains is in-situ grown on its surface to construct a superhydrophobic surface, which can achieve efficient separation of various complex samples and non-polar compounds while enhancing the chemical stability and separation selectivity of the stationary phase. It overcomes the problems of poor hydrophobic stability of existing silica-based chromatographic stationary phases in high aqueous environments and difficult elution of strongly hydrophobic compounds due to excessive adsorption.

[0006] The present invention provides a strongly hydrophobic chromatographic stationary phase modified with an octyl-chain covalently bonded triazine framework. The stationary phase comprises silica gel, and the silica gel is surface-modified with a covalently bonded triazine framework containing a hydrophobic octyl chain in its structure. The bonded phase of the covalently bonded triazine framework contains triazine rings, benzene rings, octyl chains and amino groups. The structural formula of the stationary phase is:

[0007]

[0008] Preferably, the silica gel has a particle diameter of 5 - 7 μm, a pore diameter of 8 - 14 nm, and a specific surface area of 300 m 2 g -1 。

[0009] Preferably, each gram of the silica gel contains 0.2 - 2.4 mmol of octyl chains, and the wrapping thickness of the covalently bonded triazine framework on the silica gel surface is 50 - 150 nm.

[0010] The present invention also provides a preparation method of a strongly hydrophobic chromatographic stationary phase modified with an octyl-chain covalently bonded triazine framework, comprising the following steps:

[0011] (1) Activation treatment of silica gel: Weigh a certain mass of silica gel and put it into a round-bottom flask, add a hydrochloric acid solution with a concentration of 2 - 3 mol / L, heat to 120 °C and reflux with stirring for 7 - 9 h. After filtration, wash the obtained solid with water until the pH = 6 - 7, and perform drying treatment until constant weight to obtain activated silica gel;

[0012] (2) Modification treatment of silica gel: Under nitrogen protection, add a silane coupling agent and the activated silica gel obtained in step (1) to an organic solvent, react at 100 - 120 °C for 12 - 24 h, filter and separate, wash the obtained solid successively with toluene, ethanol and acetone, and after drying treatment, obtain modified silica gel SiO2-GPTS;

[0013] (3) Aldehyde-amine condensation reaction: Load 1,3,5-tris(4-aminophenyl)triazine and 2,5-bis(octyloxy)terephthalaldehyde into a thick-walled heat-resistant glass flask in sequence, then add acetonitrile and acetic acid solution, and then add the modified silica gel SiO2-GPTS obtained in step (2). Ultrasonically treat the mixture for 5 min to make it uniformly dispersed, slowly stir and react at 45 - 90 °C for 1 - 3 d, then centrifuge and separate at 3000 - 11000 r / min, and wash the obtained solid successively with tetrahydrofuran and ethanol. After drying treatment, obtain a strongly hydrophobic chromatographic stationary phase modified with an octyl-chain covalently bonded triazine framework.

[0014] Preferably, in step (1), the ratio of silica gel to hydrochloric acid solution is (3 - 5) g : (60 - 100) mL, and the concentration of the hydrochloric acid solution is 2 - 3 mol / L.

[0015] Preferably, the silane coupling agent in step (2) is γ-glycidoxypropyltrimethoxysilane; the organic solvent is toluene, acetonitrile or N,N-dimethylformamide; the dosage ratio of activated silica gel, toluene and silane coupling agent is (1-5) g:(20-100) mL:(1.5-7.5) mL.

[0016] Preferably, in step (3), the addition ratio is 1,3,5-tris(4-aminophenyl)-s-triazine: 2,5-bis(octyloxy)terephthalaldehyde: acetonitrile: acetic acid solution: SiO2-GPTS = (0.42-0.70) g:(0.73-1.22) g:(20-60) mL:(0.6-1.8) mL:(1-3) g, and the concentration of the acetic acid solution is 6-12 mol / L.

[0017] Preferably, in step (1), the temperature of the drying treatment is 100-120 °C, and the time of the drying treatment is 8-24 h; in step (2), the temperature of the drying treatment is 80-100 °C, and the time of the drying treatment is 8-24 h; in step (3), the temperature of the drying treatment is 80-100 °C; the time of the drying treatment is 12-24 h.

[0018] The present invention also discloses an application of a strongly hydrophobic chromatographic stationary phase modified with an octyl chain covalent triazine framework, and the stationary phase is applied in the process of high performance liquid chromatography separation.

[0019] Preferably, the stationary phase has an RPLC / HILIC / PALC mixed separation mode, and it has retention and shape selectivity for shape-constrained isomers and positional isomers with different molecular planarity or spatial configurations, and is used for separating non-polar shape-constrained isomers and positional isomers.

[0020] Reaction principle of the present invention: For the preparation method of the strongly hydrophobic chromatographic stationary phase modified with an octyl chain covalent triazine framework of the present invention, first, the silica gel is activated with a hydrochloric acid solution, and then the activated silica gel is modified with a silane coupling agent to introduce γ-glycidoxypropyltrimethoxy on the silica gel surface. Finally, TAPT and DTB are used to in-situ grow a covalent triazine framework layer containing an octyl chain through a Schiff base condensation reaction, and then the strongly hydrophobic chromatographic stationary phase can be prepared. And at a reaction temperature of 45-90 °C, it is ensured that the stationary phase forms a dense "flowers on the sphere" morphology. The stationary phase preparation method provided by the present invention has the characteristics of simple and convenient process.

[0021] The strongly hydrophobic chromatographic stationary phase modified with an octyl-chain covalently linked triazine framework synthesized in the present invention includes silica gel, and uses a covalently linked triazine framework containing a hydrophobic octyl chain to modify the silica gel surface, and the bonded phase contains triazine rings, benzene rings, octyl chains and amino groups. By introducing a hydrophobic long octyl chain into the bonding unit of CTF, the structure, morphology and properties of CTF are changed to form a strongly hydrophobic chromatographic stationary phase with a "flower on a sphere" morphology. Moreover, this stationary phase has a rigid porous structure, adjustable hydrophilicity / hydrophobicity, a rich π-electron system and strong hydrophobicity (water contact angle ≥ 126°), and has good separation selectivity for non-polar compounds, and can be widely used for the separation of various samples.

[0022] Advantages of the present invention: In the present invention, SiO2 is used as a rigid core to provide mechanical support, and a dense CTF layer containing octyl chains is in-situ grown on its surface to construct a superhydrophobic surface, which can achieve efficient separation of a variety of complex samples and non-polar compounds while improving the chemical stability and separation selectivity of the stationary phase. It overcomes the problems of poor hydrophobic stability of existing silica-based chromatographic stationary phases in high-aqueous-phase environments and difficult elution of strongly hydrophobic compounds due to excessive adsorption. The strongly hydrophobic chromatographic stationary phase modified with an octyl-chain covalently linked triazine framework prepared by the present invention has the following characteristics:

[0023] (1) Strong hydrophobicity: The CTF framework contains abundant C elements, a large number of benzene ring structures and hydrophobic octyl chains, making this stationary phase have strong hydrophobicity; it overcomes the problems of poor hydrophobic stability of existing silica-based chromatographic stationary phases in high-aqueous-phase environments and difficult elution of strongly hydrophobic compounds due to excessive adsorption;

[0024] (2) High separation efficiency: Due to the rigid porous structure, designable hydrophilicity / hydrophobicity, rich π-electron system and strong hydrophobicity of CTF, this stationary phase shows high selectivity for non-polar compounds;

[0025] (3) Novel structure: The stationary phase synthesized in the present invention presents a unique "flower on a sphere" morphology;

[0026] (4) Mixed mode: The synthesized stationary phase has multiple separation modes of RPLC / HILIC / PALC, which can make up for the defects and deficiencies of a single chromatographic mode in separating complex samples. Description of the Drawings

[0027] Figure 1 It is a schematic structural diagram of the strongly hydrophobic chromatographic stationary phase modified with an octyl-chain covalently linked triazine framework of the present invention;

[0028] Figure 2 It is an XRD diagram of the strongly hydrophobic chromatographic stationary phase modified with an octyl-chain covalently linked triazine framework of the present invention;

[0029] Figure 3 SEM image of the strongly hydrophobic chromatographic stationary phase modified with octyl-chain covalently linked triazine framework of the present invention;

[0030] Figure 4 N2 adsorption-desorption diagram of the strongly hydrophobic chromatographic stationary phase modified with octyl-chain covalently linked triazine framework of the present invention;

[0031] Figure 5 Water contact angle diagram of the strongly hydrophobic chromatographic stationary phase modified with octyl-chain covalently linked triazine framework of the present invention;

[0032] Figure 6 Separation chromatogram of polycyclic aromatic hydrocarbons;

[0033] Figure 7 Chromatogram of shape-restricted isomers of tocopherol;

[0034] Figure 8 Chromatogram of shape-restricted isomers of carotenoids;

[0035] Figure 9 Chromatogram of position isomers of diethylbenzene;

[0036] Figure 10 Chromatogram of position isomers of nitroaniline;

[0037] Figure 11 Chromatogram of position isomers of dichlorobenzene. Detailed implementation manners

[0038] In order to make the technical solution of the present invention easier to understand, the technical solution of the present invention will be clearly and completely described below in a specific embodiment manner in combination with the accompanying drawings.

[0039] Example 1:

[0040] The strongly hydrophobic chromatographic stationary phase modified with octyl-chain covalently linked triazine framework in this example includes the following steps:

[0041] (1) Silica gel activation treatment: Weigh 3 g of silica gel and put it into a round-bottom flask, add 60 mL of hydrochloric acid solution with a concentration of 2 mol / L, heat to 120 °C and reflux with stirring for 7 h, filter, wash the obtained solid with water until the pH = 6, and dry it at 100 °C for 24 h until constant weight to obtain activated silica gel;

[0042] (2) Silica gel modification treatment: Under nitrogen protection, add 1.5 mL of silane coupling agent and 1 g of the obtained dry activated silica gel to 20 mL of toluene organic solvent, react at 100 °C for 12 h, filter, wash successively with toluene, ethanol, and acetone, and dry the obtained solid at 80 °C for 24 h to obtain modified silica gel SiO2-GPTS;

[0043] (3) Aldehyde-amine condensation reaction: Take 0.42 g of TAPT and 0.73 g of DTB, and successively load them into a thick-walled heat-resistant glass flask. Then add 20 mL of acetonitrile and 0.6 mL of acetic acid solution with a concentration of 6 mol / L. Then add 1 g of modified silica gel SiO2-GPTS. Ultrasonically treat the mixture for 5 min to make it evenly dispersed. Slowly stir and react at 45 °C for 1 day. Then centrifuge at 3000 r / min, and successively wash with THF and C2H5OH, and dry at 80 °C for 24 h to obtain stationary phase I.

[0044] Example 2:

[0045] The strongly hydrophobic chromatographic stationary phase modified with octyl-chain covalently bonded triazine framework in this example includes the following steps:

[0046] (1) Silica gel activation treatment: Weigh 4 g of silica gel and put it into a round-bottom flask. Add 80 mL of hydrochloric acid solution with a concentration of 2.5 mol / L, heat to 120 °C and reflux with stirring for 9 h. After filtration, wash the obtained solid with water until the pH = 6.5, and dry at 110 °C for 16 h to constant weight to obtain activated silica gel;

[0047] (2) Silica gel modification treatment: Under nitrogen protection, add 4.5 mL of silane coupling agent and 3 g of the obtained dry activated silica gel to 60 mL of toluene organic solvent. React at 110 °C for 18 h, filter, and successively wash with toluene, ethanol, and acetone. Dry the obtained solid at 90 °C for 16 h to obtain modified silica gel SiO2-GPTS;

[0048] (3) Aldehyde-amine condensation reaction: Take 0.55 g of TAPT and 0.90 g of DTB, and successively load them into a thick-walled heat-resistant glass flask. Then add 40 mL of acetonitrile and 1.2 mL of acetic acid solution with a concentration of 9 mol / L. Then add 2 g of modified silica gel SiO2-GPTS. Ultrasonically treat the mixture for 5 min to make it evenly dispersed. Slowly stir and react at 60 °C for 2 days. Then centrifuge at 11000 r / min, and successively wash with THF and C2H5OH, and dry at 100 °C for 24 h to obtain stationary phase II.

[0049] Example 3:

[0050] The strongly hydrophobic chromatographic stationary phase modified with octyl-chain covalently bonded triazine framework in this example includes the following steps:

[0051] (1) Silica gel activation treatment: Weigh 5 g of silica gel and put it into a round-bottom flask. Add 100 mL of hydrochloric acid solution with a concentration of 3 mol / L, heat to 120 °C and reflux with stirring for 9 h. After filtration, wash the obtained solid with water until the pH = 7, and dry at 120 °C for 8 h to constant weight to obtain activated silica gel;

[0052] (2) Silica gel modification treatment: Under nitrogen protection, 7.5 mL of silane coupling agent and 5 g of the obtained dry activated silica gel were added to 100 mL of toluene organic solvent, and the reaction was carried out at 120 °C for 24 h. After filtration, it was washed successively with toluene, ethanol, and acetone, and the obtained solid was dried at 100 °C for 8 h to obtain modified silica gel SiO2-GPTS;

[0053] (3) Aldehyde-amine condensation reaction: 0.70 g of TAPT and 1.22 g of DTB were successively loaded into a thick-walled heat-resistant glass flask, then 60 mL of acetonitrile and 1.8 mL of acetic acid solution with a concentration of 12 mol / L were added, and then 3 g of modified silica gel SiO2-GPTS was added. The mixture was ultrasonically treated for 5 min to make it evenly dispersed, and the reaction was slowly stirred at 90 °C for 3 d. Then it was centrifuged at 11000 r / min and washed successively with THF and C2H5OH, and dried at 100 °C for 24 h to obtain stationary phase III.

[0054] The structure of the strongly hydrophobic chromatographic stationary phase product modified with octyl-chain covalently linked triazine framework prepared by the present invention is as Figure 1 shown.

[0055] As Figure 2 shown, the synthesized novel CTF containing octyl chain has a strong diffraction peak at 2.74°, and relatively weak peaks appear at 4.73°, 5.47°, 7.26° and 25.60°, corresponding to the (100), (110), (200), (210), (101) crystal planes of the P6 / m space group respectively. By comparing the XRD curves of SiO2-GTPS and SiO2@CTF stationary phases, it can be seen that after grafting SiO2-GTPS to the novel CTF containing octyl chain, the prepared SiO2@CTF stationary phase shows the characteristic diffraction peak of the pure CTF sample at 2.74°, proving the successful synthesis of this stationary phase.

[0056] As Figure 3 shown, it can be clearly seen from the SEM image that the SiO2@CTF stationary phase grafted with octyl-chain CTF at 90 °C by aldehyde-amine condensation reaction forms a "flower on the sphere" surface morphology, and it can be clearly seen from the SiO2@CTF microspheres that are not tightly wrapped that CTF grows in-situ on the silica surface.

[0057] The specific surface area and pore size distribution of the prepared novel stationary phase material were measured by N2 adsorption-desorption experiment. As Figure 4 shown, the N2 adsorption / desorption isotherm of SiO2@CTF shows the characteristics of type IV curve, indicating that this stationary phase material has a mesoporous structure. After measurement, the BET area of SiO2@CTF is 291.89 m 2 g-1 , greater than SiO2-GPTS (215.51 m 2 g -1 ). It indicates that a specific "flowers on the sphere" loading morphology of CTF is formed on the surface of SiO2, exposing more active sites, which is beneficial to the separation of isomers.

[0058] To evaluate the hydrophilicity and hydrophobicity of this stationary phase material, contact angle characterization was carried out on SiO2@CTF. As Figure 5 shown, the water contact angle of SiO2@CTF is 126°. This shows that the SiO2@CTF stationary phase has excellent hydrophobicity, probably due to the rich C elements, hydrophobic alkyl chains and a large number of benzene ring structures in the structure.

[0059] The stationary phase 2 prepared in Example 2 was packed into a stainless steel column with a length of 150 mm and an inner diameter of 4.6 mm using a mixed solution of chromatographic grade CH2Cl2 and cyclohexanol (2:1, v / v) as the slurry. The prepared chromatographic column was used to analyze and separate samples. In the RPLC mode, shape-constrained isomers such as polycyclic aromatic hydrocarbons, tocopherols and carotenoids were separated. The results are as Figure 6 , 7 , 8 shown. The chromatographic conditions were: ACN / H2O = (90 / 10, v / v), CH3OH / H2O = (90 / 10, v / v), CH3O / H2O = (80 / 20, v / v); the flow rate was 1.0 mL / min; the detection wavelengths were 254 nm, 294 nm, 450 nm respectively.

[0060] The chromatographic column prepared with the stationary phase II obtained in Example 2 separated three positional isomers of diethylbenzene, nitroaniline and dichlorobenzene in the reversed-phase chromatography mode. The results are as Figure 9 , 10 , 11 shown. The chromatographic conditions were: ACN / H2O = (95 / 5, v / v), (60 / 40, v / v), (60 / 40, v / v); the flow rate was 1.0 mL / min; the detection wavelength was 214 nm.

[0061] It should be noted that the embodiments described herein are only partial embodiments of the present invention, rather than all implementation manners of the present invention. The embodiments are only exemplary, and their functions are only to provide a more intuitive and clear way to understand the content of the present invention, rather than a limitation on the technical solutions described in the present invention. Without departing from the concept of the present invention, all other implementation manners that can be thought of by those of ordinary skill in the art without creative work, as well as other simple substitutions and various changes to the technical solutions of the present invention, all belong to the protection scope of the present invention.

Claims

1. A strongly hydrophobic chromatographic stationary phase containing an octyl chain covalently modified triazine skeleton, characterized in that: The stationary phase includes silica gel, the silica gel is surface-modified by a covalent triazine skeleton containing a hydrophobic octyl chain in the structure, the bonding phase of the covalent triazine skeleton contains a triazine ring, a benzene ring, an octyl chain and an amino group, and the structural formula of the stationary phase is:

2. The strongly hydrophobic chromatographic stationary phase containing an octyl chain covalent triazine skeleton modified according to claim 1, characterized in that: The silica gel has a particle diameter of 5 to 7 μm, a pore size of 8 to 14 nm, and a specific surface area of ​​300 m 2 g -1 .

3. The strongly hydrophobic chromatographic stationary phase containing an octyl chain covalent triazine skeleton modified according to claim 1, characterized in that: Each gram of the silica gel contains 0.2 to 2.4 mmol of octyl chains, and the wrapping thickness of the covalent triazine skeleton on the surface of the silica gel is 50 to 150 nm.

4. A method for preparing a strongly hydrophobic chromatographic stationary phase containing an octyl chain covalently modified triazine skeleton, characterized in that: The following steps are involved: (1) Silica gel activation treatment: Weigh a certain amount of silica gel and put it into a round-bottom flask, add a hydrochloric acid solution with a concentration of 2-3 mol / L, heat to 120°C, reflux and stir to react for 7-9 hours, filter and wash the obtained solid with water to pH = 6-7, and dry to constant weight to obtain activated silica gel; (2) Silica gel modification treatment: under nitrogen protection, add silane coupling agent and activated silica gel obtained in step (1) to an organic solvent, react at 100-120° C. for 12-24 h, filter and separate, wash the obtained solid with toluene, ethanol and acetone in sequence, and dry to obtain modified silica gel SiO2-GPTS; (3) Aldehyde amine condensation reaction: 1,3,5-tris(4-aminophenyl)triazine and 2,5-bis(octyloxy)terephthalaldehyde are placed in a thick-walled heat-resistant glass flask, and then acetonitrile and acetic acid solution are added, and then the modified silica gel SiO2-GPTS obtained in step (2) is added, and the mixture is ultrasonically treated for 5 minutes to make it evenly dispersed, and slowly stirred at 45-90°C for 1-3 days, and then centrifuged at 3000-11000 r / min, and the solid is washed with tetrahydrofuran and ethanol in turn, and dried to obtain a strongly hydrophobic chromatographic stationary phase containing an octyl chain covalently modified triazine skeleton.

5. The method for preparing a strongly hydrophobic chromatographic stationary phase containing an octyl chain covalent triazine skeleton modified according to claim 4, characterized in that: In the step (1), the ratio of silica gel to hydrochloric acid solution is (3-5) g: (60-100) mL, and the concentration of the hydrochloric acid solution is 2-3 mol / L.

6. The method for preparing a strongly hydrophobic chromatographic stationary phase containing an octyl chain covalent triazine skeleton modified according to claim 4, characterized in that: The silane coupling agent in step (2) is γ-glycidyloxypropyltrimethoxysilane; the organic solvent is toluene, acetonitrile or N,N-dimethylformamide; the dosage ratio of activated silica gel, toluene and silane coupling agent is (1-5) g: (20-100) mL: (1.5-7.5) mL.

7. The method for preparing a strongly hydrophobic chromatographic stationary phase containing an octyl chain covalent triazine skeleton modified according to claim 4, characterized in that: The addition ratio in step (3) is 1,3,5-tris(4-aminophenyl)triazine:2,5-bis(octyloxy)terephthalaldehyde:acetonitrile:acetic acid solution:SiO2-GPTS=(0.42-0.70)g:(0.73-1.22)g:(20-60)mL:(0.6-1.8)mL:(1-3)g, and the concentration of the acetic acid solution is 6-12mol / L.

8. The method for preparing a strongly hydrophobic chromatographic stationary phase containing an octyl chain covalent triazine skeleton modified according to claim 4, characterized in that: The temperature of the drying treatment in step (1) is 100-120°C, and the drying treatment time is 8-24 hours; the temperature of the drying treatment in step (2) is 80-100°C, and the drying treatment time is 8-24 hours; the temperature of the drying treatment in step (3) is 80-100°C, and the drying treatment time is 12-24 hours.

9. An application of a strongly hydrophobic chromatographic stationary phase modified with an octyl chain covalent triazine skeleton, characterized in that: The stationary phase is used in a high performance liquid chromatography separation process.

10. The use of a strongly hydrophobic chromatographic stationary phase modified with an octyl chain covalent triazine skeleton as claimed in claim 9, characterized in that: The stationary phase has a RPLC / HILIC / PALC mixed separation mode, has retention and shape selectivity for shape-restricted isomers and positional isomers with different molecular planarities or spatial configurations, and is used for separating non-polar shape-restricted isomers and positional isomers.

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