CN120381686A - A dispersed liquid-liquid microextraction device and its extraction method and application - Google Patents

Abstract

The present invention provides a dispersed liquid-liquid microextraction device and an extraction method thereof, aiming to improve the extraction efficiency and enrichment effect of target compounds. The device comprises a sleeve with a cone head, a polydimethylsiloxane sponge, a magnetic stirrer, a needle and a sealing plug. The cone head is used to fill the polydimethylsiloxane sponge, which forms a hydrophobic and lipophilic microenvironment by rapidly reducing the volume, storing and adsorbing the extraction solvent. The magnetic stirrer forms a ternary mixed system of the extractant, dispersant and sample under stirring, and promotes the transfer of the target compound to the extractant by adjusting the stirring speed. The polydimethylsiloxane sponge is a hydrophobic porous material with strong adsorption for most target substances, and can also intercept large particulate substances such as lipids and macromolecular proteins. After extraction, the organic solvent containing the target substance is collected drop by drop through the needle. The device is suitable for biological samples and large-volume water samples, and can efficiently extract and enrich drugs, toxins and environmental pollutants, and has broad application prospects.

Description

Dispersion liquid micro-extraction device and its extraction method and application

Technical Field

The invention relates to a dispersion liquid-liquid microextraction device, an extraction method and application thereof.

Background

Toxicant detection in forensic science generally involves analysis of drugs, toxicants, etc. in complex biological test materials (e.g., blood, urine, hair, body fluids, etc.) and in large volumes of water samples (e.g., pond water, sewage, etc.). Due to the variety and complexity of sample types, as well as the variety of target compounds, how to efficiently and accurately extract and concentrate target substances from these complex samples is one of the key steps in forensic scientific poison testing. To address this challenge, current pretreatment methods generally rely on conventional techniques such as liquid-liquid extraction and solid-phase extraction, but these techniques generally have some drawbacks, which seriously affect pretreatment efficiency and application range.

Liquid-liquid extraction (Liquid Liquid Extraction, LLE) is widely used as a traditional pretreatment method in toxicant analysis in forensic science. The basic principle of liquid-liquid extraction is to selectively extract a target compound by partitioning the target compound in a sample by a solvent and utilizing the difference in affinity of the target compound in an organic solvent and an aqueous phase. However, liquid-liquid extraction has several significant disadvantages, which have limited practical applications.

First, liquid-liquid extraction typically requires a large amount of organic solvent. Although the solvent can effectively distribute the target compound, the organic solvent is generally toxic and has a large amount, which is liable to cause environmental pollution and risk of personnel exposure. For example, common organic solvents such as chloroform, diethyl ether, etc., while having good solubility, have high potential harm to the environment and human health. Furthermore, the solvents required for liquid-liquid extraction not only consume a large amount of resources, but also require additional waste treatment, which increases the overall cost.

Second, liquid-liquid extraction typically involves relatively cumbersome operating steps. In order to increase the extraction efficiency, multiple liquid separation, distribution and concentration are often required, which results in a significant increase in the time of the pretreatment process. In forensic science analysis, especially in cases where a fast response is required, the lengthy pre-processing procedure greatly reduces the analysis efficiency, delaying the processing of the case.

Finally, liquid-liquid extraction requires relatively high equipment and operation requirements. Due to the use of toxic organic solvents, operators need to be provided with a certain expertise and to operate in well ventilated laboratory environments. The equipment and laboratory conditions required for liquid-liquid extraction also add to the cost and complexity of pretreatment.

Solid phase extraction (Solid Phase Extraction, SPE) is used as another common sample pretreatment method, and is widely applied to the forensic science field, especially in the treatment process of complex biological samples and water samples. The principle is that the target compound is selectively adsorbed and eluted from the solid phase extraction material by eluting solvent. Solid phase extraction generally requires less solvent and is therefore more environmentally friendly than liquid-liquid extraction.

However, solid phase extraction also has some significant drawbacks, which make it somewhat limited in practical applications. First, solid phase extraction techniques often require replacement of a different solid phase extraction cartridge for a different compound of interest. The adsorption material and structure of each solid phase extraction column are different, and the applicable compound types are also different. Thus, in the handling of many different types of target compounds, it is often necessary to prepare many types of solid phase extraction cartridges, increasing the complexity and cost of the operation. In addition, the selectivity and sensitivity of solid phase extraction are affected by the solid phase material, and certain target compounds may not be efficiently separated or enriched due to poor adsorption selectivity or a stationary phase mismatch.

Second, the pretreatment process of solid phase extraction, while simplifying the use of solvents compared to liquid-liquid extraction, still requires more cumbersome steps. Common solid phase extraction procedures include sample loading, elution, concentration, etc., each requiring specific conditions and time control. Although solid phase extraction has reduced solvent consumption compared to liquid-liquid extraction, overall processing time and labor costs remain high due to the need for repeated operations and some equipment support.

In addition, reproducibility and stability of solid phase extraction are also a potential problem. Because the adsorption capacity of the solid phase column is influenced by environmental factors (such as temperature, humidity and the like), the adsorption performance of the solid phase column may change after long-term use, thereby influencing the stability of pretreatment results. In order to ensure the precision of solid phase extraction, the solid phase extraction columns usually need to be replaced periodically, which further increases the operation cost and workload.

The liquid-liquid extraction and the solid phase extraction of the two traditional sample pretreatment methods are widely applied to the detection of the drug poison in forensic science. However, because of the limitations of both of these techniques, they often do not provide adequate versatility in the face of complex and versatile samples. For example, different solvents and pretreatment regimes may need to be used for different target compounds. Moreover, certain poisons and drugs may not be as effective as the existing liquid-liquid and solid phase extraction methods, resulting in inadequate accuracy and sensitivity of the final analysis results.

Particularly in large volumes of water samples or complex biological sample processing, liquid-liquid extraction and solid phase extraction may not be able to achieve efficient extraction and concentration of the target compounds in a short time. In these cases, conventional pretreatment methods tend to require long-time operations and require high technical requirements and complicated equipment support. Along with the continuous improvement of forensic science demands, development of more efficient, environment-friendly and simple pretreatment technology is urgently needed to solve the defects of the existing method in complex sample analysis.

Disclosure of Invention

The invention aims to provide a dispersion liquid-liquid microextraction device, an extraction method and application thereof, which effectively improve the enrichment, purification and concentration effects of a target object in the liquid-liquid microextraction process, solve the problems of emulsification and solvent leakage, and are suitable for efficient and accurate chemical analysis and laboratory application.

The technical scheme adopted for solving the technical problems is as follows:

a dispersion liquid microextraction device, comprising:

A sleeve with a conical head, which provides a space for filling the hydrophobic porous polydimethylsiloxane sponge and forming a hydrophobic and oleophylic microenvironment, wherein an extraction solvent is stored and adsorbed in the sponge and forms an oil-water two-phase interface with an upper detection material;

The magnetic stirrer is a polytetrafluoroethylene stirrer and is used for adjusting the stirring speed to break the oil-water two-phase interface, so as to complete enrichment of the target compound into the extractant and inhibit the occurrence of emulsification;

The polydimethylsiloxane sponge adopts a hydrophobic and porous organic polymer material, is used for providing a hydrophobic microenvironment, adsorbing and storing an organic extraction solvent, effectively capturing macromolecules, proteins and particulate matters, and realizing enrichment, purification and concentration of a target object;

the needle head is arranged on the sleeve cone head and is used for storing a small amount of extracting agent, and the organic solvent gradually flows out from the tail end of the needle head after the extraction is finished and is used for collecting the organic solvent containing the target object;

and the sealing plug is made of silica gel, the organic solvent is prevented from being exposed and volatilized through the sealing plug, and after extraction is completed, the organic solvent is dropwise collected into a sample injection vial.

Preferably, the sleeve with the conical head is made of polyvinyl chloride material.

Preferably, the polydimethylsiloxane sponge is a synthetic polymer hydrophobic porous material or a natural hydrophobic porous material.

Preferably, the extraction solvent is any one of dichloromethane, chloroform, carbon tetrachloride and carbon disulfide, and the dispersing agent is any one of methanol, acetonitrile and acetone.

Preferably, the detection material is a biological or water sample detection material of blood, urine, urban sewage or fish pond water, and the target compound is a drug, toxin or environmental pollutant.

Preferably, the device adopts 0.1-1 ml of dichloromethane or chloroform as an organic solvent for completing the extraction and enrichment of target compounds in 0.5-5 ml of biological samples, and 0.2-2 ml of dichloromethane or chloroform as an organic solvent for extracting and enriching target compounds in 20-100 ml of large-volume water samples.

Another technical problem to be solved by the present invention is to provide an extraction method of a dispersion liquid-liquid microextraction device, comprising the following steps:

Adding a to-be-treated detection material and an organic extraction solvent into a sleeve with a conical head, wherein the sleeve is filled with hydrophobic porous polydimethylsiloxane sponge, the sponge can provide a storage space for the organic solvent and form an oil-water two-phase interface, and a target compound interacts with the organic solvent at the oil-water interface;

Starting a magnetic stirrer to stir, wherein the stirrer is made of polytetrafluoroethylene material, adjusting stirring speed to break an oil-water two-phase interface, promoting transfer of a target compound from a detection material to an extraction solvent, inhibiting emulsification, and ensuring effective enrichment of the target compound;

The target compound is adsorbed and concentrated by the hydrophobic porous polydimethylsiloxane sponge, and the hydrophobic microenvironment provided by the sponge is beneficial to enrichment and purification of the target substance, and meanwhile, interference of macromolecules and particulate matters is avoided;

After extraction is completed, the sealing plug is disassembled, the needle head device is activated, the organic solvent is allowed to slowly flow out drop by drop from the tail end of the needle head, and the organic solvent containing the target compound is collected into the collecting bottle;

if the organic solvent cannot flow out drop by drop, a pull rod with a piston can be used for pressurizing, so that the organic solvent can smoothly flow out, and the target compound in the extraction solvent is further collected.

Preferably, during the extraction, the stirring rate is controlled between 300 and 1000 revolutions per minute.

The invention aims to solve the technical problem of providing an application of the dispersion liquid-liquid microextraction device in the pretreatment process of biological detection materials and large-volume water samples, which is characterized in that the extraction is carried out on blood, urine, municipal sewage or fish pond water detection materials.

The invention aims to provide an application of the dispersion liquid-liquid microextraction device in detecting hypnotics and organophosphorus pesticides.

The beneficial effects of the invention are as follows:

By adopting a Polydimethylsiloxane (PDMS) sponge material, the target compound can be enriched efficiently under the action of magnetic stirring through the strong adsorption property. The microporous structure and the hydrophobic and oleophylic characteristics of the PDMS sponge enable the PDMS sponge to continuously adsorb and enrich target objects in the solvent when the PDMS sponge is combined with the extractant and the dispersing agent. The process can obviously improve the recovery rate and concentration effect of the target compound, ensures higher sensitivity and lower detection limit during analysis and detection, and is suitable for the rapid treatment of complex samples.

Compared with the traditional method, the dispersion liquid-liquid microextraction technology adopted by the invention obviously reduces the dependence on toxic organic solvents. Because the PDMS sponge has high-efficiency adsorption performance and simultaneously combines the dispersion effect of the dispersing agent, the required solvent amount is greatly reduced, and the waste of the solvent and the environmental pollution risk are reduced. The whole process is environment-friendly, can reduce the consumption of chemical reagents and the production of wastes to the greatest extent, and meets the requirements of green chemistry and sustainable development.

The device provided by the invention effectively breaks the interface by forming an oil-water two-phase interface in the extraction process and adopting a magnetic stirring mode, and enhances the enrichment of the target compound to the extractant. The process is efficient, complicated steps are reduced, and compared with the traditional liquid-liquid extraction method, the pretreatment time of the sample is obviously shortened. The method is simpler and faster to operate, and is suitable for the fields of forensic science, environmental monitoring and the like which need quick response.

The technology of the invention can show excellent recovery rate in various applications, especially for common hypnotics and organophosphorus pesticides, the recovery rate can reach more than 80%. By testing with a Thermo ISQ QD300 gas chromatograph, extremely low detection limits can be obtained, such as detection limits of 100 nanograms/ml (loratadine, nitro-tranquil, chlortranquil) and 20 nanograms/ml (esmolam, alprazolam, triazolam, clozapine) for hypnotics, and 80 nanograms/ml (fenthion, dimethoate) to 100 nanograms/ml (methamphetamine, dichlorvos, etc.). The characteristics of high sensitivity and low detection limit ensure that the method can accurately detect trace poison or medicine and meet the strict requirements in forensic science.

Compared with the traditional sample pretreatment method, the method has the advantages that the required sample amount is obviously reduced, and the extraction can be completed by only a small amount of sample. This not only reduces sample consumption and pressure from the sample source, but also effectively reduces the time and labor costs required for analysis. In the treatment process of a large-volume water sample or a complex biological detection material, the whole cost can be reduced on the premise of not sacrificing the analysis quality.

The dispersion liquid-liquid microextraction device adopts a sleeve design with a conical head, ensures that the hydrophobic porous PDMS sponge is effectively stored and operated in a microenvironment, forms an oil-water two-phase interface, and is beneficial to efficient adsorption and extraction of solvents. The use of the magnetic stirrer further breaks the oil-water interface, improves the extraction efficiency of the target compound, effectively inhibits the emulsification phenomenon, and ensures the stability and safety of the pretreatment process. The sealing plug is designed, so that volatilization and leakage of an organic solvent can be prevented, and safety and controllability in the operation process are ensured.

The invention can be widely applied to pretreatment processes of biological detection materials (such as blood, urine and the like) and large-volume water samples (such as pond water, sewage and the like). The method can realize efficient extraction and concentration of various target compounds such as medicines, pesticides, poisons and the like, and meets the detection requirements of different court science and environmental monitoring fields.

Drawings

FIG. 1 is a block diagram of a dispersion liquid microextraction device of the present invention;

FIG. 2 is a flow chart of the use of a dispersion liquid microextraction device according to the present invention.

Detailed description of the preferred embodiments

The principles and features of the present invention are described below with reference to the drawings, the examples are illustrated for the purpose of illustrating the invention and are not to be construed as limiting the scope of the invention. The invention is more particularly described by way of example in the following paragraphs with reference to the drawings. Advantages and features of the invention will become more apparent from the following description and from the claims. It should be noted that the drawings are in a very simplified form and are all to a non-precise scale, merely for convenience and clarity in aiding in the description of embodiments of the invention.

In the description of the present invention, it should be understood that the terms "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, are merely for convenience in describing the present invention and simplifying the description, and do not indicate or imply that the device or element being referred to must have a specific orientation, be configured and operated in a specific orientation, and thus should not be construed as limiting the present invention. Furthermore, the terms "first," "second," and the like, are used for descriptive purposes only and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first", "a second", etc. may explicitly or implicitly include one or more such feature. In the description of the present invention, unless explicitly stated and limited otherwise, the terms "mounted," "connected," and "connected" are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally connected, directly connected, or indirectly connected through an intermediary, or may be in communication with the interior of two elements.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and/or" as used herein includes any and all combinations of one or more of the associated listed items.

Example 1

Referring to FIGS. 1-2, a dispersion liquid microextraction device comprises:

The sleeve 1 with the conical head is used for providing a space to fill the hydrophobic porous polydimethylsiloxane sponge 3 through abrupt volume reduction, forming a hydrophobic and oleophylic microenvironment, storing and adsorbing an extraction solvent in the sponge, and forming an oil-water two-phase interface with the upper detection material 7;

The magnetic stirrer 2 is a polytetrafluoroethylene stirrer and is used for adjusting the stirring speed to break the oil-water two-phase interface, so as to complete enrichment of the target compound into the extractant and inhibit the occurrence of emulsification;

The polydimethylsiloxane sponge 3 adopts a hydrophobic and porous organic polymer material, is used for providing a hydrophobic microenvironment, adsorbing and storing an organic extraction solvent, effectively capturing macromolecules, proteins and particulate matters, and realizing enrichment, purification and concentration of a target object;

The needle head 4 is arranged on the sleeve cone head and is used for storing a small amount of extracting agent, and the organic solvent 6 gradually flows out from the tail end of the needle head 4 after the extraction is finished and is used for collecting the organic solvent 6 containing the target object;

And the sealing plug 5 is made of silica gel, the organic solvent 6 is prevented from being exposed and volatilized through the sealing plug 5, and after extraction is completed, the organic solvent 6 is collected into a sample injection vial drop by drop.

Polydimethylsiloxane (PDMS) sponge provides a hydrophobic and oleophilic microenvironment that allows the organic solvent 6 to efficiently adsorb and store, forming an oil-water two-phase interface. Through this microenvironment, the target compounds can be enriched and effectively purified, especially for the capture of macromolecules, proteins and particulates, ensuring efficient concentration and purity of the target.

The polytetrafluoroethylene magnetic stirrer 2 can adjust stirring speed, effectively break the oil-water two-phase interface and inhibit the emulsification phenomenon. Emulsification can result in difficult delamination of solvent and sample, affecting extraction and subsequent analysis. By avoiding emulsification, the extraction process is more stable and the final result is more reliable.

The organic solvent 6 is collected through the needle head 4 and flows out drop by drop, so that the solvent containing the target object is conveniently collected and recovered, and the solvent waste is reduced. Meanwhile, the sealing plug 5 is made of silica gel, so that the organic solvent 6 can be effectively prevented from being exposed and volatilized, the safety of an experiment process is guaranteed, the integrity of the solvent is kept, and higher repeatability and stability are provided for subsequent experiments.

The sleeve 1 with the conical head is made of polyvinyl chloride materials, the polydimethylsiloxane sponge 3 is made of an artificially synthesized high-molecular hydrophobic porous material or a natural hydrophobic porous material, the organic solvent 6 is any one of dichloromethane, chloroform, carbon tetrachloride and carbon disulfide, the dispersing agent is any one of methanol, acetonitrile and acetone, the detecting material 7 is a biological or water sample detecting material 7 of blood, urine, municipal sewage or pond water, and the target compound is a drug, toxin or environmental pollutant.

Polydimethylsiloxane (PDMS) sponge as a hydrophobic porous material is capable of efficiently adsorbing the organic solvent 6 and providing a superior hydrophobic environment. This allows for rapid enrichment, purification and concentration of the target compound (e.g., drug, toxin or environmental contaminant). Particularly in complex biological samples (such as blood and urine) or environmental water samples (such as urban sewage and fish pond water), the target compound can be effectively captured and separated, and the sensitivity and the accuracy of extraction are improved.

The organic solvent 6 (such as dichloromethane, chloroform, etc.) has good dissolving capacity, and can selectively extract different types of target compounds such as drugs, toxins or environmental pollutants. The sleeve is made of polyvinyl chloride (PVC) and has good chemical stability, and can keep corrosion resistance in various solvent environments. The design enables the device to be widely applicable to various solvents and various biological samples or water samples, and the universality and the flexibility of equipment are improved.

The polyvinyl chloride sleeve is used as an external structural material, so that the leakage of the solvent can be effectively prevented, and the safety of equipment is improved. In addition, the PDMS sponge adopting the artificial synthetic or natural hydrophobic porous material not only has good extraction effect, but also is simple and convenient to operate, and can rapidly complete the extraction and separation processes. Because the system has a sealing design, the volatilization and the exposure of the organic solvent 6 can be effectively prevented, the safety of experiments is improved, and the system is particularly important in treating toxic and harmful compounds.

The device adopts 0.1-1 ml of dichloromethane or chloroform as an organic solvent 6 for completing the extraction and enrichment of target compounds in 0.5-5 ml of biological detection materials 7, and 0.2-2 ml of dichloromethane or chloroform as the organic solvent 6 for extracting and enriching the target compounds in 20-100 ml of large-volume water samples.

The device can flexibly process samples in different volume ranges. For biological detection materials 7 (such as blood, urine, etc.) with small volume (0.5-5 ml), the target compound can be enriched efficiently by using 0.1-1 ml of dichloromethane or chloroform organic solvent 6, and high-sensitivity analysis is ensured. For a water sample (such as municipal sewage or fishpond water) with a larger volume (20-100 ml), 0.2-2 ml of solvent can be used for effectively extracting, so that the target compound can be well enriched and purified under different concentration and sample volume conditions.

The organic solvent 6 (0.1-2 ml) adopted in the scheme is optimized, so that the solvent consumption is low, and the solvent waste is effectively reduced. The method not only reduces the experiment cost, but also is beneficial to environmental protection, and avoids the pollution of excessive organic solvent 6 to the environment. Meanwhile, the extraction efficiency can be improved by precisely controlling the volume of the solvent, so that a better enrichment effect can be realized under the condition of lower solvent consumption.

Dichloromethane or chloroform is used as an organic solvent 6, so that a good extraction interface can be formed with a water sample and a target compound in a biological detection material 7, and efficient distribution and enrichment are ensured. For a water sample with larger volume, the sample volume is larger, but the high-efficiency concentration and enrichment of the target compound can be realized through a proper amount of organic solvent 6 and a proper microextraction device, and the requirements of the subsequent analysis on sensitivity and accuracy are met.

Example 2

Pretreatment for testing drug poison of complex biological detection material (urine)

The steps are as follows:

and (3) rinsing, namely adding 500 microliters of dichloromethane into the plastic sleeve, slowly pushing the pull rod, and ensuring that enough time is available for the dichloromethane to rinse the PDMS sponge material and wash off the unstable structure on the surface of the PDMS sponge material.

Loading 1 ml urine sample was added to the cartridge. The blood sample does not flow down due to the presence of the hydrophobic porous PDMS sponge at the lower end.

Extraction 100. Mu.l of dichloromethane extractant and 50. Mu.l of acetonitrile dispersant were added to the cartridge. Dichloromethane will adsorb in PDMS sponge and form an oil-water two-phase interface. The needle was closed and a magnetic stirrer was added, the stirring speed was adjusted to 800rpm, and stirring was carried out for 5 minutes. After the stirring was completed, the magnetic stirrer was taken out, and allowed to stand for 5 minutes to allow the solvent and the sample to be sufficiently layered.

And (3) sampling, namely removing the rubber plug after standing and layering, collecting dichloromethane solvent by using a sample injection small bottle with a liner, and dripping the dichloromethane solvent into the sample injection small bottle dropwise. If the organic solvent does not flow smoothly, the pressure can be appropriately increased. Observations ensure that urine samples did not enter the sample vials. And after the sampling is finished, loading the sample into a machine for gas chromatography-mass spectrometry analysis.

Aims to extract drugs or poisons from complex biological detection materials (urine) with high efficiency.

By using methylene chloride and a dispersing agent, a target compound in a blood sample can be sufficiently extracted, and extraction efficiency can be improved.

The method can ensure that poison or medicine in the urine sample is effectively concentrated, and provides higher sensitivity and accuracy for subsequent detection.

Example 3

Pretreatment for testing drug poison of large-volume water sample (pond water, sewage, etc.)

The steps are as follows:

and (3) rinsing, namely adding 500 microliters of dichloromethane into the plastic sleeve, slowly pushing the pull rod, rinsing the PDMS sponge material, and removing the unstable structure.

Loading by adding 50 ml of water sample to the cartridge. Because the PDMS sponge at the lower end has hydrophobic property, the water sample can not flow downwards.

Extraction by adding 1 ml of dichloromethane extractant and 1 ml of acetonitrile dispersant into the sleeve. Dichloromethane was adsorbed in PDMS sponge and formed an oil-water two-phase interface. The needle was closed, a magnetic stirrer was added, the stirring speed was adjusted to 800rpm, and stirring was performed for 10 minutes. After the completion of stirring, the stirrer was taken out, allowed to stand for 5 minutes, and layered.

Sampling, namely removing a rubber plug after standing and layering, collecting dichloromethane solvent by using a sample injection small bottle, and dripping the dichloromethane solvent into the sample injection small bottle dropwise. If the organic solvent does not flow smoothly, the inflow can be assisted by appropriate pressurization. And (3) ensuring that a water sample does not enter a sample injection small bottle, blowing the collected extractant nitrogen to be near dry after sampling, adding 100 microliters of methanol for redissolution, and carrying out instrument analysis.

Aims to effectively extract medicines or poisons in water from a large volume of water sample (such as pond water and sewage).

By using methylene chloride and acetonitrile as dispersing agents, the extraction efficiency of a drug or poison can be improved.

The method can effectively treat a large volume of water sample, and particularly can ensure high-sensitivity detection and reduce background interference when trace-level target compounds are required to be detected.

Example 4

Pretreatment for testing drug poison of blood sample

The steps are as follows:

Pretreatment of blood samples, namely, 1.0mL of the blood samples are removed, 600 mu L of acetonitrile is added, vortex is carried out for 30s, 1min is extracted by ultrasonic, and 10000r/min is centrifuged for 5min, and the supernatant is taken for testing.

And (3) rinsing, namely adding 500 microliters of dichloromethane into the plastic sleeve, slowly pushing the pull rod, ensuring that the dichloromethane sufficiently rinses the PDMS sponge material, and removing the unstable structure of the PDMS sponge material.

Loading, namely adding the supernatant sample into the sleeve. The sample of the detection material cannot flow downwards due to the PDMS sponge material with the hydrophobic and porous lower end.

And extracting, namely adding 0.4 milliliter of dichloromethane into the sleeve as an extracting agent, wherein the supernatant of the detecting material contains acetonitrile (dispersing agent) without adding the dispersing agent, and the dichloromethane can be adsorbed into the PDMS sponge to form an oil-water two-phase interface. The needle was closed, a magnetic stirrer was added, the rotation speed was adjusted to 800rpm, and stirring was performed for 5 minutes. After the completion of stirring, the magnetic stirrer was taken out, allowed to stand for 5 minutes, and layered.

Sampling, namely removing the rubber plug after layering is completed, collecting dichloromethane solvent by using a sample injection small bottle, and dropwise adding the solvent into the sample injection small bottle. If the organic solvent does not flow smoothly, the pressure is properly applied by using a tie rod with a rubber plug. And ensuring that the sample of the sample to be detected does not enter a sample injection small bottle, blowing the collected extractant nitrogen to be near dry, adding 100 microliters of methanol for re-dissolution, and loading the sample on a machine for gas chromatography-mass spectrometry analysis.

Aims to extract poison or medicine from blood sample and provide reliable pretreatment means for clinical detection.

According to the method, the mixed solvent of dichloromethane and acetonitrile is used, so that the extraction efficiency of trace target compounds in urine is improved, and the detection with high sensitivity and high selectivity is ensured.

The method can effectively remove the interference substances in the sample and improve the accuracy of the analysis result.

The above-mentioned embodiments of the present invention are not intended to limit the scope of the present invention, and the embodiments of the present invention are not limited thereto, and all kinds of modifications, substitutions or alterations made to the above-mentioned structures of the present invention according to the above-mentioned general knowledge and conventional means of the art without departing from the basic technical ideas of the present invention shall fall within the scope of the present invention.

Claims (10)

1. A dispersion liquid microextraction device, comprising:

The sleeve with the conical head provides a space for filling the hydrophobic porous polydimethylsiloxane sponge through rapid volume reduction, forms a hydrophobic and oleophylic microenvironment, stores and adsorbs an extraction solvent in the sponge, and forms an oil-water two-phase interface with an upper detection material;

The magnetic stirrer is a polytetrafluoroethylene stirrer and is used for adjusting the stirring speed to break the oil-water two-phase interface, so that enrichment of the target compound to the extractant is completed, mechanical demulsification can be completed by slowing down the stirring speed after extraction is completed, and the influence of the emulsification phenomenon on the recovery rate of the final target object is inhibited;

The polydimethylsiloxane sponge adopts a hydrophobic and porous organic polymer material, is used for providing a hydrophobic microenvironment, adsorbing and storing an organic extraction solvent, effectively capturing macromolecules, proteins and particulate matters, and realizing enrichment, purification and concentration of a target object;

the needle head is arranged on the sleeve cone head and is used for storing a small amount of extracting agent, and the organic solvent gradually flows out from the tail end of the needle head after the extraction is finished and is used for collecting the organic solvent containing the target object;

and the sealing plug is made of silica gel, the organic solvent is prevented from being exposed and volatilized through the sealing plug, and after extraction is completed, the organic solvent is dropwise collected into a sample injection vial.

2. The dispersion liquid microextraction device according to claim 1, wherein the tapered sleeve is made of polyvinyl chloride material.

3. The dispersion liquid microextraction device according to claim 1, wherein the polydimethylsiloxane sponge is a synthetic polymeric hydrophobic porous material or a natural hydrophobic porous material.

4. The dispersion liquid microextraction device according to claim 1, wherein the extraction solvent is any one of dichloromethane, chloroform, carbon tetrachloride, carbon disulfide, etc., and the dispersing agent is any one of methanol, acetonitrile, acetone, etc.

5. The dispersion liquid microextraction device according to claim 1, wherein the sample is blood, urine, municipal sewage or fish pond water, and the target compound is a drug, toxin or environmental pollutant.

6. The dispersion liquid microextraction device according to claim 1, wherein the device adopts 0.1-1 ml of dichloromethane or chloroform as an organic solvent for completing the extraction and enrichment of target compounds in 0.5-5 ml of biological samples, and 0.2-2 ml of dichloromethane or chloroform as an organic solvent for extracting and enriching target compounds in 20-100 ml of large-volume water samples.

7. An extraction method of a dispersion liquid microextraction device, which is characterized by comprising the following steps of:

adding a to-be-treated detection material, an organic extraction solvent and a dispersing agent into a sleeve with a conical head, wherein the sleeve is filled with hydrophobic porous polydimethylsiloxane sponge, the sponge can provide a storage space for the organic solvent and form an oil-water two-phase interface, and a target compound interacts with the organic solvent at the oil-water interface;

Starting a magnetic stirrer to stir, wherein the stirrer is made of polytetrafluoroethylene material, adjusting stirring speed to break an oil-water two-phase interface, promoting transfer of a target compound from a detection material to an extraction solvent, inhibiting emulsification, and ensuring effective enrichment of the target compound;

The target compound is adsorbed and concentrated by the hydrophobic porous polydimethylsiloxane sponge, and the hydrophobic microenvironment provided by the sponge is beneficial to enrichment and purification of the target substance, and meanwhile, interference of macromolecules and particulate matters is avoided;

After extraction is completed, the sealing plug is disassembled, the needle head device is activated, the organic solvent is allowed to slowly flow out drop by drop from the tail end of the needle head, and the organic solvent containing the target compound is collected into the collecting bottle;

if the organic solvent cannot flow out drop by drop, a pull rod with a piston can be used for pressurizing, so that the organic solvent can smoothly flow out, and the target compound in the extraction solvent is further collected.

8. The method according to claim 7, wherein the stirring rate is controlled to 300 to 1000 rpm during the extraction.

9. Use of a dispersion liquid microextraction device according to any of claims 1-6 for the pretreatment of biological samples, large volumes of water samples, characterized in that the extraction of blood, urine, municipal sewage or fish pond water samples is carried out.

10. Use of a dispersion liquid microextraction device according to any one of claims 1-6 for detecting hypnotics, drugs and pesticides.