DE102022125783A1 - Method for concentrating at least one anthropogenic target substance in a sample liquid - Google Patents

Abstract

The invention relates to a concentration of at least one anthropogenic target substance in a sample liquid, which anthropogenic target substance consists of particles and/or particles with an average particle size in the nanometer range, comprising:- adding a superabsorbent (2) to an initial liquid volume (1) of the sample liquid or adding the liquid volume (1) to the superabsorbent (2),- incubating the mixture formed from the superabsorbent (2) and the liquid volume (1) over a first period of time (t1), and- taking a first sample (4) of the liquid portion (3) of the mixture present after incubation.

Description

The invention relates to a method for concentrating at least one anthropogenic target substance in a sample liquid, which anthropogenic target substance consists of particles and/or particles with an average particle size in the nanometer range.

Nanoparticles and nano particles are playing an increasingly important role in our lives. This applies, for example, to the use and, in this context, the production of these particles and particles for a variety of applications in the pharmaceutical industry (for example in connection with encapsulated mRNA active ingredients), food technology or the electrical engineering or electronics industry (for example in connection with quantum dots).

Due to their small size and the associated changes in physical characteristics, nanoparticles can be used to transport drugs to desired organs, as they can penetrate the blood-brain barrier (e.g. suitable for use in the pharmaceutical industry) and the skin (e.g. suitable for use in the cosmetics industry). Nanoparticles are also used for diagnostic applications, for example for color detection in rapid tests based on colloidal gold. They also stabilize food and thus ensure longer shelf lives.

Nanoparticles are almost exclusively anthropogenic substances. This means that the nanoparticles have been produced by humans through industrial, commercial and municipal processes and not, for example, by biological organisms. Another aspect of nanoparticles is the pollution of our planet, as nanoparticles are often difficult to biodegrade. Nanoparticles are created, for example, from waste from the plastics industry or from the partial decomposition of plastic waste in nature (so-called secondary nanoplastics). The worldwide pollution of the environment with waste from the plastics industry is a global problem. Nanoplastic waste with particle sizes of less than 1 µm enters the ecosystem unhindered and is often not stopped by sewage treatment plants. The damage caused by microplastics and nanoplastics includes the accumulation of particles in the tissues of aquatic creatures. They also reach us humans through polluted water and via food chains. The accumulation of hydrophobic persistent organic pollutants (POPs) in the environment means an increasing additional burden on marine life and humans. Nanoparticles, or nanoparticles made of plastic, are particularly dangerous because they can pass through the cell membrane and influence cellular metabolic processes.

The collection and detection methods currently used are only suitable for macro and microplastics, not for nanoplastics. To assess environmental pollution, plastic waste is collected from surface water, for example. This takes advantage of the fact that around 98% of plastic particles are less dense than water. The plastic particles are collected using large nets with a mesh size of around 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 by size. Other approaches are based on the filtration of large volumes of water or air. The concentration of plastic particles in different bodies of water is estimated at around 1.5 x 10-5 to 0.11 g/m3.

However, in all these approaches, the plastic components <0.33 mm (i.e. parts 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 filter flow.

Micro- and nanoplastic waste is detected using spectroscopic methods (e.g. Raman or infrared spectroscopy), thermoanalytical methods (e.g. dynamic differential scanning calorimetry (DSC)), gas chromatograph mass spectrometer (GC/MS), microscopy (optical, fluorescence-based) or fluorescence-based flow cytometry. This reveals the problem that detection is very complicated due to the low concentration of nanoplastics. A new and simple concentration method would also be desirable for these fields of application.

The object of the invention is to provide a simple, rapid and universally applicable method for concentrating at least one anthropogenic target substance in a sample liquid.

This object is achieved in a surprisingly simple and universally applicable manner by means of the method defined in claim 1, the use according to claim 21 and the kit according to claim 24. Advantageous embodiments are specified in the dependent claims.

The solution is based on the use of so-called superabsorbents, with which any aqueous sample liquid can be processed in order to concentrate the nanoparticles contained in the sample liquid.

Superabsorbent polymers (SAP) are plastics that are able to absorb many times their own weight in polar liquids. These are mainly water or aqueous solutions. When the liquid is absorbed, the superabsorbent swells and forms a hydrogel. Hydrogels can form all cross-linked polymers that are polar (e.g. polyacrylamide, polyvinylpyrrolidone, amylopectin, gelatin, cellulose). However, a copolymer of acrylic acid (propenoic acid, H2C=CH-COOH) or sodium acrylate (sodium salt of acrylic acid, H2C=CH-COONa) on the one hand and acrylamide on the other is usually used, whereby the ratio of the two monomers to one another can vary. In addition, a so-called core cross-linker (CXL) is added to the monomer solution, which connects the long-chain polymer molecules formed to one another in places using chemical bridges, also known as cross-linking. These bridges make the polymer insoluble in water. This so-called base polymer may be subjected to a process known as surface cross-linking (SXL). This involves applying another chemical to the surface of the particles, which, when heated, creates a second network only on the outer layer of the grain. This shell supports the swollen gel so that it stays together even under external stress (movement, pressure).

The product is, for example, conventionally used as white granules with particle sizes of 100 to 1000 µm. It is mainly used in baby diapers, sanitary napkins, incontinence care, in dressing material and, in small quantities, in cable sheathing for deep-sea cables. Other areas of application are so-called gel beds, gel-forming extinguishing agents in fire fighting, as a mechanical stabilizer for cut flowers in a vase or as an additive for plant soil to permanently store water. However, acrylic acid neutralized with potassium hydroxide is used here because of its better environmental compatibility. In the form of spherical particles, the use of superabsorbents is known as toys under names such as "water beads", "aqua beads" or "water beads". These are superabsorbents which are commercially available in the form of balls of variable size (submillimeters to centimeters).

The invention was based on the following unexpected observation: A water sample was mixed with fluorescent nanoparticles with an average particle size of 30 nm. After adding commercially available water pearl beads and an incubation period in which the beads swelled to several times their original volume, it was found that the nanoparticles were not absorbed by the superabsorbents, but were concentrated in the remaining liquid.

This observation shows that by using superabsorbents, and in particular superabsorbents that are commercially available in the form of so-called water pearl beads, a wide variety of nanoparticles can be easily and quickly concentrated in a liquid sample. The concentrated particles can then be detected more easily because the concentration results in a higher target concentration.

With the method and means according to the invention it is possible to concentrate nanoparticles of different compositions for detection reactions efficiently, easily and quickly.

On the basis of this observation, the problem underlying the invention could be solved.

• - Zugeben eines Superabsorbers zu einem initialen Flüssigkeitsvolumen der Probenflüssigkeit oder Zugeben des Flüssigkeitsvolumens zu dem Superabsorber,
• - Inkubieren des aus dem Superabsorber und dem Flüssigkeitsvolumen gebildeten Gemisches über einen ersten Zeitraum, und
• - Entnehmen einer ersten Probe des nach dem Inkubieren vorliegenden flüssigen Anteils des Gemisches.

The method according to the invention for concentrating at least one anthropogenic target substance in a sample liquid comprises:

• - adding a superabsorbent to an initial liquid volume of the sample liquid or adding the liquid volume to the superabsorbent,
• - incubating the mixture formed from the superabsorbent and the liquid volume for a first period of time, and
• - Taking a first sample of the liquid portion of the mixture after incubation.

“Anthropogenic substances” are substances that are not created 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 as well as their degradation products and metabolites. Biomolecules that are created by microorganisms (e.g. enzymes, DNA/RNA fragments, etc.) and have similar sizes in the nanometer range do not fall under the particles or particles of anthropogenic substances mentioned in this application.

In the above-mentioned method according to the invention, the first sample taken 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 take only a partial volume of the liquid portion present as the first sample.

The first sample can be used immediately for subsequent analysis, e.g. using a spectroscopic method. It can also be further concentrated in a cascading process in one or more additional stages, e.g. by adding a superabsorbent again or adding it to a superabsorbent again and incubating again, or by using a conventional method for concentrating target substances, e.g. using one of the methods given in the introduction. If only part of the liquid portion is taken as the first sample, the target substance in the liquid portion of the mixture remaining after sampling can be further concentrated by incubating again for a second period. Both variants of the process can be repeated several times so that a higher concentration of the target substance is obtained at each stage of the cascaded concentration.

It is advantageous to reduce the initial sample volume in a first step by means of the method according to the invention using a superabsorbent, and in a subsequent second step to further concentrate the target substance by means of a conventional concentration technique, e.g. filtration, ultrafiltration, precipitation reaction, ultracentrifugation or enrichment by means of the EP2283026B1 described method. These known techniques can be used much more efficiently in already reduced sample volumes than in more diluted solutions. The method according to the invention is therefore suitable for significantly simplifying known methods for concentrating nanoparticles or nanoparticles for sample liquids with large volumes and/or which only contain the target substance in low concentrations.

As mentioned, in an advantageous embodiment, the method may comprise a further concentration of the target substance in the first sample taken after the first sample has been taken.

Further concentration of the target substance in the first sample taken can be carried out by means of a filtration, ultrafiltration or precipitation reaction technique.

• - Zugeben eines Superabsorbers zu der ersten Probe oder Zugeben der ersten Probe zu dem Superabsorber,
• - Inkubieren des aus dem Superabsorber (5) und der ersten Probe gebildeten Gemisches über einen zweiten Zeitraum, und
• - Entnehmen einer aufkonzentrierten ersten Probe des nach dem Inkubieren vorliegenden flüssigen Anteils des Gemisches.

Alternatively, the further concentration of the target substance in the first sample taken can also be carried out again - and optionally repeated in cascading fashion once or several times - by carrying out the following process steps:

• - adding a superabsorbent to the first sample or adding the first sample to the superabsorbent,
• - incubating the mixture formed from the superabsorbent (5) and the first sample for a second period of time, and
• - Taking a concentrated first sample of the liquid portion of the mixture after incubation.

In a similar way to the first stage of the cascade described above, the concentrated first sample taken from the liquid portion remaining after incubation can be Sample may comprise the entire volume of the liquid portion. Alternatively, the concentrated first sample may be a partial volume of the remaining liquid portion.

The target substance can be further concentrated in the concentrated first sample or in a further concentrated first sample obtained by further concentration, in particular by means of a superabsorbent, by means of a filtration, ultrafiltration or precipitation reaction. This is advantageous if the volume of the concentrated first sample corresponds to only a few milliliters, e.g. 1 to 10 ml.

• erneutes - und optional kaskadierend ein- oder mehrfach wiederholtes - Aufkonzentrieren der Zielsubstanz in dem nach Entnahme der ersten Probe verbliebenen flüssigen Anteil des Gemisches durch
  • - erneutes Inkubieren des nach dem Entnehmen der ersten Probe verbliebenen Gemisches aus dem verbliebenen flüssigen Anteil und dem Superabsorber über einen dritten Zeitraum; und
  • - Entnehmen einer zweiten Probe des nach dem erneuten Inkubieren vorliegenden flüssigen Anteils des Gemisches.

As already mentioned, the method according to the invention for concentrating the target substance in the remaining liquid portion of the mixture of the originally used liquid volume and the superabsorbent can comprise the following further steps after taking the first sample:

• renewed - and optionally cascading one or more times repeated - concentration of the target substance in the liquid portion of the mixture remaining after taking the first sample by
  • - re-incubating the mixture of the remaining liquid portion and the superabsorbent remaining after the first sample has been taken for a third period; and
  • - Take a second sample of the liquid portion of the mixture after re-incubation.

By incubating again, the volume of the liquid portion is further reduced and the target substance in the liquid portion is further concentrated. The concentration of the target substance is determined, among other things, by the predeterminable duration of the third period and the conditions prevailing during incubation.

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

The target substance is a nanoparticle or nano particles. Such a substance consists of an anthropogenic substance, in particular of at least one natural polymer, of at least one biocompatible synthetic polymer, of an inorganic material or of an organic material.

As mentioned, in an advantageous embodiment the superabsorbent can be a plastic or comprise a plastic that absorbs a portion of the liquid volume, e.g. a polar solvent contained in the liquid volume such as water, to form a gel or hydrogel. The plastic is advantageously selected so that it absorbs essentially no nanoparticles. This is the case, for example, with the mentioned superabsorbents made from the mentioned polymer or copolymer materials, e.g. with the commercially available water pearls, water beads, etc.

The superabsorbent can be used in the form of particles, e.g. as a powder, as granules or in the form of geometric bodies, in particular spheres (spherical particles). It can thus be added to the liquid volume or the first sample in the form of such particles or the liquid volume or the first sample can be added to the superabsorbent in this form. The particles or spheres can have a diameter of between 100 and 5000 µm.

Advantageously, the superabsorbent is commercially available superabsorbent beads, for example superabsorbent beads available under the names “Aquabeads”, “Water Beads”, “Water Pearls”, “Aqua Beads”, “Hydro Beads”, “Gel Beads”.

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

The sample liquid may be a filtrate or a centrifugation supernatant. This means that one or more separation steps are carried out before concentration in order to remove further components from the sample.

One embodiment of the method provides that the sample liquid is an environmental sample. An environmental sample is taken from the environment, for example from bodies of water such as lakes or rivers. But sediment or gas samples, for example, which are then mixed with a liquid, are also referred to as environmental samples.

• - Aufkonzentrieren der Probenflüssigkeit mittels des erfindungsgemäßen Aufkonzentrierungsverfahrens mittels der Superabsorber, und
• - Durchführen eines physikalischen Detektionsverfahrens zur qualitativen und/oder quantivativen Bestimmung der anthropogenen Zielsubstanz.

The invention further comprises a method for detecting an anthropogenic target substance in a sample liquid, comprising:

• - Concentrating the sample liquid by means of the concentration method according to the invention using the superabsorbents, and
• - Carrying out a physical detection procedure for the qualitative and/or quantitative determination of the anthropogenic target substance.

The physical detection method is used to determine whether certain nanoparticles or nanoparticles are in the concentrated sample and how high their concentration is. In the initial liquid volume, these would not be detectable using the physical detection method because their concentration is too low. A microscope is used for qualitative and/or quantitative determination. Here, for example, the nanoparticles or nanoparticles are counted in a section of a defined size. Alternatively, a fluorescence measurement method or a spectroscopic measurement method is used. For this, the nanoparticles or nanoparticles must have a fluorescent dye, which is added before concentration.

The invention also includes the use of a superabsorbent for the one-time or multiple cascading concentration of the anthropogenic target substance in a liquid sample. The liquid sample can contain a polar liquid, in particular water, wherein the superabsorbent is designed to absorb the polar liquid, e.g. water, or at least part of the polar liquid, to form a hydrogel. The superabsorbent can be made from the materials described above and used in the previously described embodiments as granules or, particularly preferably, in the form of beads, in particular commercially available water beads or aqua beads.

The cascaded concentration can comprise several stages. After each stage, a sample can be taken for analysis and the concentration process continued, or the sample or part of the sample concentrated in at least one stage after incubation of the sample with the superabsorbent can subsequently be further concentrated using other known methods.

The invention also includes a kit for carrying out the method described above. The kit can, for example, include one or more containers with superabsorbent material, into which a user can then add an initial volume of liquid for concentration or a sample that has already been concentrated in a first stage.

The liquid concentrated according to the described method or according to the described use, i.e. the liquid portion present after incubation, or a sample taken from the concentrated liquid can be fed manually or automatically to a laboratory device for further treatment or analysis. In one possible embodiment of the method or use, such a liquid or sample of the liquid can be fed into a cartridge, in particular a microfluidic cartridge, of an automatic analysis device for the automated implementation of a detection of the target substance by means of a physical detection method for the qualitative and/or quantitative determination of the anthropogenic target substance. This can be done manually or automatically.

• 1 eine schematische Darstellung der kaskadierenden Aufkonzentrierung einer Zielsubstanz in einer Flüssigkeit:
  1. a) Flüssigkeit vor dem Zusetzen eines Superabsorbers;
  2. b) Flüssigkeit nach dem Zusetzen eines Superabsorbers und Inkubieren des Gemisches;
  3. c) Aus dem Gemisch entnommene erste Probe nach Zusetzen eines weiteren Superabsorbers und Inkubieren des Gemisches;
  4. d) Verbliebenes Gemisch aus Flüssigkeit und Superabsorber, ggfs. nach Entnehmen der ersten Probe und nach erneutem Inkubieren;
• 2 eine Darstellung von Proben und Leerproben, die teilweise mittels des erfindungsgemäßen Aufkonzentrierens gewonnen und mit UV-Licht exponiert wurden; und
• 3 Auswertungen der Messdaten:
  1. a) eine grafische Darstellung der Mittelwerte der Messwerte in einem Balkendiagramm;
  2. b) eine Korrelation zwischen dem Aufkonzentrierungsgrad und der Fluoreszenzzunahme der Proben.

The invention is explained in more detail below with reference to the figures and some embodiments. These examples do not represent a limitation of the means and methods according to the invention. They show

• 1 a schematic representation of the cascading concentration of a target substance in a liquid:
  1. a) Liquid before adding a superabsorbent;
  2. b) liquid after adding a superabsorbent and incubating the mixture;
  3. c) First sample taken from the mixture after adding another superabsorbent and incubating the mixture;
  4. d) Remaining mixture of liquid and superabsorbent, if applicable after taking the first sample and after renewed incubation;
• 2 a representation of samples and blanks, some of which were obtained by means of the concentration according to the invention and exposed to UV light; and
• 3 Evaluation of the measurement data:
  1. (a) a graphical representation of the mean values of the measured values in a bar chart;
  2. b) a correlation between the degree of concentration and the increase in fluorescence of the samples.

1. 1. Zugabe eines Superabsorbers 2 zu einem Volumen einer, insbesondere wässrigen, Flüssigkeit 1, oder alternativ: Zugabe der Flüssigkeit 1 zu einem vorgelegten Superabsorber 2;
2. 2. Inkubation des Gemisches aus der Flüssigkeit 1 und dem Superabsorber 2 über einen ersten Zeitraum t1 zur Einengung (Volumenreduzierung) des flüssigen Anteils 3 des Gemisches; und anschließend
3. 3. Überführung mindestens einer ersten Probe 4 des flüssigen Anteils 3 des Gemisches in ein neues Gefäß als Probe zur weiteren Bearbeitung.

The use of superabsorbents to concentrate a target substance, in particular nanoparticles, in a polar liquid as a solvent, for example water, to concentrate the target substance in the liquid is very simple and universally applicable. A suitable method is based on 1 a and b briefly described as follows:

1. 1. Addition of a superabsorbent 2 to a volume of a, in particular aqueous, liquid 1, or alternatively: addition of the liquid 1 to a superabsorbent 2 provided;
2. 2. Incubation of the mixture of the liquid 1 and the superabsorbent 2 over a first period of time t1 to reduce the volume of the liquid portion 3 of the mixture; and then
3. 3. Transfer at least a first sample 4 of the liquid portion 3 of the mixture into a new vessel as a sample for further processing.

Further processing can, for example, be a quantitative and/or qualitative detection of the target substance in the liquid. The detection is carried out, for example, using a spectroscopic or microscopic method.

The degree of concentration and the speed of this process can be controlled very precisely by the type of superabsorbent used, by the amount used, or by the incubation time and/or the incubation temperature.

The method can therefore easily solve the problem of processing low-concentration samples for further processing of the target substances of interest, in particular nanoparticles, or their detection. The 1 a and b does not require equipment such as ultracentrifuges, expensive ultrafiltration membranes, complex processes such as PEG precipitation or general precipitation reactions for concentrating nucleic acids, etc. In addition, the process can be used universally with regard to the type of nanoparticles. A further advantage is that the superabsorbents are non-toxic and harmless and often biodegradable. The process according to the invention can therefore greatly simplify the investigation of low-concentration nanoparticles.

In the case of large-volume and/or highly diluted liquids that contain the nanoparticles or nanoparticles in a very low concentration, a cascading concentration of the target substance is an option. For example, in a first stage, the described method with the above-mentioned steps 1-3 can be used to concentrate the target substance. In a second stage, the first sample 4 can be reduced in volume to re-concentrate the target substance. This can be done either by means of a conventional filtration or precipitation process or other conventional methods. Alternatively, the re-concentration of the target substance in the first sample 4 can also be carried out, as in 1c shown, by adding fresh superabsorbent 5 to the first sample 4, or transferring the first sample 4 to a new superabsorbent 5, and incubating again over a second period t2. Additionally or alternatively, the liquid portion 6 remaining in the mixture with the superabsorbent 2 after taking the first sample 4 can be further reduced by incubating the mixture over a third period t3, as in 1 d This leads to further swelling and volume increase of the spheres consisting of the superabsorbent 2 and to further volume reduction of the liquid portion 6, which is accompanied by an increase in the concentration of the target substance in the liquid portion 6.

In both alternative process paths, further concentration stages can follow in cascading fashion.

In the following, an embodiment of the invention is described in more detail.

Example: Concentration of Rhodamine B-filled latex nanoparticles (ø 25.8 nm) in a water sample

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, thereby producing a 1:10,000-fold dilution.

Subsequently, a superabsorbent in the form of commercially available “water beads” was added to the water sample. During the concentration process by absorbing water into the water beads, samples P0, P1, P2 were taken at different times, each of which corresponded to a different concentration.

• - Leerprobe L0: Reinstwasser ohne Latexpartikel (500 ml)
• - Leerprobe L1: Einengung der 500 ml Reinstwasser auf 40 ml Reinstwasser
• - Leeprobe L2: weitere Einengung von L 1 auf 1 ml Reinstwasser
• - Probe P0: 1:10.000 Verdünnung der Latexpartikel-Stammlösung in 500 ml Reinstwasser
• - Probe P1: Einengung der 500 ml Reinstwasser auf 40 ml Reinstwasser
• - Probe P2: weitere Einengung von P 1 auf 1 ml Reinstwasser

The samples are divided into blank samples L0, L1, L2 for control (without latex nanoparticles) and samples P0, P1, P2, which contain the latex nanoparticles. Specifically, the samples are as follows:

• - Blank sample L0: Ultrapure water without latex particles (500 ml)
• - Blank sample L1: Concentration of 500 ml ultrapure water to 40 ml ultrapure water
• - Leeprobe L2: further concentration of L 1 to 1 ml ultrapure water
• - Sample P0: 1:10,000 dilution of the latex particle stock solution in 500 ml ultrapure water
• - Sample P1: Concentration of 500 ml ultrapure water to 40 ml ultrapure water
• - Sample P2: further concentration of P 1 to 1 ml ultrapure water

The particles in the respective samples were detected by measuring the fluorescence of the dye contained in the latex nanoparticles.

1 shows qualitative detection of latex nanoparticles. For this purpose, the respective samples P0, P1, P2 and the blank samples L0, L1, L2 were transferred in triplicate to a UV-transparent measuring plate. The measuring plate with the samples was then exposed to UV light. Exposure to UV light stimulates fluorescence in the samples that contain latex particles. No fluorescence can be seen in the blank samples L0, L1, L2 and fluorescence increases with increasing concentration in the samples P0, P1, P2 that contain the latex nanoparticles.

Table 1 shows a quantitative measurement of the respective samples using a fluorescence measuring device. The measurements are carried out by exciting the samples P0, P1, P2 and the blank samples L0, L1, L2 (each in triplicate) at an emission of 559 nm. While the values of the blank samples L0, L1, L2 remain stable and low with concentration, the values of the samples P0, P1, P2 that contain the nanoparticles increase proportionally to the degree of concentration. Table 1: sample Fluorescence measurements sample Fluorescence measurements P0 432.92 / 344.75 / 414.06 L0 193.38 / 168.69 / 269.60 P1 1282.19 / 1214.20 / 1292.55 L1 220.20 / 187.81 / 257.12 P2 7694.19 / 7995.08 / 8099.97 L2 237.47 / 257.65 / 234.28

In 2 The measured values listed in Table 1 are graphically displayed or evaluated. In 2a) The mean values of the respective measured values of a sample are shown as a bar chart. In 2 B) A correlation between the degree of concentration and the increase in fluorescence of samples P0 (“1”), P1 (“2”) and P2 (“3”) containing nanoparticles is shown.

The data from the experiment clearly show that the fluorescent latex nanoparticles of the sample do not diffuse into the superabsorbent (“water beads”) used, but are dissolved in the external solution. and thus the concentration of latex nanoparticles increases continuously and corresponding to the degree of concentration.

List of reference symbols

1

initial fluid volume

2, 5

Superabsorbent

3, 6

liquid portion of the mixture

4

first sample

t1, t2, t3

Periods

L0, L1, L2

Blank samples

P0, P1, P2

rehearse

QUOTES INCLUDED IN THE DESCRIPTION

This list of documents listed by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions.

Cited patent literature

• EP 2283026 B1 [0021]

Claims (24)

Method for concentrating at least one anthropogenic target substance in a sample liquid, which anthropogenic target substance consists of particles and/or particles with an average particle size in the nanometer range, comprising: - adding a superabsorbent (2) to an initial liquid volume (1) of the sample liquid or adding the liquid volume (1) to the superabsorbent (2), - incubating the mixture formed from the superabsorbent (2) and the liquid volume (1) over a first period of time (t1), and - taking a first sample (4) of the liquid portion (3) of the mixture present after incubation. Procedure according to Claim 1 , further comprising a further concentration of the anthropogenic target substance in the first sample taken (4). Procedure according to Claim 2 , wherein the further concentration of the target substance in the taken first sample (4) is carried out by means of a filtration, ultrafiltration or precipitation reaction technique. Procedure according to Claim 2 , wherein the further concentration of the target substance in the first sample (4) taken is carried out again by: - adding a superabsorbent (5) to the first sample or adding the first sample to the superabsorbent (5), - incubating the mixture formed from the superabsorbent (5) and the first sample over a second period of time (t2), and - taking a concentrated first sample of the liquid portion of the mixture present after incubation. Procedure according to Claim 4 , wherein the target substance in the concentrated first sample or in a further concentrated first sample obtained by further concentration, in particular by means of a superabsorbent (5), is further concentrated by means of a filtration, ultrafiltration or precipitation reaction. Method according to one of the Claims 1 until 5 , further comprising: reconcentrating the target substance in the liquid portion of the mixture remaining after taking the first sample by - re-incubating the mixture of the remaining liquid portion and the superabsorbent (2) remaining after taking the first sample over a third period of time (t3); and - taking a second sample of the liquid portion of the mixture present after re-incubation. Method according to one of the Claims 1 until 6 , wherein the liquid volume (1) contains a polar liquid, for example water. Procedure according to Claim 7 , wherein the particles of the anthropogenic target substance consist of at least one natural polymer, of at least one biocompatible synthetic polymer, of an inorganic material or of an organic material. Method according to one of the Claims 1 until 8th , wherein the superabsorbent (2, 5) comprises a plastic which absorbs a portion of the liquid volume, water, to form a hydrogel. Procedure according to Claim 8 and 9 , whereby the plastic essentially does not absorb any particles or particles contained in the anthropogenic target substance. Method according to one of the Claims 1 until 10 , wherein the superabsorbent (2, 5) is used in the form of particles, e.g. as powder, as granules or in the form of geometric bodies, in particular spheres. Method according to one of the Claims 1 until 11 , wherein the superabsorbent (2, 5) is used in the form of, in particular commercially available, water pearls, hydrospheres, aqua pearls, aquabeads, waterbeads, or gel beads. Method according to one of the Claims 1 until 12 , wherein the volume of the liquid portion (3) remaining after incubation is controlled by the length of the period or periods (t1, t2, t3) of incubation and/or by the type and/or amount of superabsorbent (2, 5) and/or by the temperature of the mixture prevailing during incubation. Procedure according to Claim 13 , wherein the superabsorbent (2, 5) is used in the form of particles, e.g. as powder, as granules or in the form of geometric bodies, in particular spheres, and wherein the volume of the liquid portion remaining after incubation is controlled by the size and/or number of particles. Method according to one of the preceding claims, wherein the sample liquid is a filtrate or a centrifugation supernatant Method according to one of the Claims 1 until 15 , where the sample liquid represents an environmental sample. Method for detecting an anthropogenic target substance in a sample liquid, comprising: - concentrating the sample liquid by means of a method according to one of the Claims 1 until 14 , - Carrying out a physical detection procedure for the qualitative and/or quantitative determination of the anthropogenic target substance. Procedure according to Claim 17 , whereby the determination takes place under a microscope. Procedure according to Claim 17 , where the physical detection method is a fluorescence measurement method or a spectroscopic measurement method. Procedure according to Claim 19 , whereby when using a UV or fluorescence method, a fluorescent dye is added to the sample liquid before concentration. Use of a superabsorbent (2, 5) for the single or multiple cascading concentration of at least one target substance in a liquid sample. Use according to Claim 21 , wherein the particles of the anthropogenic target substance consist of at least one natural polymer, of at least one biocompatible synthetic polymer, of an inorganic material or of an organic material. Use according to Claim 21 or 22 , wherein the liquid sample contains a polar liquid, in particular water, and wherein the superabsorbent (2, 5) is adapted to absorb the polar liquid to form a hydrogel. Kit for performing the procedure according to any of the Claims 1 until 20 .

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