WO2011012019A1

WO2011012019A1 - Separation material based on silica gel having copolymerization reaction on surface and preparation method thereof

Info

Publication number: WO2011012019A1
Application number: PCT/CN2010/073468
Authority: WO
Inventors: 郭志谋; 梁图; 金高娃; 梁鑫淼
Original assignee: 中国科学院大连化学物理研究所
Priority date: 2009-07-31
Filing date: 2010-06-02
Publication date: 2011-02-03
Also published as: CN101987293A; CN101987293B

Abstract

A separation material based on silica gel substrate and preparation method thereof are provided. The separation material based on silica gel substrate is obtained by copolymerizing two or more silane reagents on the silica gel surface to form "non-polar/polar copolymerized stationary phase" and has the following formula, wherein NP denotes non-polar groups, which comprise C_1-30 n-alkane groups, phenyl, and so on; P denotes polar groups, which comprise C_1-12 n-alkane groups jointing with Cl, Br, CN, amino group, benzenesulfonic group, sulfonic group, carboxyl group, quaternary ammonium group, alcohol group, and so on. The preparation method of the above mentioned separation material comprises the following steps: acidification preprocessing of silica gel, hydrating, copolymerizing a mixture of non-polar silane reagent and polar silane reagent on the hydrated silica gel surface, filtering, washing, drying, and so on. The separation material of the present invention has both non-polar groups and polar groups, which can provide hydrophobic applied force and several kinds of polar applied forces, and thereby improve greatly the selectivity of separation and enrichment. The separation material obtained through the preparation method of the present invention has merits such as uniform and stable bonding groups on the surface, larger bonding amount and so on, and can be applied to liquid chromatogram chromatography and solid phase extraction.

Description

Separating material based on copolymerization reaction of silica gel surface and preparation method thereof

The invention relates to a separating material, in particular to a silica gel matrix bonding "non-polar/polar copolymerized stationary phase" based on copolymerization of silica gel surface and a preparation method thereof. Background technique

Reversed-phase high performance liquid chromatography is currently the most widely used separation analysis and purification separation technology. Solid phase extraction based on reverse phase mode is also a common sample preparation and enrichment technique. Silica-based alkyl groups (e.g., octadecyl C18, octane C8, etc.) bonded stationary phases are the most commonly used separation materials for reversed phase chromatography and solid phase extraction. However, the alkyl stationary phase provides only a single hydrophobic interaction, insufficient polar interaction, and poor selectivity for retention and separation of polar compounds. The alkyl stationary phase is too hydrophobic and lacks a hydrophilic group. When the water content in the mobile phase or eluent is high, the separation material loses its infiltration, the bonded phase "collapses", and the separation ability is lost. Therefore, the introduction of polar groups on the basis of the conventional reversed-phase stationary phase, the development of a bonded stationary phase capable of providing both hydrophobic and polar interaction forces, complementing the polarity selection in reversed phase chromatography and solid phase extraction Properties and improved wettability of the separation material are important directions in the development of chromatographic separation techniques [Buszewski, B. et al, Anal. Chem. 1997, 69, 3277-3284] In addition, the introduction of polar groups can also "shield" the surface of the silica gel. Residual silanol group activity improves the separation efficiency of basic compounds.

Currently, there are two main techniques for introducing polar groups in the reverse phase stationary phase, namely, polar-embeded [Silva, CR et al, J. Chromatogr. A, 2001, 913, 65 -73] and polar-endcapped [Layne, J. et al, J. Chromatogr. A, 2002, 957, 149-164]. By introducing two kinds of polar groups such as amide, urea group and alcohol group in the non-polar bonded stationary phase, the polarity selectivity, wettability and separation efficiency of the basic compound can be effectively improved. . However, these two techniques for introducing polar groups also have certain limitations. The method of polar embedding is to insert a polar group between each non-polar ligand and silica gel, that is, the ratio between the polar group and the non-polar ligand is substantially 1:1. The ratio between the polar group and the non-polar ligand is regulated. In addition, the spatial positions of polar groups and non-polar ligands are relatively fixed and difficult to control. Some polar embedding stationary phases also present a problem of lower stability. The polar tailing method is to introduce a polar group by reacting residual silanol groups on the surface of the silica gel with a polar silane reagent after bonding the nonpolar ligand, and the number and position distribution of the polar groups are more uncertain. The polar capping phase has a problem in shielding the silanol group activity and does not significantly reduce the silanol group activity on the silica surface.

Wirth et al. developed a method for preparing a chromatographic stationary phase by horizontal polymerization of a silane reagent using silane reagent [Peter Fairbank, R. W. et al, Anal. Chem. 1995, 67, 3879-3885]. This method was used to prepare a propyl/octadecyl mixed reverse phase stationary phase and a methyl/octadecyl mixed stationary phase [Peter Fairbank, RW et al, J. Chromatogr. A, 1999, 830, 285-291 ]. In addition, the method is also used to prepare 3-chloropropyl silica gel [Hughes, MA et al, Ind. Eng. Chem. Res. 2006, 45, 6538-6547; US Patent: Patent No. 5, 695, 882]. This method provides the possibility of performing surface copolymerization of silica gel. However, techniques for preparing polar reverse phase separation materials and corresponding separation materials using this method have not yet appeared. Summary of the invention

It is an object of the present invention to provide a separation material having a "nonpolar/polar copolymerized stationary phase" as a functional group. And a method of preparing the material.

In order to achieve the above object, the present invention adopts the following technical solutions:

The structural formula of the separation material of the present invention is as follows:

Silica Gel

Among them, Silica Gel is a silica gel, and NP is a non-polar group, and includes a normal alkyl group having 1 to 30 carbon atoms, a phenyl group and the like. P is a polar group, and includes a chlorine atom, a bromine atom, a cyano group, an amine group, a benzenesulfonate group, a sulfonic acid group, a carboxyl group, a quaternary ammonium group, an alcohol bonded to a normal-chain alkyl group having 1 to 12 carbon atoms. Base.

The preparation method of the separation material of the present invention comprises the following steps:

(1) adding silica gel to a hydrochloric acid or nitric acid solution having a volume concentration of 1% to 38%, heating and refluxing for 1 to 48 hours, filtering, washing to neutrality, and drying to constant weight at 100 to 160 ° C;

(2) The dried silica gel obtained in the step (1) is placed in an atmosphere having a relative humidity of 20% to 80% for 24 to 72 hours, so that the silica gel absorbs water by weight by 0.5% to 10%;

(3) Copolymerization of silica gel surface: The hydrated silica gel obtained in the step (2) is placed in a glass or a polytetrafluoroethylene reaction vessel, and an organic solvent is added under a nitrogen atmosphere, and the mixture is uniformly stirred, and a non-polar silane reagent and a polar silane reagent mixture are added dropwise. , stirring at a temperature of 20~200 ° C for 2 to 48 hours;

The organic solvent used is an organic solvent which is immiscible with water, and includes benzenes and alkanes such as toluene, ethylbenzene, xylene, n-hexane, n-heptane, n-pentane, n-octane, cyclohexane. Use 2 mL to 100 mL of organic solvent per gram of hydrated silica gel. The structural formula of the non-polar silane reagent is:

Wherein X is a chlorine atom, a methoxy group or an ethoxy group; n is 0 to 29, and A is a phenyl group or a methyl group. The structural formula of the polar silane reagent is:

Wherein X is a chlorine atom, a methoxy group or an ethoxy group; n is 1 to 12, and B is a chlorine atom, a bromine atom, a cyano group, an amine group, a benzenesulfonic acid group, a sulfonic acid group, a carboxyl group, a quaternary ammonium group, or a diol group. Wait. The molar ratio of the non-polar silane reagent to the polar silane reagent is from 1/100 to 100/1. The polar silane reagent and the non-polar silane reagent are generally used in an amount of 0.5 mmol to 5 mmol of silane reagent per gram of hydrated silica gel;

(4) Washing and drying: The reaction system of the step (3) is cooled to room temperature, filtered under reduced pressure and washed with a solvent such as toluene, dichloromethane, methanol, water, tetrahydrofuran or methanol, and the solid product is at 60 to 100 ° C. Dry for 12 hours.

The invention has the following beneficial effects: the separation material prepared by the invention has both a non-polar group and a polar group, and can simultaneously provide hydrophobic force and various forms of polar forces, such as hydrogen bonding, dipole- Dipole action, electrostatic attraction or repulsion can greatly improve separation selectivity. Due to the introduction of polar groups, the separation material prepared by the present invention will have improved wettability under the condition that the mobile phase contains a high content of aqueous solution, and effectively avoids the problem of loss of infiltration of the conventional reverse phase separation material. In addition, the polar group can also shield the activity of silanol groups very well. Peak shape and separation efficiency of good basic compounds. The types and ratios of non-polar groups and polar groups in the stationary phase structure can be freely regulated compared to existing polar reverse phase stationary phases. The preparation method provided by the present invention can prepare various types of stationary phases by combining different kinds of non-polar groups and polar groups or adjusting the ratio of polar groups and non-polar groups, as needed. Meet the separation needs of different samples. Compared with the prior art, the stationary phase obtained by the preparation method provided by the invention has the advantages of uniform and stable surface bonding groups, large bonding amount, and the like, and has wide application range of technology. DRAWINGS

Figure 1 is a chromatogram of the infiltration property of the separation material C18HCE obtained in Example 17;

Figure 2 is a differential chromatogram of the separation material C18HCE obtained in Example 17 and a commercial C18 column in the separation of alkaloids;

Fig. 3 is a solid phase extraction chromatogram using the separation material C18/SCX-10S obtained in Example 13 for melamine. detailed description

The separation material provided by the present invention and its preparation method and application are further described below with reference to examples. The examples are intended to be illustrative only and not limiting of the invention.

Example 1

Weigh 10 g of spherical silica gel (particle size 5 μηι, pore size 10 nm, specific surface area 305 m2 / g), placed in a 250 mL glass flask, add 150 mL of a 10% hydrochloric acid solution, and heat to reflux for 12 hours. Cool to room temperature, filter, wash to neutral, and dry at 150 ° C for 24 hours. The dried silica gel was placed in a 150 mL three-neck glass bottle, and nitrogen gas with a relative humidity of 50% was continuously supplied for 48 hours to obtain a hydrated silica gel. 10.5 go. Under the condition of passing dry nitrogen, 80 mL of the hydrated silica gel was added to dry. The n-hexane was stirred well, and then a mixture of 18 mmol (7.2 mL) of octadecyltrichlorosilane and 6 mmol (0.9 mL) of 3-chloropropyltrichlorosilane was added dropwise, and the reaction was stirred at room temperature for 24 hours. The reaction system was filtered, washed successively with toluene, dichloromethane, methanol, water, tetrahydrofuran, methanol, and the product was dried at 80 ° C for 12 hours to obtain a stationary phase of the formula. Elemental analysis results: C: 16.43%, H 3.04%; Infrared spectrum: Characteristic absorption peak at 2900-2800 cm-1. Elemental analysis and infrared spectroscopy results confirmed that the non-polar/polar copolymerized stationary phase C18/HC-3 structural formula of this example was:

Example 2

The preparation method is as follows: Weigh 10 g spherical silica gel (particle size 3 μηι, pore diameter 12 nm, specific surface area 290 m 2 /g), place it in a 250 mL glass flask, and add 100 mL of a 38% hydrochloric acid solution. Heat under reflux for 2 hours, cool to room temperature, filter, wash with water until neutral, and dry at 120 ° C for 24 hours. The dried silica gel was placed in a 150 mL three-neck glass bottle, and nitrogen gas having a relative humidity of 60% was continuously supplied for 24 hours to obtain 10.3 g of hydrated silica gel. Add 80 mL of dry toluene to the hydrated silica gel under dry nitrogen, stir well, then add 16 mmol (6.4 mL) of octadecyltrichlorosilane and 8 mmol (1.9 mL) of 3-cyano The mixture of propyltrichlorosilane was stirred at 80 ° C for 24 hours. The reaction system was filtered, washed successively with toluene, dichloromethane, methanol, water, tetrahydrofuran, methanol, and the product was dried at 80 ° C for 12 hours to obtain a stationary phase of the formula. Elemental analysis results: C 18.65%, N 0.22%, H 3.44%; Infrared spectrum: 2900-2800 cm - 1 and 2300 cm - 1 characteristic absorption peak. Elemental analysis and infrared spectroscopy results confirmed that the non-polar/polar copolymerized stationary phase C18/CN-2 structural formula of this example was:

Example 3

Weigh 10 g of spherical silica gel (particle size 5 μηι, pore size 10 nm, specific surface area 305 m2 / g), placed in a 250 mL glass flask, add 150 mL of a 10% hydrochloric acid solution, and heat to reflux for 12 hours. Cool to room temperature, filter, wash to neutral, dry at 120 ° C for 24 hours. The dried silica gel was placed in a 150 mL three-necked glass bottle, and nitrogen gas having a relative humidity of 30% was continuously introduced for 72 hours to obtain hydrated silica gel 10.6 go. Under the condition of passing dry nitrogen, 100 mL of dry gel was added to the hydrated silica gel. The n-pentane was stirred well, and then a mixture of 16 mmol (6.4 mL) of octadecyltrichlorosilane and 8 mmol (1.4 mL) of 3-aminopropyltrimethoxysilane was added dropwise, and the reaction was stirred at room temperature for 24 hours. The reaction system was filtered, washed successively with toluene, dichloromethane, methanol, water, tetrahydrofuran, methanol, and the product was dried at 80 ° C for 12 hours to obtain a stationary phase of the formula. Elemental analysis results: C 17.65%, N 1.21%, H 3.64%; Infrared spectrum: Characteristic absorption peak at 2900-2800 cm-1. Elemental analysis and infrared spectroscopy results confirmed that the non-polar/polar copolymerized stationary phase C18/NH2-2 of this example has the following structural formula:

Example 4

Weigh 10 g of spherical silica gel (particle size 5 μηι, pore size 10 nm, specific surface area 305 m2 / g), placed in a 250 mL glass flask, add 150 mL of a 10% hydrochloric acid solution, and heat to reflux for 24 hours. Cool to room temperature, filter, wash to neutral, and dry at 150 ° C for 12 hours. The dried silica gel was placed in a 150 mL three-neck glass bottle, and nitrogen gas having a relative humidity of 50% was continuously supplied for 48 hours to obtain hydrated silica gel 10.5 go. Under the condition of passing dry nitrogen, 100 mL of dry water was added to the hydrated silica gel. Ethylbenzene, stir well, then add 20 mmol (8.0 mL) of octadecyltrichlorosilane and 2 mmol (1.3 mL) of p-sulfophenethyltrichlorosilane mixture, stir the reaction at 60 ° C for 24 hours. . The reaction system was filtered, washed successively with toluene, dichloromethane, methanol, water, tetrahydrofuran, methanol, and the product was dried at 80 ° C for 12 hours to obtain a stationary phase of the formula. Elemental analysis results: C 16.53%, H 2.92%; Infrared spectrum: Characteristic absorption peaks at 2900-2800 cm-1 and 1625 cm-1 confirm the non-polar/polar copolymerized stationary phase C18/SCX-10 structural formula of this example for:

Example 5

Weigh 10 g of spherical silica gel (particle size 5 μηι, pore size 10 nm, specific surface area 305 m2 / g), placed in a 250 mL glass flask, add 120 mL of a 5% hydrochloric acid solution, and heat to reflux for 24 hours. Cool to room temperature, filter, wash to neutral, and dry at 150 ° C for 1 hour. The dried silica gel was placed in a 150 mL three-necked glass bottle, and nitrogen gas having a relative humidity of 30% was continuously introduced for 72 hours to obtain a hydrated silica gel 10.6 go. Under the condition of passing dry nitrogen, 100 mL of dry water was added to the hydrated silica gel. N-hexane, stir well, then add 20 mmol (8.0 mL) of octadecyltrichlorosilane and 2.5 mmol (0.7 mL) of 3-N, N, N-trimethyl quaternary propyl trimethoxysilane mixture. The reaction was stirred at room temperature for 24 hours. The reaction system was filtered, washed successively with toluene, dichloromethane, methanol, water, tetrahydrofuran, methanol, and the product was dried at 80 ° C for 12 hours to obtain a stationary phase of the formula. Elemental analysis results: C 19.24%, N 1.20%, H 2.64%; Infrared spectrum: Characteristic absorption peak at 2900-2800 cm-1. Elemental analysis and infrared spectroscopy results confirmed that the non-polar/polar copolymerized stationary phase C18/SAX-8 structure of this example was:

SiO Example 6

The remainder of the preparation method and Example 1 except that the silane reagent added was 18 mmol (7.2 mL) of octadecyltrichlorosilane and 6 mmol (1.8 mL) of 11-bromoundecyltrichlorosilane mixture. the same. Elemental analysis Results: C 15.35%, H 3.78%; Infrared spectrum: Characteristic absorption peak at 2900-2800 cm-1. Elemental analysis and infrared spectroscopy results confirmed that the non-polar/polar copolymerized stationary phase C18/HB-3 of this example has the following structural formula:

SiO Example 7

The remainder of the preparation process was the same as in Example 1 except that the silane reagent added was 18 mmol (4.2 mL) of octyltrichlorosilane and 6 mmol (0.9 mL) of 3-propyltrichlorosilane. Elemental analysis results: C 12.35%, H 2.78%; Infrared spectrum: Characteristic absorption peak at 2900-2800 cm-1. Elemental analysis and infrared spectroscopy results confirmed that the non-polar/polar copolymerized stationary phase C8/HC-3 structural formula of this example was:

SiO Example 8

The remainder of the preparation was the same as in Example 1 except that the silane reagent added was 18 mmol (3.0 mL) of butyltrichlorosilane and 6 mmol (0.9 mL) of 3-chloropropyltrichlorosilane. Elemental analysis results: C 7.25%, H 1.77%; Infrared spectrum: Characteristic absorption peak at 2900-2800 cm-1. Elemental analysis and infrared spectroscopy confirmed that the non-polar/polar copolymerized stationary phase C4/HC-3 structure of this example was:

SiO Example 9

The remainder of the preparation was the same as in Example 1 except that the silane reagent added was 16 mmol (2.6 mL) of phenyltrichlorosilane and 8 mmol (1.2 mL) of 3-chloropropyltrichlorosilane. Elemental analysis results: C 8.23%, H 1.74%; Infrared spectrum: Characteristic absorption peaks at 2900-2800 cm-1 and 1624 cm-1. Elemental analysis and infrared spectroscopy results confirmed that the non-polar/polar copolymerized stationary phase of this example Ph/HC-2 has the following structural formula:

Si0 ₂ embodiment 10

The addition of the silane reagent was 9 mmol (3.6 mL) of octadecyltrichlorosilane, 9 mmol (2.1 mL) of octyltrichlorosilane and 6 mmol (0.9 mL) of 3-chloropropyltrichlorosilane mixture. The rest of the preparation method is the same as in the first embodiment. Elemental analysis results: C 18.76%, H 3.47%; Infrared spectrum: 2900-2800 cm-1 Characteristic absorption peak. Elemental analysis and infrared spectroscopy results confirmed the non-polar/polar copolymerized stationary phase of this example

The structural formula of C18/C8/HC-3 is:

SiO Example 11

The remainder of the preparation method was the same as that of Example 1 except that the ratio of the two silane reagents dropped was different from that of Example 1. The silane reagent added dropwise in this example was a mixture of 12 mmol (4.8 mL) of octadecyltrichlorosilane and 12 mmol (1.8 mL) of 3-chloropropyltrichlorosilane. Elemental analysis results: C 16.24%, H 3.03%; infrared spectrum: characteristic absorption peak at 2900-2800 cm-1. Elemental analysis and infrared spectroscopy results confirmed that the non-polar/polar copolymerized stationary phase C18/HC-1 structural formula of this example was:

SiO The remainder of the preparation method was the same as that of Example 1 except that the ratio of the two silane reagents dropped was different from that of Example 1. The silane reagent added dropwise in this example was a mixture of 8 mmol (3.2 mL) of octadecyltrichlorosilane and 16 mmol (2.4 mL) of 3-chloropropyltrichlorosilane. Elemental analysis results: C 14.37%, H 2.71%; Infrared spectrum: Characteristic absorption peak at 2900-2800 cm-1. Elemental analysis and infrared spectroscopy results confirmed that the non-polar/polar copolymerized stationary phase C18/HC-G5 structure of this example was:

SiO Example 13

Weigh 80 g of spherical silica gel (particle size 40 μηι, pore size 80 nm, specific surface area 400 m2/g), placed

In a 2000 mL glass flask, 1200 mL of a 10% hydrochloric acid solution was added, and the mixture was heated under reflux for 24 hours, cooled to room temperature, filtered, washed with water until neutral, and dried at 150 ° C for 12 hours. The dried silica gel was placed in a 1500 mL three-necked glass vial, and nitrogen gas having a relative humidity of 50% was continuously introduced for 48 hours to obtain 84 g of hydrated silica gel. Add 1000 mL of dry toluene to the hydrated silica gel under dry nitrogen, stir well, then add 200 mmol (80.0 mL) of octadecyltrichlorosilane and 20 mmol (12 mL) of sulfonic acid. The mixture of phenethyltrichlorosilane was stirred at room temperature for 60 hours at room temperature for 24 hours. The reaction system was filtered, washed successively with toluene, dichloromethane, methanol, water, tetrahydrofuran, methanol, and the product was dried at 80 ° C for 12 hours to obtain a stationary phase of the formula. Elemental analysis results: C 22.43%, H 4.92%; Infrared spectrum: Characteristic absorption peaks at 2900-2800 cm-1 and 1625 cm-1 confirm the non-polar/polar copolymerized stationary phase C18/SCX-10S structural formula of this example for:

SiO Example 14

The remainder of the preparation method was the same as that of Example 12 except that the ratio of the two silane reagents dropped was different from that of Example 13. The silane reagent added dropwise in this example was 200 mmol (80.0 mL) of octadecyltrichlorosilane and 2 mmol (1.2 mL) of a mixture of p-sulfonic acid phenethyltrichlorosilane. Elemental analysis results: C 24.41%, H 5.32%; Infrared spectrum: Characteristic absorption peak at 2900-2800 cm-1 confirms the non-polar/polar copolymerization phase of the present embodiment. The C18/SCX-100S structural formula is:

SiO Example 15

Weigh 40 g of spherical silica gel (particle size 5 urn, pore size 30 nm, specific surface area 80 m2 / g), placed at 1000 In a mL glass flask, 700 mL of a 10% strength hydrochloric acid solution was added, and the mixture was heated under reflux for 12 hours, cooled to room temperature, filtered, washed with water until neutral, and dried at 150 ° C for 24 hours. The dried silica gel was placed in a 500 mL three-neck glass bottle, and nitrogen gas having a relative humidity of 50% was continuously supplied for 48 hours to obtain a hydrated silica gel 40.5 go. Under the condition of passing dry nitrogen, 300 mL of dry water was added to the hydrated silica gel. The n-hexane was stirred well, and then a mixture of 20 mmol (8.0 mL) of octadecyltrichlorosilane and 10 mmol (1.5 mL) of 3-chloropropyltrichlorosilane was added dropwise, and the reaction was stirred at room temperature for 24 hours. The reaction system was filtered, washed successively with toluene, dichloromethane, methanol, water, tetrahydrofuran, methanol, and the product was dried at 80 ° C for 12 hours to obtain a stationary phase of the formula. Elemental analysis results: C 3.25%, H 0.80%; Infrared spectrum: Characteristic absorption peak at 2900-2800 cm-1. Elemental analysis and infrared spectroscopy results confirmed that the non-polar/polar copolymerized stationary phase C18/HC-2L structural formula of this example was:

Example 16

The remainder of the preparation was the same as in Example 15 except that the silane reagent added was 18 mmol (4.2 mL) of octyltrichlorosilane and 6 mmol (0.9 mL) of 3-chloropropyltrichlorosilane. Elemental analysis results: C 3.75%, H 0.92%; Infrared spectrum: Characteristic absorption peak at 2900-2800 cm-1. Elemental analysis and infrared spectroscopy confirmed that the non-polar/polar copolymerized stationary phase C8/HC-3L structural formula of this example was:

SiO Example 17

Weigh 10 g of spherical silica gel (particle size 5 μηι, pore size 10 nm, specific surface area 305 m2 / g), placed in a 250 mL glass flask, add 150 mL of a 10% hydrochloric acid solution, and heat to reflux for 12 hours. Cool to room temperature, filter, wash to neutral, and dry at 150 ° C for 24 hours. The dried silica gel was placed in a 150 mL three-neck glass bottle, and nitrogen gas with a relative humidity of 50% was continuously supplied for 48 hours to obtain a hydrated silica gel. 10.5 go. Under the condition of passing dry nitrogen, 80 mL of the hydrated silica gel was added to dry. The n-hexane was stirred well, and then a mixture of 8 mmol (3.2 mL) of octadecyltrichlorosilane and 16 mmol (2.4 mL) of 3-chloropropyltrichlorosilane was added dropwise, and the mixture was stirred at room temperature for 24 hours. The reaction system was filtered, washed successively with toluene, dichloromethane, methanol, water, tetrahydrofuran, methanol, and the product was dried at 80 ° C for 12 hours. The dried solid was placed in a 200 mL three-necked flask, and 100 mL of toluene was added, followed by 3.8 mL of trimethylchlorosilane, 7.0 mL of hexamethyldisilazane and 2.0 mL of pyridine, and the mixture was heated to 110 ° C to stir the reaction. End-sealing treatment for 24 hours. The reaction system was filtered, washed successively with dichloromethane, methanol, water, tetrahydrofuran, and methanol, and the product was dried at 80 ° C for 12 hours to obtain a separation material of the formula. Elemental analysis results: C: 11.5%, H 2.16%; Infrared spectrum: Characteristic absorption peak at 2900-2800 cm-1. Elemental analysis and infrared spectroscopy results confirmed that the non-polar/polar copolymerized stationary phase of the present embodiment has a structural formula of C18HCE:

SiO Example 18

Using the separation material C18HCE obtained in Example 17, a 4.6 X 150 mm column was packed by homogenization, and a "stop-flow test" was performed under a 100% aqueous solution to verify the wettability of the separated material. The retention time of the solute did not change before and after the flow rate was stopped (Fig. 1), indicating that the separation material has good wettability, which solves the problem of loss of infiltration of the conventional reverse phase separation material in the high water content mobile phase. The chromatographic conditions are: Column: 4.6 X 150 mm C18HCE (particle size 5 μηι)

Mobile phase: 10 mM ammonium formate solution (pH 3 );

Flow rate: 1.0 mL/min;

Column temperature: 30 °C; Detection wavelength: 260 nm.

The specific method of "stop flow rate test" is as follows: Balance the column with 10 mM ammonium formate solution for 10 minutes, run the sample, collect the data as Befroe stop flow chromatogram; then stop the flow rate for 30 minutes, and re-equilibrate the column with 10 mM ammonium formate solution. 10 minutes, the injection run, the data collected is the After stop flow chromatogram.

Example 19

Using the separation material C18HCE obtained in Example 17, a 4.6 X 150 mm column was packed by homogenization, and the difference in the separation of alkaloids from the commercial C18 column was compared. The results show that the separation material exhibits better peak shape and loading capacity than the commercial separation material (Figs. 2a and 2b) in alkaloid separation (Figs. 2c and 2d). The mass number indicated in the figure is the amount of alkaloid sample loaded. The chromatographic conditions are:

Column: 4.6 X 150 mm C18HCE (filler size 5 μηι) and 4.6 X 150 mm XBridge C18

(The particle size of the filler is 3.5 μηι)

Mobile phase conditions: mobile phase enthalpy, 0.1% formic acid water, mobile phase B, ACN; gradient conditions for C18HCE column: 0-30 min, 0%→30% B; gradient conditions for XBridge C18 column: 0-30 min, 5%→35% B; 30-40 min, 35%→60% B;

Sample: Alkaloid sample of Corydalis water extract, concentration 200 mg / mL;

Flow rate: 1.0 mL/min;

Column temperature: 30 °C;

Detection wavelength: 254 nm.

Example 20

The separation material C18/SCX-10S obtained in Example 13 was packed with a solid phase extraction (SPE) cartridge and subjected to solid phase extraction of melamine to test the adsorption performance of the separation material on melamine. The results (Fig. 3, in which Fig. 3a is a melamine standard solution, and Fig. 3b is a target fraction obtained by solid phase extraction) indicate that the separation material has a good adsorption capacity for melamine, and is suitable as a reverse phase/ion exchange mixed mode solid phase extraction filler. The solid phase extraction conditions are:

SPE cartridge: volume l mL, filled with 60 mg of separation material;

Sample: aqueous melamine solution, concentration 0.5 mg/mL;

Activate the SPE column: Rinse the SPE column with 2 mL of methanol and 2 mL of water in sequence, the flow rate is less than 1 mL/min; Load: Add 1 mL of the melamine aqueous solution sample to the SPE cartridge;

Elution: Rinse the SPE column with 2 mL of water, 2 mL of methanol and 4 mL of methanol/ammonia (1/1, v/v, 20% ammonia concentration), and collect 4 mL of methanol/ammonia elution fraction as the target fraction, nitrogen. Purge dry and dissolve in 1 mL of water.

The chromatographic conditions are:

Column: 4.6 X 150 mm C18 column (particle size 5 μηι)

Mobile phase: 10 mM ammonium formate solution (; pH 3);

Flow rate: 1.0 mL/min;

Column temperature: 30 °C;

Detection wavelength: 240 nm.

Claims

A separation material based on a surface copolymerization reaction of silica gel, characterized in that: two or more kinds of silicon germanium reagents are copolymerized on the surface of the silica gel to form a "non-polar/polar copolymerized stationary phase", and the structural formula is as follows:

Silica Gel

Wherein, Silica Gel is a silica gel; NP represents a non-polar group which is one or more of a normal chain fluorenyl group having 1 to 30 carbon atoms and a phenyl group; and P represents a polar group which is an end band One or more of a normal alkyl group having 1 to 12 carbon atoms having a chlorine atom, a bromine atom, a cyano group, an amine group, a benzenesulfonate group, a sulfonic acid group, a carboxyl group, a quaternary ammonium group and an alcohol group functional group.

A method for producing a separating material according to claim 1, characterized in that: the separation material containing two or more functional groups is prepared by a silica gel surface copolymerization reaction, comprising the following steps:

a. silica gel pretreatment: silica gel is added to a volume concentration of 1% ~ 38% hydrochloric acid or nitric acid solution, heated under reflux and stirred for 1 to 48 hours, filtered, washed with water to neutral, dried at 100~160 ° C to constant weight;

b. Hydration: Step a obtained dry silica gel is placed in an atmosphere of relative humidity of 20% ~ 80% for 24 to 72 hours, so that the silica gel absorbs water by weight 0.5% ~ 10%, to obtain hydrated silica gel;

c silica gel surface copolymerization: The hydrated silica gel obtained in step b is placed in a glass or polytetrafluoroethylene reaction vessel, and the organic solvent is added under a nitrogen atmosphere, stirred uniformly, and a non-polar silane reagent and a polar silane reagent mixture are added dropwise to maintain the temperature. Stir for 2 to 48 hours at 20~200 °C;

d. Washing and drying: The reaction system of step c is cooled to room temperature, filtered under reduced pressure, and the precipitate is washed successively with toluene, dichloromethane, methanol, water, tetrahydrofuran, methanol, and the solid product is dried at 60 to 100 ° C. 12 hours, the finished product.

The preparation method according to claim 2, wherein the organic solvent in the step c is an organic solvent which is immiscible with water, and may be one of a benzene series and an alkane.

The preparation method according to claim 3, wherein the organic solvent in the step c is toluene, ethylbenzene, xylene, n-hexane, n-heptane, n-pentane, n-octane or cyclohexane.

The preparation method according to claim 2, wherein the organic solvent is used in the step c to use 2 mL to 100 mL of an organic solvent per gram of the hydrated silica gel.

6. The preparation method according to claim 2, wherein: the structural formula of the non-polar silane reagent in step c is:

Wherein X is a chlorine atom, a methoxy group or an ethoxy group; n is 0 to 29, and A is a phenyl group or a methyl group.

7. The preparation method according to claim 2, wherein: the structural formula of the polar silane reagent in step c is:

Wherein X is a chlorine atom, a methoxy group or an ethoxy group; n is 1 to 12, and B is a chlorine atom, a bromine atom, a cyano group, an amine group, a benzenesulfonate group, a sulfonic acid group, a carboxyl group, a quaternary ammonium group or an alcohol group.

The method according to claim 2, wherein the molar ratio of the non-polar silane reagent to the polar silane reagent in step c is from 1/100 to 100/1.

9. The preparation method according to claim 2, wherein: the total amount of the non-polar silane reagent and the polar silane reagent in step c is 0.5 mmol to 5 mmoL per gram of the hydrated silica gel.