CN113398781B - A kind of microporous membrane material, preparation method and application thereof - Google Patents

Abstract

The invention discloses a microporous filter membrane material and a preparation method and application thereof, belonging to the technical field of microporous filter membrane materials. The microporous filter membrane material is prepared by carrying out amidation reaction on a hydrolyzed polyamide filter membrane obtained by hydrolyzing a polyamide filter membrane to form benzoyl. The method can effectively retain particulate impurities in a sample solution, and simultaneously avoids the adsorption of a traditional polyamide microporous filter membrane on a target compound containing carboxyl or hydroxyl in a water-methanol or water-acetonitrile solution system, thereby expanding the application range of the traditional polyamide microporous filter membrane. It can be used for preparing microporous filter membrane, especially syringe type microporous filter membrane. The microporous filter membrane material and the corresponding microporous filter membrane can be used for filtering sample solution, especially sample solution in food safety detection, and can improve the accuracy of detection results.

Description

A kind of microporous membrane material, preparation method and application thereof

technical field

The invention relates to the technical field of microporous filter membrane materials, in particular, to a microporous filter membrane material and a preparation method and application thereof.

Background technique

In the detection of food safety samples, food samples generally undergo pretreatment steps such as extraction, purification, concentration, reconstitution, and filtration, and then obtain a sample solution for analysis by analytical instruments.

The extraction of the target substance in food samples generally uses organic solvents such as acetonitrile and methanol. After the sample extract is purified, the organic solvent is further evaporated through the concentration process, and then a solution containing a certain proportion of aqueous phase (such as water-acetonitrile, water- Methanol, etc.) to dissolve the solid residue. However, the presence of aqueous phase in the solution often leads to the incomplete dissolution of sample residues, resulting in insoluble solid particles, and the reconstituted sample solution becomes a cloudy suspension.

Therefore, filtration of the sample solution is a critical step. The purpose of filtration is to remove the particulate impurities in the sample solution through the sieve interception, so as to avoid the damage of these particulate impurities to the analytical instrument (such as blocking the pipeline, blocking the chromatographic column, blocking the injection needle, contaminating the sprayer, etc.), and Reduce the interference of impurities on subsequent instrument detection signals.

At present, the filtration of sample solution mainly adopts the method of microporous membrane, and the membrane material includes polyamide, vinylidene fluoride, polytetrafluoroethylene, etc. Among them, polyamide (commonly known as "nylon") filter membrane is the most widely used in practice due to its advantages of simple synthesis process, low cost, high mechanical strength, and resistance to organic solvents. However, the polyamide membrane may also adsorb the target compounds containing carboxyl or hydroxyl groups to be detected in the solution while retaining the solid particle impurities. As a result, the detection results of such compounds are unstable and the recovery rate is reduced.

In view of this, the present invention is proposed.

SUMMARY OF THE INVENTION

One of the objectives of the present invention is to provide a microporous membrane material, which can effectively retain particulate impurities in a sample solution while avoiding the traditional polyamide microporous membrane in the water-methanol or water-acetonitrile solution system. Adsorption of carboxyl or hydroxyl target compounds.

Another object of the present invention is to provide a preparation method of the above-mentioned microporous membrane material.

The third object of the present invention is to provide an application of the above-mentioned microporous membrane material, such as for filtering a sample solution.

The fourth object of the present invention is to provide a microporous filter membrane containing the above-mentioned microporous filter membrane material.

The fifth object of the present invention is to provide an application of the above-mentioned microporous filter membrane, such as for filtering a sample solution.

The present invention can be realized as follows:

In a first aspect, the present invention provides a microporous filter membrane material, which is prepared from a hydrolyzed polyamide filter membrane obtained by hydrolysis of a polyamide filter membrane and subjected to an amidation reaction to form a benzoyl group.

In an optional embodiment, the pore size of the polyamide filter in the microporous filter material is 0.2-0.5 μm.

In a second aspect, the present invention provides a method for preparing a microporous filter membrane material according to the aforementioned embodiment, comprising the following steps: subjecting a hydrolyzed polyamide filter membrane obtained by hydrolysis of the polyamide filter membrane to an amidation reaction to form a benzoyl group.

In an optional embodiment, the hydrolyzed polyamide filter membrane is mixed with benzoic acid so that the amino groups in the hydrolyzed polyamide filter membrane react with benzoic acid to form a benzoyl group to obtain a benzoyl group surface-modified microporous filter membrane material.

In an optional embodiment, the hydrolysis includes: hydrolyzing the polyamide filter membrane in an alkaline solution to form a hydrolyzed polyamide filter membrane.

In an alternative embodiment, the solute in the alkaline solution includes sodium hydroxide or potassium hydroxide, and the solvent in the alkaline solution includes water, ethanol-water solution, methanol-water solution, or acetonitrile-water solution.

In a preferred embodiment, the alkaline solution is obtained by dissolving sodium hydroxide in an ethanol-water solution.

In an optional embodiment, the concentration of sodium hydroxide in the ethanol-water solution is 0.01-0.1 mol/L, preferably 0.05 mol/L.

In an alternative embodiment, the concentration of ethanol in the ethanol-water solution is 80-95 vt%, preferably 95 vt%.

In an alternative embodiment, the hydrolysis temperature is 20-80°C, preferably 60°C.

In an optional embodiment, the hydrolysis time is 10-30 min, preferably 20 min.

In an alternative embodiment, the hydrolysis is performed under shaking conditions.

In an optional embodiment, the preparation method further comprises: removing the residual sodium hydroxide on the surface of the hydrolyzed polyamide filter membrane.

In an optional embodiment, removing the sodium hydroxide comprises: immersing the hydrolyzed polyamide filter membrane in the first washing solution and performing ultrasonic treatment.

In an optional embodiment, the first washing solution is water or ethanol-water solution, preferably 45-55 vt% ethanol-water solution, more preferably 50 vt% ethanol-water solution.

In an optional embodiment, the washing comprises: soaking the hydrolyzed polyamide filter membrane in a 50 vt% ethanol-water solution, and after ultrasonic treatment, removing the ethanol-water solution.

In an optional embodiment, the amidation reaction is to react the washed hydrolyzed polyamide filter membrane with a solution containing benzoic acid.

In an optional embodiment, the benzoic acid-containing solution is a benzoic acid-ethanol solution or a benzoic acid-methanol solution.

In a preferred embodiment, the benzoic acid-containing solution is a benzoic acid-ethanol solution.

In an optional embodiment, the concentration of benzoic acid in the benzoic acid-ethanol solution is 1-5 vt%, preferably 5 vt%.

In an alternative embodiment, the amidation reaction temperature is 50-90°C, preferably 80°C.

In an optional embodiment, the amidation reaction time is 20-60 min, preferably 40 min.

In an optional embodiment, the preparation method further comprises washing the benzoyl surface-modified microporous filter material to neutrality.

In an optional embodiment, the washing includes: soaking the benzoyl-surface-modified microporous filter membrane material in a second washing solution, and performing ultrasonic treatment.

In an optional embodiment, the second washing solution comprises water or ethanol-water solution, preferably 45-55 vt% ethanol-water solution, more preferably 50 vt% ethanol-water solution.

In an optional embodiment, the benzoyl-surface-modified microporous membrane material is immersed in a 50 vt% ethanol-water solution, and after ultrasonic treatment, the ethanol-water solution is removed.

In an optional embodiment, the preparation method further includes: drying the benzoyl-surface-modified microporous filter membrane material washed to neutrality.

In an alternative embodiment, drying is performed at 45-55°C for 50-70 minutes, preferably 50°C for 60 minutes.

In a third aspect, the present invention provides the application of the microporous membrane material according to the foregoing embodiments, such as for filtering a sample solution.

In an optional embodiment, the sample solution is a sample solution for food safety testing.

In a fourth aspect, the present invention provides a microporous filter membrane comprising the microporous filter membrane material of the foregoing embodiments.

In an optional embodiment, the microporous filter membrane is a syringe-type microporous filter membrane.

In an optional embodiment, the syringe-type microporous filter membrane includes an upper shell and a lower shell that are engaged with each other, and the microporous membrane material is sandwiched between the upper shell and the lower shell.

In an optional embodiment, the syringe-type microporous filter membrane further includes a syringe interface connected to the upper housing, and the syringe interface and the microporous filter membrane material are not parallel and not collinear.

In an optional embodiment, the syringe-type microporous filter membrane further comprises a needle plug interface connected with the lower housing, and the needle plug interface and the microporous filter membrane material are not parallel and not collinear.

In a fifth aspect, the present invention provides the application of the microporous filter membrane according to the previous embodiment, such as for filtering a sample solution.

In an optional embodiment, the sample solution is a sample solution for food safety detection.

The beneficial effects of the present invention include:

The benzoyl group is formed by amidation reaction of the hydrolyzed polyamide filter membrane obtained by hydrolysis of the polyamide filter membrane to obtain a microporous filter membrane material modified on the surface of the benzoyl group, which can block the residual amino groups on the membrane surface, so that it can While effectively retaining particulate impurities in the sample solution, it avoids the adsorption of carboxyl or hydroxyl group-containing target compounds by traditional polyamide microfiltration membranes in water-methanol or water-acetonitrile solution systems, and expands the application range of polyamide microporous membranes. . It can be used to prepare microporous membranes, especially syringe-type microporous membranes. The above-mentioned microporous filter membrane material and the corresponding microporous filter membrane can be used to filter sample solutions, especially sample solutions in food safety testing, which can improve the accuracy of testing results.

Description of drawings

In order to illustrate the technical solutions of the embodiments of the present invention more clearly, the following briefly introduces the accompanying drawings used in the embodiments. It should be understood that the following drawings only show some embodiments of the present invention, and therefore do not It should be regarded as a limitation of the scope, and for those of ordinary skill in the art, other related drawings can also be obtained according to these drawings without any creative effort.

FIG. 1 is a schematic structural diagram of the syringe-type microporous filter membrane provided in Example 5 of the present application.

Icons: 1-Upper shell; 2-Lower shell; 3-Microporous membrane material; 4-Syringe interface; 5-Needle plug interface.

Detailed ways

In order to make the objectives, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be described clearly and completely below. If the specific conditions are not indicated in the examples, it is carried out according to the conventional conditions or the conditions suggested by the manufacturer. The reagents or instruments used without the manufacturer's indication are conventional products that can be purchased from the market.

The microporous filter membrane material provided in the present application and its preparation method and application will be specifically described below.

The present application proposes a microporous filter membrane material, which is prepared from a hydrolyzed polyamide filter membrane obtained by hydrolysis of a polyamide filter membrane and subjected to amidation reaction to form a benzoyl group.

It is worth emphasizing that there are a certain number of amino groups on the surface of the untreated polyamide membrane, which can react with compounds containing carboxyl or hydroxyl groups in the solution in a solution system containing an aqueous phase, resulting in the retention of solid particles while retaining impurities. , it may also adsorb the target compounds containing carboxyl or hydroxyl groups to be detected in the solution, making the detection results of such compounds unstable and the recovery rate reduced. In this application, by modifying the polyamide microporous membrane with benzoyl groups, the residual amino groups on the surface of the membrane are blocked, which can effectively reduce the effect of the polyamide microporous membrane on the target compounds containing carboxyl or hydroxyl groups in the water-methanol or water-acetonitrile solution system. Adsorption can be used to filter the sample solution in food safety testing, and the accuracy of the determination result of the target compound can be improved.

In an optional embodiment, the pore size of the polyamide filter in the microporous filter material is 0.2-0.5 μm.

The pore size of the microporous membrane has a great influence on the filtration of the sample solution: if the pore size of the microporous membrane is too large, it is easy to cause the microporous membrane to be unable to effectively retain solid particles and impurities, and it will not have an effective filtration effect; If the pore size of the filter membrane is too small, it is easy to cause solid particles to block the filter membrane, so that the filtrate cannot pass through the filter membrane smoothly. The present application adopts a polyamide filter membrane with a pore size of 0.2-0.5 μm, which can not only effectively retain the particulate matter in the sample solution, but also ensure that the sample solution passes through the filter membrane smoothly.

Correspondingly, the present invention also provides a method for preparing the above-mentioned microporous filter membrane material, which may include the following steps: subjecting the hydrolyzed polyamide filter membrane obtained by hydrolysis of the polyamide filter membrane to an amidation reaction to form a benzoyl group.

Specifically, the hydrolyzed polyamide filter membrane is mixed with benzoic acid, so that the amino groups in the hydrolyzed polyamide filter membrane are reacted with benzoic acid to form a benzoyl group to obtain a benzoyl group surface-modified microporous filter membrane material.

By hydrolyzing the polyamide filter membrane in an alkaline solution, the amino groups on the membrane surface can be exposed and activated (that is, the amide bonds on the surface of the polyamide filter membrane are converted into active amino groups), which is beneficial to the subsequent reaction with benzoic acid. Then, it is mixed with benzoic acid solution, so that the activated amino groups on the membrane surface react with benzoic acid to form benzoyl groups, and the residual amino groups on the membrane surface are blocked.

In an optional embodiment, the hydrolysis may be to hydrolyze the polyamide filter membrane in an alkaline solution to form a hydrolyzed polyamide filter membrane.

Wherein, the solute in the alkaline solution may include sodium hydroxide or potassium hydroxide, and the solvent in the alkaline solution may include water, ethanol-water solution, methanol-water solution or acetonitrile-water solution.

In some preferred embodiments, the alkaline solution is obtained by dissolving sodium hydroxide in an ethanol-water solution.

For reference, the concentration of sodium hydroxide in the ethanol-water solution can be 0.01-0.1 mol/L, such as 0.01 mol/L, 0.05 mol/L, 0.08 mol/L or 0.1 mol/L, etc., preferably 0.05 mol/L. L.

It is worth noting that too low concentration of alkaline solution is not conducive to the progress of the hydrolysis reaction, and too high concentration may cause excessive hydrolysis and damage the surface structure of the filter membrane. In the present application, the concentration of sodium hydroxide in the ethanol-water solution is preferably controlled to 0.05mol/L, which can effectively activate the residual amino groups on the surface of the polyamide filter membrane, and prevent excessive hydrolysis to form more active amino groups.

For reference, the concentration of ethanol in the ethanol-water solution may be 80-95vt%, such as 80vt%, 85vt%, 90vt% or 95vt%, etc., preferably 95vt%.

The ethanol-water solution with a concentration of 95 vt% can not only fully accommodate hydroxide ions and inorganic salt ions, but also has low surface tension and can fully contact the surface of the polyamide membrane, which is beneficial to the hydrolysis reaction.

For reference, the hydrolysis temperature can be 20-80°C, such as 20°C, 40°C, 50°C, 60°C or 80°C, etc., preferably 60°C.

The increase of temperature is helpful for the progress of the hydrolysis reaction, and preferably 60° C. can not only ensure the smooth progress of the hydrolysis reaction, but also facilitate the safety protection of operators.

For reference, the hydrolysis time can be 10-30min, such as 10min, 15min, 20min, 25min or 30min, etc., preferably 20min.

Preferably, the hydrolysis is carried out under shaking conditions.

It is worth noting that the residual hydroxyl groups on the surface of the polyamide filter membrane can be fully activated by shaking and hydrolyzing the polyamide filter membrane in a 95vt% ethanol-water solution containing 0.05mol/L sodium hydroxide at 60°C for 20min. It will not be excessively hydrolyzed and destroy the original structure and properties of the filter membrane.

Further, the preparation method further comprises: removing the residual sodium hydroxide on the surface of the hydrolyzed polyamide filter membrane.

For reference, removing the sodium hydroxide may include: immersing the hydrolyzed polyamide filter membrane in the first washing solution, and performing ultrasonic treatment.

The first washing solution may be water or an ethanol-water solution, that is, pure water, or an ethanol-water solution containing ethanol of any concentration. In some preferred embodiments, the first washing solution is 45-55 vt% ethanol-water solution, more preferably 50 vt% ethanol-water solution.

In an optional embodiment, the washing includes: soaking the hydrolyzed polyamide filter membrane in a 50 vt% ethanol-water solution, and after ultrasonic treatment (eg, 5-15 min), removing the ethanol-water solution. It can then be rinsed with pure water until the pH of the rinsed aqueous solution is 6.5-7.5.

In the present application, amidation reaction is to react the washed hydrolyzed polyamide filter membrane with a solution containing benzoic acid.

For reference, the solution containing benzoic acid may be a benzoic acid-ethanol solution or a benzoic acid-methanol solution, and may also be a solution jointly formed by other solvents capable of dissolving benzoic acid and benzoic acid. In a preferred embodiment, the benzoic acid-containing solution is a benzoic acid-ethanol solution.

In an optional embodiment, the concentration of benzoic acid in the benzoic acid-ethanol solution can be 1-5vt%, such as 1vt%, 2vt%, 3vt%, 4vt% or 5vt%, etc., preferably 5vt%.

It is worth noting that increasing the concentration of benzoic acid helps to improve the amidation reaction speed, but the solubility of ethanol to benzoic acid is limited, and adding excess benzoic acid to ethanol will lead to saturation of the solution and waste of reagents.

For reference, the amidation reaction temperature can be 50-90°C, such as 50°C, 60°C, 70°C, 80°C or 90°C, etc., preferably 80°C.

Taking 80°C as the amidation reaction temperature can be more conducive to the amidation reaction than other temperature conditions, and is conducive to the quick volatilization of the water produced in the amidation reaction.

For reference, the amidation reaction time can be 20-60min, such as 20min, 30min, 40min, 50min or 60min, etc., preferably 40min.

By controlling the amidation reaction time within the above-mentioned range, on the one hand, it can avoid that the reaction time is too short to cause insufficient reaction, and on the other hand, it can avoid that the reaction time is too long and cause the efficiency to decrease. Taking 40 min as the amidation reaction time can ensure that the active amino groups on the surface of the polyamide filter membrane are fully amidated to form the benzoyl modified polyamide filter membrane.

Further, the benzoyl surface-modified microporous membrane material was washed to neutrality.

For reference, the washing of the benzoyl-surface-modified microporous filter material may be: soaking the benzoyl-surface-modified microporous filter material in a second washing solution and performing ultrasonic treatment.

The second washing solution may also include water or an ethanol-water solution, specifically pure water, or an ethanol-water solution containing any concentration of ethanol. In some preferred embodiments, the second wash solution is 45-55 vt% ethanol-water solution, more preferably 50 vt% ethanol-water solution.

In an optional embodiment, the washing of the benzoyl-surface-modified microporous membrane material can be immersing the benzoyl-surface-modified microporous membrane material in a 50 vt% ethanol-water solution, and ultrasonically treating (such as After 5-15 min), the ethanol-aqueous solution was removed. Then, it can be repeatedly washed with 50vt% ethanol-water solution according to the above conditions, and then washed with pure water until the pH of the washed water solution is 6.5-7.5, indicating that the residual free benzoic acid on the membrane surface is effectively removed.

Further, the benzoyl surface-modified microporous filter membrane material washed to neutrality is dried.

For reference, the drying can be carried out under the condition of 45-55°C for 50-70min, preferably under the condition of 50°C for 60min.

It is worth emphasizing that the degree of hydrolysis-activated surface amino groups of polyamide membranes depends on the concentration of alkaline solution, hydrolysis conditions and the nature of the solvent, and the degree of benzoyl modification depends on the concentration of benzoic acid solution, reaction temperature, reaction time and The properties of the solvent and the effect of different conditions are different. The inventor obtained the above-mentioned preparation conditions of the present application only after long-term research and numerous tests and verifications. By cooperating with the above-mentioned conditions, the prepared microporous filter membrane material can effectively retain the particulate impurities in the sample solution, while at the same time, Avoid adsorption of carboxyl- or hydroxyl-containing target compounds on polyamide filters in water-methanol or water-acetonitrile solution systems.

In addition, the present application also provides the application of the above-mentioned microporous membrane material, for example, it can be used to filter a sample solution. Among them, the sample solution is preferably a sample solution used for food safety detection, which can effectively improve the accuracy of the measurement data of the target compound containing carboxyl or hydroxyl groups.

In addition, the present application also provides a microporous filter membrane, which includes the above-mentioned microporous filter membrane material.

In some optional embodiments, the above-mentioned microporous filter membrane is a syringe type microporous filter membrane.

For reference, the syringe-type microporous filter membrane includes an upper shell and a lower shell that are engaged with each other, and the microporous membrane material is sandwiched between the upper shell and the lower shell. The size of the microporous membrane material is consistent with the size of the contact surface between the upper casing and the lower casing. The peripheral edge of the microporous filter membrane material is used for abutting with the inner wall where the upper casing and the lower casing are buckled.

Further, the syringe-type microporous filter membrane further includes a syringe interface connected with the upper casing, and the syringe interface and the microporous filter membrane material are not parallel and not collinear.

Specifically, the setting direction of the syringe interface and the microporous membrane material sandwiched between the upper and lower housings are at a certain angle, preferably 90°, so that the sample solution injected from the syringe interface can pass through the microporous filter membrane. Material is well filtered.

Further, the syringe-type microporous filter membrane further includes a needle plug interface connected with the lower casing, and the needle plug interface and the microporous filter membrane material are not parallel and not collinear.

Specifically, the setting direction of the needle plug interface and the microporous filter membrane material sandwiched between the upper and lower casings also form a certain angle, preferably 90°.

Correspondingly, the present invention also provides the application of the above-mentioned microporous filter membrane, which can also be used to filter the sample solution to retain particulate impurities in the sample solution through physical action, and the filtrate can be used for subsequent instrument analysis. Similarly, the sample solution is preferably a sample solution used for food safety detection, which can effectively improve the accuracy of the measurement data of the target compound containing carboxyl or hydroxyl groups.

The features and performances of the present invention will be further described in detail below in conjunction with the embodiments.

Example 1

The present embodiment provides a preparation method of a benzoyl surface-modified polyamide microporous filter membrane material, which is specifically as follows:

Step (1): Weigh 2.00g of sodium hydroxide, dissolve it with about 200mL of 95vt% ethanol-water solution, let it stand until the sodium hydroxide solution is cooled to room temperature, and transfer all the cooled sodium hydroxide solution to a 1000mL volumetric flask , wash the beaker twice with 100mL 95vt% ethanol-water solution, transfer the solution to a volumetric flask, and then dilute to 1000mL with 95vt% ethanol-water solution, which is 0.05mol/L sodium hydroxide-95vt% ethanol-water solution;

Step (2): Take 400mL of 0.1mol/L sodium hydroxide-95vt% ethanol-water solution in a 500mL wide-mouth bottle, completely immerse a polyamide membrane with a pore size of 0.2-0.5μm in the solution, and place it in a constant temperature oscillator at Hydrolyzed for 20 min at 60°C and 200 rpm to obtain a hydrolyzed polyamide membrane;

Step (3): after the hydrolysis is completed, take out the hydrolyzed polyamide filter membrane, add 400 mL of 50% ethanol-water solution (the first washing solution), ultrasonicate for 10 min, discard the solution, and then rinse the filter membrane with pure water until the pH of the aqueous solution is 7.0±0.5;

Step (4): weigh 50 g of benzoic acid and place it in a reagent bottle, then add 1000 mL of absolute ethanol to it, and ultrasonicate it for 30 min to dissolve it to obtain a 5vt% benzoic acid-ethanol solution;

Step (5): take 400mL of 5vt% benzoic acid-ethanol solution in a 500mL wide-mouth bottle, completely immerse the hydrolyzed polyamide membrane after washing in the above step (4) in the above-mentioned benzoic acid-ethanol solution, and place it in a constant temperature oscillator The reaction was carried out at 80 °C and 200 rpm for 40 min to obtain a benzoyl surface-modified microporous membrane material;

Step (6): immerse the above-mentioned benzoyl surface-modified microporous membrane material in 50vt% ethanol-water solution (second washing solution), after ultrasonic treatment for 10min, discard the 50vt% ethanol-water solution, and repeat the operation once; Rinse with pure water until the pH of the aqueous solution is 7.0±0.5;

Step (7): placing the above-mentioned cleaned formyl surface-modified microporous filter membrane material in a blast air dryer, and drying at 50° C. for 1 hour.

Among them, the specifications of the materials and reagents used are as follows:

Sodium hydroxide: CAS No. 1310-73-2, analytical grade.

Benzoic acid: CAS No. 65-85-0, analytical grade.

Formic acid: CAS No. 64-18-6, chromatographically pure.

Ethanol: CAS No. 64-17-5, chromatographically pure.

Acetonitrile: CAS No. 75-05-8, chromatographically pure.

Methanol: CAS No. 67-56-1, chromatographically pure.

Anhydrous ethanol: CAS No. 64-17-5, analytical grade.

Polyamide microporous membrane: the pore size is 0.2 μm to 0.5 μm.

Fusaric acid: CAS No. 303-47-9, purity ≥99%.

Fumonisin B1: CAS No. 116355-83-0, purity ≥99%.

Penicillic acid: CAS No. 90-65-3, purity ≥99%.

Mycophenolic acid: CAS No. 24280-93-1, purity ≥99%.

The experimental water was Milli-Q ultrapure water.

Example 2

The difference between this embodiment and embodiment 1 is (the remaining operation steps and conditions are the same):

The alkaline solution used for hydrolysis is 0.01mol/L sodium hydroxide-80vt% ethanol aqueous solution.

The hydrolysis temperature was 20°C, and the hydrolysis time was 30 min.

The first wash was a 45 vt% ethanol-water solution.

The benzoic acid-containing solution was a 1 vt% benzoic acid-ethanol solution.

The amidation reaction temperature was 50°C, and the amidation reaction time was 60 min.

The second wash was a 45 vt% ethanol-water solution.

Drying was carried out at 45°C for 70 minutes.

Example 3

The difference between this embodiment and embodiment 1 is (the remaining operation steps and conditions are the same):

The alkaline solution used in the hydrolysis is 0.1 mol/L sodium hydroxide-90 vt% ethanol aqueous solution.

The hydrolysis temperature was 80°C, and the hydrolysis time was 10 min.

The first wash was a 55 vt% ethanol-water solution.

The benzoic acid-containing solution was a 3 vt% benzoic acid-ethanol solution.

The amidation reaction temperature was 90°C, and the amidation reaction time was 20 min.

The second wash was a 55 vt% ethanol-water solution.

Drying was carried out at 55°C for 50 min.

Example 4

The difference between this embodiment and embodiment 1 is (the remaining operation steps and conditions are the same):

The alkaline solution used in the hydrolysis is 0.05mol/L potassium hydroxide-95vt% methanol aqueous solution.

The first washing liquid is pure water.

The benzoic acid-containing solution was a 5 vt% benzoic acid-methanol solution.

The second washing liquid is pure water.

Example 5

This embodiment provides a syringe-type microporous filter membrane, please refer to FIG. 1 , the syringe-type microporous filter membrane includes an upper housing 1, a lower housing 2, a microporous filter membrane material 3, a syringe interface 4 and a needle Bolt interface 5.

The upper casing 1 and the lower casing 2 are engaged with each other, and the microporous membrane material 3 is sandwiched between the upper casing 1 and the lower casing 2 . The size of the microporous membrane material 3 is consistent with the size of the contact surface between the upper casing 1 and the lower casing 2 . The peripheral edge of the microporous filter membrane material 3 is used to abut against the inner wall of the place where the upper casing 1 and the lower casing 2 are buckled.

The syringe interface 4 is connected to the upper casing 1 and is at 90° with the microporous filter material 3 sandwiched between the upper and lower casings. The needle bolt interface 5 is connected to the lower casing 2 and is sandwiched between the upper and lower casings. The microporous membrane material 3 is 90°.

It can be prepared in the following manner: take an empty syringe-type microporous filter membrane shell (its structure includes the above-mentioned upper shell 1, lower shell 2, syringe interface 4 and needle plug interface 5), The benzoyl surface-modified polyamide microporous membrane material is cut into a circle with the same inner diameter as the shell of the hollow-syringe-type microporous membrane, and it can be placed in the shell of the hollow-syringe-type microporous membrane.

Test Example 1

Taking the benzoyl surface-modified polyamide microporous membrane material prepared in Example 1 as an example, the adsorption property was investigated.

The benzoyl surface-modified polyamide microporous membrane material prepared in Example 1 was used to filter three carboxyl-containing compounds in a 20vt% acetonitrile-water solution, and was used with ordinary polyamide microporous membranes (that is, The original polyamide filter membrane without hydrolysis and amidation reaction in Example 1) was compared.

The specific processing process is as follows:

(1) Preparation of mycotoxin solution

Take 0.1 mL each of the standard solutions of fusaric acid, fumonisin B1 and mycophenolic acid (solvent is acetonitrile) with a concentration of 100 μg/mL in a 50 mL volumetric flask, and dilute to 50 mL with 5vt% acetonitrile-water solution to obtain a concentration of 0.2 A mixed standard working solution of 3 mycotoxins including fusaric acid, fumonisin B1 and mycophenolic acid in μg/mL.

(2) Microporous membrane filtration

Take a syringe-type microporous membrane provided in Example 5, connect a 2mL plastic syringe at the upper end of the syringe interface, and use a glass injection vial to receive the filtrate at the lower end of the needle plug interface; draw 1mL of 3 kinds of mycotoxins mixed standard working solution in In the syringe, apply pressure with the syringe plunger to force the solution through the filter and into the glass injection vial; 5 in parallel.

Get a common syringe type polyamide microporous filter membrane (that is, replace the polyamide microporous membrane material in Example 5 with the original polyamide filter membrane without hydrolysis and amidation reaction), with the above operation steps to 3. A mixed standard working solution of mycotoxins was filtered, a total of 5 parallels.

(3) UPLC-MS/MS determination

A. Chromatographic conditions

Acquity UPLC BEH RP18 chromatographic column (100mm×2.1mm, 1.7μm, Waters, USA); mobile phase A: 0.1mM ammonium acetate solution (containing 0.1vt% formic acid); mobile phase B: methanol solution (containing 0.1vt% formic acid) ; column temperature 40°C; flow rate 0.3mL/min; injection volume 0.5μL. Gradient elution program: 0～2min, 95%A; 2～4min, 95%～80%A; 4min～12min, 80%～5%A; 12～12.1min, 5%～1%A; 12.1～13min , 1%A; 13～13.5min, 1%～95%A; 13.5～15min, 95%A.

B, mass spectrometry conditions

Electrospray ion source positive ion scanning (ESI+), multiple reaction monitoring mode (MRM), capillary voltage 0.6kV, ion source temperature 150℃, desolvation temperature 450℃, desolvation gas and cone gas are N ₂ , desolvation The air flow rate is 800L/h, and the cone air flow rate is 150L/h. The parameters such as parent ion, product ion, collision energy and cone voltage of the target compound are shown in Table 1.

Table 1 Retention time, precursor ion, product ion, cone voltage and collision energy of target compounds

^a is the quantitative ion.

(4) Result analysis

3 kinds of mycotoxin mixed standard working solution (A) without membrane filtration, 3 kinds of mycotoxin mixed standard working solution (B) filtered by benzoyl surface modified polyamide microporous membrane, and ordinary polyamide The mixed standard working solution (C) of the three mycotoxins filtered by the microporous membrane was used to determine the chromatographic peak areas of the three mycotoxins including fusaric acid, fumonisin B1 and mycophenolic acid by LC-MS/MS.

The recovery rate of mycotoxins was obtained by dividing the peak areas of the three mycotoxins in the solution after filtration by the peak areas of the three mycotoxins without filtration, and multiplying by 100%. The higher the recovery rate, the weaker the adsorption of the mycotoxin target by the filter; on the contrary, the lower the recovery rate, the stronger the adsorption of the filter to the mycotoxin target. The results are shown in Table 2.

Table 2 The recovery rates of three mycotoxins in 5vt% acetonitrile-water solution by different microporous membrane filtration

Target Benzoyl Surface Modified Polyamide Microporous Membrane Ordinary polyamide microporous membrane fusaric acid 92.3±2.1% 63.4±12.3% Fumonisin B1 91.4±3.3% 51.5±7.1% Mycophenolic Acid 100.3±2.8% 64.6±4.3%

Note: The recovery rate is expressed as mean ± standard deviation.

As shown in Table 2, the benzoyl surface-modified polyamide microporous membrane material prepared in Example 1 of the present application was used to filter 3 molds such as fusaric acid, fumonisin B1 and mycophenolic acid in a 5vt% acetonitrile-water solution The toxin, with an average recovery rate of 94.7%, indicated that an average of 94.7% of the three acid mycotoxins containing carboxyl groups in solution passed through the filter, and only an average of 5.3% was adsorbed on the filter.

Correspondingly, three kinds of mycotoxins such as fusaric acid, fumonisin B1 and mycophenolic acid in 5vt% acetonitrile-water solution were filtered by ordinary polyamide microporous membrane, and the average recovery rate was 59.8%. Only an average of 59.8% of the three acid mycotoxins containing carboxyl groups passed through the filter, and about 40.2% was adsorbed on the filter.

It can be seen from the comparison between the two that the benzoyl surface-modified polyamide microporous membrane material provided in Example 1 of the present application has an adsorption rate of less than 10% for acidic compounds containing carboxyl groups in the solution, while the adsorption rate of ordinary polyamide filter membranes reaches 40%. About, the benzoyl surface-modified polyamide microporous membrane provided in the present application has a far lower adsorption rate of acid compounds containing carboxyl groups in 5vt% acetonitrile-water solution than ordinary polyamide microporous membranes.

It can be seen that the benzoyl surface-modified polyamide microporous filter membrane prepared in the present application can overcome the strong adsorption of common polyamide microporous membranes to acidic compounds in solution, thereby improving the recovery rate of acidic compound filtration and expanding the common Applications of polyamide membranes.

Test Example 2

This test example provides the application of a syringe-type benzoyl surface-modified polyamide microporous membrane.

Use the syringe type benzoyl surface-modified polyamide microporous membrane provided in this application (the structure is the same as that in Example 5, and the membrane material is the benzoyl surface-modified polyamide microporous membrane material prepared in Example 1) , filter the sample solution during simultaneous determination of the three mycotoxins in the corn sample, and filter it with a common polyamide microporous membrane (that is, the original polyamide membrane without hydrolysis and amidation in Example 1). Compare the effects.

The specific processing process is as follows:

1. Pretreatment of Corn Samples

(1) Sample: Take 5g of mycotoxin-free blank corn sample and put it in a 50mL plastic centrifuge tube, add 0.01mL each of 100μg/mL fusaric acid, fumonisin B1 and mycophenolic acid standard solution (solvent is acetonitrile) , vortexed and mixed to prepare a spiked sample with a concentration of 0.2 μg/g of fusaric acid, fumonisin B1 and mycophenolic acid, respectively;

(2) Extraction: Add 10 mL of pure water and 20 mL of acetonitrile to the above-mentioned spiked sample, vortex for 1 min, add 3 g of sodium chloride, vortex for 1 min, centrifuge at 5000 rpm for 5 min, and take out the upper acetonitrile solution for later use (at this time) , the mycotoxins in the samples were extracted into acetonitrile solution);

(3) Purification: Take 5mL of the above-mentioned upper layer acetonitrile solution in a 10mL plastic centrifuge tube, add 500mg anhydrous magnesium sulfate and 500mg C18 purification material, vortex for 1min, centrifuge at 5000rpm for 5min in a centrifuge, take out 2mL supernatant and put it in another In a 10mL plastic centrifuge tube; dry with nitrogen at 60°C;

(4) Concentration: place the plastic centrifuge tube containing the above 2mL supernatant on a nitrogen blower, blow dry with nitrogen at a temperature of 60°C, then add 1mL 5vt% acetonitrile-water solution to the centrifuge tube, vortex for 1min, Make the solution fully dissolve the residue;

(5) Filtration: the above-mentioned sample concentrate is filtered with the benzoyl surface-modified polyamide microporous membrane and the common polyamide microporous membrane prepared by the present invention respectively, and the filtrate is placed in a sample injection vial for UPLC-MS/ M determination.

2. UPLC-MS/MS determination

(1) Chromatographic conditions

Acquity UPLC BEH RP18 chromatographic column (100mm×2.1mm, 1.7μm, Waters, USA); mobile phase A: 0.1mM ammonium acetate solution (containing 0.1vt% formic acid); mobile phase B: methanol solution (containing 0.1vt% formic acid) ; column temperature 40°C; flow rate 0.3mL/min; injection volume 0.5μL. Gradient elution program: 0～2min, 95%A; 2～4min, 95%～80%A; 4min～12min, 80%～5%A; 12～12.1min, 5%～1%A; 12.1～13min , 1%A; 13～13.5min, 1%～95%A; 13.5～15min, 95%A.

(2) Mass spectrometry conditions

Electrospray ion source positive ion scanning (ESI+), multiple reaction monitoring mode (MRM), capillary voltage 0.6kV, ion source temperature 150℃, desolvation temperature 450℃, desolvation gas and cone gas are N ₂ , desolvation The air flow rate is 800L/h, and the cone air flow rate is 150L/h. The parent ion, product ion, collision energy, cone voltage and other parameters of the target compound are the same as Table 1.

3. Analysis of results

According to the chromatographic peak areas of the three mycotoxins, the measured concentrations of the three mycotoxins in the spiked samples were calculated, and the measured concentrations were divided by the theoretical value of the sample spiked concentration (0.2 μg/g) to determine the recovery rate of the mycotoxins. The results are shown in Table 3.

Table 3 The recovery rate of 3 kinds of mycotoxins in corn sample concentrate by different microporous membrane filtration

Target Benzoyl Surface Modified Polyamide Microporous Membrane Ordinary polyamide microporous membrane fusaric acid 90.6±4.7% 57.1±9.4% Fumonisin B1 94.7±3.1% 44.7±6.2% Mycophenolic Acid 92.1±3.4% 60.1±3.5%

Note: The recovery rate is expressed as mean ± standard deviation.

As shown in Table 3, three kinds of mycotoxins such as fusaric acid, fumonisin B1 and mycophenolic acid in the corn sample concentrate were filtered by the syringe type benzoyl surface-modified polyamide microporous membrane provided in this application. The average recovery rate was 92.5%, indicating that 92.5% of the three acid mycotoxins containing carboxyl groups in the solution passed through the filter, and only an average of 7.5% was adsorbed on the filter.

Correspondingly, three kinds of mycotoxins such as fusaric acid, fumonisin B1 and mycophenolic acid in the corn sample concentrate were filtered by ordinary polyamide microporous membrane, and the average recovery rate was 54.0%, indicating that there were 3 mycotoxins in the solution. Only an average of 54.0% of the carboxyl-containing acid mycotoxins passed through the filter, and about 46.0% was adsorbed on the filter.

It can be seen from the comparison of the two that the syringe-type benzoyl surface-modified polyamide microporous filter membrane provided in this application has an adsorption rate of less than 10% for acidic compounds containing carboxyl groups in the corn sample concentrate, while the adsorption rate of ordinary polyamide filter membranes reaches 46%. %, and the adsorption rate of the carboxyl group-containing acid compound in the corn sample concentrate by the syringe-type benzoyl surface-modified polyamide microporous membrane provided by the application is much lower than that of the ordinary polyamide microporous membrane.

Comparative ratio

To sum up, in the present application, the hydrolyzed polyamide filter membrane obtained by the hydrolysis of the polyamide filter membrane is subjected to amidation reaction to form benzoyl groups, and the benzoyl group surface-modified microporous filter membrane material is prepared, which can seal the residual residues on the surface of the membrane. It can effectively retain the particulate impurities in the sample solution while avoiding the adsorption of the carboxyl or hydroxyl group-containing target compounds by the traditional polyamide microfiltration membrane in the water-methanol or water-acetonitrile solution system. Scope of application of microporous membranes. It can be used to prepare microporous membranes, especially syringe-type microporous membranes. The above-mentioned microporous filter membrane material and the corresponding microporous filter membrane can be used to filter sample solutions, especially sample solutions in food safety testing, which can improve the accuracy of testing results.

The above are only preferred embodiments of the present invention, and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims (36)

1. a microporous filter membrane material, is characterized in that, described microporous filter membrane material is obtained after the hydrolysis polyamide filter membrane that polyamide filter membrane obtains through hydrolysis carries out amidation reaction to form benzoyl; The hydrolysis includes: hydrolyzing the polyamide filter membrane in an alkaline solution to form a hydrolyzed polyamide filter membrane; the solute in the alkaline solution is sodium hydroxide, and the solvent in the alkaline solution is an ethanol-water solution; The concentration of the sodium hydroxide in the ethanol-water solution is 0.01-0.1 mol/L, the concentration of ethanol in the ethanol-water solution is 80-95 vt%; the hydrolysis temperature is 20-80 ° C; the hydrolysis time is 10- 30min; The amidation reaction is to react the hydrolyzed polyamide filter membrane with a solution containing benzoic acid; the solution containing benzoic acid is a benzoic acid-ethanol solution; the concentration of benzoic acid in the benzoic acid-ethanol solution is 1-5 vt% ; The amidation reaction temperature is 50-90°C; the amidation reaction time is 20-60min; The pore size of the polyamide filter membrane in the microporous filter membrane material is 0.2-0.5 μm. 2 . The method for preparing a microporous filter membrane material according to claim 1 , comprising the following steps: subjecting the hydrolyzed polyamide filter membrane obtained by hydrolysis of the polyamide filter membrane to an amidation reaction to form a benzoyl group. 3 . 3. preparation method according to claim 2 is characterized in that, described hydrolyzed polyamide filter membrane is mixed with benzoic acid to make the amino group in described hydrolyzed polyamide filter membrane and benzoic acid react to form benzoyl group, obtain Benzoyl surface-modified microporous membrane material. 4. preparation method according to claim 3 is characterized in that, the concentration of described sodium hydroxide in described ethanol-water solution is 0.05mol/L. 5. The preparation method according to claim 3, wherein the concentration of ethanol in the ethanol-water solution is 95 vt%. 6. The preparation method according to claim 3, wherein the hydrolysis temperature is 60°C. 7. preparation method according to claim 3 is characterized in that, hydrolysis time is 20min. 8. The preparation method according to claim 3, wherein the hydrolysis is carried out under shaking conditions. 9 . The preparation method according to claim 3 , wherein the preparation method further comprises: removing the residual sodium hydroxide on the surface of the hydrolyzed polyamide filter membrane. 10 . 10 . The preparation method according to claim 9 , wherein removing the sodium hydroxide comprises: immersing the hydrolyzed polyamide filter membrane in a first washing solution and performing ultrasonic treatment. 11 . 11. The preparation method according to claim 10, wherein the first washing solution is water or an ethanol-water solution. 12. The preparation method according to claim 11, wherein the first washing solution is 45-55 vt% ethanol-water solution. 13. The preparation method according to claim 12, wherein the first washing solution is a 50 vt% ethanol-water solution. 14. The preparation method according to claim 13, wherein the washing with the first washing solution comprises: immersing the hydrolyzed polyamide filter membrane in a 50 vt% ethanol-water solution, and after ultrasonic treatment, removing the Ethanol-water solution. 15 . The preparation method according to claim 9 , wherein the amidation reaction is to react the washed hydrolyzed polyamide filter membrane with a solution containing benzoic acid. 16 . 16. The preparation method according to claim 15, wherein the concentration of benzoic acid in the benzoic acid-ethanol solution is 5 vt%. 17. The preparation method according to claim 9, wherein the amidation reaction temperature is 80°C. 18. preparation method according to claim 9, is characterized in that, amidation reaction time is 40min. 19 . The preparation method according to claim 15 , wherein the preparation method further comprises washing the benzoyl surface-modified microporous membrane material to neutrality. 20 . 20 . The preparation method according to claim 19 , wherein the washing comprises: immersing the benzoyl-surface-modified microporous filter membrane material in a second washing solution and performing ultrasonic treatment. 21 . 21. The preparation method according to claim 20, wherein the second washing solution comprises water or an ethanol-water solution. 22. The preparation method according to claim 21, wherein the second washing solution is 45-55 vt% ethanol-water solution. 23. The preparation method according to claim 22, wherein the second washing solution is a 50 vt% ethanol-water solution. 24. The preparation method according to claim 23, wherein the benzoyl surface-modified microporous membrane material is immersed in 50 vt% ethanol-water solution, and after ultrasonic treatment, the ethanol-water solution is removed . 25 . The preparation method according to claim 20 , wherein the preparation method further comprises: drying the benzoyl-surface-modified microporous filter membrane material washed to neutrality. 26 . 26. The preparation method according to claim 25, wherein the drying is carried out under the condition of 45-55° C. for 50-70 min. 27. The preparation method according to claim 26, wherein the drying is carried out under the condition of 50°C for 60min. 28. The application of the microporous filter membrane material according to claim 1, wherein the microporous filter membrane material is used to filter a sample solution. 29. The application according to claim 28, wherein the sample solution is a sample solution for food safety detection. 30. A microporous filter membrane, comprising the microporous filter membrane material of claim 1. 31. The microporous filter membrane according to claim 30, wherein the microporous filter membrane is a syringe type microporous filter membrane. 32. The microporous filter membrane according to claim 31, wherein the syringe-type microporous filter membrane comprises an upper casing and a lower casing that are engaged with each other, and the microporous filter membrane material sandwiches between the upper casing and the lower casing. 33. The microporous filter membrane according to claim 32, wherein the syringe type microporous filter membrane further comprises a syringe interface connected with the upper housing, the syringe interface and the microporous filter The membrane materials are not parallel and not collinear. 34. The microporous filter membrane according to claim 33, wherein the syringe-type microporous filter membrane further comprises a needle plug interface connected with the lower casing, the needle plug interface is connected with the microporous filter. Pore filter materials are not parallel and not collinear. 35. The application of the microporous filter membrane according to any one of claims 30-34, wherein the microporous filter membrane is used to filter a sample solution. 36. The application according to claim 35, wherein the sample solution is a sample solution for food safety detection.

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