CN-122017094-A - Efficient water and soil sample microplastic separation and concentration device and application method thereof

CN122017094ACN 122017094 ACN122017094 ACN 122017094ACN-122017094-A

Abstract

The invention relates to the field of micro-plastic detection, in particular to a device and a method for separating and concentrating water and soil samples by using micro-plastic. The efficient water and soil sample microplastic separation and concentration device comprises a funnel, a rubber plug, a bottle body and a miniature vacuum pump, and is characterized in that the funnel comprises a containing part, an upper conveying pipe, an upper connecting part, a filter membrane tray, a sealing rubber ring, a lower connecting part, a lower conveying pipe and a KF16 vacuum clamp, an opening is formed in the upper end of the containing part and used for injecting a sample to be treated, the lower end of the containing part is fixedly connected with the upper end of the upper conveying pipe, the lower end of the upper conveying pipe is fixedly connected with the upper end of the upper connecting part, and the lower end of the lower connecting part is fixedly connected with the upper end of the lower conveying pipe. The invention effectively simplifies the sample injection flow, realizes the one-time efficient introduction of the sample, ensures the integrity and the representativeness of the sample while remarkably improving the analysis efficiency, and has the advantages of simple operation, good reproducibility, high detection accuracy and the like.

Inventors

WANG YANYAN
CAO WENGENG
GUO SEN
LIU YANG
YAO CHAO
FU YU
HUANG ZIYI
SONG LE

Assignees

中国地质科学院水文地质环境地质研究所
华北水利水电大学

Dates

Publication Date: 20260512
Application Date: 20260311

Claims (10)

1. The efficient water and soil sample microplastic separation and concentration device comprises a funnel, a rubber plug, a bottle body and a micro vacuum pump, and is characterized in that the funnel comprises a containing part, an upper conveying pipe, an upper connecting part, a filter membrane tray, a sealing rubber ring, a lower connecting part, a lower conveying pipe and a KF16 vacuum clamp, an opening is formed in the upper end of the containing part and used for injecting a sample to be treated, the lower end of the containing part is fixedly connected with the upper end of the upper conveying pipe, the lower end of the upper conveying pipe is fixedly connected with the upper end of the upper connecting part, the lower end of the lower connecting part is fixedly connected with the upper end of the lower conveying pipe, corresponding circular grooves are formed in the lower end of the upper connecting part and the upper end of the lower connecting part, through holes are formed in the center of the filter membrane tray, circular flanges matched with the circular grooves are respectively formed in the upper end face and the lower end face of the filter membrane tray, the sealing rubber ring is sleeved on the periphery of the filter membrane tray, the upper connecting part, the filter membrane tray and the lower connecting part are detachably and hermetically connected with the vacuum clamp, the lower conveying pipe penetrates through the rubber plug and is in sealing connection with the body, and is in sealing connection with the bottle body to provide vacuum.
2. The efficient soil and water sample microplastic separation and concentration device is characterized in that the containing portion is made of stainless steel, the diameter of an opening at the upper end is 2.5cm, the upper conveying pipe is made of stainless steel, the length of the upper conveying pipe is 5cm, the lower conveying pipe is made of stainless steel, the length of the lower conveying pipe is 7cm, the outer diameters of the upper conveying pipe and the lower conveying pipe are 0.3cm, the inner diameter of the vacuum clamp is 1.6cm, and the outer diameter of the vacuum clamp is 3cm.
3. The efficient soil and water sample microplastic separation and concentration device is characterized in that the upper connecting portion is made of stainless steel, a through hole with the diameter of 0.3cm and the depth of 0.3cm is formed in the center, the outer diameter of the upper end of the upper connecting portion is 1.5cm, the outer diameter of the lower end of the upper connecting portion is 3cm, the side wall of the lower connecting portion is a conical surface, the included angle of the conical surface is 10-15 degrees, the lower connecting portion is made of stainless steel, a through hole with the diameter of 0.3cm and the depth of 0.3cm is formed in the center, the outer diameter of the upper end of the lower connecting portion is 3cm, the outer diameter of the lower end of the lower connecting portion is 1.5cm, the side wall of the lower connecting portion is a conical surface, the included angle of the conical surface is 10-15 degrees, and the diameter of a circular groove formed between the lower end of the upper connecting portion and the upper end of the lower connecting portion is 1.2cm, and the depth of the circular groove is 0.2cm.
4. The efficient soil and water sample microplastic separation and concentration device is characterized in that the filter membrane tray is made of stainless steel, the diameter of the filter membrane tray is 1.5cm, the thickness of the filter membrane tray is 0.5cm, the diameter of circular flanges on the upper end face and the lower end face of the filter membrane tray is 1.2cm, the height of the circular flanges is 0.2cm, the diameter of a through hole in the center of the filter membrane tray is 0.3cm, the depth of the through hole is 0.9cm, a filter sand core is arranged in the through hole, an annular groove is formed in the periphery of the filter membrane tray, and the sealing rubber ring is embedded in the groove, and has the outer diameter of 2.5cm and the thickness of 0.5cm.
5. The efficient soil and water sample micro-plastic separation and concentration device according to claim 1 is characterized in that the lower conveying pipe penetrates through the rubber plug and stretches into the bottle body, an opening at the lower end of the lower conveying pipe is lower than an extraction opening arranged on the bottle body, and the micro vacuum pump is connected with the bottle body through the extraction opening.
6. The separation method of the efficient water and soil sample microplastic separation and concentration device according to any one of claims 1 to 5, which is characterized by comprising the following steps: Sample pretreatment, namely, air-drying a soil sample, sieving the soil sample by a 5mm stainless steel sieve, transferring the sieved soil sample into a 250ml beaker, adding a glass stirrer and 150ml saturated zinc chloride solution as a flotation liquid, sealing the mixture by aluminum foil paper, fully stirring the mixture by a magnetic stirrer for 10 minutes, standing the mixture for 12 hours, collecting supernatant, repeatedly supplementing the saturated zinc chloride solution, and performing the flotation operation twice, wherein the water sample can skip the step; step two, transferring the soil supernatant and the water sample into a clean beaker after being filtered by a stainless steel filter membrane, then adding a sufficient amount of ferrous sulfate solution into the beaker to completely submerge the filter membrane, sealing the filter membrane by aluminum foil paper, and carrying out Fenton digestion reaction on the sample by adding 30% hydrogen peroxide and 0.054mol/L ferrous sulfate solution according to a volume ratio of 3:1 after ultrasonic treatment of the sample for 30 min; Placing a glass fiber filter membrane with the diameter of 1.2cm on the filter membrane tray, wherein the aperture is consistent with or smaller than that of a stainless steel filter membrane, and then assembling the funnel, the rubber plug, the bottle body, the micro vacuum pump and the collecting device into the micro plastic separation concentration device; Step four, the micro-plastic separation and concentration device is opened, and a glass fiber filter membrane which is used for carrying the sample is filtered, and the glass fiber filter membrane is cut and placed on a stainless steel filter membrane for cutting; And fifthly, folding the cut glass fiber filter membrane in half, and then placing the folded glass fiber filter membrane into a thermal cracking cup for on-machine analysis of a subsequent thermal cracking gas chromatograph mass spectrometer.
7. The separation method of the efficient soil and water sample microplastic separation and concentration device, which is characterized by comprising the following steps of: The cutting opening specification of the cutter of the glass fiber filter membrane simultaneously meets the formula I, II: ; wherein: m Sample of is the mass of the sample to be measured, and the unit is mg; d is the diameter of an opening of the filter membrane cutter, and the unit is cm; d is the diameter of the cup mouth of the thermal cracking cup, and the unit is cm; h is the thickness of the filter membrane, and the unit is millimeter mm; ρ is the density of the filter membrane in grams per cubic centimeter g/cm 3 .
8. The separation method of the high-efficiency water and soil sample microplastic separation and concentration device is characterized by being used for sample pretreatment of a thermal cracking-gas chromatograph mass spectrometer for microplastic concentration characterization, and the separation method is combined with a microplastic analysis instrument, wherein the microplastic analysis instrument comprises a Fourier transform microplastic infrared spectrometer for 20-5 mm microplastic abundance characterization, a laser infrared imaging system for 10-500 μm microplastic abundance characterization, a single-particle inductive coupling plasma mass spectrometer for 600-20 μm microplastic abundance characterization and a submicron resolution infrared Raman spectroscopy combined instrument for 500nm-5mm microplastic abundance characterization, so that the omnibearing characterization of different indexes and different particle diameters of microplastic is realized.
9. The separation method of the efficient water and soil sample microplastic separation and concentration device is characterized in that the pore diameter of a stainless steel filter membrane is determined according to the detection lower limit of a combined analysis technology, wherein the detection lower limit of the microplastic particle size of a Fourier transform microscopic infrared spectrometer is 20 mu m, the detection lower limit of the microplastic particle size of a laser infrared imaging system is 10 mu m, the detection lower limit of the microplastic particle size of a single-particle inductive coupling plasma mass spectrometer is 0.6 mu m, the detection lower limit of the microplastic particle size of a submicron resolution infrared Raman microscopic combined spectrometer is 0.5 mu m, and stainless steel filter membranes with pore diameters of 20 mu m, 10 mu m, 0.6 mu m and 0.5 mu m are respectively selected for corresponding treatment.
10. The method of claim 9, wherein the pore size of the stainless steel filter membrane is determined according to the target particle size range, and when specific particle size distribution is studied, the pore size of the stainless steel filter membrane is one or more of 500 μm, 300 μm,20 μm, 10 μm, 0.6 μm, 0.5 μm, 0.45 μm and 0.22 μm to realize the sectional filtration.

Description

Efficient water and soil sample microplastic separation and concentration device and application method thereof Technical Field The invention relates to the field of micro-plastic detection, in particular to a device and a method for separating and concentrating water and soil samples by using micro-plastic based on a thermal cracking gas chromatograph mass spectrometer. Background Microplastic generally refers to plastic particles with a diameter of less than 5mm, and has attracted considerable attention worldwide as a novel environmental contaminant. The plastic products are widely used in the fields of packaging, spinning, daily consumer products and the like due to low cost and excellent performance, but are difficult to degrade naturally in the environment, so that a large amount of plastic wastes are continuously accumulated and crushed to form micro plastics. It is predicted that the total amount of plastic waste worldwide will rise to about 2.70 million tons by 2060. The microplastic has the characteristics of difficult degradation, large specific surface area, strong mobility and the like, and the occurrence state, migration and transformation rules and ecological effects of the microplastic in an environmental medium are far more complex than those of the traditional pollutants. In addition, the microplastic can interact with other pollutants in the environment, further increasing its potential risk to the ecosystem and human health. Therefore, the establishment of accurate and reliable qualitative and quantitative methods for the microplastic is a key basis for scientifically evaluating the environmental behaviors and ecological effects of the microplastic, and is an important premise for deeply disclosing the toxic action mechanism and constructing an environmental risk early warning system. The qualitative and quantitative analysis of the microplastic mainly adopts three methods, namely a microscopic analysis technology, a spectral analysis technology and a mass spectrometry technology. Microscopic analysis technology can realize qualitative and statistical analysis of the types and the quantity of the micro plastics, but is difficult to directly acquire the quality information. The spectrum analysis technology has low detection sensitivity on micro plastic particles with the particle size smaller than 5 mu m, and has difficulty in identifying composite particles with the spectrum similarity smaller than 50 percent, and the quality of the micro plastic cannot be directly measured. Compared with the prior art, the thermal cracking gas chromatography-mass spectrometry technology has both qualitative and quantitative analysis capability, has the advantages of small background interference, high detection sensitivity, capability of testing submicron particle size and the like, accurately identifies polymer types and quantifies trace amount of microplastic through characteristic pyrolysis products, can effectively analyze additives and degradation products thereof contained in the microplastic, and provides powerful technical support for pollution control and prevention and control of the microplastic. The micro-plastic analysis method based on the thermal cracking gas chromatograph mass spectrometer mainly adopts two modes of liquid sample injection and solid sample injection. Although the liquid sample injection can realize the full-quantity introduction of the sample, the pretreatment process needs multiple times of solvent volatilization, and has the advantages of complex operation, long time consumption, low efficiency and easy loss of trace target substances in multiple transfer processes. For example, china patent application publication No. CN202510126885.8 (published application day: 2025, 1, 27) discloses a method for simultaneously detecting multiple microplastic in water. The method adopts a liquid sample injection mode, and needs to be subjected to sample transfer for multiple times and heating and concentration until the solvent is completely volatilized, so that the method has the defects of long process and easy loss of target objects. For another example, china patent application with publication number CN202411249988.5 (published application day: 2024, 9, 6) discloses a method for analyzing micro-nano plastics in biological fluid. The method is also based on liquid sample injection, and the volatile sample matrix is heated at 100-150 ℃, so that the operation is complex, and the potential degradation risk on the thermally unstable polymer exists. In addition, the method has larger sample demand, is only suitable for laboratory high-concentration controllable micro-plastic samples, and is difficult to meet the high-sensitivity detection demand of trace micro-plastics in actual environment samples. Therefore, it is highly desirable to establish a high-efficiency water and soil sample microplastic separation and concentration device based on a thermal cracking gas chromatograph mass sp