Method for concentrating at least one human target substance in sample liquid

Abstract

The invention relates to the concentration of at least one man-made target substance in a sample liquid, consisting of particles and / or particles of average particle or particle size in the nanometer range, the concentration comprising: adding a superabsorbent (2) to an initial volume of liquid (1) of the sample liquid, or adding the volume of liquid (1) to the superabsorbent (2),-incubating the mixture obtained by mixing the superabsorbent (2) and the volume of liquid (1) for a first time period (t1), and-removing a first sample (4) of a liquid portion (3) of the mixture present after incubation.

Description

Technical Field

[0001] The invention relates to a method for concentrating at least one artificial target substance in a sample liquid, the artificial target substance consisting of particles and / or particles having an average particle or particle size in the nanometer range. Background Art

[0002] Nanoparticles and nanomicroparticles play an increasingly important role in our lives. For example, various applications in the pharmaceutical industry (e.g. in conjunction with encapsulated mRNA active ingredients), food technology or the electrical engineering or electronics industry (e.g. in connection with quantum dots) involve the use of these particles and microparticles and, in this context, also their production.

[0003] Due to their small size and associated changes in physical properties, nanoparticles and / or nanomicroparticles can be used to transport drugs to the desired organs, as they can penetrate the blood-brain barrier (e.g., for pharmaceuticals) and the skin (e.g., for the cosmetics industry). Nanoparticles and / or nanomicroparticles are also used in diagnostic applications, such as for color detection in rapid tests based on colloidal gold. They also stabilize foods, thereby ensuring a longer shelf life.

[0004] Nanoparticles and / or nanoparticles are almost all anthropogenic substances. This means that nanoparticles and / or nanoparticles have been produced by humans through industrial, commercial and municipal processes rather than, for example, by biological organisms. Therefore, another aspect of nanoparticles and / or nanoparticles involves the pollution of our planet, because nanoparticles and / or nanoparticles are generally difficult to biodegrade. Nanoparticles and / or nanoparticles are derived, for example, from waste materials of the plastics industry or by partial decomposition of essentially plastic waste (so-called secondary nanoplastics). The global pollution of the environment with waste materials from the plastics industry is a global problem. Nanoplastic wastes smaller than 1 μm in size enter the ecosystem unhindered and are generally not blocked by sewage treatment plants. The damage caused by microplastics and nanoplastics includes the accumulation of particles in the tissues of aquatic organisms. They also reach us humans through contaminated water and food chains. The accumulation of hydrophobic persistent organic pollutants (POPs) in the environment means an additional burden on marine life and humans. Nanoparticles and / or nanoparticles made of plastic or multiple plastics are particularly dangerous because they can pass through cell membranes and affect cell metabolic processes.

[0005] The collection and detection methods currently used are only suitable for macroplastics and microplastics, but not for nanoplastics. In order to assess environmental pollution, plastic waste is collected from surface waters, for example. This exploits the fact that about 98% of plastic particles have a lower density than water. The plastic particles are collected using large nets with a mesh size of about 0.3 mm, which are pulled over the water surface by a boat. The collected sediment is separated by size by sieving. The plastic particles are then suspended and filtered according to size. Other methods are based on the filtration of large volumes of water or air. The concentration of plastic particles in different waters is estimated to be around 1.5x10 -5 -0.11g / m 3 .

[0006] However, in all these methods, plastic components < 0.33 mm (i.e., part of the nanoparticles and nanoparticles in the micrometer range and all nanoparticles and nanoparticles in the nanometer range) are either lost or remain in the filtration cycle.

[0007] Microplastic and nanoplastic waste is detected using spectroscopic methods (e.g. Raman or infrared spectroscopy), thermal analysis methods (e.g. dynamic differential scanning calorimetry (DSC)), using gas chromatography mass spectrometry (GC / MS), using microscopy (optical, fluorescence-based) or also using fluorescence-based flow cytometry. This shows that the detection is very complicated due to the low concentrations of nanoplastics. A novel and simple concentration method is also needed for these application areas. Summary of the invention

[0008] The object of the present invention is to provide a simple, rapid and generally applicable method for concentrating at least one artificial target substance in a sample liquid.

[0009] This object is achieved in a surprisingly simple and universally applicable manner by means of a method as defined in claim 1, a use as defined in claim 21 and a kit as defined in claim 24. Advantageous embodiments are listed in the dependent claims.

[0010] The solution is based on the use of so-called superabsorbents, with which any aqueous sample liquid can be treated in order to concentrate the nanoparticles and / or nanomicroparticles contained in the sample liquid.

[0011] Superabsorbents (superabsorbent polymers, SAP) are plastics that can absorb multiples of their own weight in polar liquids. These are primarily water or aqueous solutions. When liquids are absorbed, the superabsorbent swells and forms a hydrogel. Hydrogels can be formed from all crosslinked polymers that are polar (e.g. polyacrylamide, polyvinylpyrrolidone, pullulan, gelatin, cellulose). However, copolymers of acrylic acid (acrylic acid, H2C=CH-COOH) or sodium acrylate (sodium acrylate, H2C=CH-COONa) on the one hand and acrylamide on the other hand are usually used, wherein the ratio of the two monomers to one another can vary. In addition, so-called core crosslinkers (CXLs) are added to the monomer solution and connect the long-chain polymer molecules formed to one another in place via chemical bridges (also called crosslinks). Due to these bridges, the polymer is water-insoluble. This so-called base polymer can be subjected to so-called surface crosslinking (SXL). Here, additional chemicals are applied to the surface of the particles, which, by heating, connect a second network only to the outer layer of the particles. This outer shell supports the swollen gel so that it also remains together under external load (movement, pressure).

[0012] Products are usually used, for example, as white granules with a particle size of 100-1000 μm. It is mainly used in baby diapers, sanitary napkins, incontinence care, bandages and also in small quantities in cable sheathing for deep-sea cables. Further areas of application are so-called gel beds, extinguishing agents that form gels in firefighting, as mechanical stabilizers for cut flowers in vases or as additives to plant soils in order to save water on a continuous basis. However, potassium-neutralized acrylic acid is used here due to its better environmental compatibility. The use of superabsorbents as toys is known in the form of spherical granules, with names such as "Aquabeads" or "Waterbeads". These are superabsorbents that are commercially available in the form of spheres of variable size (submillimeter to centimeter).

[0013] The present invention is based on the following unexpected observation: Mixing a water sample with fluorescent nanoparticles having an average particle or microparticle size of 30 nm, after adding commercially available water droplets and after an incubation period during which the beads swell to several times their original volume, showed that the nanoparticles were not absorbed by the superabsorbent, but concentrated in the remaining residual liquid.

[0014] This observation shows that by using superabsorbents, especially those commercially available in so-called water-globoid beads, a variety of nanoparticles can be easily and quickly concentrated in a liquid sample. The concentrated particles can then be more easily detected because the concentration leads to a higher target concentration.

[0015] Using the method and device according to the present invention, nanoparticles of a wide range of compositions can thus be efficiently, easily and quickly concentrated for detection reactions.

[0016] Based on this observation, the object of the present invention can be achieved.

[0017] The method for concentrating at least one artificial target substance in a sample liquid according to the present invention comprises:

[0018] - adding the superabsorbent to the initial volume of liquid of the sample liquid or adding this volume of liquid to the superabsorbent,

[0019] - a mixture obtained by incubating for a first period of time mixing the superabsorbent and the volume of liquid, and

[0020] - Removing a first sample of the liquid portion of the mixture present after incubation.

[0021] "Anthropogenic substances" are substances that are not produced by nature but by humans, for example through industrial, commercial or municipal processes. They include, for example, plastics, but also pesticides, pharmaceuticals, personal care products and industrial chemicals and their degradation products and metabolites. For example, biomolecules produced by microorganisms (e.g. enzymes, DNA / RNA fragments, etc.) and having similar sizes in the nanometer range are not particles and / or microparticles of anthropogenic substances as referred to in this application.

[0022] In the above-described method according to the invention, the first sample removed from the liquid portion of the mixture of liquid and superabsorbent present after incubation can be the entire remaining liquid portion. However, it is also possible to remove only a partial volume of a given liquid portion as the first sample.

[0023] The first sample can be used directly for subsequent analysis, for example by means of spectroscopic methods. However, it can also be further concentrated in one or more additional stages in the cascade process, for example by re-addition of superabsorbent and / or re-addition to superabsorbent and incubation, or by means of conventional methods for concentrating the target substance, for example by one of the methods specified at the beginning. If only a part of the liquid fraction is removed as the first sample, the target substance in the liquid fraction of the mixture remaining after the sample removal can be further concentrated by re-incubation in a second time period. Both variants of the method can be repeated so that a higher concentration of the target substance is obtained at each stage of the cascade concentration.

[0024] Advantageously, in the first stage, the initial sample volume is reduced by the method according to the invention using a superabsorbent, and in the subsequent second stage, the further concentration of the target substance is carried out by means of conventional concentration techniques, for example filtration, ultrafiltration, precipitation reaction, ultracentrifugation or by means of the method described in EP2283026 B1. These known techniques can be used significantly more effectively than in the solution of the stronger dilution in the sample volume that has been reduced. Therefore, the method according to the invention is applicable to the known methods of nanoparticles or nano-microparticles that are used to significantly simplify the large volume sample liquid and / or sample liquid that only contain low concentration target substance.

[0025] As mentioned, in advantageous embodiments, after removing the first sample, the method can include further concentrating the target substance in the removed first sample.

[0026] Further concentration of the target substance in the removed first sample can be performed by filtration, ultrafiltration or precipitation reaction techniques.

[0027] Alternatively, however, further concentration of the target substance in the removed first sample can also be carried out again or optionally in a cascade manner one or more times by carrying out the following method steps:

[0028] - adding the superabsorbent to the first sample or adding the first sample to the superabsorbent,

[0029] - incubating, during a second period of time, a mixture obtained by mixing the superabsorbent (5) and the first sample, and

[0030] - A first sample after concentration by removing the liquid portion of the mixture present after the incubation.

[0031] As described above, in the first stage of the cascade, the concentrated first sample removed from the liquid portion remaining after incubation can comprise the entire volume of the liquid portion. Alternatively, the concentrated first sample can be a partial volume of the remaining liquid portion.

[0032] By means of filtration, ultrafiltration or precipitation reaction, the target substance can be further concentrated in the concentrated first sample or in the further concentrated first sample obtained by further concentration, in particular by means of a superabsorbent. It is advantageous if the volume of the concentrated first sample corresponds to only a few milliliters, for example 1 to 10 mL.

[0033] As described above, the method for concentrating a target substance according to the present invention can include the following additional steps: after removing the first sample from the remaining liquid portion of the mixture of the liquid and superabsorbent of the originally used volume:

[0034] The target substance in the liquid portion of the mixture remaining after the removal of the first sample is re-concentrated by the following means, optionally in cascade, and individually or repeatedly,

[0035] - re-incubating the mixture remaining after removing the first sample from the remaining liquid portion and the superabsorbent for a third period of time; and

[0036] - Removing a second sample of the liquid portion of the mixture present after re-incubation.

[0037] As a result of the further incubation, the volume of the liquid portion is further reduced and the target substance is thus further concentrated in the liquid portion. The concentration of the target substance is determined in particular by the prespecifiable duration of the third time period and the conditions prevailing during the incubation.

[0038] In the method according to the invention, the volume of liquid initially used can contain a polar liquid, in particular as a main component. In an advantageous embodiment of the method according to the invention, the volume of liquid can contain a polar solvent, in particular as a main component. For example, the volume of liquid can consist of a polar solvent with a mass fraction of at least 50%. For example, the polar liquid or polar solvent can be water.

[0039] The target substance is a nanoparticle and / or a nanoparticle. Such a substance consists of an artificial substance, in particular of at least one natural polymer, at least one biocompatible synthetic polymer, an inorganic material or an organic material.

[0040] As mentioned above, in an advantageous embodiment, the superabsorbent can be a plastic or contain a plastic that absorbs a certain proportion of the volume of liquid, for example a polar solvent contained in the volume of liquid (such as water), to form a gel or hydrogel. Advantageously, the plastic is selected so that it does not substantially absorb nanoparticles. For example, this is the case in the above-mentioned superabsorbents made of the above-mentioned polymer and / or copolymer materials (such as commercially available Waterbeads, etc.).

[0041] The superabsorbent can be used in the form of particles, for example as powder particles, as granules, or in the form of geometric bodies, in particular beads (spherical particles). It can thus be added to the volume of liquid and / or the first sample in the form of such particles, or the volume of liquid and / or the first sample can be added to the superabsorbent in this form. The diameter of the particles or beads can be between 100 and 5000 μm.

[0042] Advantageously, the superabsorbent is a commercially available superabsorbent sphere - for example, superabsorbent beads available under the names "Aquabeads", "Waterbeads", "Hydroballs", "Gelballs".

[0043] In an advantageous method embodiment, the volume of the liquid portion remaining after the incubation step, and therefore the concentration of the target substance in the remaining liquid portion, is controlled by the length of the incubation period or periods, the amount of liquid added to the initially used volume of the sample liquid and / or the size and amount of superabsorbent particles or superabsorbent spheres in the first sample and / or the temperature prevailing during the incubation.

[0044] The sample liquid can be provided to constitute a filtrate or a centrifuge supernatant. Prior to concentration, one or more separation steps are performed to remove additional components from the sample.

[0045] One embodiment of the method provides that the sample liquid constitutes an environmental sample. The environmental sample is taken from the environment, for example from a body of water, such as a lake or a river. However, for example sediment or gas samples mixed with a liquid are also referred to as environmental samples.

[0046] The present invention also includes a method for detecting an artificial target substance in a sample liquid, comprising:

[0047] - concentrating the sample liquid using a superabsorbent using the concentration method according to the invention, and

[0048] - Physical detection methods for the qualitative and / or quantitative determination of anthropogenic target substances.

[0049] Physical detection methods are used to determine whether certain nanoparticles and / or nanoparticles are present in the concentrated sample or how high their concentration is. In the initial liquid volume, these will not be detected by physical detection methods because their concentration is too low. Microscopy is used for qualitative and / or quantitative determination. In this case, for example, nanoparticles and / or nanoparticles are counted in segments of defined size. Alternatively, fluorescence measurement methods or spectroscopic measurement methods are used. For this purpose, the nanoparticles and / or nanoparticles must contain fluorescent dyes, which are added in particular before concentration.

[0050] The invention also includes the use of superabsorbents for the concentration of artificial target substances in liquid samples, which is carried out once or multiple times in a cascade manner. The liquid sample can contain a polar liquid, especially water, wherein the superabsorbent is designed to absorb the polar liquid, such as water, or at least a part of the polar liquid, thereby forming a hydrogel. The superabsorbent can be formed from the above-mentioned materials and can be used as granules in the above-mentioned embodiments, or particularly preferably in the form of beads, especially commercially available Waterbeads, Waterbeads or Aquabeads.

[0051] Cascade concentration can include several stages. After each stage, the sample can be removed for analysis and the concentration process can be continued, or the sample can be concentrated in at least one stage after incubation with a superabsorbent, or a portion of the sample can be further concentrated subsequently using other known methods.

[0052] The invention also includes a kit for carrying out the above method. The kit can include, for example, one or more containers with pre-placed superabsorbent, to which the user can then add the initial volume of liquid for concentration or the sample already concentrated in the first stage.

[0053] The liquid concentrated according to the method and / or according to the use, i.e. the liquid fraction present after the incubation, or the sample removed from the concentrated liquid can be supplied manually or automatically to a laboratory instrument for further processing or analysis. In a possible embodiment of the method or use, such a liquid or a sample of the liquid can be added to a cartridge (in particular a microfluidic cartridge) of an automatic analysis device in order to automatically perform the detection of the target substance by means of a physical detection method for the qualitative and / or quantitative determination of the artificial target substance. This can take place manually or in an automatic manner. BRIEF DESCRIPTION OF THE DRAWINGS

[0054] The present invention is explained in more detail below with reference to the accompanying drawings and some exemplary embodiments. These embodiments do not represent any limitation of the reagents and methods according to the present invention. In the accompanying drawings:

[0055] Figure 1 It is a schematic diagram of the cascade concentration of the target substance in the liquid;

[0056] a) liquid before the addition of superabsorbent;

[0057] b) the liquid after adding the superabsorbent and incubating the mixture;

[0058] c) after adding additional superabsorbent and incubating the mixture, removing the first sample from the mixture;

[0059] d) optionally removing the remaining mixture of liquid and superabsorbent after the first sample and after re-incubation;

[0060] Figure 2 is a representation of samples and blank samples, some of which were obtained by means of concentration according to the invention and exposure to UV light; and

[0061] Figure 3 shows the evaluation of the measurement data:

[0062] a) Graphical representation of the mean of the measured values ​​in a bar graph;

[0063] b) Correlation between the degree of enrichment and the fluorescence increase of the samples. DETAILED DESCRIPTION

[0064] The use of superabsorbents for concentrating target substances, in particular nanoparticles and / or nanomicroparticles, in polar liquids as solvents (e.g. water) for concentrating the target substances in the liquid is very simple and generally available. Figure 1 a and Figure 1 b Briefly describe the appropriate method:

[0065] 1. adding a superabsorbent 2 to a volume of liquid 1, in particular an aqueous liquid, or alternatively: adding a liquid 1 to a superabsorbent 2;

[0066] 2. incubation of the mixture of liquid 1 and superabsorbent 2 for a first period of time t1 for concentrating (reducing the volume of) the liquid portion 3 of the mixture; and then

[0067] 3. Transferring at least one first sample 4 of the liquid portion 3 of the mixture into a new container as sample for further processing.

[0068] Further processing can be, for example, quantitative and / or qualitative detection of target substances in the liquid, for example, using spectroscopic or microscopic methods.

[0069] The degree of concentration and the speed of the process can be controlled very accurately by means of the type of superabsorbent used, by means of the amount used, or by means of the incubation time and / or the incubation temperature.

[0070] By this method, the problem of processing low concentrated samples for further processing of target substances of interest, in particular nanoparticles and / or nanomicroparticles, or their detection can be easily solved. Figure 1 a and Figure 1 The method shown in b works under the situation of no equipment, and equipment is such as ultracentrifuge, expensive ultrafiltration membrane, complicated method as PEG precipitation or general precipitation reaction that is used for concentrated nucleic acid etc.In addition, this method can generally use with respect to the type of nanoparticle and / or nano-microparticle.Other advantage is that superabsorbent is nontoxic and safe, and also is biodegradable usually.Can greatly simplify the research of low-concentration nanoparticle and / or nano-microparticle according to method of the present invention.

[0071] In the case of large volumes and / or strongly diluted liquids containing very low concentrations of nanoparticles and / or nanomicroparticles, cascade concentration of the target substance is possible. For example, in a first stage, the described method can be used together with steps 1-3 described above in order to concentrate the target substance. In a second stage, the volume of the first sample 4 can be reduced in order to re-concentrate the target substance. This can be done with the aid of conventional filtration or precipitation methods or other conventional methods. Alternatively, however, re-concentration of the target substance in the first sample 4 can also take place, such as Figure 1 c, by adding fresh superabsorbent 5 to the first sample 4, or transferring the first sample 4 to new superabsorbent 5 and incubating it again for a second period of time t2. Additionally or alternatively, the liquid portion 6 remaining in the mixture with the superabsorbent 2 after removing the first sample 4 can be further reduced by incubating the mixture for a third period of time t3, as shown in FIG. Figure 1 This results in further swelling with an increase in the volume of the spheres consisting of the superabsorbent 2 and in a further volume reduction in the liquid portion 6 , which is accompanied by an increase in the concentration of the target substance in the liquid portion 6 .

[0072] In two alternative process paths, further cascade enrichment stages can be followed.

[0073] Exemplary embodiments of the present invention will be described in detail below.

[0074] Exemplary embodiment: Concentration of Rhodamine B-filled latex nanoparticles ( 25.8nm)

[0075] The latex nanoparticles were provided by the Fraunhofer Institute for Applied Polymer Research. The concentration of the latex particles in the stock solution was 2.02 M%. The particles were added to a 500 ml water sample and a 1:10,000 dilution was produced.

[0076] Subsequently, a superabsorbent in the form of commercially available "Waterbeads" was added to the water sample. During the concentration by absorption of water into Waterbeads, samples P0, P1, P2 were taken at different times, each corresponding to a different concentration.

[0077] The samples were divided into blank samples L0, L1, L2 (without latex nanoparticles) for control and samples P0, P1, P2 containing latex nanoparticles. Specifically, the samples were as follows:

[0078] - Blank sample L0: Ultrapure water without latex particles (500ml)

[0079] - Blank sample L1: Concentrate 500ml ultrapure water to 40ml ultrapure water

[0080] - Blank sample L2: further concentrate L1 into 1 ml of ultrapure water

[0081] - Sample P0: 1:10,000 dilution of latex particle stock solution in 500 ml ultrapure water

[0082] - Sample P1: Concentrate 500ml ultrapure water to 40ml ultrapure water

[0083] - Sample P2: P1 is further concentrated into 1 ml of ultrapure water

[0084] The particles in the corresponding samples are detected by measuring the fluorescence of the dye contained in the latex nanoparticles.

[0085] Figure 1 The qualitative detection of latex nanoparticles is shown. For this reason, the corresponding samples P0, P1, P2 and blank samples L0, L1, L2 are transferred to UV transparent measuring plates in triplicate. The measuring plate with the sample is then exposed to UV light. Exposure to UV light causes the fluorescence excitation of latex particles in the sample. No fluorescence is seen in blank samples L0, L1, L2, and the fluorescence increased by increasing the concentration of the samples P0, P1, P2 comprising latex nanoparticles.

[0086] Table 1 shows the quantitative measurement of the corresponding samples using the fluorescence measurement device. The measurement was performed by exciting the samples P0, P1, P2 and the blank samples L0, L1, L2 (each in triplicate) at 559 nm emission. While the values ​​of the blank samples L0, L1, L2 were consistently maintained at low concentrations, the values ​​of the samples P0, P1, P2 containing nanoparticles increased in proportion to the degree of concentration.

[0087] Table 1:

[0088]

[0089] exist Figure 2 In , the measured values ​​listed in Table 1 are displayed or evaluated graphically. Figure 2 In a), the mean values ​​of the corresponding measured values ​​of the samples are shown as a bar graph. Figure 2 In b), the correlation between the degree of enrichment and the fluorescence increase of the nanoparticle-containing samples P0 ("1"), P1 ("2") and P2 ("3") is shown.

[0090] The data from the experiments clearly show that the fluorescent latex nanoparticles of the sample do not diffuse into the superabsorbent used (“Waterbeads”), but remain in the external solution and that the concentration of the latex nanoparticles thereby increases continuously and corresponds to the degree of concentration.

[0091] Reference numerals list

[0092] 1 Initial liquid volume

[0093] 2.5 Superabsorbent

[0094] 3.6 Liquid part of the mixture

[0095] 4 First Sample

[0096] Time periods t1, t2, and t3

[0097] L0, L1, L2 blank samples

[0098] P0, P1, P2 samples

Claims

1. A method for concentrating at least one artificial target substance in a sample liquid, the artificial target substance consisting of particles and / or particles having an average particle and / or particle size in the nanometer range, the method comprising: - adding a superabsorbent (2) to an initial volume of liquid (1) of said sample liquid or adding said volume of said liquid (1) to said superabsorbent (2), - incubating over a first period of time (t1) a mixture obtained by mixing said superabsorbent (2) and said volume of said liquid (1), and - Removing a first sample (4) of the liquid portion (3) of said mixture present after the incubation.

2. The method according to claim 1, Further including: The artificial target substance in the removed first sample (4) is further concentrated.

3. The method according to claim 2, in, The further concentration of the target substance in the removed first sample (4) is performed by filtration, ultrafiltration or precipitation reaction technology.

4. The method according to claim 2, in, The further concentration of the target substance in the removed first sample (4) is performed again by: - adding a superabsorbent (5) to the first sample or adding the first sample to the superabsorbent (5), - incubating over a second period of time (t2) the mixture obtained by mixing said superabsorbent (5) and said first sample, and - a first sample after concentration by removing the liquid portion of said mixture present after the incubation.

5. The method according to claim 4, in, By means of filtration, ultrafiltration or precipitation reaction, the target substance is further concentrated in the concentrated first sample or in the further concentrated first sample obtained by further concentration, in particular by means of the superabsorbent (5).

6. The method according to any one of claims 1 to 5, Further including: The target substance in the liquid portion of the mixture remaining after removing the first sample is re-concentrated by, - re-incubating, during a third time period (t3), the mixture remaining after removing said first sample from the remaining liquid portion and said superabsorbent (2); and - removing a second sample of said liquid portion of said mixture present after re-incubation.

7. The method according to any one of claims 1 to 6, in, The volume of the liquid (1) comprises a polar liquid, such as water.

8. The method according to claim 7, in, The particles and / or the microparticles of the artificial target substance consist of at least one natural polymer, at least one biocompatible synthetic polymer, an inorganic material or an organic material.

9. The method according to any one of claims 1 to 8, in, The superabsorbent (2, 5) comprises a plastic material which absorbs a portion of the volume of the liquid, water, thereby forming a hydrogel.

10. The method according to claims 8 and 9, in, The plastic does not substantially absorb any particles and / or microparticles contained in the anthropogenic target material.

11. The method according to any one of claims 1 to 10, in, The superabsorbent (2, 5) is used in particulate form, for example as a powder, as granules, or in the form of geometric bodies, in particular spheres.

12. The method according to any one of claims 1 to 11, in, The superabsorbents ( 2 , 5 ) are used, in particular, in the form of commercially available “Hydroballs”, “Aquabeads”, “Waterbeads” or “Gelballs”.

13. The method according to any one of claims 1 to 12, in, The volume of the liquid portion (3) remaining after incubation is controlled by the length of the incubation period or periods (t1, t2, t3) and / or the type and / or amount of superabsorbent (2, 5) and / or the temperature of the mixture prevailing during incubation.

14. The method according to claim 13, in, The superabsorbent (2, 5) is used in particulate form, for example as a powder, as granules, or in the form of geometric bodies, in particular spheres, and the volume of the liquid fraction remaining after incubation is controlled by the size and / or the number of the particles.

15. The method according to any one of the preceding claims, in, The sample liquid constitutes the filtrate or the centrifugation supernatant.

16. The method according to any one of claims 1 to 15, in, The sample liquid constitutes the environmental sample.

17. A method for detecting an artificial target substance in a sample liquid, comprising: - concentrating the sample liquid by the method according to any one of claims 1 to 14; - Physical detection methods for the qualitative and / or quantitative determination of said anthropogenic target substances.

18. The method according to claim 17, wherein: The determination takes place under a microscope.

19. The method according to claim 17, wherein: The physical detection method is a fluorescence measurement method or a spectrum measurement method.

20. The method according to claim 19, wherein: When UV or fluorescence methods are used, a fluorescent dye is added to the sample liquid prior to concentration.

21. Use of a superabsorbent (2, 5) for concentrating at least one target substance in a liquid sample once or multiple times in a cascade manner.

22. The use according to claim 21, in, The particles and / or the microparticles of the artificial target substance consist of at least one natural polymer, at least one biocompatible synthetic polymer, an inorganic material or an organic material.

23. The use according to claim 21 or claim 22, in, The liquid sample comprises a polar liquid, in particular water, and wherein the superabsorbent (2, 5) is designed to absorb the polar liquid, thereby forming a hydrogel.

24. A kit for performing the method according to any one of claims 1-20.

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