CN115290623A - Method for extracting degradable micro-plastic from biological tissue - Google Patents

Method for extracting degradable micro-plastic from biological tissue Download PDF

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CN115290623A
CN115290623A CN202111236977.XA CN202111236977A CN115290623A CN 115290623 A CN115290623 A CN 115290623A CN 202111236977 A CN202111236977 A CN 202111236977A CN 115290623 A CN115290623 A CN 115290623A
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plastic
biological tissue
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张宴
于文逸
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Nanjing University
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Nanjing University
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    • G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
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    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N1/00—Sampling; Preparing specimens for investigation
    • G01N1/28—Preparing specimens for investigation including physical details of (bio-)chemical methods covered elsewhere, e.g. G01N33/50, C12Q
    • G01N1/40—Concentrating samples
    • G01N1/4077—Concentrating samples by other techniques involving separation of suspended solids
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N1/00—Sampling; Preparing specimens for investigation
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    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N1/00—Sampling; Preparing specimens for investigation
    • G01N1/28—Preparing specimens for investigation including physical details of (bio-)chemical methods covered elsewhere, e.g. G01N33/50, C12Q
    • G01N1/286—Preparing specimens for investigation including physical details of (bio-)chemical methods covered elsewhere, e.g. G01N33/50, C12Q involving mechanical work, e.g. chopping, disintegrating, compacting, homogenising
    • G01N2001/2866—Grinding or homogeneising
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N1/00—Sampling; Preparing specimens for investigation
    • G01N1/28—Preparing specimens for investigation including physical details of (bio-)chemical methods covered elsewhere, e.g. G01N33/50, C12Q
    • G01N1/40—Concentrating samples
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    • G01—MEASURING; TESTING
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Abstract

The invention discloses a method for extracting degradable micro-plastic from biological tissues, which is characterized by comprising the following steps: (1) Washing biological tissue, cutting into pieces, and crushing for later use; (2) Adding appropriate amount of crushed biological tissue into hydrochloric acid solution containing pepsin, oscillating for the first time, and adding H 2 O 2 After the second oscillation, carrying out vacuum filtration by using a PTFE hydrophilic filter membrane; (3) Soaking the PTFE hydrophilic filter membrane into NaI solution for ultrasonic treatment, then washing with NaI solution, standing the solution, and carrying out vacuum filtration on the upper layer solution to obtain a retentate; (4) For the trapped mattersAnd identifying and counting the line Raman spectrum. The method can ensure that the degradable micro-plastic can be conveniently and quickly extracted from the biological tissue on the premise of minimum influence on the plastic, is convenient for accurately analyzing the type and abundance of the degradable micro-plastic in the organism, and provides technical support for further researching the enrichment, migration and transformation rules and health risk evaluation of the degradable plastic in the organism.

Description

Method for extracting degradable micro-plastic from biological tissue
Technical Field
The invention belongs to the technical field of environmental health risk evaluation, and particularly relates to a method for extracting degradable micro-plastic from biological tissues.
Background
Microplastics are plastic particles with a diameter of less than 5mm, the origin of which can be divided into primary and secondary microplastics. The primary micro plastic is plastic particles directly added into products, and comprises plastic microbeads, particle plastic products and the like in cosmetics and household products; the secondary micro plastic is plastic particles with smaller size formed by large blocks of plastic entering the environment under the actions of mechanical abrasion, light aging, chemical reaction, biological crushing and the like. The potential risks of the micro-plastics to the organisms mainly come from direct ingestion and toxin release, on the one hand, the micro-plastics, once eaten by the organisms by mistake, can block the digestive tract and even cause pathological damage to organ tissues; on the other hand, plasticizers carried by the micro-plastics themselves and persistent organic pollutants adsorbed from the environment may be released in the organism causing complex toxic effects.
Biodegradable plastics have become the most promising substitute for traditional non-degradable plastics due to their environmental friendliness, and are now widely used in agricultural films, food packaging, medical devices and hygiene products. However, the degradation rate of so-called "biodegradable plastics" is estimated based on ideal conditions in industrial composting systems, and the actual life cycle of degradable plastics in real environments may be greatly extended or even comparable to that of conventional plastics due to differences in temperature, humidity and microorganisms. Therefore, the degradation of biodegradable plastics in natural environments and the influence on ecosystem are largely unknown, and the analysis of degradable microplastics in organisms is a necessary means to study the solution of the above problems. However, a method for rapidly, efficiently and nondestructively extracting the degradable micro-plastic from the organism is lacked at present, and the related research on the health risk evaluation of the degradable micro-plastic is severely restricted.
At present, the method for extracting the micro-plastics in the biological tissue is mainly a chemical reagent digestion method, and mainly comprises acid digestion (HNO) 3 、HClO 4 ) Alkali digestion (KOH, naOH) and strong oxidant digestion (H) 2 O 2 NaClO), enzymatic digestion (pepsin, pancreatin, proteinase K) and combinations of the above. However, these methods were originally directed to non-degradable microplasticsThe severe chemical reactions developed, and at high temperatures, may destroy degradable plastics.
Therefore, when researching the enrichment, migration and transformation rules of the degradable micro-plastic in the organism and health risks thereof, the existing method has great influence on the properties of the degradable micro-plastic and cannot efficiently and nondestructively separate the degradable micro-plastic from the organism tissue, and an efficient and mild digestion and separation method for extracting the degradable micro-plastic from the organism tissue is needed.
Disclosure of Invention
The technical problem to be solved by the invention is as follows: aiming at the general lack of a method for extracting degradable micro-plastics from organisms, a method for extracting the degradable micro-plastics from organism tissues is provided. The method can simply, quickly and efficiently analyze the types and abundance of the micro-plastics enriched in the organism, has small influence on the plastics, and is convenient for identification and statistics by using the micro-Raman spectrum.
The technical purpose of the invention is realized by the following technical scheme:
one aspect of the present invention provides a method for extracting degradable micro-plastic from biological tissue, comprising the steps of:
(1) Washing, shearing and crushing the biological tissue to obtain a crushed biological tissue for later use;
(2) Taking appropriate amount of the crushed biological tissue, adding 0.063mol/L hydrochloric acid solution containing 0.5% pepsin (w/v), oscillating for the first time, adding 30% H 2 O 2 (w/v), after the second oscillation, performing vacuum filtration by using a PTFE hydrophilic filter membrane;
(3) The PTFE hydrophilic filter membrane obtained above was immersed at a density of 1.5g/cm 3 Performing ultrasonic treatment on the NaI solution, continuously flushing a PTFE hydrophilic filter membrane by using the NaI solution, standing the obtained solution, and performing vacuum filtration on the upper-layer solution through the PTFE hydrophilic filter membrane to obtain a retentate;
(4) Drying and microscopic examination are carried out on the obtained trapped substance, suspected plastic particles are selected for Raman spectrum detection, an identification map is obtained, the micro-plastics are identified according to an identification standard, and then counting statistics is carried out respectively according to the micro-plastics of different materials.
Preferably, the biological tissue in step (1) includes soft tissues, muscles and visceral tissues of fish, shrimp, crab, bivalves, squid.
Preferably, the first oscillation condition in step (2) is: the temperature is 37 ℃ and the time is 3h.
Preferably, the second oscillation condition in step (2) is: the temperature is 40 ℃ and the time is 12h.
Preferably, the pore size of the PTFE hydrophilic filter membrane in the step (2) is 1 μm.
Preferably, the density in step (3) is 1.5g/cm 3 The NaI solution is prepared according to the following method: 178g NaI was dissolved in 180mL of ultrapure water at 20 ℃.
Preferably, the ultrasonic treatment conditions in step (3) are: the frequency is 40KHz, and the time is 10-15 min.
The invention has the following beneficial effects:
1. the method disclosed by the invention can quickly, efficiently and accurately extract the degradable micro-plastic in the biological tissue on the premise of ensuring the minimum influence on the degradable micro-plastic. The method of the invention is based on a combined digestion method of pepsin and hydrogen peroxide to remove easily digested organic substances in tissues, and simultaneously, the density separation is carried out on organic substances and inorganic substances which are difficult to digest, such as fish bones, sand in shellfish bodies and the like, degradable plastics with the density smaller than that of NaI solution float on the surface of salt solution, and the inorganic substances with higher density and the organic substances which are difficult to digest are deposited at the bottom of the solution. Firstly, releasing the solution of the lower layer (about 90 percent of the total volume) from a lower port, and filtering the solution to obtain filtrate which can be recycled; then pouring out the solution (accounting for about 10 percent of the total volume) of the upper layer from the upper port, carrying out vacuum filtration, extracting the degradable micro plastic, and finally carrying out identification and statistics by using a micro Raman spectrum.
2. The digestion and density separation method provided by the invention can be used for efficiently digesting biological tissues without obviously influencing the physicochemical characteristics of degradable plastics, and the digestion is carried out by adopting the traditional single strong acid and strong base, so that the digestion time is long, the digestion is incomplete, and the influence on the physicochemical characteristics of plastics is large in the digestion process.
Drawings
FIG. 1 is a flow chart of a preparation method of the present invention;
FIG. 2 is a graph of digestion efficiency for examples 1-4 of the present invention;
FIG. 3 is a graph of digestion efficiency for comparative examples 1 and 2;
FIG. 4 is a comparison graph of Raman spectra of PBS plastic before and after extraction of degradable micro-plastic in biological tissue according to the present invention;
FIG. 5 is a comparison graph of Raman spectra of PCL plastic before and after extraction of degradable micro-plastic in biological tissue according to the present invention;
FIG. 6 is a comparison graph of Raman spectra of PHA plastics before and after extraction of degradable micro-plastics in biological tissues according to the present invention;
FIG. 7 is a comparison graph of Raman spectra of PLA plastics before and after extraction of degradable micro-plastics in a biological tissue according to the present invention;
FIG. 8 is a comparison graph of Raman spectra of starch-based plastics before and after extraction of degradable micro-plastics in biological tissues according to the present invention;
FIG. 9 is a graph of the organic matter remaining on the PTFE hydrophilic filter membrane after the biological tissue digestion test of the present invention;
FIG. 10 is a micrograph of a degradable micro-plastic extracted after a digestion experiment of a biological tissue according to the present invention;
FIG. 11 is a micrograph of a degradable micro-plastic extracted after a digestion experiment of a biological tissue according to the present invention;
FIG. 12 is a micrograph of a degradable micro plastic extracted after a biological tissue digestion experiment according to the present invention.
Detailed Description
In order to make the technical means, the creation features, the achievement purposes and the effects of the invention easy to understand, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the embodiments of the present invention and the accompanying drawings. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
Example 1
(1) Biological tissue collection and homogenization: clam samples collected from the field or purchased commercially are brought back to the laboratory in ice boxes and stored in a-20 ℃ freezer. The surface of the clams was cleaned with ultrapure water to remove any adhering particles. Soft tissue of the clam was minced with scissors and disrupted with a homogenizer, and 2g of the disrupted tissue was placed in a 250mL glass beaker, three replicates.
(2) Sample digestion: 30mL of a 0.063mol/L hydrochloric acid solution containing 0.5% pepsin (w/v) was added to the beaker of step (1), and after shaking at 37 ℃ for 3 hours, 30mL of H was added thereto 2 O 2 (w/v) the solution was shaken at 40 ℃ for 12 hours, and then vacuum filtered through a PTFE hydrophilic filter.
(3) Density separation: transferring the PTFE hydrophilic filter obtained in the step (2) to a 250mL beaker and adding 30mL of a filter having a density of 1.5g/cm to the beaker 3 After the NaI solution (178 g of NaI is dissolved in 180mL of ultrapure water at the temperature of 20 ℃) is subjected to ultrasonic treatment for 15 minutes at 40KHz in an ultrasonic cleaning instrument, repeatedly flushing a PTFE hydrophilic filter membrane with the NaI solution for three times while controlling the total solution volume to be not more than 50mL, sequentially taking out the PTFE hydrophilic filter membrane, transferring the solution in a beaker to a 60mL separating funnel, standing for 30 minutes, and performing vacuum suction filtration on the lower-layer solution (which accounts for about 90% of the total volume) through the PTFE hydrophilic filter membrane to recycle the filtrate; and pouring the upper solution (accounting for about 10 percent of the total volume) from an upper opening, performing vacuum filtration on the PTFE hydrophilic filter membrane, and drying and weighing the intercepted matters on the PTFE hydrophilic filter membrane.
And drying and weighing the PTFE hydrophilic filter membrane. The digestion efficiency is shown in fig. 2, corresponding to clams in the figure.
Example 2
(1) Biological tissue collection and homogenization: squid samples collected from the field or purchased commercially are brought back to the laboratory in ice boxes and stored in a-20 ℃ freezer. The surface of the squid is washed with ultrapure water to remove any adhering particles. The soft tissues of the squid are cut into pieces by scissors and crushed by a homogenizer, and then 2g of the crushed tissues are put into a 250mL glass beaker, and three samples are paralleled.
(2) Sample digestion: adding 30mL of 0.063mol/L hydrochloric acid solution containing 0.5% pepsin (w/v) to the beaker of step (1), shaking at constant temperature of 37 ℃ for 3 hours, and then adding 20mL of 30% H 2 O 2 (w/v) the solution was shaken at 40 ℃ for 12 hours, and then vacuum filtered through a PTFE hydrophilic filter.
(3) Density separation: transferring the PTFE hydrophilic filter obtained in the step (2) to a 250mL beaker and adding 30mL of a filter having a density of 1.5g/cm to the beaker 3 After the NaI solution (178 g of NaI is dissolved in 180mL of ultrapure water at the temperature of 20 ℃) is subjected to ultrasonic treatment for 15 minutes at 40KHz in an ultrasonic cleaning instrument, the PTFE hydrophilic filter membrane is repeatedly washed with the NaI solution for three times while the total volume of the solution is controlled to be not more than 50mL, the PTFE hydrophilic filter membrane is sequentially taken out, the solution in a beaker is transferred to a 60mL separating funnel to be kept stand for 30 minutes, and the lower layer solution (which accounts for about 90 percent of the total volume) is subjected to vacuum filtration through the PTFE hydrophilic filter membrane, so that the filtrate can be recycled; and pouring the upper layer solution (accounting for about 10 percent of the total volume) from the upper opening, and drying and weighing the intercepted matters on the PTFE hydrophilic filter membrane through vacuum filtration of the PTFE hydrophilic filter membrane.
Drying and weighing the PTFE hydrophilic filter membrane. Digestion efficiency is shown in FIG. 2, corresponding to squid in the figure.
Example 3
(1) Biological tissue collection and homogenization: samples of portunids collected from the field or purchased commercially were brought back to the laboratory in ice boxes and stored in a-20 ℃ freezer. The surfaces of the swimming crabs were cleaned with ultrapure water to remove any adhering particles. Soft tissues of portunids are sheared by scissors and crushed by a homogenizer, and then 2g of crushed tissues are put into a 250mL glass beaker, and three samples are paralleled.
(2) Sample digestion: 30mL of a 0.063mol/L hydrochloric acid solution containing 0.5% pepsin (w/v) was added to the beaker of step (1), and after shaking at 37 ℃ for 3 hours, 30mL of H was added thereto 2 O 2 (w/v) the solution was shaken at 40 ℃ for 12 hours, and then vacuum filtered through a PTFE hydrophilic filter.
(3) Density separation: transferring the PTFE hydrophilic filter obtained in the step (2) to a 250mL beaker and adding 30mL of a filter having a density of 1.5g/cm to the beaker 3 After the NaI solution (178 g of NaI is dissolved in 180mL of ultrapure water at the temperature of 20 ℃) is subjected to ultrasonic treatment for 15 minutes at 40KHz in an ultrasonic cleaning instrument, the PTFE hydrophilic filter membrane is repeatedly washed with the NaI solution for three times while the total volume of the solution is controlled to be not more than 50mL, the PTFE hydrophilic filter membrane is sequentially taken out, the solution in a beaker is transferred to a 60mL separating funnel to be kept stand for 30 minutes, and the lower layer solution (which accounts for about 90 percent of the total volume) is subjected to vacuum filtration through the PTFE hydrophilic filter membrane, so that the filtrate can be recycled; and pouring the upper layer solution (accounting for about 10 percent of the total volume) from the upper opening, and drying and weighing the intercepted matters on the PTFE hydrophilic filter membrane through vacuum filtration of the PTFE hydrophilic filter membrane.
Drying and weighing the PTFE hydrophilic filter membrane. Digestion efficiency is shown in fig. 2, corresponding to portunus trituberculatus.
Example 4
(1) Biological tissue collection and homogenization: crayfish samples collected from the field or purchased commercially are brought back to the laboratory in ice boxes and stored in a-20 ℃ freezer. The surface of the crayfish was cleaned with ultrapure water to remove any adhering particles. Soft tissue of crayfish was cut with scissors and crushed with a homogenizer, and 2g of the crushed tissue was put into a 250mL glass beaker, three samples in parallel.
(2) Sample digestion: 30mL of a 0.063mol/L hydrochloric acid solution containing 0.5% pepsin (w/v) was added to the beaker of step (1), and after shaking at 37 ℃ for 3 hours, 30mL of H was added thereto 2 O 2 (w/v) the solution was shaken at 40 ℃ for 12 hours, and then vacuum filtered through a PTFE hydrophilic filter.
(3) Density separation: transferring the PTFE hydrophilic filter obtained in the step (2) to a 250mL beaker and adding 30mL of a filter having a density of 1.5g/cm to the beaker 3 After the NaI solution (178 g of NaI is dissolved in 180mL of ultrapure water at the temperature of 20 ℃) is subjected to ultrasonic treatment for 15 minutes at 40KHz in an ultrasonic cleaning instrument, the PTFE hydrophilic filter membrane is repeatedly washed with the NaI solution for three times while the total volume of the solution is controlled to be not more than 50mL, the PTFE hydrophilic filter membrane is sequentially taken out, the solution in a beaker is transferred to a 60mL separating funnel to be kept stand for 30 minutes, and the lower layer solution (which accounts for about 90 percent of the total volume) is subjected to vacuum filtration through the PTFE hydrophilic filter membrane, so that the filtrate can be recycled; and pouring the upper layer solution (accounting for about 10 percent of the total volume) from the upper opening, and drying and weighing the intercepted matters on the PTFE hydrophilic filter membrane through vacuum filtration of the PTFE hydrophilic filter membrane.
Drying and weighing the PTFE hydrophilic filter membrane. The digestion efficiency is shown in fig. 2, corresponding to crayfish in the figure.
Comparative example 1
(1) Biological tissue collection and homogenization: clam samples collected from the field or purchased commercially are brought back to the laboratory in ice boxes and stored in a-20 ℃ freezer. The surface of the clams was cleaned with ultrapure water to remove any adhering particles. Soft tissue of the clam was minced with scissors and disrupted with a homogenizer, and 2g of the disrupted tissue was placed in a 250mL glass beaker, three replicates.
(2) Sample digestion: adding 40mL of 30% (w/v) HNO to the beaker of step (1) 3 And (3) oscillating the solution at the constant temperature of 40 ℃ for 12 hours, performing vacuum filtration by using a PTFE hydrophilic filter membrane, and drying and weighing the retentate on the PTFE hydrophilic filter membrane.
Drying and weighing the PTFE hydrophilic filter membrane. Digestion efficiency is shown in FIG. 3, corresponding to HNO in the graph 3 。
Comparative example 2
(1) Biological tissue collection and homogenization: clam samples collected from the field or purchased commercially are brought back to the laboratory in ice boxes and stored in a-20 ℃ freezer. The surface of the clams was cleaned with ultrapure water to remove any adhering particles. Soft tissue of the clam was minced with scissors and disrupted with a homogenizer, and 2g of the disrupted tissue was placed in a 250mL glass beaker, three replicates.
(2) Sample digestion: adding 40mL of 30% (v/v) H to the beaker of step (1) 2 O 2 And (3) oscillating the solution at the constant temperature of 40 ℃ for 12 hours, performing vacuum filtration by using a PTFE hydrophilic filter membrane, and drying and weighing the retentate on the PTFE hydrophilic filter membrane.
And drying and weighing the PTFE hydrophilic filter membrane. The digestion efficiency is shown in FIG. 3, corresponding to H in the figure 2 O 2 。
Application example 1 Raman Spectroscopy identification and statistics
The method for identifying and counting the Raman spectrum of the retentate obtained by the method of the embodiment 1 comprises the following specific steps:
(1) Biological tissue collection and homogenization: clams collected from the field or purchased commercially are brought back to the laboratory in ice boxes and stored in a-20 ℃ freezer. The surface of the clams was cleaned with ultrapure water to remove any adhering particles. The muscle or intestinal tract was minced with scissors and the tissue was disrupted with a homogenizer, and then 2g of the disrupted tissue was placed in a 250mL glass beaker for the subsequent plastic extraction step.
(2) Sample digestion: 30mL of a 0.063mol/L hydrochloric acid solution containing 0.5% pepsin (w/v) was added to the beaker of step (1), and after shaking at 37 ℃ for 3 hours, 30mL of H was added thereto 2 O 2 (w/v) the solution was shaken at 40 ℃ for 12 hours, and then vacuum filtered through a PTFE hydrophilic filter.
(3) Density separation: transferring the PTFE hydrophilic filter obtained in the step (2) to a 250mL beaker and adding 30mL of a filter having a density of 1.5g/cm to the beaker 3 The NaI solution (178 g of NaI dissolved in 180mL of ultrapure water at 20 ℃) of (1) was subjected to ultrasonic treatment in an ultrasonic cleaning apparatus for 15 minutes, and then the PTFE hydrophilic filter was repeatedly rinsed three times with the NaI solution while controlling the total solution volume to not more than 50mL, and the PTFE hydrophilic filters were sequentially removed, and the solution in the beaker was transferred to a 60mL separation funnel and allowed to stand for 30 minutes, and the lower layer solution (about 90% of the total volume) was passed throughAfter the PTFE hydrophilic filter membrane is subjected to vacuum filtration, filtrate can be recycled; and pouring the upper solution (accounting for about 10 percent of the total volume) from an upper opening, performing vacuum filtration through a PTFE hydrophilic filter membrane, and detecting the trapped substance by Raman spectroscopy.
(4) Identifying and counting the Raman spectrum: and (3) drying and microscopic examination are carried out on the retentate obtained by vacuum filtering the upper solution on the PTFE hydrophilic filter membrane, and suspected plastic particles are selected for Raman spectrum identification and Raman spectrum comparison before and after digestion (see figures 4-8) and microscope image observation and analysis (see figures 9-12).
According to the results, the digestion method provided by the invention can efficiently digest biological tissues without obviously influencing the physicochemical characteristics of the degradable plastics, the traditional single strong acid or hydrogen peroxide is adopted for digestion, the digestion is incomplete, and the influence on the optical characteristics and the form of the degradable micro-plastics is large in the digestion process.
Although the present invention has been described with reference to a preferred embodiment, it should be understood that various changes, substitutions and alterations can be made herein without departing from the spirit and scope of the invention as defined by the appended claims.

Claims (7)

1. A method for extracting degradable micro-plastic from biological tissue, which comprises the following steps:
(1) Washing, shearing and crushing the biological tissue to obtain a crushed biological tissue for later use;
(2) Taking appropriate amount of the crushed biological tissue, adding 0.063mol/L hydrochloric acid solution containing 0.5% pepsin (w/v), oscillating for the first time, adding 30% H 2 O 2 (w/v), after the second oscillation, carrying out vacuum filtration by using a PTFE hydrophilic filter membrane;
(3) The PTFE hydrophilic filter membrane obtained above was immersed at a density of 1.5g/cm 3 Carrying out ultrasonic treatment on the NaI solution, continuously washing a PTFE hydrophilic filter membrane by using the NaI solution, standing the obtained solution, and carrying out vacuum filtration on the upper layer solution through the PTFE hydrophilic filter membrane to obtain a retentate;
(4) Drying and microscopic examination are carried out on the obtained trapped substance, suspected plastic particles are selected for Raman spectrum detection, an identification map is obtained, the micro-plastics are identified according to an identification standard, and then counting statistics is carried out respectively according to the micro-plastics of different materials.
2. The method of claim 1, wherein the biological tissue in step (1) comprises soft tissue, muscle and visceral tissue of fish, crustaceans, bivalves and mollusks.
3. The method according to claim 1, wherein the first oscillation condition in step (2) is: the temperature is 37 ℃ and the time is 3h.
4. The method of claim 1, wherein the second oscillation condition in step (2) is: the temperature is 40 ℃ and the time is 12h.
5. The method according to claim 1, wherein the pore size of the PTFE hydrophilic filter in step (2) is 1 μm.
6. The method according to claim 1, wherein the density in step (3) is 1.5g/cm 3 The NaI solution is prepared according to the following method: 178g NaI was dissolved in 180mL of ultrapure water at 20 deg.CAnd (4) neutralizing.
7. The method according to claim 1, wherein the sonication conditions in step (3) are: the frequency is 40KHz, and the time is 10-15 min.
CN202111236977.XA 2021-10-24 2021-10-24 Method for extracting degradable micro-plastic from biological tissue Pending CN115290623A (en)

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