DE202014004218U1 - Device of particle tracking analysis with the aid of scattered light (PTA) and for the detection and characterization of particles in liquids of all kinds in the order of nanometers - Google Patents

Abstract

Device for the detection and characterization of particles (23) in liquids of all kinds in the order of nanometers of a suspension in a cell wall (9) with the following features: a) a cell wall (9) of rectangular cross section made of black glass with sintered optical windows (11 ) is covered on a longitudinal surface and an adjacent transverse surface with an L-shaped heating and cooling element (1), the cell wall (9) resting on the transverse surface on a base (2) which is supported in a defined manner via vibration dampers (4), b ) the cell wall (9) on the transverse surface, which is opposite the transverse surface that forms the support of the cell wall (9), is irradiated in the middle by an irradiation device through an optical glass window (11) and at right angles to the optical axis of the irradiation device observed through a further optical glass window (11) by an observation device (6, 6a), c) the common focus of the B The radiation device and the focus of the observation device can be moved by motor via the spatial inner region of the cell wall (9) to an arbitrary point by a control device, d) the surface of the cell wall (9) which is opposite the optical glass window (11) through which the radiation device is irradiated , has a further optical glass window (11) in the middle, this area of the cell housing (9) being covered from the outside by a nano-carbon layer (5) of the same area, e) the area of the cell wall (9) in which The temperature of the optical glass window (11) through which the optical axis of the observation device runs is monitored by two thermistors (8).

Description

The invention relates to a device of particle tracking analysis with the aid of scattered light and for the detection and characterization of particles in liquids of all kinds in the order of nanometers.

Suspensions and emulsions as disperse material systems are common forms of particles in liquids. Their applications range from printer ink to cosmetic emulsions to new materials such as Quantum Dots. Furthermore, nanobubbles, particles in water, particles in pharmaceutical administrations and exosomes, which are nanoparticles with messenger function emitted by body cells, belong to particles in liquids. The particles occur as single original occurring objects or as aggregates in the form of agglomerates or aggregates. In agglomerates, the individual components have a loose bond to each other, while aggregates are separated only by strong forces, for example by grinding operations.

There is a great interest in quantifying the particles in size, shape and as an agglomerate or aggregate, and quantitatively detecting mixtures thereof. In the field of imaging methods, this is possible in the optical microscope up to a size of several 100 nm, in the electron microscope down to a lowest size of a few nm. In no process, however, can you distinguish between agglomerates and aggregates. The electron microscopic examination suffers from the complex sample preparation, the duration and the cost of the analysis.

The optical scattered light analysis is in contrast to optical microscopy and electron microscopy an indirect measurement method for characterizing the particle size. It is used because particles less than 1 μm (1000 nm) escape direct observation because of the diffraction limit.

In a scattered light microscope, the light scattered by particles is used to locate the particles and track their movement in a video film. There are two versions of scattered light microscopes, the dark field scattered light microscope with white light illumination and the dark field laser scattered light microscope with laser illumination (discussed below).

By analyzing the translational Brownian diffusion motion of each individual particle and then converting the measured diffusion constants of each individual particle into particle size by the Stokes-Einstein formula, the particle size distribution is derived.

• 1) Die Wirkung von Partikeln liegt unter anderem in ihrer Größenordnung. So kann die Brillanz einer Farbe unter anderem von der Größenverteilung abhängig sein, der Ort der Wirkung einer pharmazeutischen Verabreichung von der Größe des Trägerpartikels, zum Beispiel eines Liposomentröpfchens oder von mit Proteinen beschichteten Goldpartikeln.
• 2) Weiterhin gibt die Größe von Partikeln Auskunft über ihre Qualität, Einheitlichkeit und Einsetzbarkeit. Sind zum Beispiel zu viel Agglomerate einer Partikelsorte (Proteine) vorhanden oder andersartige Stoffe beigemischt, so stellt sich ihre Verwendbarkeit in Frage.
• 3) Auch die Partikelform stellt ein wichtiges Diskriminierungsmerkmal dar. In homogenisierter Milch zum Beispiel sind die Fetttröpfchen auf die Größe der Kaseinteilchen zu 300 nm zerkleinert. Der Unterschied zwischen beiden Anteilen besteht nur in der Form. In gängigen Größenmessverfahren DLS, Dynamische Lichtstreuung, Scheibenzentrifuge und Ultraschallspektroskopie können Fetttröpfchen und Kasein nicht voneinander unterschieden werden. Die Partikelform von Partikeln unterhalb einer Größe von ca. 1 μm ist bisher nur mit Hilfe der Elektronenmikroskopie messbar. Allerdings nur statisch und nach einer massiven Probenaufbereitung. Eine dynamische in-situ-Beobachtung der Partikel in der Trägerflüssigkeit ist nicht möglich.
• 4) Die Unsicherheit über die Richtigkeit des Ergebnisses einer Größenverteilung hängt bei den gängigen DLS Streulichtverfahren damit zusammen, dass das vom Streulichtvolumen ausgehende Streulicht auf einem einzigen Detektorelement kollektiv gesammelt wird. Die Fluktuation des Streulichtsignals wird zur Größenverteilung herangezogen. Dabei kann nicht unterschieden werden, ob die Fluktuation von der translatorischen Bewegung der Teilchen herrührt, auf welcher die Berechnung der Partikelgröße nach Umrechnung mit Hilfe der Stokes-Einstein-Gleichung beruht, oder von der Rotation von unförmigen Teilchen. Denn die Schwerpunktsveränderugen eines rotierenden Teilchenaggregates zum Beispiel tragen zum kollektiven Streulichtsignal bei und führen zu einem „parasitären” Feinanteil, der aber nicht als solcher erkannt werden kann. Eine zusätzliche Unsicherheit entsteht bei Stoffgemischen, deren Streulichtverhalten unterschiedlich ist. Bei Stoffmischungen kommt es deshalb zu einer Fehlbeurteilung der verschiedenen Anteile. Sind die Partikel der unterschiedlichen Stoffe gleich groß, kann erst gar nicht vermutet werden, dass mehr als eine Stoffart in der Probe vorhanden ist und schon gar nicht, welche Anteile davon vorhanden sind.
• 5) Im Elektronenmikroskop als bildgebendem Verfahren ist die Form messbar. Es lassen sich aber Agglomerate nicht von Aggregaten auseinanderhalten.
• 6) Deshalb ist es wünschenswert ein Verfahren zu entwickeln, das ähnlich wie ein Elektronenmikroskop Mustererkennung bietet, jedoch wesentlich schnelle und preiswerter ist und nur wenig Risiko zur Probenveränderung durch die Aufbereitung der Probe zur Messung beinhaltet.
• 7) Des Weiteren ist es wünschenswert aus der diskreten Analyse der einzelnen Teilchen, die per Videofilm verfolgt werden, möglichst viele Merkmale zu unterscheiden. Denn während der Ortsveränderung der Teilchen, zum Teil auch aus dem Mikroskopfokus heraus, nehmen die Partikel eine ständig wechselnde Orientierung zum beobachtenden Mikroskop ein. Dabei werden hohe Intensitätsschwankungen der einzelnen Partikel festgestellt. Alle diese Erscheinungen werden zwar klassisch als eine Schwierigkeit der Partikel Tracking Messmethode angesehen. Positiv gesehen bieten diese Schwierigkeiten jedoch die immense Chance a) die Translation der Partikel von der Rotation zu unterscheiden und damit parasitäre Feinanteile auszuschließen und b) eine Menge zusätzlicher Information aus dem dynamischen Verhalten der Partikel während ihrer Reise im Videofilm abzuleiten. Dies unterscheidet sich von den anderen Methoden wie DLS, Elektronenmikroskopie und Scheibenzentrifuge.
• 8) In dieser Erfindung wird also die dynamische Multiparameter-Analyse als Vorteil genutzt, um aus der geschilderten Dynamik noch mehr als bisher möglich wertvolle Informationen zu gewinnen.
• 9) Eine große Schwierigkeit im PTA-Verfahren bleibt die Tatsache, dass zur Analyse von Nanopartikeln ein enorm hoher Lichtkontrast (Signal/Rausch-Verhältnis im Videodetektor) hergestellt werden muss, Denn die Lichtstreuung der Nanopartikel nimmt zu kleineren Durchmessern hin mit der 6. Potenz ab. Vor allem ist darauf zu wirken, dass der Lichtkontrast der schwach leuchtenden Partikel zum Untergrund maximal ist und nicht durch Störlicht geschwächt wird. Mit einer empfindlichen Kamera alleine ist es nicht getan. In einer Streulichtanordnung ist immer parasitäres Licht durch Reflexe des anregenden Laserlichts an Kanten und Zellwänden vorhanden, das auch auf irgendeine Weise seinen Weg in die Videokamera findet. Der Vergleich zum optimalen schwarzen Nachthimmel bei der Sternenbeobachtung ist naheliegend. Die Erfindung von Maßnahmen zur Kontrastverbesserung dient dazu die dynamische Mustererkennung an Nanopartikeln in einem möglichst weiten Größenbereich durchführen zu können.
• 10) Eine weitere Schwierigkeit der PTA Messtechnik ergibt sich aus der Tatsache, dass mit einer Kameraeinstellung jeweils nur ein kleiner Größenmessbereich von maximal 8 zu 1 gleichzeitig aufgenommen werden kann. Bei Proben mit einer breiteren Partikelgrößenverteilung sind bis zu 3 Probenverdünnungsstufen a 1:3 bis 1:4 mit bis zu 3 unterschiedlichen Kameraeinstellungen nötig. Eine Verdünnungsautomatik kombiniert mit einer intuitiven Kameraeinstellung würde die Messung wesentlich vereinfachen und beinah fehlerfrei von der Bedienung her gestalten. Die zusätzliche Anbringung einer Miniatur pH-Sonde ist ein weiterer Schritt in Richtung Automatik. Bei den meisten Anwendern von PTA geht es um biochemisch medizinische Diagnosen. Hier geht es um kleinste Probenmengen und oft um Personal, das mit neuartigen Analysemethoden Schwierigkeiten hat. Bei Proben mit der Notwendigkeit Zetapotential zu messen ist es wichtig die ionischen Eigenschaften der Umgebungsflüssigkeit zu messen und zu registrieren. Die beiden wichtigen Parameter welche den ionischen Zustand in der Umgebung der Partikelgrenzfläche charakterisieren, sind Leitfähigkeit und pH. Sie sollen automatisch und ohne Zutun des Personals mit registriert werden.

Upon application of an electric field to the disperse material system, the electrophoretic migration and, in turn, the electrical charge at the particle interface to the surrounding liquid are obtained. With the help of, for example, the Smoluchowsi formula, the measured electrophoretic mobility is converted into the so-called zeta potential.
Disperse systems are known to be associated with the thermodynamically unstable systems. The period of time in which such dispersions remain stable is essential for applicability. A very often observed instability arises from coagulation of particles, which can lead to irreversible particle size growth, or to complete separation between the liquid phase and the particle phase. To reduce coagulation serve several precautions. One of these is the electrostatic stabilization. It makes use of the fact that the approximation of the same direction charged particles is made difficult by their electrostatic repulsion. This repulsion is more efficient the higher the ionic charge of the particles on their interface with the medium. Decisive for this is the electrostatic particle interface potential "PGP"., In particular the often derived from the electrophoretic movement zeta potential (see above). This potential is considered to be a measure that determines the degree of repulsion between adjacent dispersed particles. It thus has significance with regard to the stability of disperse systems. In the stray light arrangements described above, the sample is outwardly at rest, only the particles inside the sample typically move according to their size and shape.

• 1) The effect of particles is, inter alia, in their magnitude. Thus, the brilliance of a color may depend, inter alia, on the size distribution, the location of the effect of a pharmaceutical administration on the size of the carrier particle, for example a liposome droplet or protein-coated gold particles.
• 2) Furthermore, the size of particles gives information about their quality, uniformity and applicability. If, for example, too much agglomerate of a particle type (proteins) is present or other substances are added, their usability is questionable.
• 3) The particle shape is also an important discriminating feature. In homogenized milk, for example, the fat droplets are minced to the size of the casein particles to 300 nm. The difference between the two shares is only in the form. In common size measurement methods DLS, dynamic light scattering, disc centrifuge and ultrasound spectroscopy can Fat droplets and casein are indistinguishable from each other. The particle shape of particles below a size of approximately 1 μm has hitherto been measurable only with the aid of electron microscopy. However, only static and after a massive sample preparation. Dynamic in situ observation of the particles in the carrier liquid is not possible.
• 4) The uncertainty about the correctness of the result of a size distribution in the current DLS scattered light methods is related to the fact that the scattered light emanating from the scattered light volume is collected collectively on a single detector element. The fluctuation of the scattered light signal is used for size distribution. It can not be distinguished whether the fluctuation is due to the translational motion of the particles on which the calculation of the particle size is based on conversion using the Stokes-Einstein equation or of the rotation of non-shaped particles. For the center of gravity changes of a rotating particle aggregate, for example, contribute to the collective scattered light signal and lead to a "parasitic" fines, which can not be recognized as such. An additional uncertainty arises in substance mixtures whose scattered light behavior is different. For substance mixtures, therefore, there is a misjudgment of the different proportions. If the particles of the different substances are the same size, it can not be surmised that more than one type of substance is present in the sample, let alone what proportions of it are present.
• 5) In the electron microscope as an imaging method, the shape is measurable. However, agglomerates can not be distinguished from aggregates.
• 6) Therefore, it is desirable to develop a method that provides pattern recognition similar to an electron microscope, but is significantly faster and less expensive and involves little risk of sample change by preparing the sample for measurement.
• 7) Furthermore, it is desirable to distinguish as many features as possible from the discrete analysis of the individual particles being tracked by video. Because during the change of location of the particles, in part also out of the microscope focus, the particles take on a constantly changing orientation to the observing microscope. In this case, high intensity fluctuations of the individual particles are detected. Although all these phenomena are classically regarded as a difficulty of particle tracking measurement method. However, from a positive point of view these difficulties offer the immense opportunity a) to distinguish the translation of the particles from the rotation and thus to exclude parasitic fines and b) to derive a lot of additional information from the dynamic behavior of the particles during their journey in the video film. This is different from the other methods like DLS, electron microscopy and disc centrifuge.
• 8) In this invention, so the dynamic multiparameter analysis is used as an advantage to gain from the described dynamics even more than previously possible valuable information.
• 9) A major difficulty in the PTA process remains the fact that for the analysis of nanoparticles an enormously high light contrast (signal / noise ratio in the video detector) has to be produced, because the light scattering of the nanoparticles increases to smaller diameters with the sixth power from. Above all, it must be ensured that the light contrast of the weakly luminous particles to the substrate is maximum and not weakened by stray light. With a sensitive camera alone, it is not enough. In a stray light arrangement parasitic light is always present due to reflections of the exciting laser light on edges and cell walls, which also somehow finds its way into the video camera. The comparison to the optimal black night sky in the star observation is obvious. The invention of measures for contrast enhancement serves to be able to perform the dynamic pattern recognition of nanoparticles in the widest possible size range.
• 10) Another difficulty of the PTA measurement technique arises from the fact that with a camera setting only a small size measuring range of maximum 8 to 1 can be recorded simultaneously. For samples with a broader particle size distribution, up to 3 sample dilution levels a 1: 3 to 1: 4 with up to 3 different camera settings are required. An automatic dilution combined with an intuitive camera setting would simplify the measurement and make it almost error-free from the operation. The additional attachment of a miniature pH probe is another step towards automatic. Most users of PTA are concerned with biochemical medical diagnoses. This is about the smallest sample quantities and often about personnel who have difficulties with novel analysis methods. For samples with the need to measure zeta potential, it is important to measure and register the ionic properties of the surrounding fluid. The two important parameters that characterize the ionic state in the environment of the particle interface are conductivity and pH. They should be registered automatically and without the intervention of the staff.

• a) die Küvette 14 ist über eine Lagerung 32 definiert positioniert,
• b) die Küvette 14 wird über eine optische Bestrahlungseinrichtung 10-12-16-18 bestrahlt und im rechten Winkel zur optischen Achse der Bestrahlungseinrichtung von einer Beobachtungseinrichtung 30 beobachte,
• c) die Lage des Fokus der Bestrahlungseinrichtung und die Lage des Fokus der Beobachtungseinrichtung sind jeweils einzeln motorisch über den räumlichen Innenbereich der Küvette bzw. vermittels Fokussiereinstellung 27 verfahrbar.

In the case of the applicant itself DE 10 2008 007 743 B3 A method and apparatus are described which deal with the detection of particle distribution in liquids. It should be noted that there are several physical methods for measuring PGP. The state of the art is here inter alia on the US Pat. No. 3,764,512 in which a device for the optical detection of particles of a suspension in a cuvette 14 is shown with the following features:

• a) the cuvette 14 is about a storage 32 defined,
• b) the cuvette 14 is via an optical irradiation device 10 - 12 - 16 - 18 irradiated and at right angles to the optical axis of the irradiation device of an observation device 30 watch
• c) the position of the focus of the irradiation device and the position of the focus of the observation device are each individually motor-driven via the spatial inner region of the cuvette or by means of focusing adjustment 27 traversable.

This device has the disadvantage that the optical arrangement has to be set manually by manual adjustment of the two focus positions until the image is seen sharply.

• a) die Küvette (1) ist über eine Lagerung (5) definiert positioniert,
• b) die Küvette (1) wird über eine optische Bestrahlungseinrichtung bestrahlt und im rechten Winkel zur optischen Achse der Bestrahlungseinrichtung von einer Beobachtungseinrichtung beobachtet,
• c) der Fokus der Bestrahlungseinrichtung und der Fokus der Beobachtungseinrichtung sind motorisch über den räumlichen Innenbereich der Küvette (1) in einen beliebigen Punkt durch eine Steuerungsvorrichtung verfahrbar,
• d) eine Annäherung der Position des Fokus der Bestrahlungseinrichtung an die Position des Fokus der Beobachtungseinrichtung, oder umgekehrt, zum Zweck der Scharfstellung in einem Punkt wird in einer Detektionsvorrichtung überwacht und/oder an einem Bildschirm dargestellt.

To eliminate these disadvantages is in the DE 10 2008 007 743 B3 according to claim 1, a device for the optical detection of particles ( 13 ) of a suspension in a cuvette ( 1 ), with the following characteristics under protection:

• a) the cuvette ( 1 ) is about a storage ( 5 ) defined,
• b) the cuvette ( 1 ) is irradiated via an optical irradiation device and observed at right angles to the optical axis of the irradiation device by an observation device,
• c) the focus of the irradiation device and the focus of the observation device are motorized via the spatial interior of the cuvette ( 1 ) can be moved to any point by a control device,
• d) an approximation of the position of the focus of the irradiation device to the position of the focus of the observation device, or vice versa, for the purpose of focusing in a point is monitored in a detection device and / or displayed on a screen.

Although this method is universally applicable, but limited in the measurement of nanoparticles by scattered light or fluorescent light by the Störlichthintergrund. The device according to the invention has the object to minimize the Störlichthintergrund.

This object is achieved with a device according to claim 1

The device according to the invention will be described in more detail below. They show in detail:

1 : a cross-section of the cell wall and a spatial view

2 : a spatial view of the cell with peripheral arrangements

3 : a spatial view of the cell in a special design

4 : a representation to clarify the measuring principle

The 1 shows a cross section of the cell wall and a spatial view. The, containing the suspension to be examined, in cross section rectangular shaped cell wall 9 stands with its cross section in the center of the left part of this figure. This cell wall 9 is on the left side of a, in cross-section L-shaped, heating and cooling element 1 whose function will be described later. The entire device is on a pedestal 2 stored, in turn, by means of vibration damping elements 4 is secured against vibrations from the area of the environment. To illuminate the suspension is at the top of the cell wall 9 a laser 10 provided, whose basic beam path through a dashed line in the middle through the cell wall 9 leads, implied. The beam of the laser 10 after he hits the cell wall 9 has passed through an opening, shown as permeable, on the opposite side of the cell wall 9 and gets there from a nano-carbon layer 5 , which is also behind an opening, shown as permeable, recorded and thermally neutralized. The function of the layer 5 will be described later. At right angles to this dashed line is the optical axis 3 a digital video camera 6 and a microscope objective 6a , also indicated by a dashed line. Also this optical axis 3 passes through an opening, shown as permeable. At the intersection of these two dashed lines, the particles to be examined are observable. In the beam path of the digital video camera 6 is a filter changer 7 provided, which, as required, different color filters the lens of the camera 6 can switch on. Furthermore, in the beam path of the digital video camera is a microscope objective 6a arranged. On this side of the digital video camera 6 observed part of the cell wall 9 are two thermistors 8th provided that register the heat development of the cell wall. in the right part of 1 is a spatial view of the cell wall 9 shown from the arrangement of the left side of the 1 shown openings is better visible. The previously described openings constitute optical glass windows 11 that is in the cell wall 9 are sintered. To achieve a uniform temperature distribution in the cell serve the heating and cooling element 1 and the nano-carbon layer 5 , This layer 5 directs the laser 10 at the exit of the laser from the cell wall 9 through the window 11 caused thermal radiation immediately laterally and in the cooling element 1 from. This largely avoids thermal convection in the cell. Heat convection is competing for the particle diffusion and electrophoretic motion to be measured in the field, so avoid it.

The 2 shows a spatial view of the cell with peripheral arrangements. In addition to the known cell wall 9 with their sintered glass optical windows 11 Here are the heating and cooling element 1 and those at the bottom of the cell wall 9 attached nano-carbon coating 5 to recognize. On the two narrow sides of the cell wall 9 is each a negative and a positive electrode 19 appropriate. These electrodes 19 each consist of two electrodes, each with an outer electrode outside the cell wall 9 and an associated inner electrode. at which the relevant electric field is tapped, within the cell wall 9 located. In this way, disturbing effects such as blistering are compensated. By applying a controllable electrical voltage, the electrophoretic movement of particles to be examined can be effected hereby. On the right narrow side of the cell wall 9 are two dosing pumps 13 and 16 for the supply of rinsing or diluting solution or suspension from a storage container 12 respectively. 15 intended. On the left narrow side of the cell wall 9 is a surge tank 14 appropriate. On the right narrow side is also a miniature mixing chamber 17 for receiving the sample suspension 12 or from a syringe. With simultaneous addition of sample and dilution solution from the containers 12 and 15 a defined dilution of the sample is achieved. At an outlet of the mixing chamber ( 17 ) is a miniature pH probe 18 appropriate.

The 3 shows a spatial view of the cell in a special design. Here is shown in principle and by way of example, as by means of a rotatable disc 20 optionally a specific laser 10 can be selected from a plurality and can be used rapidly, as required, to study a particular suspension.

The 4 shows a representation to illustrate the possibilities of the measuring principle according to the invention. Using the example of a particle shown as an irregular conglomerate 23 with a diameter of 100 nm it is shown here that this particle 23 if it has moved in a time delta t by a distance delta x, not just as a size peak 21 in the investigation, but that another, smaller size peak 22 , which so far remained unnoticed, can also be interpreted accurately. Because while so far, as already mentioned, the smaller peak 22 has been overlooked or attributed to the influence of a smaller particle, it is possible with the device according to the invention to recognize that the smaller peak 22 the influence of the rotation of the particle 23 is attributable.

Overall, this is a first-time and automatic evaluation of the dynamic scattered light pattern analysis. In this case, the number of primary particles, agglomerates and aggregates are determined. An evaluation of the scattered light shape parameters (secondary shape parameters), an evaluation of the intensity of the scattered particle light, the scattered light scattering surface and all the dynamic values thereof are performed. This results in the fluctuation range of these parameters. In addition, an evaluation of the proportions of different types of particles is possible (for example, milk: milk droplets, milk exosomes, caseins (example mixture particles and nanobubbles).

The complex analysis of the described motion sequences requires a special control algorithm

LIST OF REFERENCE NUMBERS

1

Heating and cooling element (Peltier element)

2

stand base

3

optical reference line

4

vibration damping element

5

Nano-carbon layer

6

Digital video camera

6a

microscope objective

7

filter changer

8th

thermistor

9

cell wall

10

laser

11

optical glass window

12

Storage tank for dilution solution

13

Dosing pump for the dilution solution

14

surge tank

15

sample container

16

Dosing pump for the sample

17

mixing chamber

18

Miniature pH measuring probe

19

electrodes

20

Wechselscheibe

21

Size peak as indicator for a translation

22

Size peak as indicator for a rotation

23

particle

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been 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 assumes no liability for any errors or omissions.

Cited patent literature

• DE 102008007743 B3 [0008, 0010]
• US 3764512 A [0008]

Claims (5)

Device for detecting and characterizing particles ( 23 ) in liquids of all kinds on the order of nanometers of a suspension in a cell wall ( 9 ) having the following features: a) a cell wall ( 9 ) rectangular section of black glass with sintered optical windows ( 11 ) is on a longitudinal surface and an adjacent transverse surface with an L-shaped heating and cooling element ( 1 ), whereby the cell wall ( 9 ) on the transverse surface on a pedestal ( 2 ) rests on the vibration damper ( 4 ) is defined, b) the cell wall ( 9 ) is on the transverse surface, the transverse surface of the support of the cell wall ( 9 ) in the center of an irradiation device through an optical glass window ( 11 ) and at right angles to the optical axis of the irradiation device through a further optical glass window ( 11 ) from an observation device ( 6 . 6a c) the common focus of the irradiation device and the focus of the observation device are motor-driven over the spatial inner area of the cell wall ( 9 ) can be moved to any point by a control device, d) the area of the cell wall ( 9 ) the optical glass window ( 11 ) through which irradiates the irradiation device, opposite, has in the middle of another optical glass window ( 11 ), wherein this surface of the cell housing ( 9 ) from the outside of an identical nano-carbon layer ( 5 ), e) the area of the cell wall ( 9 ) in which the optical glass window ( 11 ) through which the optical axis of the observer passes is determined by two thermistors ( 8th ) monitored for their temperature. Apparatus according to claim 1 or 2, characterized in that the two end faces of the cuboid cell wall ( 9 ) each with an electrode ( 19 ) of an electrical voltage source, each of these electrodes ( 19 ) consists of an outer and an associated inner electrode Apparatus according to claim 2, characterized in that in the optical axis of the observation device an arrangement ( 7 ) is provided, with the various filters can be switched into the beam path. Device according to one of the preceding claims, characterized in that the irradiation device is a laser ( 10 ) and the observation device a digital video camera ( 6 ) with a Mikoskopobjektiv ( 6a ), Device according to one of the preceding claims, characterized in that on one end face of the cuboid cell wall ( 9 ) a storage container ( 12 ) Rinsing solutions or dilution solutions with a subsequent dosing pump ( 13 ) and at the other end a compensation tank ( 14 ) is provided for sample liquid, wherein an additional sample container ( 15 ) with an associated metering pump ( 16 ) is provided, and wherein from the reservoir ( 12 ) and the sample container ( 15 ) Liquids of a mixing chamber ( 17 ) can be fed in a metered manner, and wherein in the region of the mixing chamber ( 17 ) a miniature pH probe is attached.

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