Trypsin-induced degradation method of mask melt-blown cloth and degradation product analysis method thereof

Abstract

A trypsin-induced mask melt-blown fabric degradation method, comprising: taking mask melt-blown fabric products, preparing mask melt-blown fabric samples; placing the mask melt-blown fabric samples in a ball mill and performing vacuum grinding to prepare mask melt-blown fabric samples; weighing the mask melt-blown fabric samples, dispersing them with water, and preparing a mask melt-blown fabric dispersion liquid with a certain concentration; mixing the mask melt-blown fabric dispersion liquid with a trypsin solution, and the mass ratio of the trypsin to the mask melt-blown fabric is 10 ‑7 ~10 5 , and placing it in a vortex oscillator for uniform mixing; placing the mask melt-blown fabric dispersion liquid and the trypsin mixture in a water-proof incubator for incubation; and completing the degradation of the mask melt-blown fabric. The present application not only has the excellent characteristics of low cost, universality, and strong degradation ability, etc., is suitable for biodegradation research and practical application, but also provides data support for health risk assessment of mask melt-blown non-woven fabric by evaluating its adsorption and degradation of pollutants, has significant innovation and important scientific significance.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of biodegradation and degradation product analysis, and particularly relates to a trypsin-induced mask melt-blown fabric degradation method and a degradation product analysis method thereof. BACKGROUND

[0002] Disposable masks were mainly used for protection in medical facilities, biochemical laboratories and industrial activities, and are now widely used in daily life by the public. Medical masks are generally composed of three layers of non-woven material (spun-bonded-melt-blown-spun-bonded), and the middle melt-blown non-woven layer plays a filtering role. N95 masks are also composed of multi-layer non-woven fabric materials. The most common raw material for producing melt-blown non-woven fabric is polypropylene (PP), which mainly comes from oil and natural gas and is also used to make plastic bags, plastic bottles, agricultural films, etc. PP is not only one of the most widely used thermoplastics, but also the most commonly found plastic in the environment.

[0003] PP and polyethylene (PE) of mask melt-blown fabric are difficult to degrade in the environment. Laboratory studies estimate that the complete natural degradation of thermoplastic waste takes 10-1000 years, depending on the surrounding environment, and PP and PE waste fragments may exist for more than 10 years after landfill. Current biodegradation methods for plastics are basically related to hydrolytic enzymes and esterases, but the main object of action is PET, a plastic containing hydrolysis sites. For mask melt-blown fabric PP, which is chemically inert due to the lack of hydrolysis sites, it is extremely difficult to be biodegraded. So far, there has been no report that melt-blown fabric can be biodegraded in vivo.

[0004] Therefore, in view of the problems in the prior art, the present application provides a trypsin-induced mask melt-blown fabric degradation method and a degradation product analysis method thereof. SUMMARY

[0005] A first object of the present application is to provide a trypsin-induced mask melt-blown fabric degradation method to overcome the defects of PP plastic of mask melt-blown fabric in the prior art, such as lack of hydrolysis sites, chemical inertness, and difficulty in biodegradation, which causes environmental risks and safety problems.

[0006] A second object of the present application is to provide a degradation product analysis method using the trypsin-induced mask melt-blown fabric degradation method to overcome the defects of PP plastic of mask melt-blown fabric in the prior art, such as lack of hydrolysis sites, chemical inertness, and difficulty in biodegradation, which causes environmental risks and safety problems.

[0007] To achieve the first object of the present application, the present application provides a trypsin-induced mask melt-blown fabric degradation method, which comprises:

[0008] Performing step S1-1: taking the mask melt-blown fabric product, preparing a mask melt-blown fabric sample;

[0009] Performing step S1-2: placing the mask melt-blown fabric sample in a ball mill and performing vacuum grinding to prepare a mask melt-blown fabric sample;

[0010] Performing step S1-3: weighing the ground mask melt-blown fabric sample, dispersing it with water, and preparing a mask melt-blown fabric dispersion liquid with a certain concentration;

[0011] Performing step S1-4: mixing the mask melt-blown fabric dispersion liquid with a trypsin solution, and the mass ratio of the trypsin to the mask melt-blown fabric is 10 -7 ~10 5 , and placing it in a vortex oscillator to mix uniformly;

[0012] Performing step S1-5: placing the mask melt-blown fabric dispersion liquid mixed with the trypsin in a water-jacket incubator for incubation;

[0013] Performing step S1-6: completing the trypsin-induced degradation of the mask melt-blown fabric.

[0014] Optionally, the vacuum grinding time is 4-24 h.

[0015] Optionally, the mask melt-blown fabric in step S1-4 is prepared by filtering the ground mask melt-blown fabric.

[0016] Optionally, the concentration of the mask melt-blown fabric dispersion liquid is 10 -7 ~10 5 μg / mL.

[0017] Optionally, the trypsin is from an animal or a plant.

[0018] Optionally, the incubation condition is a dark or light environment, and the temperature is 0-37℃.

[0019] Optionally, the incubation time is 0-21 d.

[0020] Optionally, the degradation rate of the mask melt-blown fabric particles is 55%-100%.

[0021] To achieve another object of the present application, the present application provides a degradation product analysis method of a trypsin-induced mask melt-blown fabric degradation method, the degradation product analysis method of the trypsin-induced mask melt-blown fabric degradation, comprising:

[0022] Performing step S2-1: taking the incubated mask melt-blown fabric dispersion liquid mixed with the trypsin, and dropping it on a microtiter plate MTP 384 stainless steel non-polished target plate;

[0023] Performing step S2-2: without additional matrix, the mixed solution on the microtiter plate MTP 384 stainless steel non-polished target plate is placed in a fume hood for natural volatilization;

[0024] Performing step S2-3: after the mixed solution on the microtiter plate MTP 384 stainless steel non-polished target plate is dried, the target plate is placed on the target holder of the matrix assisted laser desorption ionization time-of-flight mass spectrometer, and the degradation products are detected by mass spectrometry.

[0025] Optionally, the characterization technology of the mask melt-blown fabric degradation products is morphological characterization and molecular characterization by mass spectrometry.

[0026] Optionally, the characteristic absorption of the mask melt-blown fabric and the mass spectrometry range of the degradation products are within 1000 m / z.

[0027] Optionally, the characteristic absorption of the mask melt-blown fabric and the mass spectrometry range of the degradation products are within 1000 m / z.

[0028] Optionally, the degradation path of the mask melt-blown fabric includes an oxidation path and a nitration path, and the conversion products after degradation include oxidation products and nitration products.

[0029] In summary, the trypsin-induced mask melt-blown fabric degradation method and degradation product analysis method of the present application not only have the advantages of low cost, universality, strong degradation capacity, etc., and are suitable for biodegradation research and practical application, but also provide data support for health risk assessment of the mask melt-blown fabric by evaluating the adsorption and degradation of pollutants, which has significant innovation and important scientific significance. BRIEF DESCRIPTION OF DRAWINGS

[0030] Figure 1 The figure shows the flow chart of the trypsin-induced mask melt-blown fabric degradation method of the present application;

[0031] Figure 2 The figure shows the flow chart of the trypsin-induced mask melt-blown fabric degradation method of the present application;

[0032] Figure 3 The figure shows the scanning electron microscope image of the mask melt-blown fabric without the addition of trypsin;

[0033] Figure 4 The figure shows the scanning electron microscope image of the mask melt-blown fabric after 48h incubation with trypsin;

[0034] Figure 5 The figure shows the MALDI-TOF MS mass spectrum of the mask melt-blown fabric in the low mass region;

[0035] Figure 6MALDI-TOF MS spectra of mask melt-blown fabric incubated with trypsin for 48 h. DETAILED DESCRIPTION

[0036] To illustrate the technical content, structural features, purposes and effects of the present application, the following will be described in detail in conjunction with the embodiments and the accompanying drawings.

[0037] Please refer to Figure 1 , Figure 1 The trypsin-induced mask melt-blown fabric degradation method and degradation product analysis method of the present application are shown in the flow chart. The trypsin-induced mask melt-blown fabric degradation method and degradation product analysis method comprise:

[0038] Step S1-1 is performed: Take the mask melt-blown fabric product and prepare a mask melt-blown fabric sample;

[0039] Step S1-2 is performed: Place the mask melt-blown fabric sample in a ball mill and perform vacuum grinding to prepare a mask melt-blown fabric sample;

[0040] Step S1-3 is performed: Weigh the ground mask melt-blown fabric sample, disperse it with water, and prepare a mask melt-blown fabric dispersion liquid of a certain concentration;

[0041] Step S1-4 is performed: Mix the mask melt-blown fabric dispersion liquid with the trypsin solution, and the mass ratio of trypsin to mask melt-blown fabric is 10 -7 ~ 10 5 , and place it in a vortex shaker to mix evenly;

[0042] Step S1-5 is performed: Place the mask melt-blown fabric dispersion liquid mixed with trypsin in a water-jacketed incubator for incubation;

[0043] Step S1-6 is performed: Complete the trypsin-induced mask melt-blown fabric degradation.

[0044] Generally, mask melt-blown fabric is considered to be inert and can resist biological digestion or degradation. In order to prove that trypsin can induce the degradation of mask melt-blown fabric under mild conditions, the degradation products are analyzed. Please refer to Figure 2 , and refer to Figure 1 , Figure 2 The degradation product analysis method of trypsin-induced mask melt-blown fabric degradation is shown in the flow chart. The degradation product analysis method of trypsin-induced mask melt-blown fabric degradation comprises:

[0045] Step S2-1 is performed: Take the mask melt-blown fabric dispersion liquid mixed with trypsin after incubation and drop it on a microtiter plate MTP 384 stainless steel non-polished target plate;

[0046] Performing step S2-2: no additional matrix is added to the mixed solution on the microtiter plate MTP 384 stainless steel non-polished target plate, and it is placed in a fume hood for natural volatilization.

[0047] Performing step S2-3: after the mixed solution on the microtiter plate MTP 384 stainless steel non-polished target plate is dried, the target plate is placed on the target holder of a matrix assisted laser desorption ionization time-of-flight mass spectrometer (MALDI-TOF MS), and the degradation products are detected by mass spectrometry by the MALDI-TOF MS.

[0048] In order to more directly disclose the technical solutions of the present application and highlight the beneficial effects of the present application, the trypsin-induced mask melt-blown fabric degradation method and degradation product analysis method will be described in conjunction with specific embodiments. In the specific embodiments, the process parameters, step sequence, etc. used in the trypsin-induced mask melt-blown fabric degradation method and degradation product analysis method are only for illustration and should not be regarded as a limitation on the technical solutions of the present application.

[0049] Please refer to Figure 3 , Figure 4 , and in conjunction with Figure 1 , Figure 2 , Figure 3 , which shows the scanning electron microscope pattern of the mask melt-blown fabric without adding trypsin. Figure 4 which shows the scanning electron microscope pattern of the trypsin-induced mask melt-blown fabric after 96h incubation. The trypsin-induced mask melt-blown fabric degradation method and degradation product analysis method comprises:

[0050] Performing step S1-1: take the mask melt-blown fabric product and prepare a mask melt-blown fabric small sample;

[0051] Performing step S1-2: place the mask melt-blown fabric small sample in a ball mill and perform vacuum grinding to prepare a mask melt-blown fabric sample; wherein the vacuum grinding time is 4-24h. Ball milling can change the surface properties of the mask melt-blown fabric, thereby promoting degradation.

[0052] Performing step S1-3: weigh the ground mask melt-blown fabric sample, disperse it with water, and prepare a mask melt-blown fabric dispersion liquid with a certain concentration; wherein the concentration of the mask melt-blown fabric dispersion liquid is 10 -7 -10 5 μg / mL.

[0053] Performing step S1-4: mix the mask melt-blown fabric dispersion liquid with a trypsin solution, and the mass ratio of the trypsin to the mask melt-blown fabric is 10 -7 -10 5 , and place it in a vortex shaker for uniform mixing. Wherein the trypsin comes from an animal or plant body.

[0054] Step S1-5 is performed: the mask melt-blown fabric dispersion liquid and the trypsin mixed solution are placed in a water-jacketed incubator for incubation; wherein the incubation conditions are dark or light environment, and the temperature is 0-37°C. The incubation time is 0-21 days.

[0055] Step S1-6 is performed: trypsin-induced degradation of the mask melt-blown fabric is completed. The degradation rate of the mask melt-blown fabric particles is 55%-100%.

[0056] In order to prove that the trypsin can induce the degradation of the mask melt-blown fabric under mild conditions, the degradation products are analyzed. Please refer to Figure 5 、 Figure 6 , and in combination with the MALDI-TOF MS spectrum of the mask melt-blown fabric in the low mass region shown in Figures 1 to 4 , Figure 5 Figure 6 The MALDI-TOF MS spectrum of the mask melt-blown fabric incubated for 96h under the action of trypsin is shown. The degradation product analysis method of the trypsin-induced degradation of the mask melt-blown fabric includes:

[0057] Step S2-1 is performed: the incubated mask melt-blown fabric dispersion liquid and trypsin mixed solution is taken and dropped on a microtiter plate MTP 384 stainless steel non-polished target plate; non-limitingly, for example, 2μL of the incubated mask melt-blown fabric dispersion liquid and trypsin mixed solution is measured.

[0058] Step S2-2 is performed: the mixed solution on the microtiter plate MTP 384 stainless steel non-polished target plate is placed in a fume hood without additional matrix, and is naturally volatilized;

[0059] Step S2-3 is performed: after the mixed solution on the microtiter plate MTP 384 stainless steel non-polished target plate is dried, the target plate is placed on the target holder of the matrix-assisted laser desorption ionization time-of-flight mass spectrometer (MALDI-TOF MS), and the degradation products are detected by MALDI-TOF MS.

[0060] Wherein, the characterization techniques of the mask melt-blown fabric degradation products include morphological characterization and mass spectrometric molecular characterization. The characteristic absorption of the mask melt-blown fabric and the mass spectrum range of the degradation products are within 1000m / z. More specifically, the characteristic absorption of the mask melt-blown fabric and the mass spectrum range of the degradation products are in the small molecule region below 1000m / z.

[0061] ​As a specific embodiment, the model of the mass spectrometer is Bruker Daltonics Autoflex IIISmartbean MALDI-TOF mass spectrometer, the frequency of 200Hz of 355nm Nd:YAG is used, the laser power is set to 70% in positive ion and negative ion modes, and the MS range is 0-3000. Figure 3 、 Figure 4 It can be known that after the addition of trypsin, the morphology and quantity of the mask melt-blown cloth are obviously changed. The content gradually decreases with the extension of time, proving that the mask melt-blown cloth is metabolically transformed by trypsin. At the same time, the morphology of the mask melt-blown cloth is transformed from strip-shaped into granular, and the size is obviously reduced. Figure 5 It can be known that without the addition of a matrix, the measured mask melt-blown cloth has characteristic molecular peak clusters in the low mass region of the MALDI-TOF MS, proving that the degradation product analysis method of the application can be directly used for the analysis of the mask melt-blown cloth sample without the addition of a matrix when the sample is prepared. Figure 6 It can be known that the MALDI-TOF MS result shows that the mask melt-blown cloth is metabolically transformed after the co-incubation with trypsin, proving that the degradation of the mask melt-blown cloth is induced by the co-incubation with trypsin. The degradation path of the mask melt-blown cloth includes an oxidation path and a nitrogenation path, and the transformed products after the degradation include oxidation products and nitrogenation products. It can be known from the degradation product analysis that the mask melt-blown cloth can be degraded in a living body, even in a human body, and the human body has a certain clearance capacity for the mask melt-blown cloth.

[0062] Obviously, the trypsin-induced mask melt-blown cloth degradation method and degradation product analysis method of the application not only have excellent characteristics such as low cost, universality and strong degradation capacity, are suitable for biodegradation research and practical application, but also provide data support for the health risk assessment of the mask melt-blown non-woven fabric by evaluating the adsorption and degradation of pollutants, have significant innovation and important scientific significance.

[0063] In summary, the trypsin-induced mask melt-blown cloth degradation method and degradation product analysis method of the application not only have excellent characteristics such as low cost, universality and strong degradation capacity, are suitable for biodegradation research and practical application, but also provide data support for the health risk assessment of the mask melt-blown non-woven fabric by evaluating the adsorption and degradation of pollutants, have significant innovation and important scientific significance.

[0064] Those skilled in the art should understand that various modifications and variations can be made to the application without departing from the spirit or scope of the application. Thus, if any modification or variation falls within the scope of the appended claims and their equivalents, it is considered that the application encompasses these modifications and variations.

Claims

1. A method of degrading a trypsin-induced mask meltblown fabric, the method comprising: contacting the mask meltblown fabric with a protease enzyme; and incubating the mask meltblown fabric with the protease enzyme for a period of time sufficient to degrade the mask meltblown fabric. The trypsin-induced mask melt-blown fabric degradation method comprises the following steps: Step S1-1: Take the mask melt-blown fabric product and prepare a mask melt-blown fabric sample; Step S1-2: Put the mask melt-blown fabric sample into a ball mill and perform vacuum grinding to prepare a mask melt-blown fabric sample; Step S1-3: Weigh the ground mask melt-blown fabric sample, disperse it with water, and prepare a mask melt-blown fabric dispersion liquid with a certain concentration; The step S1-4 is performed: mixing the mask melt-blown fabric dispersion liquid with the trypsin solution, and the mass ratio of the trypsin mixed with the mask melt-blown fabric is 10 -7 ~ 10 5 , and placed in a vortex oscillator for mixing evenly; Step S1-5: Put the mask melt-blown fabric dispersion liquid and the trypsin mixture into a water-jacketed incubator for incubation; Step S1-6: Complete the trypsin-induced mask melt-blown fabric degradation.

2. The method of claim 1, wherein the trypsin-induced degradation of the mask meltblown fabric is characterized by, The vacuum grinding time is 4-24 hours.

3. The method of claim 1, wherein the trypsin-induced degradation of the mask meltblown fabric is characterized by, The mask melt-blown fabric in step S1-4 is prepared by filtering the mask melt-blown fabric dispersion liquid after ball milling.

4. The method of claim 1, wherein the trypsin-induced degradation of the mask meltblown fabric is characterized by, The mask melt-blown cloth dispersion liquid concentration is 10 -7 ~ 10 5 μg / mL.

5. The method of claim 1, wherein the trypsin-induced degradation of the mask meltblown fabric is characterized by, The trypsin is from an animal or a plant.

6. The method of claim 1, wherein the trypsin-induced degradation of the mask meltblown fabric is characterized by, The incubation time of the mask melt-blown fabric dispersion liquid and the trypsin mixture in the water-jacketed incubator is 0-21 days.

7. The method of claim 1, wherein the trypsin-induced degradation of the mask meltblown fabric is characterized by, The incubation condition is in the dark or light environment, and the temperature is 0-37℃.

8. The method of claim 1, wherein the trypsin-induced degradation of the mask meltblown fabric is characterized by, The degradation rate of the mask melt-blown fabric particles is 55%-100%.

9. A method for analyzing the degradation product of the method for degrading the trypsin-induced mask melt-blown fabric according to claim 1, characterized by, The trypsin-induced mask melt-blown fabric degradation product analysis method comprises the following steps: Step S2-1: Take the mask melt-blown fabric dispersion liquid and the trypsin mixture after incubation, and drop it on a microtiter plate MTP 384 stainless steel non-polished target plate; Step S2-2: No additional matrix is added to the mixture on the microtiter plate MTP 384 stainless steel non-polished target plate, and it is placed in a fume hood for natural volatilization; Step S2-3: After the mixture on the microtiter plate MTP 384 stainless steel non-polished target plate is dried, the target plate is placed on the target holder of a matrix-assisted laser desorption ionization time-of-flight mass spectrometer, and the degradation products are detected by MALDI-TOF MS.

10. The method of claim 9, wherein the method of analyzing the degradation products of the trypsin-induced degradation of the mask meltblown fabric is characterized by, The characterization technology of mask melt-blown fabric degradation products is morphological characterization and mass spectrometric molecular characterization.

11. The method of claim 10, wherein the method of analyzing the degradation products of the trypsin-induced degradation of the mask meltblown fabric is characterized by, The characteristic absorption of mask melt-blown fabric and the mass spectrometry range of degradation products are within 1000 m / z.

12. The method of claim 11, wherein the method of analyzing the degradation products of the trypsin-induced degradation of the mask meltblown fabric is characterized by, The characteristic absorption of mask melt-blown fabric and the mass spectrometry range of degradation products are within 1000 m / z.

13. The method of claim 9, wherein the method of analyzing the degradation products of the trypsin-induced degradation of the mask meltblown fabric is characterized by, The characteristic absorption of mask melt-blown fabric and the mass spectrometry range of degradation products are within 1000 m / z. The degradation pathway of mask melt-blown fabric includes oxidation pathway and nitrogenation pathway, and the conversion products after degradation include oxidation products and nitrogenation products.

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