Novel graphene oxide coated adsorption material as well as preparation method and application thereof

Abstract

The invention provides a novel graphene oxide coated adsorption material as well as a preparation method and application thereof. The preparation method comprises the following steps: modifying plant sporopollen with 3-aminopropyltriethoxysilane, and then carrying out ultrasonic dispersion in a toluene-water reaction system for 30 minutes. Then adding a certain amount of graphene oxide, carrying out ultrasonic dispersion for 30 minutes, and stirring the mixture at 60 DEG C for 6 hours, so that the graphene oxide is coated on the surfaces of the modified material particles. And washing the synthesized graphene oxide coated material with water at 70 DEG C, and drying at 60 DEG C for 12 hours to successfully prepare the lipophilic solid-phase extraction adsorbent. The supporting material sporopollen purifying material is rich in source, good in biocompatibility, non-toxic and pollution-free. The prepared graphene oxide coated adsorption material is complete in morphology, stable in property, high in binding force and large in specific surface area, has a lipophilic adsorption effect and can well adsorb various polycyclic aromatic hydrocarbon compounds.

Description

Technical Field

[0001] The invention relates to the field of functionalized materials and analytical technology, in particular to a novel graphene oxide coated adsorption material, a preparation method thereof and application thereof. Background Art

[0002] PAHs have become one of the major pollutants of concern due to their widespread presence and toxicological properties. PAHs can form adducts with DNA, causing genetic damage, inducing birth defects, respiratory and nervous system diseases. For this reason, many countries have established limit standards for PAH residues in agricultural products. The European Food Safety Authority (EFSA) has identified 16 PAHs as priority PAHs for food monitoring, including benzo[a]anthracenes (BaA), benzo[b]fluoranthene (BbF), benzo[k]fluoranthene (BkF), benzo[ghi]perylene (BgP), ​​benzo[a]pyrene (BaP), Cl2, DhA, IcP, benzo[j]fluoranthene (BjF), cyclopenta[cd]pyrene (CPP), dibenzo[a,e]pyrene (DeP), dibenzo[a,h]pyrene (DhP), dibenzo[a,i]pyrene (DiP), dibenzo[a,l]pyrene (DlP), 5-methylphenanthrene (5MC) and benzo[c]fluorene (BcL). The EU also has regulations on the content of PAHs in food (Commission Regulation (EU) No 835 / 2011). The United States Environmental Protection Agency (US EPA) recommends monitoring a group of 16 PAHs (called US EPA PAHs), including acenaphthene (AcP), acenaphtheneethylene (AcPy), anthracene (Ant), fluoranthene (FL), fluorene (Flu), naphthalene (Nap), phenanthrene (Phe), pyrene (Pyr), benzo[a]anthracenes (BaA), benzo[b]fluoranthene (BbF), benzo[k]fluoranthene (BkF), benzo[ghi]perylene (BgP), ​​benzo[a]pyrene (BaP), benzo[a,h]anthracene (DhA) and indeno[1,2,3-cd]pyrene (IcP); PAHs in food are generally believed to be caused by environmental contamination. US EPA stipulates that the sum of PAH markers in food should not exceed 10μg / kg (oils and fats), 35μg / kg (cocoa beans and their derivatives), 30μg / kg (meat and aquatic products), and 1.0μg / kg (infant food and dietary foods with special medical protocols). However, due to the special structure of PAH pollutants, they are almost not retained on a series of purification fillers, which brings certain difficulties to the inspection. Therefore, it is urgent to find a material that can be used for simple and rapid purification of PAHs.

[0003] The shell of plant spores (spore pollen) has excellent chemical stability, high strength and unique microstructure. As a natural green material, plant spores have been used in drug delivery and carbon materials. In addition, plant spore pollen has a strong adsorption capacity due to its porous structure and hydroxyl groups. At the same time, combined with graphene as a supporting material, sporopollenin will become a promising solid phase extraction adsorbent for polycyclic aromatic hydrocarbons. At present, the supporting materials for preparing graphene-coated materials are usually inorganic or organic preparation materials, which have disadvantages such as pollution, complex synthesis and non-green. Summary of the invention

[0004] The purpose of the present invention is to provide a novel graphene oxide coated adsorbent material, a preparation method and an application thereof. The present invention prepares a novel graphene oxide coated adsorbent material using sporopollenin as a supporting material. The prepared adsorbent material can be used as a solid phase extraction adsorbent for polycyclic aromatic hydrocarbons to achieve the enrichment and purification of polycyclic aromatic hydrocarbons, thus meeting the urgent need for rapid detection of polycyclic aromatic hydrocarbon residues in current food.

[0005] The present invention is achieved in that:

[0006] A method for preparing a novel graphene oxide coated adsorbent material is prepared according to the following steps:

[0007] Step 1, screening Lycopodium spore powder, removing impurities, preparing complete sporopollenin by accelerated solvent method, and drying for later use;

[0008] Step 2, infiltrating the sporopollenin with toluene according to a certain sporopollenin mass to toluene volume ratio (g / mL), and magnetically stirring for 10-60 minutes;

[0009] Step 3, adding a certain volume of 3-aminopropyltriethoxysilane (APTES, 98%) solution, and continuing to stir under nitrogen atmosphere for 6-48 hours (60° C.);

[0010] Step 4, filtering the solution in step 3, washing with a certain volume of anhydrous ethanol, and vacuum drying at 70-100° C. for 6-48 hours to prepare an APTES-modified sporopollenin product (APTES-Modified LP);

[0011] Step 5, take 50-200 mg of APTES-Modified LP product, add 50-300 mL of toluene, then add 200-500 mL of deionized water, and ultrasonically disperse for 10-60 minutes;

[0012] Step 6, adding 25-100 mg of graphene oxide (GO) and ultrasonically dispersing for 10-60 minutes;

[0013] Step 7, stirring the above solution at 60-100° C. for 6-48 hours to coat the surface of the APTES-Modified LP particles with GO to synthesize the GO@APTES-Modified LP material;

[0014] Step 8, the GO@APTES-Modified LP material was washed by centrifugation and 70°C water for 2-4 times;

[0015] Step 9. Finally, the sporopollenin sample coated with graphene oxide prepared above is dried at 60-80° C. for 12-24 hours to obtain a novel graphene oxide coated adsorption material.

[0016] The method of the present invention is to prepare an adsorption material based on plant sporopollenin. The prepared novel graphene oxide-coated sporopollenin adsorption material can be applied to the pretreatment of polycyclic aromatic hydrocarbon residue detection samples, and can achieve the enrichment and purification of various polycyclic aromatic hydrocarbon residues. The PAHs are 24 PAHs of EPAPAH16 and EU PAH15+1: naphthalene, acenaphthene, acenaphthene, fluorene, phenanthrene, anthracene, fluoranthene, pyrene, benzo[c]fluorene, benzo[a]anthracene, cyclopentenyl[cd]pyrene, chrysene, 5-methylchrysene, benzo[b]fluoranthene, benzo[k]fluoranthene, benzo[j]fluoranthene, benzo[a]pyrene, indeno[1,2,3-cd]pyrene, dibenzo[a,h]anthracene, benzo[g,h,i]perylene, dibenzo[a,l]pyrene, dibenzo[a,e]pyrene, dibenzo[a,i]pyrene, and dibenzo[a,h]pyrene.

[0017] Compared with the prior art, the advantages of the present invention are:

[0018] (1) The present invention is the first to prepare a pre-treatment purification material for polycyclic aromatic hydrocarbon residue detection based on plant sporopollenin, and has developed a new type of green and efficient purification material. The plant sporopollenin used is a natural ingredient with abundant sources, no pollution, and good biocompatibility.

[0019] (2) The method is simple to prepare, and the graphene oxide coated adsorbent material can be obtained by a two-step synthesis reaction; the graphene oxide coated adsorbent material prepared by the present invention has a complete morphology, stable properties, stronger binding force, large specific surface area, uniform coating, avoids interference from impurities, has a lipophilic adsorption effect, and can well adsorb a variety of polycyclic aromatic hydrocarbon compounds.

[0020] (3) The graphene oxide coated material prepared by this method has a uniform morphology and a micron size, which fully meets the requirements of a solid phase extraction purification adsorbent. Graphene oxide has physical adsorption properties such as electrostatic action, π-π stacking effect and hydrogen bonding. At the same time, combined with the multi-hydroxyl functional groups on the surface, it has a lipophilic adsorption effect and can well adsorb polycyclic aromatic hydrocarbons. The sporopollenin adsorption purification material can simply, quickly and efficiently separate and enrich polycyclic aromatic hydrocarbons. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 These are scanning electron microscope photos of plant pollen at different processing stages in Example 1 of the present invention.

[0022] Figure 2 This is the particle size analysis of the APTES-Modified LP product in Example 1 of the present invention.

[0023] Figure 3 It is the infrared spectra of plant spore pollen, sporopollenin, APTES-Modified LP product, graphene oxide and graphene oxide coated adsorption material in Example 1 of the present invention.

[0024] Figure 4 Schematic diagram of the structure of the dispersed solid phase extraction purification tube in Example 2 of the present invention.

[0025] Figure 5 24 PAH ion information and TIC diagram in Example 3 of the present invention. DETAILED DESCRIPTION

[0026] The present invention will be further described below in conjunction with specific embodiments. The embodiments given below are only for illustrating the present invention, but not for limiting the scope of the present invention. The embodiments provided below can be used as a guide for further improvement by those of ordinary skill in the art, and do not constitute a limitation of the present invention in any way.

[0027] The experimental methods in the following examples, unless otherwise specified, are all conventional methods, and are performed according to the techniques or conditions described in the literature in the field or according to the product instructions. The materials, reagents, etc. used in the following examples, unless otherwise specified, can all be obtained from commercial channels.

[0028] Example 1, a method for preparing a novel graphene oxide-coated adsorption material based on plant spore pollen.

[0029] Step 1, screening Lycopodium spore powder, removing impurities, preparing complete sporopollenin by accelerated solvent method, and drying for later use.

[0030] Step 2, take 5 g of sporopollenin, add it into 500 mL of toluene, and stir it magnetically for 30 minutes.

[0031] Step 3, add 33.3 mL of APTES (98%) solution, and continue stirring for 24 hours (60° C.) under nitrogen atmosphere to obtain a sporopollenin dispersion (10 mg / mL).

[0032] Step 4, take 250 mL of the sporopollenin dispersion prepared above, filter it, rinse it with 250 mL of ethanol, and dry it under vacuum at 70° C. for 24 hours to prepare an APTES-Modified LP product.

[0033] Step 5, take 150 mg of APTES-Modified LP product, add 200 mL of toluene, then add 400 mL of deionized water, and disperse by ultrasonic for 30 minutes.

[0034] Step 6, add 100 mg of graphene oxide (GO) and disperse by ultrasonic for 30 minutes.

[0035] Step 7: Stir the mixture at 60° C. for 6 hours to allow GO to coat the surface of the APTES-Modified LP particles.

[0036] In step 8, the GO@APTES-Modified LP material was washed by centrifugation and 70°C water for 4 times.

[0037] Step 9. Finally, the sporopollenin sample coated with graphene oxide prepared above is dried at 60° C. for 12 hours to obtain a novel graphene oxide coated adsorption material.

[0038] The materials were characterized by field emission scanning electron microscopy (SEM), Fourier transform infrared spectrometer (IR), and particle size analyzer (EA), as follows:

[0039] (1) Particle size and morphology characterization

[0040] The morphology and particle size of the prepared sporopollenin material were observed using a NOVA NANO 230 field emission scanning electron microscope (FEI Company, USA). Figure 1 A1 is plant spore pollen (or natural spore pollen), A2 is the prepared spore pollen material, Figure 1 It can be seen that the average particle size of the prepared sporopollenin material is 31.3 μm, and the surface is loose and porous; B1 and B2 are APTES-modified sporopollenin materials, and the modified sporopollenin materials still show a complete honeycomb structure; C1 and C2 are graphene oxide-coated sporopollenin materials, showing a complete coating effect, indicating that the material has been successfully prepared.

[0041] (2) Analysis and testing of APTES-modified sporopollenin materials

[0042] The APTES-Modified LP product was analyzed and the results are shown in Figure 2 .Depend on Figure 2 It can be seen that after APTES treatment, the wave number is 1100-1200cm -1 There is a strong absorption peak due to the stretching vibration of Si-OC. In addition, 1030cm -1 There is an absorption peak of Si-C at 800-900cm -1 The absorption peak of Si-O was found at 100 nm. The results showed that 3-aminopropyltriethoxysilane (APTES) was grafted onto the surface of the sporopollenin material by bonding. The physical particle size of the material was measured using a Mastersizer 2000 laser particle size analyzer (Malvern, UK). The results showed that the average particle size of the material particles was 33.4 μm, and the particles were dispersed and uniform.

[0043] (3) Functional group characterization

[0044] The IRTracer 100 Fourier transform infrared spectrometer (Shimadzu, Japan) was used to characterize the functional group changes of plant spores, sporopollenin, APTES-Modified LP products, graphene oxide, and graphene oxide-coated adsorbent materials, such as Figure 3 As shown. Figure 3 It can be seen that natural pollen is 3007cm -1 and 1745cm -1 Vibration at: This is the CH stretching vibration and C=O stretching in aliphatic groups, which may come from unsaturated fatty acid esters. After accelerated solvent extraction, the intensity of this vibration obviously disappears, indicating that this type of substance is effectively removed. Vibration: 1713cm -1 Vibration at 1607cm: This is a carbonyl (C=O) stretching vibration, which may come from an alkyl ester or a carboxylic acid. -1 The vibration at 3390 cm appears in all Lycopodium spore spectra. -1 There is a stronger / broader absorption peak near 1110cm -1 The peak at 1630cm is the vibration absorption peak of COC; -1 The absorption peak at 1725cm -1 The peak at is the stretching vibration peak of C=O on the carboxyl group of graphene oxide, indicating that graphene oxide has at least four functional groups: -OH, -COOH, COC, and -C=O. Figure 3 It can be seen that the new graphene oxide coated material clearly shows the characteristic absorption peak of sporopollenin (3007cm -1 ) and the characteristic absorption peak of graphene oxide (3390cm -1 ).

[0045] The results show that a unique combination of chemical functional groups is formed during the preparation of graphene oxide-coated materials.

[0046] Example 2, a dispersed solid phase extraction purification tube prepared based on the graphene oxide coated adsorption material in Example 1.

[0047] like Figure 4 As shown, the dispersed solid phase extraction purification tube includes a 15 mL centrifuge tube and 50 mg of the graphene oxide-coated adsorption material prepared in Example 1.

[0048] Example 3: The novel graphene oxide-coated adsorbent material in Example 1 is used to purify milk powder extract.

[0049] The novel graphene oxide coated adsorption material prepared by the method of the present invention is used for sample pretreatment for polycyclic aromatic hydrocarbon residue detection. The specific steps of the sample pretreatment technology are as follows:

[0050] ① Seal the milk powder sample and mark it.

[0051] ② Accurately weigh 2g of milk powder in a 50mL centrifuge tube (tube 1), add 5mL of deionized water and mix well, then add 10mL of acetonitrile-saturated n-hexane mixture (1:1, v / v), vortex for 1min, and ultrasonicate for 10min. After ultrasonication, add an extraction salt bag (4g of anhydrous magnesium sulfate, 1g of sodium chloride, 1g of sodium citrate, 0.5g of disodium hydrogen citrate) and a ceramic homogenizer, vortex quickly for 1min, and centrifuge at 8000rpm for 10min at 4℃.

[0052] ③ Use the dispersed solid phase extraction purification tube (tube 2) in Example 2 to transfer the supernatant of tube 1 to the dispersed solid phase extraction purification tube (tube 2), vortex for 1 min, centrifuge at 8000 rpm for 10 min at 4°C, discard the supernatant, and finally, add 2 mL of n-hexane for elution, filter the eluate with a 0.22 μm filter membrane, concentrate the eluate to near dryness in a nitrogen flow at 40°C, then redissolve it with ethyl acetate to 500 μL, pass the membrane and apply it to the machine for GC-QE analysis.

[0053] ④GC-QE chromatographic conditions: The chromatographic column was a DB-EUPAH quartz capillary column (20m×0.18mm, 0.14μm); the temperature program was: 50℃ for 2min, then increased to 220℃ by 15℃, then increased to 315℃ by 3.5℃, and maintained for 10min. The injection port temperature was 270℃, the carrier gas (He) flow rate was 1.6mL / min, the injection volume was 1μL, and the injection was non-split.

[0054] ⑤GC-QE mass spectrometry conditions: EI ion source (70 eV), ion source temperature 270 ° C, transfer line temperature 280 ° C. Full-scan MS acquisition mode (mass acquisition range 50-450 m / z), at m / z 133.01356, the mass resolution was set to 60000 FWHM. C-Trap offset was -4 V, and AGC target value was set to 1e6. The total running time was 50.5 min.

[0055] ⑥ Determine the retention time of the compound, determine the target compound based on the matching score, compound name, structural formula, CAS number and deconvolution peak situation, and comprehensively consider the response value and fragment ion mass number to determine the quantitative ion and qualitative ion of the target compound. Figure 5 As shown. Figure 5 It can be seen that the material prepared in Example 1 of the present invention can simultaneously adsorb 24 kinds of polycyclic aromatic hydrocarbons, and the 24 kinds of polycyclic aromatic hydrocarbons are: naphthalene, acenaphthylene, acenaphthene, fluorene, phenanthrene, anthracene, fluoranthene, pyrene, benzo[c]fluorene, benzo[a]anthracene, cyclopentenyl[cd]pyrene, chrysene, 5-methylchrysene, benzo[b]fluoranthene, benzo[k]fluoranthene, benzo[j]fluoranthene, benzo[a]pyrene, indeno[1,2,3-cd]pyrene, dibenzo[a,h]anthracene, benzo[g,h,i]perylene, dibenzo[a,l]pyrene, dibenzo[a,e]pyrene, dibenzo[a,i]pyrene, and dibenzo[a,h]pyrene.

[0056] The series of detailed descriptions listed above are only specific descriptions of feasible implementation methods of the present invention. They are not intended to limit the scope of protection of the present invention. Any equivalent implementation methods or changes that do not deviate from the technical spirit of the present invention should be included in the scope of protection of the present invention.

Claims

1. A method for preparing a novel graphene oxide coated adsorbent material, characterized in that: The steps include: S1, screening plant spore pollen, removing impurities, preparing complete sporopollenin by accelerated solvent method, and drying for later use; S2, soaking the sporopollenin with toluene and then stirring magnetically for 10-60 minutes; S3, adding 3-aminopropyltriethoxysilane solution to the solution in step S2, and stirring for 6-48 hours under a nitrogen atmosphere; S4, filtering the solution in step S3, washing with anhydrous ethanol, and vacuum drying at 70-100° C. for 6-48 hours to prepare a modified sporopollenin product; S5. Take the modified sporopollenin product, add toluene and deionized water, and disperse by ultrasonic for 10-60 minutes; S6, adding graphene oxide to the solution in step S5 above, and ultrasonically dispersing for 10-60 minutes; S7, stirring the solution of step S6 at 60-100° C. for 6-48 hours to coat the surface of the modified sporopollenin product particles with graphene oxide; S8, centrifuging the material obtained in step S7, and washing it in 70°C water for 2-4 times; S9. Finally, the sample obtained in the above step S8 is dried at 60-80° C. for 12-24 hours to obtain a novel graphene oxide-coated adsorption material.

2. The method for preparing the novel graphene oxide coated adsorbent material according to claim 1, characterized in that: In step S1, the plant pollen is Lycopodium spores.

3. The method for preparing the novel graphene oxide coated adsorbent material according to claim 1, characterized in that: In step S2, the ratio of the mass of sporopollenin to the volume of toluene is 5 g:500 mL.

4. The method for preparing the novel graphene oxide coated adsorbent material according to claim 1, characterized in that: In step S5, the ratio of the mass of the modified sporopollenin product to the volume of toluene and water is: 150 mg: 200 mL: 400 mL.

5. A novel graphene oxide coated adsorption material prepared by the method according to any one of claims 1 to 4.

6. Use of the novel graphene oxide coated adsorption material according to claim 5 in the pretreatment of samples for detection of polycyclic aromatic hydrocarbon residues.

7. The use according to claim 6, characterized in that: The polycyclic aromatic hydrocarbons include: naphthalene, acenaphthylene, acenaphthene, fluorene, phenanthrene, anthracene, fluoranthene, pyrene, benzo[c]fluorene, benzo[a]anthracene, cyclopentenyl[cd]pyrene, chrysene, 5-methylchrysene, benzo[b]fluoranthene, benzo[k]fluoranthene, benzo[j]fluoranthene, benzo[a]pyrene, indeno[1,2,3-cd]pyrene, dibenzo[a,h]anthracene, benzo[g,h,i]perylene, dibenzo[a,l]pyrene, dibenzo[a,e]pyrene, dibenzo[a,i]pyrene, and dibenzo[a,h]pyrene.

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