A method for the degradation of meltblown nonwoven fabric for face masks induced by metabolic enzymes and a method for analyzing degradation products.

Abstract

A method for inducing the degradation of meltblown nonwoven fabric for face masks using metabolic enzymes includes: taking a meltblown nonwoven fabric product to prepare a small sample; placing the small sample in a ball mill and vacuum grinding it to prepare a sample; weighing the sample and dispersing it in water to prepare a meltblown nonwoven fabric dispersion of a certain concentration; mixing the meltblown nonwoven fabric dispersion with a metabolic enzyme solution and mixing them evenly in a vortex mixer; incubating the mixture of the meltblown nonwoven fabric dispersion and the metabolic enzyme in a water-jacketed incubator; and completing the degradation of the meltblown nonwoven fabric. This invention not only enables the biodegradation and metabolism of meltblown nonwoven fabric under mild conditions under the induction of metabolic enzymes, overcoming the misconception that meltblown nonwoven fabric is inert and resistant to biological digestion or degradation, but also provides a novel enzymatic method for removing contaminants from meltblown nonwoven fabric based on the special degradation ability of metabolic enzymes. This method is simple to operate, highly efficient, and innovative.

Description

Technical Field

[0001] This invention relates to the field of biodegradation and degradation product analysis technology, and in particular to a method for metabolic enzyme-induced degradation of meltblown nonwoven fabric for face masks and a method for analyzing degradation products. Background Technology

[0002] With the widespread use of face masks, the potential environmental risks and biosafety issues they pose have increasingly drawn public attention. To maximize the utilization of masks and minimize risks, methods such as incineration, burial, and recycling are commonly used for disposal. However, these methods have limited processing capacity, extremely low efficiency, and a high risk of secondary pollution. Statistics show that the global usage of disposable medical masks has reached 3.4 × 10⁻⁶. 9 The production of disposable masks accounts for 0.84% ​​of the world's total plastic consumption, but the recycling rate of these masks is less than 1%.

[0003] Therefore, the degradation of face masks, especially environmentally friendly biodegradation, has become a breakthrough in solving this problem. Meltblown nonwoven fabric, a crucial component of face masks, has a high molecular weight plastic structure, primarily composed of polypropylene (PP). Current biodegradation methods for plastics mainly involve hydrolytic enzymes and esterases, but these primarily target PET-type plastics containing hydrolytic sites. PP-type plastics used in face mask meltblown fabric lack hydrolytic sites and are chemically inert, making them extremely difficult to biodegrade. To date, there are no reports of face mask meltblown nonwoven fabric being biodegraded in vivo.

[0004] Therefore, in view of the problems existing in the prior art, the designer of this case, based on years of experience in this industry, actively researched and improved the technology, and thus came up with the present invention of a method for the degradation of meltblown nonwoven fabric for masks induced by metabolic enzymes and a method for analyzing degradation products. Summary of the Invention

[0005] The first objective of this invention is to provide a metabolic enzyme-induced degradation method for meltblown fabric used in masks, which addresses the shortcomings of existing technologies, such as the lack of hydrolysis sites, relatively inert chemical properties, and extreme difficulty in biodegradation, leading to environmental risks and safety issues.

[0006] The second objective of this invention is to address the shortcomings of existing technologies, such as the lack of hydrolysis sites and relatively inert chemical properties of PP plastic meltblown fabric for masks, which makes it extremely difficult to be biodegraded, thus causing environmental risks and safety issues. This invention provides a method for analyzing degradation products using a metabolic enzyme-induced degradation method for meltblown fabric for masks.

[0007] To achieve the first objective of this invention, this invention provides a method for the degradation of meltblown nonwoven fabric for face masks induced by metabolic enzymes. The method includes:

[0008] Perform step S1-1: Take the meltblown fabric product for masks and prepare a small sample of meltblown fabric for masks;

[0009] Perform step S1-2: Place the small sample of meltblown fabric for the mask in a ball mill and perform vacuum grinding to prepare a sample of meltblown fabric for the mask;

[0010] Perform steps S1-3: Weigh the ground mask meltblown fabric sample, disperse it in water, and prepare a mask meltblown fabric dispersion of a certain concentration.

[0011] Perform steps S1-4: Mix the meltblown fabric dispersion for masks with the glutathione S-transferase solution and place them in a vortex mixer to mix evenly;

[0012] Perform steps S1-5: Incubate the mask meltblown fabric dispersion and glutathione S-transferase mixture in a water-jacketed incubator;

[0013] Perform steps S1-6: Complete the degradation of the meltblown fabric for the mask induced by glutathione S-transferase.

[0014] Optionally, the vacuum grinding time is 2 to 24 hours.

[0015] Optionally, the concentration of the meltblown nonwoven fabric dispersion for the mask is 10. -7 ~10 4 μg / mL.

[0016] Optionally, the glutathione S-transferase is derived from animal or plant organisms.

[0017] Optionally, the mass ratio of the glutathione S-transferase to the meltblown nonwoven fabric for the mask is 10:1. -8 ~10 4 .

[0018] Optionally, the incubation conditions are a dark or light environment with a temperature of 0–37°C.

[0019] Optionally, the incubation time is 0 to 21 days.

[0020] Optionally, the degradation rate of the meltblown fabric particles in the mask is 50% to 100%.

[0021] To achieve another objective of the present invention, the present invention provides a method for analyzing degradation products of meltblown nonwoven fabric for face masks using a metabolic enzyme-induced degradation method. The method for analyzing degradation products of meltblown nonwoven nonwoven fabric for face masks using a metabolic enzyme-induced degradation method includes:

[0022] Step S2-1: Take the incubated mask meltblown fabric dispersion and glutathione S-transferase mixture and drop it onto the MTP 384 stainless steel non-polished target plate of the microtiter plate.

[0023] Perform step S2-2: Do not add any additional matrix to the mixture on the MTP 384 stainless steel unpolished target plate of the microtiter plate, and place it in a fume hood to evaporate naturally;

[0024] Step S2-3: After the mixture on the micro-titer plate MTP 384 stainless steel unpolished 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 using MALDI-TOF MS.

[0025] Optionally, the characterization techniques for the degradation products of meltblown nonwoven fabric used in masks include morphological characterization and molecular characterization by mass spectrometry.

[0026] Optionally, the characteristic absorption and degradation product mass spectra of the meltblown nonwoven fabric for masks are within the range of 1000 m / z.

[0027] Optionally, the mass spectrometry range of the characteristic absorption and degradation products of the meltblown nonwoven fabric for masks is in the small molecular region below 1000 m / z.

[0028] Optionally, the degradation pathway of the meltblown nonwoven fabric for masks includes an oxidation pathway and a nitridation pathway, and the conversion products after degradation include oxidation products and nitridation products.

[0029] In summary, the metabolic enzyme-induced degradation method for meltblown nonwoven fabric used in face masks and the analysis method for degradation products of this invention not only enable the biodegradation and metabolism of meltblown nonwoven fabric under mild conditions induced by glutathione S-transferase, but also demonstrate the degradation process through complementary multiple technologies. This breaks the misconception that meltblown nonwoven fabric is inert and resistant to biological digestion or degradation, updating the existing understanding of the biological fate of meltblown nonwoven fabric. Furthermore, based on the special degradation ability of metabolic enzymes on meltblown nonwoven fabric, this invention provides a new enzymatic method for removing contaminants from meltblown nonwoven fabric, which is simple to operate, highly efficient in detection, and original. Attached Figure Description

[0030] Figure 1 The diagram shown is a flowchart of the method for the degradation of meltblown nonwoven fabric for face masks induced by metabolic enzymes according to the present invention.

[0031] Figure 2 The diagram shows the flowchart of the analysis method for degradation products of meltblown nonwoven fabric for face masks induced by metabolic enzymes.

[0032] Figure 3 The image shown is a scanning electron microscope image of meltblown fabric for face masks without the addition of glutathione S-transferase.

[0033] Figure 4 The image shown is a scanning electron microscope image of glutathione S-transferase-induced meltblown fabric for face masks after incubation for 48 hours.

[0034] Figure 5The image shows the MALDI-TOF MS mass spectrum of meltblown nonwoven fabric for face masks in the low-mass region.

[0035] Figure 6 The image shown is a MALDI-TOF MS mass spectrum of meltblown fabric for face masks after incubation with metabolic enzymes for 48 hours. Detailed Implementation

[0036] To explain in detail the technical content, structural features, objectives, and effects of this invention, the following will provide a detailed description in conjunction with embodiments and accompanying drawings.

[0037] Please see Figure 1 , Figure 1 The diagram shows a flowchart of the metabolic enzyme-induced degradation method for meltblown nonwoven fabric used in face masks according to the present invention. The metabolic enzyme-induced degradation method for meltblown nonwoven fabric used in face masks and the method for analyzing the degradation products include:

[0038] Perform step S1-1: Take the meltblown fabric product for masks and prepare a small sample of meltblown fabric for masks;

[0039] Perform step S1-2: Place the small sample of meltblown fabric for the mask in a ball mill and perform vacuum grinding to prepare a sample of meltblown fabric for the mask;

[0040] Perform steps S1-3: Weigh the ground mask meltblown fabric sample, disperse it in water, and prepare a mask meltblown fabric dispersion of a certain concentration.

[0041] Perform steps S1-4: Mix the meltblown fabric dispersion for masks with the glutathione S-transferase solution and place them in a vortex mixer to mix evenly;

[0042] Perform steps S1-5: Incubate the mask meltblown fabric dispersion and glutathione S-transferase mixture in a water-jacketed incubator;

[0043] Perform steps S1-6: Complete the degradation of the meltblown fabric for the mask induced by glutathione S-transferase.

[0044] Typically, meltblown nonwoven fabric for face masks is considered inert and resistant to biological digestion or degradation. To demonstrate that metabolic enzymes can induce the degradation of meltblown nonwoven fabric under mild conditions, the degradation products were analyzed. Please refer to [link to relevant documentation]. Figure 2 and in conjunction with reference Figure 1 , Figure 2 The diagram shows a flowchart of a method for analyzing degradation products of meltblown nonwoven fabric used in face masks, induced by metabolic enzymes. The method includes:

[0045] Step S2-1: Take the incubated mask meltblown fabric dispersion and glutathione S-transferase mixture and drop it onto the MTP 384 stainless steel non-polished target plate of the microtiter plate.

[0046] Perform step S2-2: Do not add any additional matrix to the mixture on the MTP 384 stainless steel unpolished target plate of the microtiter plate, and place it in a fume hood to evaporate naturally;

[0047] Step S2-3: After the mixture on the micro-titer plate MTP 384 stainless steel unpolished 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 mass spectrometry using MALDI-TOF MS.

[0048] To more intuitively reveal the technical solution of the present invention and highlight its beneficial effects, the method for degrading meltblown nonwoven fabric for masks induced by metabolic enzymes and the method for analyzing degradation products are now described in conjunction with specific embodiments. In the specific embodiments, the process parameters and sequence of steps used in the method for degrading meltblown nonwoven fabric for masks induced by metabolic enzymes and the method for analyzing degradation products are merely examples and should not be considered as limitations on the technical solution of the present invention.

[0049] Please see Figure 3 , Figure 4 and in conjunction with reference Figure 1 , Figure 2 , Figure 3 The image shown is a scanning electron microscope image of meltblown fabric for face masks without the addition of glutathione S-transferase. Figure 4 The image shown is a scanning electron microscope image of glutathione S-transferase-induced meltblown nonwoven fabric for face masks after incubation for 48 hours. The method for inducing the degradation of meltblown nonwoven fabric using metabolic enzymes and the method for analyzing the degradation products include:

[0050] Perform step S1-1: Take the meltblown fabric product for masks and prepare a small sample of meltblown fabric for masks;

[0051] Step S1-2: Place the small sample of meltblown fabric for the mask in a ball mill and perform vacuum grinding to prepare the meltblown fabric sample for the mask; the vacuum grinding time is 2-24 hours. Ball milling can change the surface properties of the meltblown fabric for the mask, thereby promoting degradation.

[0052] Perform steps S1-3: Weigh the ground mask meltblown fabric sample, disperse it in water, and prepare a mask meltblown fabric dispersion of a certain concentration; wherein, the concentration of the mask meltblown fabric dispersion is 10. -7 ~10 4 μg / mL.

[0053] Perform steps S1-4: Mix the mask meltblown fabric dispersion with the glutathione S-transferase solution, and vortex mix them thoroughly; wherein the mass ratio of glutathione S-transferase to mask meltblown fabric is 10:1. -8 ~10 4The glutathione S-transferase described herein is derived from animal or plant organisms.

[0054] Perform steps S1-5: Place the mask meltblown fabric dispersion and glutathione S-transferase mixture in a water-jacketed incubator for incubation; wherein the incubation conditions are a dark or light environment, and the temperature is 0-37℃. The incubation time is 0-21 days.

[0055] Perform steps S1-6: Complete the glutathione S-transferase-induced degradation of the meltblown nonwoven fabric used in face masks. The degradation rate of the meltblown nonwoven fabric particles is 50%–100%.

[0056] To demonstrate that the metabolic enzymes can induce the degradation of meltblown nonwoven fabric for face masks under mild conditions, the degradation products were analyzed. Please refer to [link to relevant documentation]. Figure 5 , Figure 6 and in conjunction with reference Figures 1-4 , Figure 5 The image shows the MALDI-TOF MS mass spectrum of the meltblown fabric for face masks in the low-mass region. Figure 6 The image shows a MALDI-TOF MS mass spectrum of meltblown nonwoven fabric for face masks after incubation for 48 hours with glutathione S-transferase. The analytical method for the degradation products of the aforementioned metabolic enzyme-induced degradation of meltblown nonwoven fabric for face masks includes:

[0057] Step S2-1: Take the incubated mask meltblown fabric dispersion and glutathione S-transferase mixture and drop it onto a microtiter plate (MTP 384 stainless steel unpolished target plate); non-limitingly, for example, measure 2 μL of the incubated mask meltblown fabric dispersion and glutathione S-transferase mixture. The glutathione S-transferase is a phase II metabolic enzyme involved in in vivo biotransformation.

[0058] Perform step S2-2: Do not add any additional matrix to the mixture on the MTP 384 stainless steel unpolished target plate of the microtiter plate, and place it in a fume hood to evaporate naturally;

[0059] Step S2-3: After the mixture on the micro-titer plate MTP 384 stainless steel unpolished 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 mass spectrometry using MALDI-TOF MS.

[0060] The characterization techniques for the degradation products of meltblown nonwoven fabric used in face masks include morphological characterization and molecular characterization by mass spectrometry. The characteristic absorption and degradation products of meltblown nonwoven fabric for face masks have a mass spectrometric range within 1000 m / z. More specifically, the characteristic absorption and degradation products of meltblown nonwoven fabric for face masks have a mass spectrometric range in the small molecular region below 1000 m / z.

[0061] In a specific implementation, the mass spectrometer used is a Bruker Daltonics Autoflex III Smartbean MALDI-TOF mass spectrometer, employing a 355nm Nd:YAG laser at a frequency of 200Hz. In both positive and negative ion modes, the laser power is set to 70%, and the MS range is 0–3000. Figure 3 , Figure 4 It can be seen that the morphology and quantity of the meltblown fabric in masks changed significantly after the addition of glutathione S-transferase. The content gradually decreased over time, proving that glutathione S-transferase caused metabolic transformation of the meltblown fabric. Simultaneously, the morphology of the meltblown fabric changed from strip-like to granular, and the size decreased significantly. Figure 5 It can be seen that, without the addition of a matrix, the measured meltblown nonwoven fabric for masks exhibits characteristic molecular peak clusters in the low-mass region of MALDI-TOFMS, proving that the degradation product analysis method of this invention can be directly used for the analysis of meltblown nonwoven fabric samples for masks without the addition of a matrix during sample preparation. Figure 6 MALDI-TOF MS results showed that the meltblown nonwoven fabric underwent metabolic transformation after co-incubation with glutathione S-transferase, proving that co-incubation with glutathione S-transferase induced the degradation of the meltblown nonwoven fabric. The degradation pathway of the meltblown nonwoven fabric includes oxidation and nitrification pathways, and the degradation products include oxidation products and nitrification products. Analysis of these degradation products indicates that the meltblown nonwoven fabric can be degraded in vivo, even in the human body, and that the human body has a certain ability to remove the meltblown nonwoven fabric.

[0062] Clearly, the metabolic enzyme-induced degradation method for meltblown nonwoven fabric used in face masks described in this invention can achieve the biodegradation and metabolism of meltblown nonwoven fabric under mild conditions under the induction of glutathione S-transferase. The degradation process is demonstrated through complementary multiple technologies, overturning the misconception that meltblown nonwoven fabric is inert and resistant to biological digestion or degradation. This invention identifies multiple degradation products through mass spectrometry and proposes a transformation mechanism of meltblown nonwoven fabric in vivo, updating the existing understanding of the biological fate of meltblown nonwoven fabric. Based on the special degradation ability of metabolic enzymes on meltblown nonwoven fabric, a novel enzymatic method for removing contaminants from meltblown nonwoven fabric is provided.

[0063] In summary, the metabolic enzyme-induced degradation method for meltblown nonwoven fabric used in face masks and the analysis method for degradation products of this invention not only enable the biodegradation and metabolism of meltblown nonwoven fabric under mild conditions induced by glutathione S-transferase, but also demonstrate the degradation process through complementary multiple technologies. This breaks the misconception that meltblown nonwoven fabric is inert and resistant to biological digestion or degradation, updating the existing understanding of the biological fate of meltblown nonwoven fabric. Furthermore, based on the special degradation ability of metabolic enzymes on meltblown nonwoven fabric, this invention provides a new enzymatic method for removing contaminants from meltblown nonwoven fabric, which is simple to operate, highly efficient in detection, and original.

[0064] Those skilled in the art will understand that various modifications and variations can be made to this invention without departing from its spirit or scope. Therefore, if any modification or variation falls within the scope of the appended claims and their equivalents, the invention is considered to cover such modifications and variations.

Claims

1. A method for inducing the degradation of meltblown nonwoven fabric for face masks using metabolic enzymes, characterized in that, The method for inducing the degradation of meltblown nonwoven fabric for face masks by metabolic enzymes includes: Perform step S1-1: Take the meltblown fabric product for masks and prepare a small sample of meltblown fabric for masks; Perform step S1-2: Place the small sample of meltblown fabric for the mask in a ball mill and perform vacuum grinding to prepare a sample of meltblown fabric for the mask; Perform steps S1-3: Weigh the ground mask meltblown fabric sample, disperse it in water, and prepare a mask meltblown fabric dispersion of a certain concentration. Performing step S1-4: mix the mask melt-blown cloth dispersion liquid with the glutathione S-transferase solution, and place it in a vortex oscillator to mix uniformly; the mass ratio of the glutathione S-transferase mixed with the mask melt-blown cloth is 10 -8 ~ 10 4 ; Perform steps S1-5: Place the mask meltblown fabric dispersion and glutathione S-transferase mixture in a water-jacketed incubator for incubation; the incubation conditions are dark or light environment, temperature is 0-37℃; the incubation time is 0-21 days; Perform steps S1-6: Complete the degradation of the meltblown fabric for the mask induced by glutathione S-transferase.

2. The method for induced degradation of meltblown nonwoven fabric for face masks by metabolic enzymes as described in claim 1, characterized in that, The vacuum grinding time is 2 to 24 hours.

3. The method for induced degradation of meltblown nonwoven fabric for face masks by metabolic enzymes as described in claim 1, characterized in that, The mask melt-blown cloth dispersion liquid concentration is 10 -7 ~ 10 4 μg / mL.

4. The method for induced degradation of meltblown nonwoven fabric for face masks by metabolic enzymes as described in claim 1, characterized in that, The glutathione S-transferase is derived from animal or plant organisms.

5. The method for induced degradation of meltblown nonwoven fabric for face masks by metabolic enzymes as described in claim 1, characterized in that, The degradation rate of the meltblown fabric particles in the mask is 50% to 100%.

6. A method for analyzing degradation products using the metabolic enzyme-induced degradation method for meltblown nonwoven fabric used in face masks as described in claim 1, characterized in that, The method for analyzing degradation products of the metabolic enzyme-induced degradation of meltblown nonwoven fabric for face masks includes: Step S2-1: Take the incubated mask meltblown fabric dispersion and glutathione S-transferase mixture and drop it onto the MTP 384 stainless steel non-polished target plate of the microtiter plate. Perform step S2-2: Do not add any additional matrix to the mixture on the MTP 384 stainless steel unpolished target plate of the microtiter plate, and place it in a fume hood to evaporate naturally; Step S2-3: After the mixture on the micro-titer plate MTP 384 stainless steel unpolished 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 using MALDI-TOF MS.

7. The method for analyzing degradation products using the metabolic enzyme-induced degradation method for meltblown nonwoven fabric used in face masks as described in claim 6, characterized in that, The characterization techniques for the degradation products of meltblown nonwoven fabric used in face masks are morphological characterization and molecular characterization by mass spectrometry.

8. The method for analyzing degradation products using the metabolic enzyme-induced degradation method for meltblown nonwoven fabric used in face masks as described in claim 7, characterized in that, The characteristic absorption and degradation product mass spectra of meltblown nonwoven fabric for face masks are within the range of 1000 m / z.

9. The method for analyzing degradation products using the metabolic enzyme-induced degradation method for meltblown nonwoven fabric used in face masks as described in claim 8, characterized in that, The characteristic absorption and degradation products of meltblown nonwoven fabric for face masks are located in the small molecular region below 1000 m / z.

10. The method for analyzing degradation products using the metabolic enzyme-induced degradation method for meltblown nonwoven fabric used in face masks as described in claim 6, characterized in that, The degradation pathway of meltblown nonwoven fabric for face masks includes oxidation and nitridation pathways, and the conversion products after degradation include oxidation products and nitridation products.

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