阅读说明：本技术 一种接枝型阴离子交换树脂色谱填料及其制备方法 (Grafting type anion exchange resin chromatographic packing and preparation method thereof ) 是由 周亚茹 刘世江 张鑫 于 2020-12-11 设计创作，主要内容包括：本发明主要公布了一种接枝型阴离子交换树脂色谱填料及其制备方法,制备方法包括以下步骤：首先利用聚苯乙烯二乙烯基苯微球表面残余的双键将羧酸基团接枝到聚合物微球的表面,然后利用缩合剂活化作用将聚乙烯亚胺表面的胺基与羧基发生反应生成得到含有胺基的聚合物微球,将聚合物依次与环氧化合物和含有β双羟基的胺类化合物反应,最后得到该亲水性阴离子交换树脂色谱填料。制备的填料在一定程度上克服出峰时间长,峰形差等问题,而且该工艺操作简单,反应快,稳定性好。(The invention mainly discloses a grafted anion exchange resin chromatographic packing and a preparation method thereof, wherein the preparation method comprises the following steps: firstly, grafting carboxylic acid groups on the surfaces of polymer microspheres by using residual double bonds on the surfaces of polystyrene divinyl benzene microspheres, then reacting amino groups and carboxyl groups on the surfaces of polyethyleneimine by using the activation of a condensing agent to generate polymer microspheres containing amino groups, and reacting the polymer with an epoxy compound and an amine compound containing beta-dihydroxy in sequence to finally obtain the hydrophilic anion exchange resin chromatographic packing. The prepared filler overcomes the problems of long peak-out time, poor peak shape and the like to a certain extent, and the process has simple operation, fast reaction and good stability.)

1. A preparation method of a grafted anion exchange resin chromatographic packing is characterized by comprising the following steps:

taking polystyrene-divinylbenzene as a matrix of the polymer microsphere, and grafting a monomer containing carboxyl onto the surface of the microsphere under the action of an initiator to obtain the polymer microsphere containing carboxylic acid groups;

reacting polyethyleneimine with carboxylic acid groups on the surface of the polymer microsphere containing carboxylic acid groups through a condensing agent to obtain the polymer microsphere containing amino groups on the surface;

reacting the polymer microsphere containing the amino with an epoxy compound to obtain a polymer microsphere containing an epoxy group;

adding an amine compound containing beta dihydroxy into a polymer microsphere containing epoxy groups to react in a solution to obtain the quaternary amino anion chromatographic packing containing beta dihydroxy.

2. The method of claim 1, wherein the polymeric microspheres are polystyrene-divinylbenzene microspheres, ethylvinylbenzene-divinylbenzene microspheres, and allylglycidyl ester-divinylbenzene microspheres.

3. The method for preparing the grafted anion exchange resin chromatographic packing according to claim 2, wherein the polymer microspheres have a particle size of 3 to 10 μm, a degree of crosslinking of 5 to 80% and a pore size of 50 to 2000A.

4. The method for preparing a graft type anion exchange resin chromatography packing according to claim 1, wherein the monomer having a carboxyl group is any one of acrylic acid, methacrylic acid, thioglycolic acid.

5. The method for preparing a grafted anion exchange resin chromatographic packing according to claim 1, wherein the molecular weight of polyethyleneimine is 600 to 10000, and the polyethyleneimine is any one of branched polyethyleneimine and ethylenediamine-terminated polyethyleneimine.

6. The method of claim 1, wherein the epoxy compound is 1, 4-butanediol diglycidyl ether or ethylene glycol diglycidyl ether.

7. The method of claim 1, wherein the amine compound containing β -dihydroxy is N-methyldiethanolamine, N-ethyldiethanolamine, or diethanolamine.

8. A grafted anion exchange resin chromatographic packing characterized in that the grafted anion exchange resin is prepared by the method of any one of claims 1 to 7.

Technical Field

The invention relates to the field of ion chromatographic packing, in particular to a grafted anion exchange resin chromatographic column packing and a preparation method thereof.

Background

Ion chromatography is a chromatographic method for analyzing anions and cations, and the application relates to many fields, such as environmental analysis, food detection, medical application and the like. The method can be divided into ion exchange chromatography, ion pair chromatography and ion exclusion chromatography according to the principle, wherein the ion exchange chromatography is the most widely applied one. The core component of a chromatographic system is a chromatographic column, which determines the separation effect of chromatography. The chromatographic column packing mainly comprises an organic stationary phase and an inorganic stationary phase. The organic polymer has the advantages of controllable appearance, acid and alkali resistance, strong stability, easy modification and the like, and brings a plurality of new applications for the analysis of various samples.

Generally, anion exchange resin chromatography packing consists essentially of a matrix, spacer groups and functional groups, and although the functional groups determine the binding sites for ion exchange, the matrix and spacer groups can also affect the final separation by affecting the charge density on the resin surface or by non-ionic binding with the target ion. Especially, the matrix and the space group have hydrophobic effect, and the non-ionic combination effect has more obvious effect on polarizable anions, thereby causing the problems of overlong retention time, poor peak shape, tailing and the like.

To solve the above problems, a more hydrophilic compound should be used in the grafting process. Polyethyleneimine is a hydrophilic polyamine polymer rich in primary, secondary and tertiary amines, which can provide ion exchange sites or be further modified to obtain more quaternary amine groups. Hydroxyl is a hydrophilic group, and if a proper amount of hydroxyl groups are introduced in the grafting process, the hydrophilic effect of the exchange resin filler per se can be increased.

The invention mainly aims at improving the hydrophilicity of the exchange resin filler correspondingly.

Disclosure of Invention

The invention aims to provide a grafted anion exchange resin chromatographic packing and a preparation method thereof, the chromatographic packing prepared by the method overcomes the problems of long peak-out time and poor peak shape, and the process has the advantages of simple operation, fast reaction and good chemical stability.

In order to achieve the above object, the present invention provides a preparation method of a grafted anion exchange resin chromatographic packing, comprising the following steps:

taking polystyrene-divinylbenzene as a matrix of the polymer microsphere, and grafting a monomer containing carboxyl onto the surface of the microsphere under the action of an initiator to obtain the polymer microsphere containing carboxylic acid groups;

reacting polyethyleneimine with carboxylic acid groups on the surface of the polymer microsphere containing carboxylic acid groups through a condensing agent to obtain the polymer microsphere containing amino groups on the surface;

reacting the polymer microsphere containing the amino with an epoxy compound to obtain a polymer microsphere containing an epoxy group;

adding an amine compound containing beta dihydroxy into a polymer microsphere containing epoxy groups to react in a solution to obtain the quaternary amino anion chromatographic packing containing beta dihydroxy.

Optionally, the polymer microspheres are any one of polystyrene-divinylbenzene microspheres, ethylvinylbenzene-divinylbenzene microspheres, and allyl glycidyl ester-divinylbenzene microspheres.

Optionally, the polymer microspheres have a particle size of 3-10 μm, a crosslinking degree of 5-80%, and a pore diameter of 50-2000A.

Optionally, the monomer containing a carboxyl group is any one of acrylic acid, methacrylic acid, and thioglycolic acid.

Optionally, the molecular weight of the polyethyleneimine is 600-10000, and the polyethyleneimine is any one of branched polyethyleneimine and ethylenediamine-terminated polyethyleneimine.

Optionally, the epoxy compound is 1, 4-butanediol diglycidyl ether or ethylene glycol diglycidyl ether.

Optionally, the amine compound containing beta dihydroxy is N-methyldiethanolamine or N-ethyldiethanolamine or diethanolamine

The invention provides a preparation method of an anion exchange resin chromatographic packing, according to the specific implementation steps, the anion exchange resin chromatographic packing is prepared, the process operation for preparing the packing is relatively simple, and the packing obtained through the grafting reaction has better chemical stability compared with the combination of the ion interaction and the bonding.

The invention provides a preparation method of an anion exchange resin chromatographic packing, wherein PEI grafting and dihydroxyamine are common, but the PEI grafting and the dihydroxyamine are combined to increase the hydrophilic capacity of a space group of the PEI grafting and the dihydroxyamine, so that the effect of non-ionic combination on polarizable anions is reduced.

Drawings

FIG. 1 is a schematic diagram of the synthesis of a grafted anion exchange resin chromatography packing prepared in example 1;

FIG. 2 is a chromatogram of separation of 7 anions by an ion chromatographic column filled with the grafted anion exchange resin chromatographic packing prepared in example 2.

Detailed Description

The present invention will be further described with reference to the following examples. It is to be understood that the embodiments described are only a few embodiments of the present invention, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given in the introduction without inventive step, are within the scope of protection of the invention.

The invention provides a preparation method of a grafted anion exchange resin chromatographic packing, which comprises the following steps: s1, grafting carboxylic acid groups by utilizing double bonds suspended on the surfaces of polystyrene-divinylbenzene (PS-DVB) microspheres; s2, reacting the amine group of the polyethyleneimine branched chain with the polymer microsphere containing carboxylic acid groups by using a condensing agent to generate an amide bond, so as to obtain the polymer microsphere containing multistage amine groups on the surface; s3, reacting the polymer microsphere containing the multistage amino groups with an epoxy compound to obtain an epoxy group-containing polymer microsphere; s4, adding an amine compound containing beta dihydroxy into a polymer microsphere containing an epoxy group to react in a solution, wherein in the reaction, an epoxy branched chain reacts with the amine compound containing beta dihydroxy, hydroxyl is introduced to the surface of the polymer, and meanwhile, an epoxy bond is broken to obtain beta hydroxy, so that the anion exchange resin chromatographic packing containing beta dihydroxy is obtained. The beta-dihydroxyl group can increase the hydrophilicity of the polymer microsphere on one hand and can provide a hyperbranched binding site on the other hand. The preparation method has the advantages of simple operation, better hydrophilicity and better chemical stability of the anion exchange resin chromatographic packing obtained by the grafting reaction.

According to an embodiment of the present invention, the surface of the polymeric microspheres contains double bonds, which enable further graft modification. Specifically, the polymer microspheres may be polystyrene-divinylbenzene microspheres or ethylvinylbenzene-divinylbenzene microspheres or allylglycidyl ester-divinylbenzene microspheres. The polymer microsphere has the particle size of 3-10 mu m, the crosslinking degree of 5-80% and the pore diameter of 50-2000A. In the present invention, the polymer microspheres have an aperture ratio and a particle diameter capable of maintaining the mechanical strength and pressure resistance of the polymer.

According to embodiments of the present invention, the carboxylic acid groups grafted to the polymer microspheres may be acrylic acid or methacrylic acid, or thioglycolic acid, and the carboxylic acid groups are capable of reacting with residual double bonds on the surface of the polymer, introducing the carboxylic acid groups to the surface of the polymer microspheres, and without introducing excessive branching. Generally, fewer branches create less steric hindrance near the target group to be reacted, enabling the reaction to proceed quickly in a short time.

According to the embodiment of the invention, the molecular weight of the polyethyleneimine is within the range of 600-10000, and the structure of the polyethyleneimine is linear, branched or net-shaped, but in view of spatial distribution, the surface of the branched or net-shaped polyethyleneimine contains more amino groups, and after the polyethyleneimine reacts with carboxylic acid, the polyethyleneimine can provide required binding sites for subsequent experiments, so that the exchange capacity of the exchange resin is increased.

According to the embodiment of the invention, the beta dihydroxyamino compound can be N-methyldiethanolamine, N-ethyldiethanolamine or diethanolamine. The beta-dihydroxyamino compound is introduced to form quaternary ammonium group and provide beta-dihydroxyl radical to increase the hydrophilicity of the ion exchange resin stuffing.

According to the embodiment of the invention, in the step S1, a proper amount of ethanol can be added, so that the polymer microspheres are more uniformly dispersed, and the carboxylic acid grafting reaction time is set to be 2-24 h, so that the residual double bonds are fully reacted. If the reaction time is short, the double bond reaction is insufficient, the binding site is insufficient, and the chemical stability is poor. If the reaction time is prolonged, the process flow takes a long time, and in order to make the reaction more sufficient in an effective time, the grafting time should be properly selected.

According to the embodiment of the invention, in the step S2, the reaction temperature of the polymer microsphere containing carboxylic acid groups and the polyethyleneimine is within 50-80 ℃, the reaction time is 2-12 h, and the formation of amide bonds can be further facilitated under the catalysis of the condensing agent at a proper temperature and for an effective time length.

According to the embodiment of the invention, in the step S3, the reaction temperature of the epoxy compound and the polymer microsphere containing the multistage amino group is 50-80 ℃, the reaction time is 30-120 min, the exchange capacity of the exchange resin can be increased to a certain extent if the reaction time is too long or the temperature is too high, but the peak emergence time is long due to the too high capacity, and the overall effect of the chromatographic column is affected.

According to the embodiment of the invention, in step S4, the reaction temperature of the amine compound containing β -dihydroxy and the polymer microsphere containing epoxy group is set to 50-80 ℃, the reaction time is 30-120 min, and the epoxy group in the epoxy compound reacts with a large amount of free amine groups on the surface of the polymer microsphere to convert into quaternary amine groups at the reaction temperature and the reaction time.

In conclusion, the method for preparing the grafted anion exchange resin chromatographic packing has the advantages of simple synthetic process operation, fast reaction and good stability.

In a further aspect of the present invention, the present invention provides a grafted anion exchange resin chromatographic packing obtained by the above embodiment, which can further improve the separation performance of an ion chromatographic column.

According to the specific embodiment of the invention, in the preparation method of the grafted anion exchange resin chromatographic packing, the column loading pressure can be selected from 20-60 MPa, and the column loading time can be selected from 0.5-3 h.

The following is a specific example of the present invention, and 7 anions were tested using the prepared ion-packed exchange resin.

Example 1

Reagent: acrylic acid, 2- (7-azabenzotriazole) -N, N, N ', N' -tetramethyluronium Hexafluorophosphate (HATU), Polyethyleneimine (PEI), 1, 4-butanediol diglycidyl ether, N-methyldiethanolamine solution were purchased from Highai avastin; PS/DVB microspheres (particle size 5 microns, degree of crosslinking 55%, pore size 300A) were purchased from Sozhou Nami Microscience, Inc.

The instrument equipment comprises: the device comprises a three-neck flask, a G4 sand core funnel and suction filtration device, a mechanical stirring device, a Wan instrument 6100 ion chromatograph and a column packing machine.

(1) Weighing 3g of polymer microspheres, dissolving the polymer microspheres in 45mL of 20% ethanol solution, placing the solution into a 100mL three-neck flask after uniform ultrasonic dispersion, then placing the flask into a water bath at 70 ℃, adding 2.4mL of acrylic acid and 15mL of azobisisobutyronitrile with the concentration of 1%, and continuing to mechanically stir for 4 hours. And after the reaction is stopped, carrying out suction filtration on the reaction product by using a sand core funnel of G4, washing the reaction product for three times by using ethanol and deionized water in sequence, and drying the reaction product for later use.

(2) Placing the polymer in a three-neck flask, adding 40mL of a mixed solution of 2% HATU and 10% PEI, setting the reaction temperature at 65 ℃, mechanically stirring for 4 hours, after the reaction is stopped, performing suction filtration on a reaction product by using a sand core funnel of G4, and then washing the reaction product by deionized water for three times.

(3) Transferring the polymer into a three-neck flask, adding 60mL of 10% 1, 4-butanediol diglycidyl ether solution, setting the reaction temperature at 60 ℃, mechanically stirring for 1h, performing suction filtration by using a G4 sand core funnel after the reaction is finished, and then washing with deionized water for three times.

(4) And transferring the cleaned polymer into a three-neck flask, adding 60mL of N-methyldiethanolamine solution with the concentration, setting the reaction temperature to be 60 ℃, mechanically stirring for 1h, performing suction filtration by using a G4 sand core funnel after the reaction is finished, and then washing with deionized water for three times. Drying for standby, the synthetic schematic diagram of which is shown in figure 1.

Example 2

Anion exchange resin Filler Performance testing

Weighing the prepared ion exchange resin filler, adding 50mL of deionized water, performing ultrasonic oscillation for 2min, removing bubbles, pouring the solution into a homogenizing tank of a column filling machine after the solution is uniformly dispersed, adjusting the pressure of the column filling machine to 30MPa, taking down a chromatographic column after the column filling machine is filled for 1h, and testing the separation performance after the column filling machine is packaged.

And (3) testing conditions are as follows:

testing reagent: 7 common anions (F)^-、Cl^-、NO^2-、Br^-、NO^3-、PO₄ ^3-、SO4^2-)

Flow rate: 1.2 mL/min;

leacheate: 10mM KOH

A chromatographic column: 4.6 x 150mm

FIG. 2 is a diagram of the chromatographic separation of the above 7 common anions. The figure shows that the ions can be completely separated, which shows that the chromatographic column packing has excellent separation effect on 7 anions, and can realize rapid separation on 7 anions within 12 min.