CN102814168A - Preparation method and application of loofah sponge surface malachite green molecular imprinting adsorbing material - Google Patents

Abstract

The invention discloses a malachite green molecularly imprinted adsorption material on the surface of loofah. Alcohol dimethacrylate is used as a cross-linking agent, azobisisobutyronitrile is used as an initiator, and tetrahydrofuran is used as a solvent to prepare the polymer, and the malachite green template molecule is removed with a hydrochloric acid-acetone mixed solution, and the above-mentioned loofah surface is also provided. The application method of malachite green molecularly imprinted adsorption material, the malachite green molecularly imprinted adsorption material on the surface of loofah of the present invention can separate and enrich malachite green in aqueous solution under normal temperature and pressure conditions, and has specificity and selectivity and good Excellent mechanical properties, good chemical stability, fast adsorption, easy elution, biodegradable, simple process, regeneration ability, and environmental friendliness, which can improve the detection limit of malachite green.

Description

A preparation method and application of malachite green molecularly imprinted adsorption material on the surface of loofah

technical field

The present invention relates to a preparation method and application technology of a molecularly imprinted adsorption material, in particular to a preparation method of a malachite green molecularly imprinted adsorption material on the surface of a loofah, and a method for rapidly detecting malachite green in aquatic products and water. Applied techniques in methods.

Background technique

Malachite green is a kind of green crystal with metallic luster. It belongs to triphenylmethane dyes. It was widely used in pottery, textile, leather, food and cell chemical staining in the middle of the last century. Since 1933, it has been used in aquaculture as an insect repellant, fungicide, and preservative. It has been used to prevent and treat saprolegniasis, gill mold disease, and small melon worm disease in various aquatic animals, especially in saprolegniasis. In the treatment of diseases, it has shown special effects. However, because malachite green and its metabolites have side effects such as inhibition of cholinesterase activity, high toxicity, high residue, carcinogenicity, teratogenicity, and mutagenicity, they are very harmful to humans. Many countries in the world have listed it as an aquaculture product. Banned drugs, in 1993 the US FDA listed malachite green as a carcinogenic chemical substance for priority research. In May 2002, my country included malachite green in the "List of Veterinary Drugs and Their Compounds Prohibited for Food Animals" (Announcement No. 193 of the Ministry of Agriculture). Malachite green has been listed as a prohibited drug for aquaculture in the "Guidelines for the Use of Pollution-free Food and Fishing Drugs in Agricultural Industry Standards of the People's Republic of China" (NY507122002). However, due to its remarkable effect and low price, there has not been a better substitute in the field of saprolegniasis prevention and control, and it is still widely used by aquaculture industry. It is one of the key organic pollutants monitored in product hygiene and safety. Therefore, it is very important to quickly and accurately detect malachite green in aquatic products, but because the matrix of aquatic products is relatively complex, it brings difficulties to the detection, so separation means should be used to separate malachite green from the matrix before detection ; while the amount of malachite green in the water of aquaculture aquatic products is very low, which cannot reach the detection limit of various analytical methods, and can only be accurately measured after enrichment. Therefore, a kind of adsorption material with specific selectivity to malachite green is synthesized. It is very important to separate and detect malachite green.

Highly selective materials with molecular recognition function have been attracting people's attention. Molecular imprinting technology is currently one of the main methods for preparing highly selective materials. Molecularly imprinted polymers prepared according to this technology have a predetermined and specific recognition performance due to the "memory" function of the three-dimensional structure of imprinted molecules, and have very broad application prospects in the fields of separation science and biomimetic science. Patent Application No. 200710304752.7 discloses a method for preparing malachite green molecularly imprinted polymers. The traditional method for preparing imprinted polymers is: dissolving template molecules, functional monomers, cross-linking agents and initiators in a certain proportion In a solvent (porogen), after initiating polymerization under appropriate conditions, a massive highly cross-linked rigid polymer is obtained. The currently reported malachite green molecularly imprinted polymers are all synthesized in this way; Sieve to obtain granules of the required size. The device required by this method is simple and universal, but there are usually the following problems: (1) the controllability is poor during the grinding process, some irregular particles are inevitably produced, and some imprinted spots are destroyed at the same time. Qualified particles are generally less than 50%, resulting in obvious waste; (2) template molecules are too deeply embedded, difficult to elute, template leakage and low mechanical properties; On the other hand, its mass transfer rate is faster, while others are embedded in the polymer body, affected by steric hindrance, have poor accessibility, and the rate of recombination with template molecules is slow, thereby reducing the utilization rate of imprinted sites. In order to solve the above problems, as a new method, surface imprinting has become a research hotspot in recent years. The so-called surface molecular imprinting is to take certain measures to combine all the binding sites on the surface with good accessibility, which is beneficial to the template. Detachment and recombination of molecules. Therefore, it is very important to choose an ideal support to synthesize surface imprinted adsorption materials. The supports currently used are mainly carbon microspheres and silica gel particles. The patents with application numbers 200410072308.3, 201010156001.7, and 201010242495.0 are all imprinted adsorption supported by silica gel spheres. Material; Patent Application No. 201010137822.6 discloses an imprinted adsorption material supported by carbon microspheres.

Resource shortage and environmental pollution have become two major problems in today's world. Therefore, using natural renewable resources to develop environmentally friendly products and technologies will become an inevitable trend of sustainable development. Loofah is a very rich renewable resource on the earth. It has the characteristics of light weight, low price, non-toxicity, large specific surface area, good mechanical properties, degradable and environmentally friendly, and it is hydrophilic and rich in ligands. , It is easy to carry out chemical modification, and it is an ideal polymer support. Domestic loofah modified as the application of adsorbent, in the patent application number 200810034735.0 discloses the alkalization modification method of loofah and its application; in the patent application number 200810034737.X discloses etherification loofah The preparation method and its application in metal ion adsorption, the preparation method of thiol functionalized loofah and its application in metal ion adsorption are disclosed in the patent application number 200910019165.2; it is disclosed in the patent application number 201010293780.5 The preparation of lead ion imprinted adsorption material on the surface of loofah and its application in the adsorption of lead ions are disclosed; the preparation method of a melamine molecularly imprinted adsorption material and its application in the adsorption of melamine are disclosed in the patent application number 201010293776.9. It is supported by loofah.

There are also studies abroad on the chemical modification and adsorption properties of loofah. Nasreen et al. studied the use of loofah as an immobilized carrier, attached to microella with special adsorption function for metal ions, to treat sewage containing Cd ²⁺ . However, there are no published patents and literature reports on using loofah as a support to synthesize malachite green molecularly imprinted adsorption materials.

Contents of the invention

One of the purposes of the present invention is to provide a preparation method of malachite green molecule imprinted adsorption material on the surface of loofah. Adsorption material with high selectivity and specific recognition ability.

The purpose of the present invention is achieved through the following technical solutions.

A method for preparing a malachite green molecularly imprinted adsorption material on the surface of loofah, characterized in that the method has the following process steps:

(1) Alkalized loofah: the natural material loofah and an appropriate amount of NaOH aqueous solution with a concentration of 8 to 12% by mass, soaked at room temperature for 20 to 30 hours, reacted azeotropically in the alkaline system for 0.5 to 1.5 hours, and cooled Finally, wash with deionized water until neutral, and dry at 80°C after suction filtration to obtain alkalized loofah;

(2) Preparation of mercapto loofah: the characteristics are: in the reactor, add according to the following composition mass percentages, mercaptoacetic acid: 25～40%, tetrahydrofuran: 32～50%, alkalized loofah: 15～30%, concentrated sulfuric acid: 0.10~0.5%, the sum of the contents of each component is 100%, stoppered, react at 40±2°C for 30~45h, then wash with deionized water and filter with suction until the filtrate is neutral, wash with a small amount of acetone , and dried in an oven at 40±2°C to obtain mercapto loofah;

(3) Alkylation loofah preparation: the characteristics are: in the reactor, add according to the following composition mass percentage, acetone: 50～75%, phenyl-trimethoxysilane: 5～15%, mercapto loofah: 12～ 30%, the sum of the contents of each component is 100%, stoppered, mixed evenly at room temperature, static reaction for 0.5-1.5h, then washed with deionized water, suction filtered until the filtrate is neutral, washed with a small amount of acetone, put Dried in an oven at 80±2°C to obtain alkylated loofah;

(4) Preparation of malachite green molecularly imprinted adsorption material on the surface of loofah: add according to the following composition mass percentage, tetrahydrofuran: 45-65%, malachite green: 0.4-1.2%, itaconic acid: 2.0-7.5%, methacrylic acid : 1.0～4.2%, ethylene glycol dimethacrylate: 15～36%, alkylated loofah: 10～28%, azobisisobutyronitrile: 0.3～1.0%, the sum of the contents of each component is 100%, pass inert gas for 5-15 minutes to remove oxygen, seal and isolate from the air, react in a constant temperature water bath at 65-70°C for 20-30 hours, filter and wash;

(5) Removal of template ions: Soxhlet extraction with 0.3mol/L～0.6mol/L hydrochloric acid acetone solution for 10～15h, and then wash with acetonitrile until no malachite green can be detected in the washing solution, place at 40 Drying in a vacuum drying oven at ±2°C is the malachite green molecularly imprinted adsorption material on the surface of the loofah.

Another object of the present invention is to provide the application of malachite green molecularly imprinted adsorption material on the surface of loofah in the identification and adsorption of malachite green in the analysis of aquatic products. The feature is: the prepared malachite green molecularly imprinted adsorption material on the surface of the loofah is directly placed in the aqueous solution, and is adsorbed by a static method; adsorption method, the flow rate is 0.10 ~ 0.45mL/min. After adsorption, it is eluted with 0.3mol/L-0.6mol/L acetone hydrochloride solution, and the content of malachite green in the eluent is determined by spectrophotometry.

Advantage and effect of the present invention are:

(1) The present invention prepares the malachite green molecularly imprinted adsorption material on the surface of the loofah, because it is a molecularly imprinted polymer on the surface of the loofah, and its adsorption sites are all on the surface of the adsorbent, which is conducive to the adsorption and elution of template molecules, The elution time is short, the adsorption capacity is strong, and the efficiency is high. Its maximum adsorption capacity for malachite green molecules is 312mg/g, and the highest adsorption rate can reach 95%. The supporting raw material loofah has a wide range of sources, is biodegradable, and is a renewable resource. Large-scale use can drive the agricultural industrialization process of my country's agriculture, especially in poor and backward areas, increase farmers' income, and has dual economic and social benefits.

(2) The preparation process of the malachite green molecularly imprinted adsorption material on the surface of the loofah of the present invention is simple, the conditions are easy to control, and the production cost is low.

(3) The highly selective adsorption material obtained by the present invention is malachite green molecularly imprinted adsorption material on the surface of loofah, with itaconic acid and methacrylic acid as bifunctional monomers, malachite green as imprinted molecules, and loofah as support body, and then add a cross-linking agent to prepare the malachite green molecularly imprinted adsorption material on the surface of loofah by bulk polymerization. The malachite green molecularly imprinted polymer prepared by the method has specific holes, has a specific recognition ability for malachite green, has high selectivity, and does not adsorb other coexisting substances.

(4) The malachite green molecularly imprinted adsorption material on the surface of the loofah prepared by the present invention has good physical and chemical stability and excellent mechanical stability, and the adsorption operation of the malachite green molecule is simple.

Description of drawings

Fig. 1 is a scanning electron microscope image of a dextran gel;

Figure 2 is a scanning electron micrograph of the Sudan Red molecularly imprinted adsorption material on the surface of the dextran gel;

Detailed ways

Example 1

(1) Loofah pretreatment: loofah is derived from loofah fruit, obtained by peeling and removing the core, cutting loofah into small pieces, washing with water, drying in vacuum, crushing, and sieving with a 20-mesh sieve;

(2) Preparation of alkalized loofah: 50% of the total mass of the loofah with pulverization, with a concentration of 8% NaOH aqueous solution, soaked at room temperature for 24h, azeotroped in this alkaline system for 1h, and deionized water after cooling Wash until the pH is 7, and dry at 80°C after suction filtration to obtain alkalized loofah;

(3) Preparation of mercapto loofah: In a stoppered Erlenmeyer flask, add 18mL of thioglycolic acid, 20mL of tetrahydrofuran, 8g of alkalized loofah, add 0.1mL of concentrated sulfuric acid, stopper, heat the solution at a constant temperature of 40°C, and react for 40h under stirring , cooled to room temperature and filtered, then washed with deionized water until the filtrate was neutral, washed with a small amount of acetone, and dried in an oven at 40±2°C to obtain mercapto loofah;

(4) Preparation of alkylated loofah: add 18mL of acetone to a four-neck flask, add 2.0mL of phenyl-trimethoxysilane, add 5.0g of mercapto loofah, stopper, mix well at room temperature, stand still for 1.0h, and then use Washing with deionized water and suction filtration until the filtrate is neutral, washing with a small amount of acetone, and drying in an oven at 80°C to obtain alkylated loofah;

(5) Preparation of malachite green molecularly imprinted adsorption material on the surface of loofah: add 30mL tetrahydrofuran, 0.3g malachite green, 1.5g itaconic acid, 2.0mL methacrylic acid, and 8.0g ethylene glycol in a four-neck flask Alcohol dimethacrylate, add 10g of alkylated loofah, add 0.1g of azobisisobutyronitrile, pass through nitrogen for 10min to remove oxygen, seal and isolate from air, react in a constant temperature water bath at 70°C for 24h, filter and wash;

(6) Removal of template ions: Soxhlet extraction with 0.3 mol/L hydrochloric acid acetone solution for 12 hours, then washing with acetonitrile until no malachite green can be detected in the washing solution, and then drying in a vacuum oven at 40°C. It is the malachite green molecularly imprinted adsorption material on the surface of the loofah.

Example 2

(1) Loofah pretreatment: loofah is derived from loofah fruit, obtained by peeling and removing the core, cutting loofah into small pieces, washing with water, drying in vacuum, crushing, and sieving with a 20-mesh sieve;

(2) Preparation of alkalized loofah: 50% of the total mass of the loofah with pulverization, with a concentration of 8% NaOH aqueous solution, soaked at room temperature for 24h, azeotroped in this alkaline system for 1h, and deionized water after cooling Wash until the pH is 7, and dry at 80°C after suction filtration to obtain alkalized loofah;

(3) Preparation of mercapto loofah: In a stoppered Erlenmeyer flask, add 18mL of thioglycolic acid, 20mL of tetrahydrofuran, 8g of alkalized loofah, add 0.1mL of concentrated sulfuric acid, stopper, heat the solution at a constant temperature of 40°C, and react for 40h under stirring , cooled to room temperature and filtered, then washed with deionized water until the filtrate was neutral, washed with a small amount of acetone, and dried in an oven at 40±2°C to obtain mercapto loofah;

(4) Preparation of alkylated loofah: add 20mL of acetone to a four-neck flask, add 5.0mL of phenyl-trimethoxysilane, add 10g of mercapto loofah, stopper, mix well at room temperature, stand still for 1.0h, and then use Washing with ionic water and suction filtration until the filtrate is neutral, washing with a small amount of acetone, and drying in an oven at 80°C to obtain alkylated loofah;

(5) Preparation of malachite green molecularly imprinted adsorption material on the surface of loofah: add 35mL tetrahydrofuran, 0.5g malachite green, 2.5g itaconic acid, 2.0mL methacrylic acid, and 12g ethylene glycol in a four-neck flask Dimethacrylate, add 15g of alkylated loofah, add 0.2g of azobisisobutyronitrile, blow nitrogen for 10min to remove oxygen, seal and isolate from air, react in a constant temperature water bath at 70°C for 24h, filter and wash;

(6) Removal of template ions: Soxhlet extraction with 0.5 mol/L hydrochloric acid acetone solution for 10 h, and then washing with acetonitrile until no malachite green is detected in the washing liquid, and then drying in a vacuum oven at 40°C. It is the malachite green molecularly imprinted adsorption material on the surface of the loofah.

Example 3

(1) Loofah pretreatment: loofah is derived from loofah fruit, obtained by peeling and removing the core, cutting loofah into small pieces, washing with water, drying in vacuum, crushing, and sieving with a 20-mesh sieve;

(2) Preparation of alkalized loofah: 50% of the total mass of the pulverized loofah, with a concentration of 10% NaOH aqueous solution, soaked at room temperature for 30h, azeotroped in the alkaline system for 0.6h, cooled with deionized Washing with water until the pH is 7, drying at 80°C after suction filtration, to obtain alkalized loofah;

(3) Preparation of mercapto loofah: In a stoppered Erlenmeyer flask, add 12mL of thioglycolic acid, 20mL of tetrahydrofuran, 10g of alkalized loofah, add 0.1mL of concentrated sulfuric acid, stopper, heat the solution at a constant temperature of 40°C, and react for 45h under stirring , cooled to room temperature and filtered, then washed with deionized water until the filtrate was neutral, washed with a small amount of acetone, and dried in an oven at 40°C to obtain mercapto loofah;

(4) Preparation of alkylated loofah: add 30mL of acetone to a four-neck flask, add 4.0mL of phenyl-trimethoxysilane, add 7.0g of mercapto loofah, stopper, mix well at room temperature, stand still for 1.0h, and then use Washing with deionized water and suction filtration until the filtrate is neutral, washing with a small amount of acetone, and drying in an oven at 80°C to obtain alkylated loofah;

(5) Preparation of malachite green molecularly imprinted adsorption material on the surface of loofah: add 40mL tetrahydrofuran, 0.4g malachite green, 2.0g itaconic acid, 2.0mL methacrylic acid, and 20g ethylene glycol in a four-neck flask For dimethacrylate, add 16g of alkylated loofah, add 0.3g of azobisisobutyronitrile, pass through nitrogen for 10min to remove oxygen, seal and isolate from air, react in a constant temperature water bath at 70°C for 24h, filter and wash;

(6) Removal of template ions: Soxhlet extraction with 0.3 mol/L hydrochloric acid acetone solution for 15 hours, and then washing with acetonitrile until no malachite green can be detected in the washing liquid, and drying in a vacuum oven at 40°C. It is the malachite green molecularly imprinted adsorption material on the surface of the loofah.

Example 4

(1) Loofah pretreatment: loofah is derived from loofah fruit, obtained by peeling and removing the core, cutting loofah into small pieces, washing with water, drying in vacuum, crushing, and sieving with a 20-mesh sieve;

(2) Preparation of alkalized loofah: 50% of the total mass of the pulverized loofah, with a concentration of 10% NaOH aqueous solution, soaked at room temperature for 30h, azeotroped in the alkaline system for 0.6h, cooled with deionized Washing with water until the pH is 7, drying at 80°C after suction filtration, to obtain alkalized loofah;

(3) Preparation of mercapto loofah: In a stoppered Erlenmeyer flask, add 12mL of thioglycolic acid, 20mL of tetrahydrofuran, 10g of alkalized loofah, add 0.1mL of concentrated sulfuric acid, stopper, heat the solution at a constant temperature of 40°C, and react for 45h under stirring , cooled to room temperature and filtered, then washed with deionized water until the filtrate was neutral, washed with a small amount of acetone, and dried in an oven at 40°C to obtain mercapto loofah;

(4) Preparation of alkylated loofah: add 30mL of acetone to a four-neck flask, add 3.0mL of phenyl-trimethoxysilane, add 10g of mercapto loofah, stopper, mix well at room temperature, stand still for 1.0h, and then use Washing with ionic water and suction filtration until the filtrate is neutral, washing with a small amount of acetone, and drying in an oven at 80°C to obtain alkylated loofah;

(5) Preparation of malachite green molecularly imprinted adsorption material on the surface of loofah: add 50mL tetrahydrofuran, 0.4g malachite green, 2.0g itaconic acid, 2.0mL methacrylic acid, and 14g ethylene glycol in a four-neck flask Dimethacrylate, add 10g of alkylated loofah, add 0.2g of azobisisobutyronitrile, blow nitrogen for 10min to remove oxygen, seal and isolate from air, react in a constant temperature water bath at 70°C for 24h, filter and wash;

(6) Removal of template ions: Soxhlet extraction with 0.5 mol/L hydrochloric acid acetone solution for 10 h, and then washing with acetonitrile until no malachite green is detected in the washing liquid, and then drying in a vacuum oven at 40°C. It is the malachite green molecularly imprinted adsorption material on the surface of the loofah.

Example 5

Application method of malachite green molecularly imprinted adsorption material on the surface of loofah: dynamic adsorption method, detection of malachite green in the sample, and detection by spectrophotometry after separation. The specific steps of the method are as follows:

(1) Preparation of the extraction column: the prepared loofah surface malachite green molecularly imprinted adsorption material is used as the homogenate liquid, and the column is wet-packed, and the column is used for multiple times with water;

(2) For samples containing malachite green, the malachite green molecularly imprinted adsorption material on the surface of loofah is used for dynamic adsorption treatment, passing through the adsorption column at a flow rate of 0.20mL/min, and then adsorbed with 0.5mol/L acetone hydrochloride Elution, the content of malachite green in the eluate was determined by spectrophotometry.

Example 6

Application method of malachite green molecularly imprinted adsorption material on the surface of loofah: static adsorption, detection of malachite green in the sample, and detection by spectrophotometry after separation. The specific method is as follows:

Take different concentrations of malachite green aqueous solution, add the same amount of malachite green molecularly imprinted adsorption material on the surface of loofah under the same conditions, and absorb by shaking for 20 minutes. After separation, use 0.4mol/L hydrochloric acid acetone solution to measure Determine the concentration of malachite green in the supernatant.

The obtained malachite green molecular imprinted material on the surface of the loofah has a maximum adsorption capacity of 312 mg/g for malachite green molecules, and a maximum adsorption rate of 95%.

Claims (5)

1. the preparation method of luffa surface malachite green molecular engram sorbing material is characterized in that: be that this method has following processing step:

(1) alkalization luffa: be 8～12% the NaOH aqueous solution with natural material luffa and an amount of mass percentage concentration; Soak 20～30h under the room temperature,, spend deionised water after the cooling to neutral at this alkaline system azeotropic reaction 0.5～1.5h; 80 ℃ of oven dry behind the suction filtration, luffa must alkalize;

(2) sulfydryl luffa preparation: characteristics are: in reactor, add TGA by the following mass percent of forming: 25～40%, and oxolane: 32～50%; The alkalization sponge gourd: 15～30%, the concentrated sulfuric acid: 0.10～0.5%, each constituent content sum is absolutely, jumps a queue; Under 40 ± 2 ℃, reaction 30～45h spends deionised water, suction filtration then, is till the neutrality to filtrating; After the small amount of acetone washing, be placed on drying in 40 ± 2 ℃ of baking ovens, obtain the sulfydryl luffa;

(3) alkylation luffa preparation: characteristics are: in reactor, add acetone by the following mass percent of forming: 50～75%, and phenyl-trimethoxy silane: 5～15%; The sulfydryl luffa: 12～30%, each constituent content sum is absolutely, jumps a queue, and mixes under the room temperature; Arrest reaction 0.5～1.5h spends deionised water, suction filtration then, is till the neutrality to filtrating; After the small amount of acetone washing, be placed on drying in 80 ± 2 ℃ of baking ovens, obtain the alkylation luffa;

(4) luffa surface malachite green molecular engram sorbing material preparation: add oxolane by the following mass percent of forming: 45～65%, malachite green: 0.4～1.2%; Itaconic acid: 2.0～7.5%, methacrylic acid: 1.0～4.2%, ethylene glycol dimethacrylate: 15～36%; The alkylation luffa: 10～28%, azodiisobutyronitrile: 0.3～1.0%, each constituent content sum is absolutely; Feed inert gas 5～15min and remove oxygen; Sealing is isolated with air, in 65～70 ℃ of waters bath with thermostatic control, reacts 20～30h, filtration washing;

(5) removing of template ion: with hydrochloric acid acetone soln soxhlet extraction 10～15h of 0.3mol/L～0.6mol/L; Wash with acetonitrile again; Wash cleaning solution and detect, place 40 ± 2 ℃ of vacuum drying chambers dry, be luffa surface malachite green molecular engram sorbing material less than till the tonyred.

2. the preparation method of luffa according to claim 1 surface malachite green molecular engram sorbing material, it is characterized in that: the mol ratio of itaconic acid and methacrylic acid is 1: 0.8～1.2.

3. according to the preparation method of the surface of the luffa described in claim 1 step (4) malachite green molecular engram sorbing material, it is characterized in that: inert gas is an argon gas, nitrogen.

4. according to the preparation method of the surface of the luffa described in claim 1 step (4) malachite green molecular engram sorbing material, it is characterized in that: the feeding inert gas time can not be less than 5min.

5. the application that according to the surperficial malachite green molecular engram material of the luffa of claim 1 preparation the malachite green selective absorption is separated.

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