Method for extracting perfluorinated / polyfluorinated compounds based on confinement fluid

Abstract

The invention relates to the technical field of environmental and biological analysis and detection, in particular to a method for extracting perfluorinated / polyfluorinated compounds based on confinement fluid. The method comprises the following steps: providing a multi-dimensional reticular nanopore material; growing mutually staggered carbon nanofibers on the surface of a substrate through a chemical vapor deposition method; loading a confinement fluid in a pore channel of the multi-dimensional reticular nano-pore channel material; contacting the material with a to-be-detected sample, and extracting; desorbing the extracted material by using a desorption solvent to obtain a desorption solution; and detecting the perfluorinated / polyfluorinated compounds in the desorption solution. A multi-dimensional net-shaped nano pore channel formed by mutual staggering of the carbon nanofibers provides a stable multi-dimensional micro-nano confinement space for confinement fluid. According to the structure, mass transfer and distribution of a target analyte from a complex matrix to a confinement fluid are greatly promoted, so that efficient enrichment of various perfluoro / polyfluoro compounds is realized, and the recovery rate and the detection sensitivity of the method are improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of environmental and biological analysis detection technology, and particularly relates to a method for extracting perfluoro / polyfluoro compounds based on confined fluid. BACKGROUND

[0002] As a class of emerging pollutants with environmental persistence, bioaccumulation and potential toxicity, perfluoro / polyfluoro compounds (PFCs) are widely present in environmental water, sediments and organisms. Due to their extremely low environmental concentration and high biological toxicity, it is essential to establish efficient and accurate pretreatment and detection methods for environmental monitoring, biological exposure assessment and health risk research.

[0003] Currently, trace analysis of PFCs mainly relies on traditional sample pretreatment techniques such as solid-phase extraction and liquid-phase extraction. These methods are usually tedious, time-consuming, and require the use of large amounts of organic solvents, which not only increases the cost but also makes it difficult to meet the requirements of green analysis. More importantly, they cannot achieve in vivo or in situ detection, limiting their application in real-time monitoring and biological dynamic analysis.

[0004] To overcome the shortcomings of traditional methods, in situ detection techniques such as electrochemical sensing and optical sensing have been introduced for rapid screening of PFCs. However, these methods still face limitations in practical application: on the one hand, their response signal to trace PFCs is weak, making it difficult to achieve stable detection at low concentrations; on the other hand, some short-chain PFCs (such as perfluorobutane sulfonic acid and perfluorobutyric acid) have strong polarity and weak affinity with sensing materials, resulting in low capture efficiency and failing to meet the requirements of trace exposure risk assessment in biological samples. In addition, coexisting substances in complex biological or environmental matrices easily interfere with signal transduction, further reducing the selectivity and reliability of detection, making it difficult to achieve accurate qualitative and quantitative analysis.

[0005] Therefore, there is an urgent need to develop a new sample pretreatment method that can achieve rapid, in situ, high sensitivity and be suitable for trace PFCs analysis in complex matrices, in order to improve the overall detection efficiency and provide reliable technical support for precise analysis and risk control in related fields. SUMMARY

[0006] The purpose of the present application is to provide a method for extracting perfluoro / polyfluoro compounds based on confined fluid to solve the problems in the prior art.

[0007] To achieve the above purpose, the present application provides a method for extracting perfluoro / polyfluoro compounds based on confined fluid, comprising the following steps: S1. Providing a multi-dimensional net-like nanochannel material: growing interlaced carbon nanofibers on the surface of a substrate by chemical vapor deposition; S2. loading the confined fluid into the pores of the multi-dimensional net-like nano-porous material; S3. contacting the multi-dimensional net-like nano-porous material loaded with the confined fluid with the sample to be tested for extraction; S4. desorbing the material after extraction using a desorption solvent to obtain a desorption solution; S5. detecting perfluoro / polyfluoro compounds in the desorption solution.

[0008] Preferably, in S1, the material of the substrate is selected from carbon fiber or glass fiber filter membrane.

[0009] Preferably, in S2, the confined fluid is selected from one or more of a mixture of methanol and water, methanol, and acetonitrile.

[0010] Preferably, in S2, the ratio of the volume of the confined fluid to the mass of the multi-dimensional net-like nano-porous material is 3.75-7.50 µL: 1 mg.

[0011] Preferably, in S3, the sample to be tested is a liquid sample selected from biological fluid or environmental water sample.

[0012] Preferably, when the sample to be tested is biological fluid, the extraction is performed by needle tip in-situ extraction; when the sample to be tested is environmental water sample, the extraction is performed by vortex extraction.

[0013] Preferably, in S3, the extraction time is 10-60 s.

[0014] Preferably, in S4, the desorption solvent is selected from one or more of a mixture of methanol and ammonia, methanol, and acetonitrile.

[0015] Preferably, in S4, the desorption time is 10-60 s.

[0016] The present application has the following advantages: 1. This invention provides a method for extracting perfluorinated / polyfluorinated compounds based on confined fluids, comprising the following steps: providing a multidimensional network nanoporous material: growing interwoven carbon nanofibers on a substrate surface via chemical vapor deposition; loading a confining fluid into the pores of the multidimensional network nanoporous material; contacting the multidimensional network nanoporous material loaded with the confined fluid with the sample to be analyzed for extraction; desorbing the extracted material using a desorption solvent to obtain an eluent; and detecting the perfluorinated / polyfluorinated compounds in the eluent. The multidimensional network nanoporous material formed by the interwoven carbon nanofibers provides a stable multidimensional micro / nano confined space for the confined fluid. This structure greatly promotes the mass transfer and distribution of target analytes from the complex matrix to the confined fluid, thereby achieving efficient enrichment of various perfluorinated / polyfluorinated compounds, especially short-chain, highly polar perfluorinated / polyfluorinated compounds that are difficult to capture efficiently using traditional methods, improving the recovery rate and detection sensitivity of the method.

[0017] 2. This invention demonstrates high flexibility and adaptability in application. On the one hand, for different test samples (biological fluids and environmental water samples), this invention provides two suitable operating modes: needle-tip in-situ extraction and vortex extraction, both of which have the advantages of simple operation and short time consumption. On the other hand, the core function of this invention relies on the multidimensional network nanoporous channel structure formed by the interlacing of carbon nanofibers, which has no special dependence on the growth substrate material. Experiments show that materials grown on carbon fiber or glass fiber filter membranes exhibit similar high extraction performance. Therefore, in practical applications, suitable substrate materials can be flexibly selected according to the differentiated requirements of mechanical strength, flexibility, or cost in specific scenarios, which enhances the universality and practical value of this method.

[0018] 3. The entire extraction and desorption process requires a small volume of organic solvent, which significantly reduces the use of toxic and harmful reagents and the generation of waste liquid compared with traditional liquid phase extraction or solid phase extraction, thereby reducing costs and environmental burden and embodying the concept of green and sustainable analysis.

[0019] 4. The desorption solution obtained after desorption using this invention can be directly used for analysis with precision instruments such as high-performance liquid chromatography-tandem mass spectrometry. The combination of efficient pretreatment and highly sensitive detection technology constitutes a complete solution for the accurate qualitative and quantitative analysis of trace targets in complex matrices, providing strong technical support for fields such as environmental monitoring, food safety, and biomedical research. Attached Figure Description

[0020] Figure 1 This is a SEM characterization image of carbon nanofibers / carbon fibers (CNFs / CFs) in Example 1 of the present invention; Figure 1 The 1 in the image represents the surface SEM characterization of CNFs / CFs. Figure 1Figure 2 is a SEM cross-sectional representation of CNFs / CFs; Figure 2 Figure 4 is a schematic diagram of the effect of the confined fluid type on the extraction efficiency of the present application; Figure 3 Figure 5 is a schematic diagram of the effect of the ratio of the volume of the confined fluid to the mass of the multi-dimensional network nanochannel material on the extraction efficiency of the present application; Figure 4 Figure 6 is a schematic diagram of the effect of the extraction time on the extraction efficiency of the present application; Figure 5 Figure 7 is a schematic diagram of the effect of the desorption solvent type on the extraction efficiency of the present application; Figure 6 Figure 8 is a schematic diagram of the effect of the desorption time on the extraction efficiency of the present application; Figure 7 Figure 9 is a schematic diagram of the effect of the substrate material on the extraction efficiency of the present application. DETAILED DESCRIPTION

[0021] The present application provides a method for extracting perfluoro / multi-fluorine compounds based on a confined fluid, comprising the following steps: S1. Providing a multi-dimensional network nanochannel material: growing carbon nanofibers that are interlaced with each other on the surface of a substrate by chemical vapor deposition; S2. Loading the confined fluid into the channels of the multi-dimensional network nanochannel material; S3. Contacting the multi-dimensional network nanochannel material loaded with the confined fluid with the sample to be tested for extraction; S4. Desorbing the material after extraction using a desorption solvent to obtain a desorption solution; S5. Detecting the perfluoro / multi-fluorine compounds in the desorption solution.

[0022] In the present application, in S1, the substrate material is selected from carbon fiber or glass fiber filter membrane.

[0023] In the present application, in S1, before growing carbon nanofibers that are interlaced with each other on the surface of a substrate, the substrate is also subjected to pretreatment, which includes: (1) sequentially subjecting the substrate to de-pulp treatment and acidification treatment to obtain a treated substrate; (2) loading a catalyst on the surface of the treated substrate to obtain a substrate containing the catalyst.

[0024] In the present application, in S2, the confined fluid is selected from one or more of a mixture of methanol and water, methanol, and acetonitrile.

[0025] In the present application, in the mixture of methanol and water, the volume ratio of methanol to water is 2-4:1.

[0026] In the present application, in S2, the ratio of the volume of the confined fluid to the mass of the multi-dimensional net-like nanochannel material is 3.75-7.50 µL:1 mg.

[0027] In the present application, in S3, the sample to be tested is a liquid sample selected from biological fluids or environmental water samples.

[0028] In the present application, when the sample to be tested is a biological fluid, in-situ extraction by needle tip is adopted: a multi-dimensional net-like nanochannel material is inserted into the needle tip of a Hamilton syringe to prepare a needle tip device, a confined fluid is pushed through the needle tip and loaded into the channels of the multi-dimensional net-like nanochannel material; the needle tip is inserted into the sample to be tested, so that the multi-dimensional net-like nanochannel material loaded with the confined fluid contacts the sample to be tested for extraction; a desorption solvent is pushed through the needle tip to desorb the material after extraction, and a desorption solution is obtained; high performance liquid chromatography-tandem mass spectrometry is used to detect perfluoro / polyfluoro compounds in the desorption solution.

[0029] In the present application, when the sample to be tested is an environmental water sample, vortex extraction is adopted for extraction: a confined fluid is added dropwise on the surface of a multi-dimensional net-like nanochannel material, so that the confined fluid is loaded into the channels of the multi-dimensional net-like nanochannel material; the multi-dimensional net-like nanochannel material loaded with the confined fluid is placed in the sample to be tested for vortex extraction; the material after extraction is taken out and placed in a desorption solvent for vortex desorption, and a desorption solution is obtained; high performance liquid chromatography-tandem mass spectrometry is used to detect perfluoro / polyfluoro compounds in the desorption solution.

[0030] In the present application, in S3, the extraction time is 10-60 s.

[0031] In the present application, in S4, the desorption solvent is selected from one or more of a mixture of methanol and ammonia water, methanol, and acetonitrile.

[0032] In the present application, in the mixture of methanol and ammonia water, the mass fraction of ammonia water is 25-28%, and the volume ratio of methanol to ammonia water is 48-50:1.

[0033] In the present application, in S4, the desorption time is 10-60 s.

[0034] In the present application, the perfluoro / polyfluoro compounds include one or more of perfluorohexane-1-sulfonic acid (PFHxS), perfluorobutane sulfonic acid (PFBS), perfluorobutyric acid (PFBA), perfluoropentanoic acid (PFPeA), perfluorohexanoic acid (PFHxA), perfluoroheptanoic acid (PFHpA), perfluorooctanoic acid (PFOA), perfluorononanoic acid (PFNA), and perfluorodecanoic acid (PFDA).

[0035] The present invention will be further described below with reference to the accompanying drawings and embodiments. Unless otherwise defined, the technical or scientific terms used in this invention should be understood in their ordinary sense by those skilled in the art. The features mentioned above or in the specific examples mentioned in this invention can be combined arbitrarily, and these specific embodiments are only used to illustrate the invention and are not intended to limit the scope of the invention.

[0036] Example 1 This embodiment provides a method for extracting perfluorinated / polyfluorinated compounds based on confined fluids, comprising the following steps: First, the carbon fiber substrate (labeled CFs) was calcined at 450℃ for 30 min, then placed in 250 mL of acetone and extracted by Soxhlet extraction for 12 h to obtain desizing fibers. Next, the desizing fibers were immersed in a mixture of nitric acid solution (63% by mass) and sulfuric acid solution (98% by mass) (volume ratio of nitric acid solution to sulfuric acid solution 1:3) for 12 h. After immersion, the fibers were washed with deionized water until neutral and dried at 80℃ to obtain the treated substrate. The treated substrate was then immersed in a catalyst solution for 12 h. The catalyst solution was prepared by mixing tetraethyl orthosilicate, P123, water, ethanol, hydrogen chloride, and nickel nitrate in a molar ratio of 1:0.0103:9.36:21.4:0.04:0.4. After immersion, the substrate was removed and calcined at 450℃ for 30 min to remove P123, resulting in a substrate containing the catalyst. The substrate containing the catalyst was placed in a tube furnace and heated to 600°C at a rate of 5°C / min under a nitrogen atmosphere (flow rate of 150 cc / min). Hydrogen gas (25 cc / min) was then introduced for 30 min, followed by acetylene gas (35 cc / min) for another 30 min. After the reaction, interwoven carbon nanofibers (labeled CNFs) grew on the surface of the CFs, forming a multidimensional network nanoporous material (labeled CNFs / CFs).

[0037] The multi-dimensional mesh nano-porous material is inserted into the needle tip of a Hamilton syringe (250 μL, Hamilton Company, USA) to prepare a needle tip device. The confined fluid (methanol) is slowly pushed through the needle tip to be loaded in the pores of the multi-dimensional mesh nano-porous material (the volume ratio of the confined fluid to the mass of the multi-dimensional mesh nano-porous material is 5 μL: 1 mg). The needle tip is inserted into the sample to be tested (biological fluid-cerebrospinal fluid), so that the multi-dimensional mesh nano-porous material loaded with the confined fluid is in contact with the cerebrospinal fluid. Extraction is performed at a flow rate of 200 μL / min (the flow rate of the cerebrospinal fluid through the needle tip). The extraction time is set to 30 s. The desorption solvent (a mixture of methanol and ammonia water (the volume ratio is 49:1), and the mass fraction of the ammonia water is 26%) is pushed through the needle tip at a flow rate of 200 μL / min to desorb the material after the extraction. The desorption time is set to 30 s to obtain a desorption solution. The perfluoro / polyfluoro compounds in the desorption solution are detected by high performance liquid chromatography-tandem mass spectrometry.

[0038] Example 2 The present example provides an extraction method for perfluoro / polyfluoro compounds based on a confined fluid, which comprises the following steps: The CNFs / CFs are prepared by the same method as in Example 1.

[0039] The confined fluid (methanol) is added dropwise on the surface of the multi-dimensional mesh nano-porous material to load the confined fluid in the pores of the multi-dimensional mesh nano-porous material (the volume ratio of the confined fluid to the mass of the multi-dimensional mesh nano-porous material is 5 μL: 1 mg). The multi-dimensional mesh nano-porous material loaded with the confined fluid is placed in the sample to be tested (environmental water sample-tap water) on a micro vortex mixer (Shanghai Huxi Analysis Instrument Factory Co., Ltd.). The extraction is performed by vortexing (the rotation speed is 3000 rpm) for 30 s. The material after the extraction is taken out and placed in a desorption solvent (a mixture of methanol and ammonia water (the volume ratio is 49:1), and the mass fraction of the ammonia water is 26%). The desorption is performed by vortexing (the rotation speed is 3000 rpm) for 30 s to obtain a desorption solution. The perfluoro / polyfluoro compounds in the desorption solution are detected by high performance liquid chromatography-tandem mass spectrometry.

[0040] Example 3 The present example provides an extraction method for perfluoro / polyfluoro compounds based on a confined fluid, which is different from Example 1 in that the confined fluid is modified to acetonitrile.

[0041] Example 4 The present example provides an extraction method for perfluoro / polyfluoro compounds based on a confined fluid, which is different from Example 1 in that the confined fluid is modified to a mixture of methanol and water (the volume ratio is 3:1).

[0042] Example 5 This example provides a method for extraction of perfluoro / polyfluoro compounds based on confined fluid, which is different from example 2 in that the confined fluid is modified to be acetonitrile.

[0043] Example 6 This example provides a method for extraction of perfluoro / polyfluoro compounds based on confined fluid, which is different from example 2 in that the confined fluid is modified to be a mixture of methanol and water (volume ratio of 3:1).

[0044] Example 7 This example provides a method for extraction of perfluoro / polyfluoro compounds based on confined fluid, which is different from example 1 in that the ratio of the volume of the confined fluid to the mass of the multi-dimensional mesh nanochannel material is modified to be 3.75 µL: 1 mg.

[0045] Example 8 This example provides a method for extraction of perfluoro / polyfluoro compounds based on confined fluid, which is different from example 1 in that the ratio of the volume of the confined fluid to the mass of the multi-dimensional mesh nanochannel material is modified to be 7.50 µL: 1 mg.

[0046] Example 9 This example provides a method for extraction of perfluoro / polyfluoro compounds based on confined fluid, which is different from example 2 in that the ratio of the volume of the confined fluid to the mass of the multi-dimensional mesh nanochannel material is modified to be 3.75 µL: 1 mg.

[0047] Example 10 This example provides a method for extraction of perfluoro / polyfluoro compounds based on confined fluid, which is different from example 2 in that the ratio of the volume of the confined fluid to the mass of the multi-dimensional mesh nanochannel material is modified to be 7.50 µL: 1 mg.

[0048] Example 11 This example provides a method for extraction of perfluoro / polyfluoro compounds based on confined fluid, which is different from example 1 in that the extraction time is modified to be 10 s.

[0049] Example 12 This example provides a method for extraction of perfluoro / polyfluoro compounds based on confined fluid, which is different from example 1 in that the extraction time is modified to be 60 s.

[0050] Example 13 This example provides a method for extraction of perfluoro / polyfluoro compounds based on confined fluid, which is different from example 2 in that the extraction time is modified to be 10 s.

[0051] Example 14 This example provides a method for extraction of perfluoro / polyfluoro compounds based on confined fluids, which differs from Example 2 in that the time of extraction is modified to 60 s.

[0052] Example 15 This example provides a method for extraction of perfluoro / polyfluoro compounds based on confined fluids, which differs from Example 1 in that the desorption solvent is modified to methanol.

[0053] Example 16 This example provides a method for extraction of perfluoro / polyfluoro compounds based on confined fluids, which differs from Example 1 in that the desorption solvent is modified to acetonitrile.

[0054] Example 17 This example provides a method for extraction of perfluoro / polyfluoro compounds based on confined fluids, which differs from Example 2 in that the desorption solvent is modified to methanol.

[0055] Example 18 This example provides a method for extraction of perfluoro / polyfluoro compounds based on confined fluids, which differs from Example 2 in that the desorption solvent is modified to acetonitrile.

[0056] Example 19 This example provides a method for extraction of perfluoro / polyfluoro compounds based on confined fluids, which differs from Example 1 in that the time of desorption is modified to 10 s.

[0057] Example 20 This example provides a method for extraction of perfluoro / polyfluoro compounds based on confined fluids, which differs from Example 1 in that the time of desorption is modified to 60 s.

[0058] Example 21 This example provides a method for extraction of perfluoro / polyfluoro compounds based on confined fluids, which differs from Example 2 in that the time of desorption is modified to 10 s.

[0059] Example 22 This example provides a method for extraction of perfluoro / polyfluoro compounds based on confined fluids, which differs from Example 2 in that the time of desorption is modified to 60 s.

[0060] Example 23 This example provides a method for extraction of perfluoro / polyfluoro compounds based on confined fluids, which differs from Example 1 in that the carbon fiber substrate is modified to a glass fiber filter membrane substrate (labeled GFs), and correspondingly, the resulting multi-dimensional meshed nanochannel material is labeled CNFs / GFs.

[0061] Example 24 The present example provides a method for extracting perfluoro / polyfluoro compounds based on a confined fluid, which is different from Example 2 in that the carbon fiber substrate is modified to a glass fiber filter membrane substrate (marked as GFs), and accordingly, the obtained multi-dimensional mesh nano-pore material is marked as CNFs / GFs.

[0062] Experimental Example 1 The carbon nanofiber / carbon fiber (CNFs / CFs) prepared in Example 1 was subjected to scanning electron microscopy characterization, and the SEM characterization graph of the carbon nanofiber / carbon fiber (CNFs / CFs) in Example 1 was obtained, as shown in FIG. 1. Figure 1 Figure 1 FIG. 1 is a SEM characterization graph of the CNFs / CFs, wherein 1 is a surface SEM characterization graph of the CNFs / CFs, Figure 1 2 is a cross-sectional SEM characterization graph of the CNFs / CFs. It can be seen from FIG. 1 that the surface of the CNFs / CFs is uniformly covered with a three-dimensional mesh structure formed by the interlaced carbon nanofibers, and the structure has abundant nanoscale pores. Figure 1

[0063] Experimental Example 2 To systematically evaluate the extraction performance of the method of the present application, the desorption solution obtained after extraction and desorption in Examples 1-24 was detected and analyzed by high performance liquid chromatography-tandem mass spectrometry. The detection used a combined system composed of an Agilent 1290 high performance liquid chromatography system and an Agilent 6420 triple quadrupole mass spectrometer (QqQ-MS), and nine representative perfluoro / polyfluoro compounds (PFHxS, PFBS, PFBA, PFPeA, PFHxA, PFHpA, PFOA, PFNA, PFDA) were quantitatively analyzed.

[0064] By adding standard compounds of known concentration to the blank biological fluid (cerebrospinal fluid) and environmental water sample (tap water) matrix, a matrix standard addition recovery experiment was carried out, and the extraction recovery rate was taken as the core index for evaluating the extraction efficiency. The extraction recovery rate calculation formula is: (the peak area of the target compound measured after extraction and desorption by the method of the present application / the peak area measured by direct injection of the same concentration standard) x 100%. To comprehensively evaluate the universal performance of the method in different matrices, the recovery rate data of the biological fluid (cerebrospinal fluid) and the environmental water sample (tap water) were combined and processed, and the average recovery rate range was taken as the characterization.

[0065] Analyzing Examples 1, 2 and Examples 3-6, the effect of the type of confined fluid on the extraction efficiency was obtained, as shown in FIG. 3. Figure 2 Analyzing Examples 1, 2 and Examples 7-10, the effect of the ratio of the volume of the confined fluid to the mass of the multi-dimensional mesh nano-pore material on the extraction efficiency was obtained, as shown in FIG. 4.​​Figure 3 The extraction time versus extraction efficiency is analyzed by analyzing Example 1, 2 and Example 11-14, and a diagram is shown in FIG. 6. Figure 4 The desorption solvent type versus extraction efficiency is analyzed by analyzing Example 1, 2 and Example 15-18, and a diagram is shown in FIG. 7. Figure 5 The desorption time versus extraction efficiency is analyzed by analyzing Example 1, 2 and Example 19-22, and a diagram is shown in FIG. 8. Figure 6 The substrate material versus extraction efficiency is analyzed by analyzing Example 1, 2 and Example 23-24, and a diagram is shown in FIG. 9. Figure 7

[0066] From the above analysis, it can be concluded that the method exhibits the best extraction efficiency when the confined fluid is methanol, the ratio of the volume of the confined fluid to the mass of the multi-dimensional mesh nano-porous material is 5 µL:1 mg, the extraction time is 30 s, the desorption solvent is a mixture of methanol and ammonia water (volume ratio is 49:1), and the desorption time is 30 s. From the above analysis, it can be concluded that the extraction efficiency of the two types of substrates has no significant difference. This indicates that the multi-dimensional mesh nano-porous material formed by the interlaced carbon nanofibers is the core of realizing high-efficiency extraction, and the change of the substrate type does not affect its core function. Figures 2-6 Figure 7

[0067] Therefore, the present application adopts the above-mentioned extraction method for perfluoro / multi-fluorine compounds based on a confined fluid, and provides a stable multi-dimensional micro-nano confined space for the confined fluid through the multi-dimensional mesh nano-porous material formed by the interlaced carbon nanofibers. This structure greatly promotes the mass transfer and distribution of the target analyte from the complex matrix to the confined fluid, thereby realizing the efficient enrichment of various perfluoro / multi-fluorine compounds and improving the recovery rate and detection sensitivity of the method.

[0068] Finally, it should be noted that the above examples are only used to illustrate the technical solutions of the present application and not to limit them. Although the present application has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present application can still be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present application.​​​

Claims

1. A method for extracting perfluorinated / polyfluorinated compounds based on confined fluid, characterized in that, Includes the following steps: S1. Provides multidimensional network nanoporous materials: interwoven carbon nanofibers are grown on the substrate surface by chemical vapor deposition; S2. Loading confined fluid into the pores of a multidimensional network nanoporous material; S3. The multidimensional mesh nanoporous material loaded with finite-domain fluid is brought into contact with the sample to be tested for extraction; S4. Use a desorption solvent to desorb the extracted material to obtain an eluent; S5. Detect perfluorinated / polyfluorinated compounds in the desorption solution.

2. The extraction method for perfluorinated / polyfluorinated compounds based on confined fluid according to claim 1, characterized in that, In S1, the substrate material is selected from carbon fiber or glass fiber filter membrane.

3. The extraction method for perfluorinated / polyfluorinated compounds based on confined fluid according to claim 1, characterized in that, In S2, the confined fluid is selected from one or more of the following: a mixture of methanol and water, methanol, and acetonitrile.

4. The extraction method for perfluorinated / polyfluorinated compounds based on confined fluid according to claim 1, characterized in that, In S2, the ratio of the volume of the confined fluid to the mass of the multidimensional network nanoporous material is 3.75-7.50 µL: 1 mg.

5. The extraction method for perfluorinated / polyfluorinated compounds based on confined fluid according to claim 1, characterized in that, In S3, the sample to be tested is a liquid sample, selected from biological body fluids or environmental water samples.

6. The extraction method for perfluorinated / polyfluorinated compounds based on confined fluid according to claim 5, characterized in that, When the sample to be tested is a biological fluid, needle tip in-situ extraction is used; when the sample to be tested is an environmental water sample, vortex extraction is used.

7. The extraction method for perfluorinated / polyfluorinated compounds based on confined fluid according to claim 1, characterized in that, In S3, the extraction time is 10-60 seconds.

8. The extraction method for perfluorinated / polyfluorinated compounds based on confined fluid according to claim 1, characterized in that, In S4, the desorption solvent is selected from one or more of the following: a mixture of methanol and ammonia, methanol, and acetonitrile.

9. The extraction method for perfluorinated / polyfluorinated compounds based on confined fluid according to claim 1, characterized in that, In S4, the desorption time is 10-60 seconds.

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