CN112525635A - Method for extracting micro-plastic - Google Patents
Method for extracting micro-plastic Download PDFInfo
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- CN112525635A CN112525635A CN202011312649.9A CN202011312649A CN112525635A CN 112525635 A CN112525635 A CN 112525635A CN 202011312649 A CN202011312649 A CN 202011312649A CN 112525635 A CN112525635 A CN 112525635A
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Abstract
The invention provides a method for extracting micro-plastic, which takes the micro-plastic in facial cleanser as a target to separate pollutants, the facial cleanser is dispersed in a salt solution, the micro-plastic floats on an upper layer, after a lower layer solution is discarded, an organic solvent is used for defoaming an upper layer liquid containing the plastic, the micro-plastic is precipitated on a lower layer, after the upper layer solution is discarded, the extracted micro-plastic is washed, vacuum filtered and dried, and finally the dried micro-plastic is obtained. The extraction method provided by the invention can efficiently eliminate colloid and foam in the facial cleanser, does not affect the physicochemical characteristics of the micro-plastics, solves the problems of long time consumption, low efficiency, filter membrane blockage caused by colloid and the like in the extraction process in the prior art, avoids using an organic solvent with high toxicity, ensures the health of experimenters, is economic and environment-friendly, and provides a new method for separating micro-plastic pollutants in the facial cleanser.
Description
Technical Field
The invention belongs to the field of environmental health risk evaluation, and particularly relates to a method for extracting micro-plastic.
Background
Microplastics (Microplastics) refer to plastic granules having a particle size of less than 5mm, and on the one hand, from industrial products of plastic granules discharged into water environment through rivers, sewage treatment plants, etc., such as microplastic granules contained in cosmetics, etc., or plastic granules and resin granules as industrial raw materials, are called primary Microplastics. On the other hand, the plastic particles are formed by the large plastic wastes which are split and reduced in volume through physical, chemical and biological processes and are called secondary micro-plastics. Domestic and foreign researches show that the micro-plastic is difficult to completely remove in the environment, and a series of harmful effects, such as physical injury, histological and cytological changes and even death, can be caused after the micro-plastic is eaten by animals by mistake. With the increasing production and usage of plastics worldwide, the environmental hazards and health risks associated with micro-plastic contamination are becoming a focus of concern.
Cosmetics containing scrub components are common in the market, mainly comprise cleansing products such as facial cleanser, shower gel, perfumed soap, scrub cream, bath salt and the like, and mainly play roles in removing cutin and deeply cleaning skin. The frosted component is mostly particles with the particle size of less than 1mm, wherein polyethylene micro plastic accounts for the most part and is the most widely used one. While micro-plastics are safe for use in cosmetics, the amount of micro-plastics in the ocean is increasing with increased emissions. Investigations have found that only in the uk annually, the use of such cosmetics brings about approximately 80 tons of micro-plastic waste to the ocean; nearly 100 tons of micro-plastic enter the ocean each year in the united states alone due to the use of this cosmetic. Based on the harmful ecological reaction of the micro-plastics, related laws are implemented in the United states, Canada and other countries to forbid the production and sale of products containing the micro-plastics, but China has not yet provided relevant regulations in this respect.
Therefore, in the prior art, a simple, efficient, economical and practical method is needed to extract the micro-plastics in the cosmetics so as to solve the problem of environmental pollution caused by the micro-plastics.
Disclosure of Invention
The invention aims to provide a method for extracting micro-plastics from cosmetics, which has the characteristics of high separation efficiency, simplicity and easiness in operation, small size of the extracted micro-plastics, environmental friendliness and the like, and provides technical support for subsequent accurate qualitative and quantitative detection.
In order to achieve the object of the present invention, the present invention provides a method for extracting a micro plastic, the method comprising:
step 1, extracting a crude product of the micro-plastic from a salt solution/sample system by adopting a liquid separation operation based on the relative density difference between the micro-plastic and the salt solution;
and 3, washing the extracted micro plastic for multiple times by using ultrapure water, filtering by using a vacuum filtering device, and drying the micro plastic obtained by final filtration in an oven to obtain the dried micro plastic.
Preferably, in the step 1, the extraction of the crude micro-plastic from the salt solution/sample system comprises:
adding a salt solution into a sample for primary dispersion, stirring until no flocculence exists, transferring the sample into a separating funnel, standing for layering, discarding a lower layer solution to obtain an upper layer micro-plastic crude product, and keeping the micro-plastic crude product in the separating funnel.
Preferably, the salt solution is a sodium chloride solution with the concentration of 2-10%.
Preferably, the mass to volume ratio of the sample to the sodium chloride solution is 3: 50.
Preferably, in the step 1, the rotation speed of the stirring is 400-; the standing time is 1-10 min.
Preferably, in the step 2, the extraction of the micro-plastics from the absolute ethyl alcohol/micro-plastics crude system comprises:
adding absolute ethyl alcohol into the separating funnel with the micro plastic crude product for defoaming;
and shaking the separating funnel uniformly, then standing, and settling the micro plastic at the bottom of the separating funnel after standing because the density of the absolute ethyl alcohol is less than that of the micro plastic, and discarding the upper solution to obtain the micro plastic.
Preferably, the mass volume ratio of the facial cleanser sample to the absolute ethyl alcohol is 1: 15 to 20.
Preferably, in the step 2, the standing time is 1-10 min.
Preferably, in the step 3, the filter membrane of the vacuum filtration device is a 0.45 μm nitrocellulose membrane;
the drying temperature is 60 ℃, and the drying time is 10-20 h.
Preferably, after the step 2, the method further comprises: repeating the step 1 and the step 2 for several times until the finally obtained micro plastic is a transparent solution and no obvious foam is generated.
The embodiment of the invention provides a method for extracting micro-plastic, which comprises the following steps: step 1, extracting a crude product of the micro-plastic from a salt solution/sample system by adopting a liquid separation operation based on the relative density difference between the micro-plastic and the salt solution; step 2, based on the relative density difference between the micro-plastic and absolute ethyl alcohol, adopting a liquid separation operation, and purifying a micro-plastic crude product by using the absolute ethyl alcohol to obtain the micro-plastic; and 3, washing the finally obtained micro plastic for multiple times by adopting ultrapure water, filtering by adopting a vacuum filtering device, and drying the finally filtered micro plastic in an oven to obtain the dried micro plastic. Compared with the prior art, the method provided by the invention has at least the following beneficial effects:
(1) according to the extraction method provided by the embodiment of the invention, the micro-plastics in the frosted facial cleanser are taken as a target to separate pollutants, the layering is realized by utilizing the relative density difference between the micro-plastics and the salt solution and the absolute ethyl alcohol organic solvent, and then the layered system is separated by adopting a simple liquid separation operation, so that the micro-plastics in the cosmetics are extracted. The operation of liquid separation is to directly separate the lamellar system, so the method provided by the invention has simple operation process and greatly shortens the time consumed by the whole extraction process.
(2) The extraction method provided by the embodiment of the invention separates and extracts the micro-plastics in the facial cleanser based on the relative density difference between the micro-plastics and the salt solution and the organic solvent, can quickly and simply extract the micro-plastics in the cosmetics under the condition of ensuring the minimum influence on the micro-plastics, improves the identification effect of a scanning electron microscope, a Fourier infrared spectrometer and a laser particle size analyzer on the micro-plastics, improves the extraction efficiency, and solves the problems of long time consumption, low efficiency and the like in the extraction process in the prior art.
(3) The extraction method provided by the embodiment of the invention has the advantages that the absolute ethyl alcohol is used for purifying the micro plastic, the use of an organic solvent with high toxicity is avoided, the health of workers is guaranteed, and the method is economical and environment-friendly.
(4) According to the extraction method provided by the embodiment of the invention, when the separation is realized by using the relative density difference between the micro-plastic and the salt solution, and the lower layer solution is discarded, a large amount of colloid is removed, and the micro-plastic is remained on the upper layer, and when the separation is realized by using the relative density between the micro-plastic and the organic solvent, not only a large amount of foams can be removed, but also the micro-plastic is remained at the bottom of the separating funnel. The extraction method provided by the invention can efficiently eliminate colloid and foam in the mixed solution, does not obviously influence the physical and chemical characteristics of the micro-plastic, solves the problems of long time consumption for direct stirring, low efficiency, blockage of a filter membrane by colloid and the like, and simultaneously avoids using organic solvents with high toxicity such as 1, 4-dioxane, acetone, acetonitrile and the like, thereby ensuring the health of experimenters.
Drawings
FIG. 1 shows a flow chart of a method for extracting micro-plastics in an embodiment of the invention;
FIG. 2 shows a schematic process flow diagram for extracting micro-plastics under preferred conditions in an embodiment of the present invention;
FIG. 3 shows an SEM image of a micro plastic in example 1 of the present invention;
FIG. 4 shows a Fourier infrared spectrum of a micro-plastic in example 1 of the present invention;
FIG. 5 shows a particle size distribution diagram of the micro plastic in example 1 of the present invention;
FIG. 6 shows a macroscopic picture of the micro-plastic extracted in example 1 of the present invention;
FIG. 7 is a graph showing a comparison of extraction quality of the micro plastic when pure water, a 2% sodium chloride solution, a 5% sodium chloride solution, a 10% sodium chloride solution, and a 20% sodium chloride solution are respectively selected as the first-step dispersion solvent in the invention Experimental example 1;
FIG. 8 is a graph showing the comparison of the extraction quality of the micro plastic when acetonitrile, absolute ethanol, methanol, isopropanol and acetone are respectively used as the second step dispersion solvent in Experimental example 2 of the present invention.
Detailed Description
In order to make the aforementioned objects, features and advantages of the present invention comprehensible, embodiments accompanied with figures are described in further detail below. The following examples are given for the detailed implementation and specific operation of the present invention, but the scope of the present invention is not limited to the following examples.
With the prior art for extracting micro-plastics from samples, the following problems exist: (1) directly adding a sample into boiling water, stirring the mixture to hardly damage an emulsification system of the cosmetic, blocking a filter membrane during subsequent suction filtration, and wasting time and labor; (2) the used organic dispersing solvent has high toxicity and pungent smell, and generates certain toxicity to human bodies; (3) the addition of the antifoaming agent in the intermediate process results in a decrease in the solution density and a decrease in the efficiency of the extraction of the microplastic.
Aiming at the problems in the prior art, the invention aims to provide the method for extracting the micro-plastic from the cosmetics, which has the advantages of high separation efficiency, simplicity, easiness in operation, small size of the micro-plastic extraction, environmental friendliness and the like, and provides technical support for subsequent accurate qualitative and quantitative detection. In order to achieve the purpose of the invention, the technical idea proposed by the invention is as follows: separating pollutants by taking micro-plastic in the facial cleanser as a target, dispersing the facial cleanser in a salt solution, enabling the micro-plastic to float on an upper layer, removing a lower layer solution, defoaming by using an organic solvent, precipitating the micro-plastic at the bottom, removing an upper layer solution, repeatedly washing the extracted micro-plastic, carrying out vacuum filtration and drying to achieve the purpose of separating the micro-plastic in the facial cleanser.
Based on the technical concept provided above, the invention provides a method for extracting micro-plastics, which can be applied to extracting micro-plastics in cleaning products such as facial cleanser, shower gel, soap, scrub cream, bath salt and the like, and as shown in fig. 1, the extraction method comprises the following steps:
step 1(S11), extracting a crude product of the micro plastic from a salt solution/sample system by adopting a liquid separation operation based on the relative density difference between the micro plastic and the salt solution.
In specific implementation, the steps may include: adding a salt solution into the sample for primary dispersion, stirring until no flocculence exists, transferring the flocculence into a separating funnel, standing for layering, discarding the solution at the lower layer to obtain the crude micro-plastic at the upper layer, and keeping the crude micro-plastic in the separating funnel. Wherein the salt solution is a sodium chloride solution with the concentration of 2-10%; the mass-to-volume ratio of the sample to the sodium chloride solution is 3: 50; the stirring speed is 400-1500r/min, and the stirring time is 2-10 min; standing for 1-10 min.
For convenience of understanding, the specific implementation process of the step can also be as follows:
in the implementation step, the salt solution without toxicity and pungent smell is used as the dispersion solution, so that the problem of toxicity to human bodies caused by using the organic solvent with toxicity and pungent smell as the dispersion solution is solved. And moreover, the salt solution is used as a dispersion solution, an emulsification system in a sample can be quickly destroyed, the release rate of the micro-plastic is accelerated, and the extraction efficiency is improved.
And 2, extracting the micro plastic from the absolute ethyl alcohol/micro plastic crude product system by adopting a liquid separation operation based on the relative density difference of the micro plastic and the absolute ethyl alcohol (S12).
In specific implementation, adding absolute ethyl alcohol into a separating funnel with a micro plastic crude product for defoaming; shaking the separating funnel evenly, then standing, settling the micro plastic at the bottom of the separating funnel after standing because the density of the absolute ethyl alcohol is less than that of the micro plastic, and discarding the upper solution to obtain the micro plastic.
In the implementation step, the mass-volume ratio of the facial cleanser sample to the absolute ethyl alcohol is 1: 15-20; standing for 1-10 min.
And step 3(S13), washing the extracted micro plastic for multiple times by using ultrapure water, filtering by using a vacuum filtering device, and drying the micro plastic obtained by final filtration in an oven to obtain the dried micro plastic.
In specific implementation, the micro plastic obtained in the step 2 is repeatedly washed by ultrapure water, filtered by a vacuum filter device, and finally dried in an oven to constant weight and weighed. In the present embodiment, the filter membrane of the vacuum filtration apparatus is a nitrocellulose membrane of 0.45 μm; the drying temperature is 60 ℃, and the drying time is 10-20 h.
In this embodiment, preferably, after step 2, the method further includes: repeating the step 1 and the step 2 for several times until the finally obtained micro plastic is a transparent solution and no obvious foam is generated.
In this embodiment, on one hand, the micro plastic is extracted from the sample by adopting a liquid separation mode based on the relative density difference, and the liquid separation mode does not require complex operations such as stirring, boiling water dissolution, filtration and the like, so that the extraction method provided by the embodiment of the invention has the advantages of simplicity and easiness in operation, and also solves the problems that an emulsification system of the sample is difficult to damage when the sample is directly added into boiling water for stirring, so that a filter membrane is blocked during subsequent filtration, and time and labor are wasted. On the other hand, the micro-plastic is extracted in a liquid separation mode, so that the problem that the structure of the micro-plastic is damaged by mechanical operations such as stirring and the like is solved.
Moreover, in the embodiment, the method provided by the invention can extract the micro plastic from the sample by only carrying out liquid separation twice on the sample, so that the extraction method provided by the invention has the characteristics of good economy, simple operation, short time consumed in the extraction process and the like; in addition, the reagents used for twice liquid separation are respectively a salt solution and absolute ethyl alcohol, and no other toxic organic reagent is used, so that the extraction method has the advantages of environmental friendliness, no harm to human bodies and the like.
In another embodiment of the invention, the micro-plastic in the facial cleanser is taken as a target for separating pollutants, and the 2% sodium chloride solution and the absolute ethyl alcohol are respectively taken as a dispersing solvent and an antifoaming agent, so that the micro-plastic separation efficiency can be better improved. In the embodiment, the facial cleanser is dispersed in the salt solution, the micro plastic floats on the upper layer, the solution on the lower layer is discarded, the organic solvent is used for defoaming, the micro plastic is precipitated at the bottom, the solution on the upper layer is discarded, the washing is repeated, the vacuum filtration and the drying are carried out, and the purpose of separating the micro plastic in the facial cleanser is achieved.
The specific steps of this example are as follows:
step (1), sample treatment: weighing a certain mass of a commercially available facial cleanser sample, adding a certain volume of salt solution with a certain concentration for primary dispersion, stirring until uniform suspension (no obvious flocculence) is obtained, transferring the suspension into a separating funnel, standing until the density of the salt solution is higher than that of the micro-plastic, floating the micro-plastic on the liquid surface, and discarding the lower solution. Adding a certain volume of organic solvent for defoaming, and settling the micro plastic at the bottom of the funnel after standing because the density of the organic solvent is less than that of the micro plastic, and discarding the upper solution.
Step (2) sample extraction: and (2) repeatedly washing the micro plastic obtained in the step (1) by using ultrapure water, filtering by using a vacuum filtering device, drying the final extract in an oven to constant weight, and weighing. The experiment is repeated for 3-5 times, the average extraction mass of the micro-plastic is calculated, and parameters such as the type, concentration and volume of the salt solution, the quality of the facial cleanser, the type and volume of the organic solvent and the like in the step (1) are optimized.
Under the optimal extraction condition, the micro-plastics in the facial cleanser are accumulated and separated and extracted for many times by adopting the separation method in the step (1) and the average extraction quality is calculated; the experiment was repeated 3-5 times.
And (4) observing the appearance of the micro plastic by using a scanning electron microscope, and analyzing the type and the particle size of the micro plastic by using a Fourier infrared spectrometer and a laser particle size analyzer.
In this embodiment, further, in the step (2), the extraction method in the step (1) is optimized, and the optimal input mass of the facial cleanser sample is 3g, the optimal concentration of the sodium chloride solution is 2%, the optimal input volume is 50ml, and the optimal input volume of the absolute ethyl alcohol is 50 ml.
Fig. 2 shows a schematic process flow diagram of the extraction of the micro plastic under the preferred conditions in the embodiment of the present invention, and as shown in fig. 2, the optimal process flow is as follows by using the extraction method provided by the present invention: firstly, 3g of facial cleanser sample is obtained according to the optimal proportion, and is added into a sodium chloride solution (with the concentration of 2 percent and the volume of 50ml) to be uniformly mixed, then the uniformly mixed first mixed system is moved into a separating funnel to be kept stand and separated (in the process of separating, because the micro plastic is in the upper layer liquid, the lower layer liquid is discarded); then, adding 50ml of absolute ethyl alcohol into the upper layer liquid, shaking up to obtain a second mixed system, standing, separating liquid (because the micro plastic is at the lower layer, the upper layer liquid is discarded); then, repeating the operation of separating liquid based on the sodium chloride solution and the absolute ethyl alcohol for 2-3 times; and finally, repeatedly washing the extracted micro-plastic with ultrapure water, filtering by using a vacuum filtering device, drying the final extract in an oven to constant weight, and weighing.
In this example, further, in step (1), the ratio of the mass of the facial cleanser sample to the concentration of the salt solution was (1-5) g: (0.02-0.2) g/ml, wherein the ratio of the mass of the facial cleanser sample to the volume of the organic solvent is (1-5) g: (30-100) ml.
In this example, further, in step (1), the stirring is carried out at 1500r/min for 2-10 minutes.
In this example, further, in the step (1), the standing time is 1 to 10 minutes.
The invention provides a method for extracting micro-plastics from facial cleanser, wherein a facial cleanser sample can be well dispersed in a salt solution, the micro-plastics with the density smaller than that of the salt solution are reserved, the organic solvent is used for defoaming in the second step, the micro-plastics with the density larger than that of the organic solvent are reserved, the influence of adding an alcohol defoaming agent to the solution density in the middle process is eliminated, time and labor are saved, the method is economical and environment-friendly, the influence on the properties of the micro-plastics is small, and the micro-plastics can be observed and identified conveniently by using a scanning electron microscope, a Fourier infrared spectrometer and a laser particle size analyzer.
The experimental result shows that when the separation is realized by using the relative density difference between the micro-plastic and the salt solution, and the solution on the lower layer is discarded, a large amount of colloid is removed, and the micro-plastic is retained on the upper layer, and when the separation is realized by using the relative density between the micro-plastic and the organic solvent, a large amount of foam can be removed, and the micro-plastic is retained at the bottom of the separating funnel. The extraction method provided by the invention can efficiently eliminate colloid and foam in the mixed solution, does not obviously influence the physical and chemical characteristics of the micro-plastic, solves the problems of long time consumption for direct stirring, low efficiency, blockage of a filter membrane by colloid and the like, and simultaneously avoids using organic solvents with high toxicity such as 1, 4-dioxane, acetone, acetonitrile and the like, thereby ensuring the health of experimenters.
In order that those skilled in the art will better understand the present invention, preferred embodiments of the present invention will now be described in detail with reference to the following examples. It is to be understood that the following examples are given for illustrative purposes only and are not intended to limit the scope of the present invention. Various modifications and alterations of this invention will become apparent to those skilled in the art without departing from the spirit and scope of this invention.
Materials, reagents and the like used in the following examples are commercially available unless otherwise specified.
Example 1
(1) Sample treatment: weighing 3g of a commercial facial cleanser sample, adding 50mL of 2% sodium chloride solution for dispersing, treating for 5 minutes under the magnetic stirring condition of 600r/min until uniform suspension (no obvious flocculence) is obtained, transferring to a 125mL separating funnel, standing for 10 minutes, floating the micro-plastic on the liquid surface, discarding the lower layer solution, keeping the height of 0.5-1.0cm in the liquid surface of the separating funnel, adding 50mL of absolute ethyl alcohol for defoaming, and shaking uniformly. After standing for 10 minutes, the micro plastic is settled at the bottom of the funnel, the upper solution layer is discarded by a pipette, and the height of the liquid surface of the separating funnel is kept to be 0.5-1.0 cm.
(2) Sample extraction: repeatedly washing the residual solution obtained in the step (1) with ultrapure water, performing vacuum filtration by using a 0.45-micron nitrocellulose membrane, drying the final extract in an oven at 60 ℃ to constant weight, weighing, observing the morphology of the extract by using a scanning electron microscope, and analyzing the type and particle size of the micro-plastic by using a Fourier infrared spectrometer and a laser particle size analyzer.
Fig. 3 is an SEM image of the micro plastic extracted in this example. Fig. 3 shows a partial surface microstructure of the micro plastic, and the result shows that the surface of the micro plastic is rough and rugged, and has an irregular shape.
Fig. 4 is a fourier-infrared-spectrum image of the micro plastic extracted in this example. To identify the composition and type of the microplastic, ATR-FTIR analysis was used. As shown in FIG. 4, 2920cm-1And 2850cm-1The absorption peak at (A) is respectively attributed to-CH2Asymmetric stretching vibration of-and-CH2Symmetrical telescopic vibration of-1460 cm-1The peak at (A) is due to-CH2Bending vibration of 719cm-1The peak value of (A) is attributed to- (CH)2)nAnd (n ≧ 4) in-plane oscillation. Therefore, it is assumed by analysis that the extracted micro-plastic may be polyethylene.
Fig. 5 is a particle size distribution image of the micro plastic extracted in the example. FIG. 5 shows that the particle size distribution of the micro-plastics is different from 150 μm to 700 μm, wherein the maximum content of particles is concentrated at 350 μm and the particle size is in a normal distribution trend. Fig. 8 shows a macroscopic picture of the micro-plastic extracted in the embodiment of the present invention, as shown in fig. 6, the micro-plastic product can be extracted from the facial cleanser by the extraction method provided by the present invention.
The result analysis shows that the method realizes the successful extraction of the micro-plastic in the cosmetics.
Experimental example 1
The experimental example is used for verifying the influence of sodium chloride solutions with different concentrations on the extraction efficiency of the micro-plastic.
Weighing 3g of a commercial facial cleanser sample, adding 50mL of ultrapure water, treating for 5 minutes under the stirring condition of 600r/min until the suspension is uniform (no obvious flocculence), transferring to a 125mL separating funnel, standing for 10 minutes, floating the micro-plastic on the liquid surface, discarding the lower solution, keeping the height of 0.5-1.0cm in the liquid surface of the separating funnel, adding 50mL of absolute ethyl alcohol, and shaking uniformly. After standing for 10 minutes, the micro plastic is settled at the bottom of the funnel, the upper solution layer is discarded by a pipette, and the height of the liquid surface of the separating funnel is kept to be 0.5-1.0 cm. Repeatedly washing the obtained residual solution with ultrapure water, vacuum filtering with 0.45 μm nitrocellulose membrane, oven drying the final extract in an oven at 60 deg.C to constant weight, and weighing.
The concentration of the sodium chloride solution was then varied to 2%, 5%, 10%, 20%, respectively, and the remaining steps were repeated at least three times for each experiment as described above.
FIG. 7 shows that when sodium chloride salt solutions with different concentrations are used as the first step dispersion solution to extract the micro-plastics, the separation effect is obviously better than that of pure water, which may be that the density of pure water is similar to that of polyethylene micro-plastics, and the micro-plastics and the solution cannot be well separated, thus indicating that the salt solution is a main factor influencing the separation effect of the micro-plastics. Meanwhile, the concentration of the salt solution has certain influence on the extraction effect of the micro-plastic, and the extraction effect is best when the concentration of the sodium chloride solution is 2%, and is influenced when the concentration of the sodium chloride solution is increased, so that the 2% sodium chloride solution is finally selected as the first-step dispersion solution according to the quality of the extracted micro-plastic.
Experimental example 2
The experimental example is used for verifying the influence of different organic solvents on the extraction efficiency of the micro-plastic.
Weighing 3g of a commercial facial cleanser sample, adding 50mL of 2% sodium chloride solution, processing for 5 minutes under the mechanical stirring condition of 600r/min until uniform suspension (no obvious flocculence) is obtained, transferring the suspension into a 125mL separating funnel, standing for 10 minutes, floating the micro-plastic on the liquid surface, discarding the lower layer solution, keeping the height of 0.5-1.0cm in the liquid surface of the separating funnel, adding 50mL of absolute ethyl alcohol, and shaking uniformly. Standing for 10min, depositing the micro plastic at the bottom of the funnel, removing the upper solution with 5ml pipette, and keeping the liquid surface height of the separating funnel at 0.5-1.0 cm. Repeatedly washing the obtained residual solution with ultrapure water, vacuum filtering with 0.45 μm nitrocellulose membrane, oven drying the final extract in an oven at 60 deg.C to constant weight, and weighing.
Then the types of the organic solvents are respectively changed into acetonitrile, methanol, isopropanol and acetone. The remaining steps were as described above, repeated at least three times for each experiment.
Fig. 8 shows that when absolute ethyl alcohol is used as the second-step dispersion solvent, although various organic solvents can eliminate foams, the extraction effect of the absolute ethyl alcohol is obviously better than that of acetonitrile, methanol, isopropanol and acetone, and the absolute ethyl alcohol is finally selected because other solvents have certain toxicity, are easy to cause harm to human bodies and the environment and are expensive.
For simplicity of explanation, the method embodiments are described as a series of acts or combinations, but those skilled in the art will appreciate that the present invention is not limited by the order of acts, as some steps may occur in other orders or concurrently in accordance with the invention. Further, those skilled in the art will appreciate that the embodiments described in the specification are preferred embodiments and that the acts and elements referred to are not necessarily required to practice the invention.
The method for extracting the micro-plastic provided by the invention is described in detail above, and the principle and the implementation mode of the invention are explained by applying specific examples, and the description of the examples is only used for helping to understand the method and the core idea of the invention; meanwhile, for a person skilled in the art, according to the idea of the present invention, there may be variations in the specific embodiments and the application scope, and in summary, the content of the present specification should not be construed as a limitation to the present invention.
Claims (10)
1. A method of extracting a micro-plastic, the method comprising:
step 1, extracting a crude product of the micro-plastic from a salt solution/sample system by adopting a liquid separation operation based on the relative density difference between the micro-plastic and the salt solution;
step 2, extracting the micro plastic from an absolute ethyl alcohol/micro plastic crude product system by adopting a liquid separation operation based on the relative density difference of the micro plastic and the absolute ethyl alcohol;
and 3, washing the extracted micro plastic for multiple times by using ultrapure water, filtering by using a vacuum filtering device, and drying the micro plastic obtained by final filtration in an oven to obtain the dried micro plastic.
2. The method of claim 1, wherein in the step 1, the extracting the crude micro-plastic from the salt solution/sample system comprises:
adding a salt solution into a facial cleanser sample for primary dispersion, stirring until no flocculence exists, transferring the mixture into a separating funnel, standing for layering, discarding a lower layer solution to obtain an upper layer of crude micro-plastic product, and keeping the crude micro-plastic product in the separating funnel.
3. The method according to claim 2, wherein the salt solution is a sodium chloride solution having a concentration of 2-10%.
4. The method according to claim 3, wherein the mass to volume ratio of the facial cleanser sample to the sodium chloride solution is 3: 50.
5. The method as claimed in claim 2, wherein in the step 1, the rotation speed of the stirring is 400-1500r/min, and the stirring time is 2-10 min; the standing time is 1-10 min.
6. The method of claim 2, wherein in the step 2, the extraction of the micro-plastic from the absolute ethanol/micro-plastic crude system comprises:
adding absolute ethyl alcohol into the separating funnel with the micro plastic crude product for defoaming;
and shaking the separating funnel uniformly, then standing, and settling the micro plastic at the bottom of the separating funnel after standing because the density of the absolute ethyl alcohol is less than that of the micro plastic, and discarding the upper solution to obtain the micro plastic.
7. The method according to claim 6, wherein the mass-to-volume ratio of the facial cleanser sample to the absolute ethyl alcohol is 1: 15 to 20.
8. The method according to claim 6, wherein in the step 2, the standing time is 1-10 min.
9. The method according to claim 1, wherein in the step 3, the filter membrane of the vacuum filtration device is a 0.45 μm nitrocellulose membrane;
the drying temperature is 60 ℃, and the drying time is 10-20 h.
10. The method of claim 1, wherein after step 2, the method further comprises: repeating the step 1 and the step 2 for several times until the finally obtained micro plastic is a transparent solution and no obvious foam is generated.
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113311144A (en) * | 2021-05-20 | 2021-08-27 | 江南大学 | Method for evaluating toxicity of micro-plastic based on behavioral indexes of daphnia magna |
| CN115414279A (en) * | 2022-08-31 | 2022-12-02 | 吉林化工学院 | Method for extracting micro plastic particles from facial cleanser |
Citations (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2007060462A1 (en) * | 2005-11-28 | 2007-05-31 | The University Of Sheffield | Particle-stabilised foams |
| CN101696052A (en) * | 2009-10-27 | 2010-04-21 | 哈尔滨工业大学 | Method for degrading nitrosodimethylamine in water by zinc |
| CN103272411A (en) * | 2013-06-07 | 2013-09-04 | 南京四新科技应用研究所有限公司 | Foam inhibitor and preparation method thereof |
| CN108181154A (en) * | 2017-11-23 | 2018-06-19 | 广东海洋大学 | The detection method of micro- plastics in a kind of organism |
| CN108177273A (en) * | 2017-12-27 | 2018-06-19 | 南京师范大学 | A kind of continuous separation and concentration device and method of micro- plastics |
| CN108375670A (en) * | 2018-01-18 | 2018-08-07 | 上海大学 | The extracting method and small testing device of micro- plastics in dewatered sludge |
| CN108593401A (en) * | 2018-02-27 | 2018-09-28 | 浙江工业大学 | The separation method of water environment or the micro- plastics of marine product sub-micron grade |
| CN109679136A (en) * | 2018-12-20 | 2019-04-26 | 南阳师范学院 | A method of micro- plastics are separated from streamside, library shore band |
| CN110186863A (en) * | 2019-05-08 | 2019-08-30 | 浙江工业大学 | The detection method of the micro- plastic degradation situation in mulch source in a kind of pair of soil |
| CN110773331A (en) * | 2019-09-30 | 2020-02-11 | 河南大学 | Enrichment device for separating micro-plastics in environmental soil and sediments |
| CN111346729A (en) * | 2020-03-10 | 2020-06-30 | 天津市生态环境监测中心 | High-efficiency separation device and separation method for marine micro-plastic |
-
2020
- 2020-11-20 CN CN202011312649.9A patent/CN112525635B/en active Active
Patent Citations (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2007060462A1 (en) * | 2005-11-28 | 2007-05-31 | The University Of Sheffield | Particle-stabilised foams |
| CN101696052A (en) * | 2009-10-27 | 2010-04-21 | 哈尔滨工业大学 | Method for degrading nitrosodimethylamine in water by zinc |
| CN103272411A (en) * | 2013-06-07 | 2013-09-04 | 南京四新科技应用研究所有限公司 | Foam inhibitor and preparation method thereof |
| CN108181154A (en) * | 2017-11-23 | 2018-06-19 | 广东海洋大学 | The detection method of micro- plastics in a kind of organism |
| CN108177273A (en) * | 2017-12-27 | 2018-06-19 | 南京师范大学 | A kind of continuous separation and concentration device and method of micro- plastics |
| CN108375670A (en) * | 2018-01-18 | 2018-08-07 | 上海大学 | The extracting method and small testing device of micro- plastics in dewatered sludge |
| CN108593401A (en) * | 2018-02-27 | 2018-09-28 | 浙江工业大学 | The separation method of water environment or the micro- plastics of marine product sub-micron grade |
| CN109679136A (en) * | 2018-12-20 | 2019-04-26 | 南阳师范学院 | A method of micro- plastics are separated from streamside, library shore band |
| CN110186863A (en) * | 2019-05-08 | 2019-08-30 | 浙江工业大学 | The detection method of the micro- plastic degradation situation in mulch source in a kind of pair of soil |
| CN110773331A (en) * | 2019-09-30 | 2020-02-11 | 河南大学 | Enrichment device for separating micro-plastics in environmental soil and sediments |
| CN111346729A (en) * | 2020-03-10 | 2020-06-30 | 天津市生态环境监测中心 | High-efficiency separation device and separation method for marine micro-plastic |
Non-Patent Citations (6)
| Title |
|---|
| ALICIA HERRERA 等: "Novel methodology to isolate microplastics from vegetal-rich samples", 《MARINE POLLUTION BULLETIN》 * |
| INGRID HINTERSTEINER 等: "Characterization and quantitation of polyolefin microplastics in personal-care products using high-temperature gel-permeation chromatography", 《ANALYTICAL AND BIOANALYTICAL CHEMISTRY》 * |
| MOELLER, JULIA N.等: "Finding microplastics in soils:a review of analytical methods", 《ENVIRONMENTAL SCIENCE & TECHNOLOGY》 * |
| 屈沙沙 等: "双密度分离法提取化妆品中的聚乙烯微珠", 《卫生研究》 * |
| 屈沙沙: "聚乙烯微珠对三氯生的吸附/解吸行为机制研究", 《中国优秀硕士学位论文全文数据库 工程科技Ⅰ辑》 * |
| 逍遥仙人掌: "消泡剂的使用", 《百度文库》 * |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113311144A (en) * | 2021-05-20 | 2021-08-27 | 江南大学 | Method for evaluating toxicity of micro-plastic based on behavioral indexes of daphnia magna |
| CN115414279A (en) * | 2022-08-31 | 2022-12-02 | 吉林化工学院 | Method for extracting micro plastic particles from facial cleanser |
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