Infrared measuring device, especially for the spectrometry of aqueous systems, preferably multiple component systems

The present invention relates Infrarotmeßvorrichtungen, in particular for aqueous systems, comprising at least one measuring unit, in particular a measuring cell, comprising at least one ATR body and at least one infrared light source. The invention further relates to the use of the infrared measuring device according to the invention for the, in particular essentially simultaneous, qualitative and quantitative determination of components in particular aqueous systems, preferably multi-component systems.

Infrared spectroscopy is known to those skilled in the art and is used in particular in organic chemistry for the determination of functional groups (see <nplcit id="ncit0001" npl-type="b"><text>Spectroscopic Methods in Organic Chemistry, M. Hesse et. al., Georg Thieme Verlag, Stuttgart, 1984, Chapter 2</text></nplcit>), Which can be measured in all three states, and in the released state the samples. In addition to use in structural analysis has also been proposed to use IR spectroscopic methods for process analysis.

In the <patcit id="pcit0001" dnum="DE3605518A1"><text>DE 36 05 518 A1</text></patcit> is a measuring cell for IR spectrometry described, with the can be recorded continuously by small amounts of sample absorption and emission spectra, so that, for example chromatographically separated sample fractions can be continuously detected. One developing a measuring cell, which has a so-called ATR crystal (ATR = attenuated total reflection). As infrared light source such comes with a continuous spectrum for use. Once, an inner wall of the measuring cell forming surface of the ATR crystal to be provided with a stationary phase of a chromatography process to investigate a measuring cell flowing through the sample, it is proposed in parallel or subsequently also ATR fluorescence, phosphorescence or Raman spectra to eat. To be able to measure even very small amounts of sample, is in the<patcit id="pcit0002" dnum="DE3605518A1"><text>DE 36 05 518 A1</text></patcit> a measuring cell is disclosed, whose central region is filled by an additional element, whereby the construction of the measuring cell is very complicated and clogging when flowing through can not be excluded. In order to still be able to continue the measurement, the complete measurement cell is then usually replaced. Incidentally, the<patcit id="pcit0003" dnum="DE3605518"><text>DE 36 05 518</text></patcit> refer on the continuous control of Chromatographieverfabxen addition no evidence, decide whether or not how to with the described measuring cell detect certain substances qualitatively or quantitatively.

In the <patcit id="pcit0004" dnum="DE10015615A1"><text>DE 100 15 615 A1</text></patcit> is a measuring device for the detection of traces of gaseous substances which are present in extremely low concentrations described. This is a gas measurement system with an open optical measuring section for spectroscopic measurement of at least one component of a gas sample with a laser source, comprising a reference gas sample for the gas to be measured, two radiation detectors for the main beam and the reference beam and at least two radiation reflectors. With the gas measurement system disclosed, for example, optical measuring sections of 1 to 200 meters can be measured, which can be dispensed with a retroreflector. As laser sources a pulsed radiation in the near coming up mid-infrared emitting quantum cascade laser or a near-infrared-emitting continuous operation continuous radiation laser diode that emits a strongly divergent beam with an opening angle α of approximately 35 °, for use. With the gas measurement system in accordance with<patcit id="pcit0005" dnum="DE10015615A1"><text>DE 100 15 615 A1</text></patcit> can detect gases such as hydrogen sulfide, ammonia, hydrochloric acid and methane.

According to <patcit id="pcit0006" dnum="DE4324141A1"><text>DE 43 24 141 A1</text></patcit> can also be low isopropanol contents (&lt;10%) determine continuously in humidity means for printing machines, when working with a pulsed IR radiation source for a modified four-beam method. As an infrared radiation source, in turn, is one having a continuous spectrum in the near infrared region into consideration. Further details are Infrarotmeßverfahren this document also not apparent.

In order to determine the concentration of ingredients in aqueous liquids reliably and reproducibly is, according to <patcit id="pcit0007" dnum="DE19748849A1"><text>DE 197 48 849 A1</text></patcit> selectively subjecting the analyte to be measured before the measurement of a chemical reaction, which causes the other components of the liquid sample unaffected Moreover, the chemical reaction with the analyte has to be such that a satisfactory IR spectrometric concentration determination is made possible. Again, no other than the conventional, a continuous spectrum exhibiting infrared sources are used. This procedure for determination of polar substances in aqueous systems is also very complex and expensive and moreover only a few analytes, that is, those which undergo the required chemical reaction, limited.

In the production of alcoholic and non-alcoholic beverages, it is necessary to be able to the concentration of the respective ingredients as possible at any point, suitably continuously determined in order to minimize product waste, and can ensure the highest possible quality. The content of eg sugar or alcohol in beverages is still determined nowadays despite the now available, well developed spectrometric method on density measurements. These processes are very complicated, requiring sophisticated and demanding measurement technology and are only conditionally suitable for continuous measurement, ie for example for on-line use.

In particular for quality wines, the question of the authenticity of the designated products can be at the present time mostly only using very expensive techniques such as multidimensional NMR spectroscopy reliably ascertained. Moreover, only highly skilled workers to operate such NMR devices and evaluate the spectra obtained with these.

In addition, as required in medical diagnostics, even for routine tests of blood or urine regularly larger sample volumes, which means a high Materialwie brings personnel expense, and is often perceived as unpleasant by the treated patients as well as the staff.

Of the <patcit id="pcit0008" dnum="DE19734618A1"><text>DE 197 34 618 A1</text></patcit> an analysis device for in-vivo analysis in the body of a patient can be seen. This is an infrared measuring device in the form of a einstechbaren in the skin cannula, designed for spectrometry of interstitial fluid in the skin tissue, in particular for the detection of glucose and thereby an ATR body and at least one quantum cascade laser operated. The measurement takes place with the aid of an optical fiber is coupled into the radiation and which is perforated at least over a partial section, so that interstitial fluid can pass through the cannula wall to a extending in the cannula measuring section of the optical fiber. To avoid interference by larger molecules such as proteins and caused to achieve sufficient measuring accuracy, according to the<patcit id="pcit0009" dnum="DE19734618A1"><text>DE 197 34 618 A1</text></patcit> the optical fiber is wrapped in a semipermeable membrane. By appropriate sealing measures must also ensure that the interstitial fluid can not pass through remaining columns in a disturbing amount of the optical fiber. To accomplish this, epoxy resins are in addition to install. To protect the optical fiber against corrosion it can with a very thin evaporated metal layer, for example made of silver, be provided. The usually very thin optical fibers are often perforate only with expensive laser drilling. When a pore content of preferably at least 50%, the production of needles designed in accordance with the<patcit id="pcit0010" dnum="DE19734618A1"><text>DE 197 34 618 A1</text></patcit> therefore very time consuming and costly.

The <patcit id="pcit0011" dnum="WO9610198A"><text>WO 96/10198</text></patcit> describes a special embodiment of a device suitable for the ATR spectroscopy optical fiber. This optical fiber has a radiation-permeable core and this radiation a reflective on its inner wall, surrounding the core shell layer. Along a partial portion of the optical fiber is a substantially half-cylinder-shaped element has been removed, so that the latter has a single flat surface, on which the coupled-in radiation can be totally reflected. It is necessary to ensure that the enclosure over the entire length of the optical fiber has a thickness which allows the evanescent field of the coupled radiation does not interact with a surrounding the optical fiber medium, since a specific interaction only on the flat face of the described to be held subsection. Further details are not given in this document.

The <patcit id="pcit0012" dnum="EP0206433A2"><text>EP 0206433 A2</text></patcit> discloses an immersion probe for IR spectroscopy comprising a prism, in which can be coupled via optical fibers measuring radiation. The prism used for the measurement shall first have at least two at an angle to each other disposed adjacent measurement areas. In order to achieve sufficient measuring accuracy, the method requires the<patcit id="pcit0013" dnum="EP0206433A2"><text>EP 0206433 A2</text></patcit> for determining the concentration of substances having at least two reference measurements Kalibrationsmedien in which the to be tested substance is present in a known concentration.

Also in the <patcit id="pcit0014" dnum="DE19856951A1"><text>DE 198 56 951 A1</text></patcit> describes an ATR probe, which comprises a cylindrical protection casing, at the free end face of a prism is arranged which has a wettable with the medium to be analyzed surface on which a coupled-in light beam is reflected. According to the<patcit id="pcit0015" dnum="DE19856951A1"><text>DE 198 56 951 A1</text></patcit> can be spectroscopically analyzed with such a probe in such a way that two separate light beams that differ in their angle of incidence on the wettable surface of the prism and / or in their polarization state are used fluid media. For example, n can be from the wavelength-dependent reflection coefficients for both angles of the refractive index and calculate the absorption coefficient k numerically.

The <patcit id="pcit0016" dnum="DE4200869A1"><text>DE 42 00 869 A1</text></patcit>, Discloses an infrared microscope spectrometer with which also perform spectrometric ATR measurement and in which can be easily adjust the optical axis.

According Hvozdara et al. (Summary of the conference report of the International Conference on advanced vibrational spectroscopy ICAVS, Turku, Finland, August 2001) one can use sensors for the analysis of aqueous media that exploit the absorption of evanescent waves by utilizing the principle of attenuated total reflection by use of radiation in the middle infrared range. In this way can be investigated enriched analytes for example on a suitable polymer coating. While it is suggested that new applications, should gradually reveal through the use of quantum cascade lasers, however, be made on this general wishful thinking, no further details.

The <patcit id="pcit0017" dnum="EP0670492A2"><text>EP 0670492 A2</text></patcit> is concerned with the provision contained in the urine substances by detecting and analyzing the absorption behavior of radiation in the visible and near infrared region by means of multivariate regression analysis. Here, appropriate wavelengths be chosen with a specific correlation coefficient between the concentration and the absorption capacity of an aqueous solution comprising correspondingly standardized aqueous solutions of the test analytes.

In the <patcit id="pcit0018" dnum="DE4333560A1"><text>DE 43 33 560 A1</text></patcit> is described containing an ATR crystal in the form of an immersion probe that can be used for on-line monitoring of chemical production processes even under high pressure and at high temperature and only minimal maintenance requires a measuring cell. This is achieved by an ultrasound source for cleaning the measuring surface of product residues is arranged in front of the measurement surface of the ATR crystal. The ATR-measurement cell according<patcit id="pcit0019" dnum="DE4333560A1"><text>DE 43 33 560 A1</text></patcit> is designed as an insertion probe for a chemical reactor and has a product chamber facing the measurement surface and a mirrored back. For evaluation of the measurement radiation of the ATR crystal leaving measurement beam is supplied via an optical fiber cable a FT-IR spectrometer. Further information about the limits and possibilities and applications that go beyond the use in chemical engineering, are not given in this document.

In the <patcit id="pcit0020" dnum="US5214286A"><text>US 5,214,286</text></patcit> describes an insertable in the IR spectroscopy device with which it should be possible to adjust the circular cross-sectional shape and size of the radiation used in FT-IR spectrometer to IR elements that date from dispersively operating spectrometers.

According to the <patcit id="pcit0021" dnum="WO9905509A"><text>WO 99/05509</text></patcit> is used to analyze biological molecules, preferably at an applied in the form of a so-called monolayer on at least one side of the ATR body, have attached very thin metal layer, an ATR body. Preferably, use is made of gold layers with a thickness of 5 to 10 nm. The body corresponding to the ATR measurement radiation is preferably evaluated on a FT-IR spectrometer.

Also solid body can be in accordance with the <patcit id="pcit0022" dnum="WO9966312A"><text>WO 99/66312</text></patcit> directly analyzed using an IR spectrometer based on the use of an ATR body. In this case, the solid sample body is pressed with high pressure on the surface of the ATR crystal. For such an application, ATR prisms have proven based on diamond materials. In order not to falsify the measurement result by an attenuated total reflection interacting with the pressing device, is between the one the measuring radiation and outcoupling prism and facing the measuring medium ATR body extensively incorporated a reflective layer, the only one and decoupled radiation passes. On the measurement of liquid or other systems using the illustrated IR spectrometer device is in the<patcit id="pcit0023" dnum="WO9966312A"><text>WO 99/66312</text></patcit> received at any point.

In the <patcit id="pcit0024" dnum="EP0652301A1"><text>EP 0652301 A1</text></patcit> is described with the aid of a pyrolytic graphite cathode, a plasma coating method for making a thin diamond-like carbon coating. However, can be found in this document no evidence that under the described conditions of plasma coating also high-quality coated ATR body are accessible.

It would therefore be desirable to have access to devices and methods, which can also be small and even very small amounts of ingredients in particular aqueous systems qualitatively and quantitatively determined very accurately and quickly in a simple manner.

The present invention therefore had the object of finding a measuring device which is easy to manufacture and handle, are also characterized by extreme robustness even in continuous operation, for example under Produktionsbedigungen in the manufacture of beverages, as well as by extreme precision in the qualitative and quantitative distinguished determination of components in liquids. the invention also had the object, several side by side in an aqueous liquid present ingredients or components, especially those polar in nature, simultaneously or nearly simultaneously to analyze.

Accordingly, a Infiarotmeßvorrichtung was found, wherein the measuring unit includes at least one ATR body which comprises at least two planar, substantially parallel boundary surfaces comprises, which is transparent to the measuring radiation and has a refractive index which is greater than the one at least one boundary surface adjacent, to be examined medium, in particular greater than or equal to 1.5, wherein the IR measuring radiation is attenuated at least at one of the flat, parallel delimiting surfaces of the ATR body at least six times totalreflektierbar. The plane boundary surface of the ATR body has thus advantageously via a continuous, uniform measurement distance within which a measuring beam is at least six times attenuated totalreflektierbar, that can interact with an adjacent medium.

Preferably, the flat, essentially parallel boundary surfaces substantially non-reflected or completely non-reflected are configured, so do not have a mirrored surface or not adjoin one.

Quantum cascade lasers, which are suitable for the measuring device according to the invention, for example, are known from <patcit id="pcit0025" dnum="EP0676839A"><text>EP 0676839 A</text></patcit> as well as from the <patcit id="pcit0026" dnum="US5509025A"><text>US 5,509,025</text></patcit> known, in which the basic functioning and their structure are described. is preferred to employ quantum cascade lasers that emit electromagnetic radiation in the middle infrared range. as eligible for the infrared measuring device according to the invention, those quantum cascade lasers into consideration which emit only a defined frequency, especially in the middle infrared region, as well as those which have two, three, four, five or more frequencies, especially from the middle infrared region, radiate can. Furthermore, it can also be resorted to such a quantum cascade lasers that emit defined frequency bands. Of course, these Infrarotmeßvorrichtungen also be equipped with not only one, but two or more quantum cascade lasers described above. If in a measuring device according to the invention, a quantum cascade laser is used, which is capable of emitting electromagnetic radiation of at least two different frequencies, especially from the middle infrared region, or if several quantum cascade lasers are used in such a measuring device side by side, the electromagnetic radiation, especially if it has different frequencies simultaneously or nearly simultaneously, or are emitted in chronological order. In this way, it is possible to characterize the behavior of a spectrometric substance in a sample comprising. Furthermore, it is possible more present in a sample components in the shortest possible time, simultaneously or nearly simultaneously to investigate ie. Almost simultaneously or simultaneously for the purposes of the present invention means that signals are emitted slightly offset in time that no significant differences compared to the detected at the same time absolutely emitted radiation absorption signals can be seen from the respective detected absorption signals.

In a preferred embodiment, electromagnetic radiation in the form of pulses is emitted with a defined period of time and / or intensity of the quantum cascade laser used. This pulse duration and / or intensity can be freely selected within a wide range and can be used to produce for each to be examined ingredient optimized spelctrometrische examination conditions. Thus, if several ingredients are to be measured in a sample, depending on the frequency of the emitted electromagnetic radiation of different length pulse durations and / or intensities of different strengths can be selected. For example, ingredients with weakly absorbing chromophores pulses can be exposed to longer duration, while strongly absorbing substances very short pulse durations sufficient to detect a satisfactory signal can. Already this different absorption behavior can be used for analysis and for the purpose of immediate adjustment stored in a standing to a detector operatively connected evaluation unit or integrated into appropriate analytical programs. Accordingly, it is with the infrared measuring device according to the invention possible electromagnetic radiation of different frequencies, either from only one quantum cascade laser or radiate through the use of several quantum cascade lasers, in any sequence, for example, in sequential order. This applies in particular to the pulsed radiation previously described.

On the free choice of the pulse repetition frequencies of the emitted electromagnetic radiation according to the invention the pulse pattern and / or intensity pattern can be used which are tailored to the particular analytical problem. For example, with knowledge or reason to suspect the present in a liquid or possibly present ingredients that Freque coins, pulse durations and / or intensities are specified such that the nature and extent of the detected signals with the aid of an evaluation unit, in particular a computerized evaluation , can be determined without difficulty what ingredients in what concentrations, in the sample examined present-This pattern of pulse sequence, pulse length and / or pulse intensity of two or more frequencies can in turn be used to produce certain patterns of response signals for certain compositions are characteristic. In this way it is possible to determine within a very short time, certain ingredients are present whether or at what concentration in a sample. Accordingly, particularly preferred is electromagnetic radiation of different frequency and / or intensity in accordance with a multiplex pattern, in particular in pulsed fashion, is radiated. Here, for a known multiplex spectrometers or electric multiplexers, the detector side are primarily used to resort. Secondly, preferred are those multiplexers are used according to the invention, which not only affect the detector or control wavelength-specific, but select the to-emitting wavelengths and / or intensities and control the broadcast sequence or the Ausstrahlungsrouster. The invention used according to the multiplexer controls or regulates in accordance with another embodiment, in addition, the intensity of the respective measuring radiation, in particular depending on the particular measurement problem. These so-called optical multiplexers thus coordinate the radiation source and the detector and agree them with one another. Such multiplexer switch inter alia measuring radiation after a cut to the measurement problem pulse train in and out, especially among wavelength-dependent modulation of intensity, and consequently control the light source. The detected signals are preferably analyzed by means of known methods such as factor analysis, multiple least square algorithms or neural network analysis for this purpose is regularly accessed to computerized evaluation.

Moreover, it is possible using quantum cascade lasers, to send not only radiation of different frequencies and / or intensities in a given time sequence by the ATR body. Rather, they may also emit different frequencies at the same time, wherein in particular the number and frequency of the emitted radiation can be continuously varied. In this way, frequency patterns can be put together, generate the characteristic absorption signals for to be examined compositions, whereby multi-component mixtures, in particular also in aqueous systems, in a short time can be analyzed. The analysis method described above can also be described with matrix-coding / decoding matrix.

The embodiment according to the invention an FT-IR measuring apparatus has at least one light source which is capable of a continuous or continuously emit a multi-wavelength spectrum. Such light sources are to the person skilled for example as a Nernst-pins which are made of rare earth consists essentially of zirconium oxide and additives, as well as so-called Globare consisting essentially of silicon carbide, known. In addition comes as a light source, an electrically conductive ceramic in question. Basically, the light sources may be used that emit over the entire spectral range infrared or only on certain portions of this spectrum. For the determination of constituents with FT-IR measuring apparatus of the invention preferably are those light sources are used which emit electromagnetic radiation in the mid-infrared region, ie in the range of about 2 microns to about 25 microns, particularly from about 2.5 microns to about 12 microns ,

The recorded in the detector of the FT-IR spectrometry interferogram, which records a superposition of all occurring in the spectrum of wavelengths, in the evaluation unit, with computer assistance by Fourier transformation in the frequencies of the individual vibration disassembled details of the Fourier transform, for example, are at NB <nplcit id="ncit0002" npl-type="b"><text>Colthup, LH Daly, SE Wiberley, Introduction to Infrared and Raman Spectroscopy, Academic Press, San Diego, 1990</text></nplcit>Finding, which is hereby incorporated by reference. With FT-IR measuring device of the invention can be more ingredients essentially simultaneously determine with high sensitivity, speed and WeIIenzahlenpräzision.

The detectors for the registration of the measuring radiation can be used on all standard, coming in Infrarotmeßvorrichtungen used systems.

As far as the detected signals to be further processed or evaluated for this purpose are well-known to those skilled in evaluation, in particular computer-aided evaluation into account. An evaluation for the purposes of the present invention may also include a data storage and / or a display unit, for example, include a recorder or a screen. These elements can of course also be present separately.

In a preferred embodiment, the inventive measuring device has an exchangeable control unit. For example, a first evaluation unit be replaced with a second or further evaluation. This is possible from the termination of a first measurement or a self-contained measurement and during a measurement done, for example, when you realize that a requested connection is not present or does can be detected readily, so that in the following the search further for a ingredient can be tackled. This has the advantage that, for example on a first evaluation, an evaluation program for a particular analytical problem exists, which can be substituted when changing the analysis task to a second or further evaluation with a cut on the new task evaluator. Preferably, the evaluation units are in the form of evaluation modules before, which can be produced active compounds with the inventive measuring device, in particular with the detector, in a simple manner, for example, in the form of plug-in or Einschiebmodulen. As has been found advantageous to make the respective evaluation units distinguishable by different shape and / or color. Further, two or more analysis programs available to an evaluation unit which can be enabled in a Ausfiihrungsfonn as needed. About the evaluation unit can be for example, the multiplexer influence or drive. can with the evaluation unit therefore also be taken to influence the radiation source (s) or a frequency selection, pulse sequence and intensity assignment of the radiated measuring radiation are specified for a particular analytical problem.

In the infrared measuring device according to the invention for use next measuring unit comprises at least one ATR body, ATR body are referred to in the art as ATR crystals, although these systems do not necessarily have to be in crystal form. Accordingly, as well as sintered silver chloride a functioning ATR body / crystal represents. In principle, such ATR body useful herein that are completely or partially transparent to the measuring radiation.

As the material for the ATR body used any material out of the question, which is for the radiation used, especially for electromagnetic radiation in the middle infrared region transparent and moreover is highly refractive or high refractive index and has a refractive index greater than the analyte of air and / or than the one with the infrared measuring device according to the invention or analyzable medium. Suitable materials for the ATR body include diamond, sapphire, cadmium telluride, thallium bromide-iodide, silicon, germanium, zinc selenide, zinc sulphide, Magnesiumdifluorid, cesium iodide, silver chloride, Kalziumdifluorid, potassium bromide or sodium chloride. For the skilled artisan will appreciate that certain of the advancing materials mentioned do not, because of their solubility in water aqueous systems for the measurement purpose, for example an ATR body of sodium chloride. In a further embodiment, on ATR body from a material transparent to infrared radiation material, in particular a polymer material, having a refractive index preferably ≥ 1.5, in particular of polyethylene, resorted to.

The ATR body preferably forms with at least one flat boundary surface of a side wall of the measuring unit or cell. Under the proviso that the ATR body has two planar, substantially parallel boundary surfaces, of the ATR body may otherwise be present in any desired geometry, as long as they permit an incident beam can be adjusted such that the latter before its exit from the ATR body total of at least twice or three times, preferably at least six times, preferably seven times has been totally reflected at least attenuated at one or more planes substantially parallel boundary surfaces. In one embodiment of the invention optimal analysis results in terms of sensitivity, accuracy and speed are also obtained for aqueous multicomponent systems with six or seven such total reflections already. Here, the ATR body has to be designed in the shape and size such that at least six or seven attenuated total reflections occur along a measuring section. Under test section will present the portion of the ATR body understood comes into contact with the medium to be analyzed and which is total attenuated total reflections available

In a further embodiment, at least two boundary surfaces of the measuring unit or cell, in particular opposed walls of the measurement cell, in each case one ATR body, in particular in each case one ATR body comprising at least two plane, substantially parallel boundary surfaces. In addition may be made of one ATR body and the entire measuring cell.

In a further preferred embodiment, the measuring cell is a flow cell. This has the advantage that, for example also processes can be in a variety of manufacturing processes, preferably in the on-line mode, examined. These flow cells are particularly suitable for use in process analysis and in the study of body fluids such as blood.

Moreover, it is possible to configure the measuring cell or the ATR body as an immersion probe to analyze samples as systems that otherwise poorly or can not be measured with the aid of the infrared measuring device according to the invention. Such immersion probe is especially suitable for sample checks in different processes in which aqueous and non-aqueous systems are used. For example, can be easily urine, blood, fruit juices, beer, liquor, wine, washing liquors or waste water on ingredients, eg polar substances such as saccharides, for example, glucose, alcohols such as ethanol, or phosphoric esters studied using an immersion probe. Further possible analysis of ingredients in milk and dairy products such as curd cheese or yogurt without the need of any special preparation of these products.

In a further embodiment, at least one boundary surface of the ATR body, which is the medium to be analyzed can be exposed, or exposed, provided with a coating which is transparent to the measuring radiation. In particular, if the coating has a thickness that is less than the wavelength of the measurement radiation used, can be made of how any of the measuring radiation transparent coating material. The thickness and strength of the coating, however, is critical if it is the coating material is such for one ATR body, ie roughly has a refractive index that matches that of the respectively used ATR body. For example, an ATR material such as zinc sulfide or zinc selenide, which is particularly preferably used for the ATR body used in the invention, be provided with a layer of diamond, were obtained in this way, tagged with extremely resist staud and inert coating ATR body. Particularly preferably, the diamond layer according to one of HJ Neubert in Optics, February 2002 Page 11 method described is applied. Thereafter, it is generated with the aid of a carbon dioxide laser with a power of about 6-7 kW near one surface a temperature in the range 15000-20000 ° C. Via argon bubbling in this field, a plasma is generated. Are you gaseous hydrocarbons, such as methane, in this plasma-free carbon atoms are formed, which can be deposited on a substrate, in this case on a flat boundary surface of an ATR body, forming a diamond layer of very low thickness. Advantageously, the coating previously described is particularly useful materials for ATR bodies which are toxic, soluble, z. B. in the sample medium, and / or sensitive to mechanical stress. Particularly suitable for the measuring device according to the invention are ATR body of zinc sulfide or zinc selenide, which are provided with a coating, in particular a diamond coating.

In a preferred embodiment the coating of the ATR body of the infrared measuring device according to the invention has a thickness that is less than, preferably half, wavelength of the infrared measuring radiation used, in particular a thickness in the range of about 2 nm to about 25 microns, more preferably from about 2 microns to about 12 microns, and in particular at about 5 microns. A suitable coating thickness range thus extends from 2 nm to 12 microns. The thickness of the coating is more preferably in a range of about a quarter of the measuring wavelength. Furthermore, it is advisable to use a coating that hinsichtich thickness and composition is homogeneous and has a smooth surface. It is of advantage if the unevenness in the coating does not exceed the amount of about a quarter of the measurement wavelength on average. Suitably, use is made of such coatings, are not, even partially, reflecting the measuring beam. The coating has a double function, by one hand, protects the process medium from contamination with, possibly toxic, ATR Körpex material and secondly the ATR body against mechanical damage. In the investigation of aqueous systems, in particular, coatings have been proven, which do not allow diffusion of water molecules through this layer to the ATR body.

In another preferred embodiment, instead of a diamond coating, a layer of a transparent or translucent plastic, in particular polyethylene may be used.

In a further advantageous embodiment, the can be provided with a coating ATR body materials are selected from sapphire, cadmium telluride, thallium iodide, silicon, germanium, zinc sulphide, zinc selenide Magnesiumdifluorid, cesium iodide, silver chloride, Kalziumdifluorid, potassium bromide and sodium chloride, with zinc selenide and zinc sulfide preferably are.

In particular, the fact that in the Infrarotmeßvorrichtungen inventive electromagnetic radiation of two or more frequencies can be used simultaneously or nearly simultaneously, will both always destructively interfered with the under examination system for use as a measuring cell as well especially when used as an immersion probe only briefly and generally ,

In an advantageous embodiment of the invention, the measurement unit is a pressure-stable measuring unit. A measuring unit according to the invention, particular measuring cell, is accordingly distinguished also by the fact that the measuring unit comprises at least one ATR body which comprises at least two planar, substantially parallel boundary surfaces comprises the is transparent to the measuring radiation and has a refractive index which is greater than the one at least one boundary surface adjoining the medium to be examined, in particular greater than or equal to 1.5, wherein the measuring unit is pressure stable. Pressure stable in the sense of the present invention should also include that the measuring unit essentially functioning properly even at high exterior as well as high internal pressures that as there are no leaks or damage occur and that the measuring process is not disturbed by high external pressures. is preferred to employ units of measurement, in particular load cells, above all flow cells and immersion probes, which are pressure-stable even at particular outside pressures up to about 100 bar. Be particularly expedient such measuring units have been found that are bar pressure-stable in the range 1 to 25 In particular, the ATR body as such, have to be designed pressure-stable and, for example, to have adequate strength. Pressure-resistant measuring units are suitable for example for use in process analysis, for example, without changing the manufacturing conditions, be able to follow the actual progress of the manufacturing process in real time. Pressure-resistant measuring units can be used accordingly in beverage production, for example in the production of beer, or in chemical processes. This is also advantageous that the inventive measuring device with the aid of a pressure-resistant measuring unit polar substances, such as carbohydrates and alcohols, can be qualitatively and quantitatively determined.

With the infrared measuring device according to the invention both individual ingredients as well as complex mixtures of ingredients in sample systems can be clearly and accurately investigate and characterize particular using electromagnetic radiation in the middle infrared range, where it is possible ingredients qualitatively and / or quantitatively determine in particular in aqueous systems.

This is the first time also, particularly in on-line mode can be used, infrared measuring device before that, for the analysis of aqueous systems, in particular beer, wine, spirits, soft drinks, fruit juices, waste water, washing liquors, process fluids or body fluids such blood, saliva, lymph or urine, may be used. For example, it is possible, the sugar and / or alcohol content, such as glucose and / or ethanol content to determine simultaneously or nearly simultaneously in liquids. With knowledge of the possibly present in a sample components can be limited to specific frequencies or frequency ranges to search for signals to be detected, of which very high sensitivities are achieved. For example, by means of the infrared measuring device according to the invention in aqueous systems side by side present different saccharide such as fructose, glucose and galactose, are identified.

In a preferred embodiment of the invention are as ingredients of beverages, such as beer, wine, spirits, milk, dairy products, soft drinks or fruit juices, in the production or processing and / or filling by means of FT-IR measuring device according to the invention using a flow cell qualitatively and quantitatively determined. In this, possibly also coexisting ingredients may be, for example alcohols, such as ethanol, methanol, propanol or butanol, carbohydrates, carbon dioxide and / or proteins act, the ingredients are, whatever their size adjacent analyzed.

In one embodiment of the invention, the inventive device is used to determine the ingredients of fruits and vegetables quantitatively and / or qualitatively. Here a flat surface of an ATR body a measuring unit can be placed or pressed on, for example, fresh cut, pulp of fruits or vegetables in one embodiment. A below-described hollow body, which is equipped with an ATR body, is particularly well suited for these measurements. In the same way, the degree of maturity of grapes can eg be determined by the in operative connection with an infrared measuring device according to the invention ATR body, is immersed, for example, in an embodiment of an immersion probe or the aforementioned hollow body, brought into direct contact with the pulp or this.

The infrared measuring device according to the invention is particularly suitable in particular for the determination of components especially in medicine or veterinary medicine. For example, can be detected qualitatively and / or quantitatively from body fluids such as blood, urine, saliva or lymph ingredients. In this way, conditions for rapid diagnosis are created. For example, using a flow cell, if the blood such as glucose, urea, creatinine or triglycerides, as well as alcohols, such as ethanol, are desired even on-line, that is in real time mode, determined. Accordingly, the infrared measuring device according to the invention is suitable for example for use in dialysis. The replaced blood can continually examined for particular other critical components and the time at which the blood is sufficiently purified can be accurately determined. This eliminates unnecessarily long dialysis times. Also due to the small dimensionable ATR body, it is no problem to access for use in dialysis to disposable or recyclable flow cells. Expediently, such a flow cell is configured as a module that can be readily integrated into a test section, eg in a blood conducting cannula.

Information on the status of being cleaned in dialysis blood may also provide by the distinction made by the Infrarotmeßvonichtung inventive spectroscopic study of the costs incurred in the blood purification washing or replacement fluid. According to the invention said measuring means is also used for the determination of components in this wash liquid. Hereby the advantage is associated, that the measurement no longer has to take place under sterile conditions, however fast information about the state of the purified blood are made possible.

However, for the determination, for example, the aforesaid blood constituents with the device of the invention also are already sufficient amounts of about 100 ul, particularly when the measuring apparatus according to the invention containing comes to a continuous spectrum emitting radiation source used, as well as quantities &lt;20 .mu.l, and in particular when the invention measuring device containing the quantum cascade laser is used, in order to obtain accurate information as to if so in what concentration as present which substances in the blood. In contrast to conventional blood analysis method one has to rely on much smaller volumes of blood and is moreover without other consumables, such as syringe bodies and cannulas from. In addition, the removal of small amounts of blood made much easier, as well as with regard to maintaining sterile conditions.

In a further inventive Ausfuhrunäsforan a urinal is provided, comprising a urinal basin, comprising at least one ATR body with at least two levels, in particular substantially parallel boundary surfaces, which is transparent to the measuring radiation and has a refractive index which is greater than that of a adjacent to at least one boundary surface, to be examined medium, in particular groE than or equal to 1.5, in which a laser beam, in particular at least one beam of a quantum cascade laser, preferably with a wavelength in the mid-infrared region, can be coupled; and / or at least one drain line, in which a measuring unit, in particular measuring cell comprising at least one ATR body with at least two flat boundary surfaces, which is transparent to the measuring radiation and has a refractive index which is larger than the one adjacent to at least one boundary surface , to be examined medium, in particular greater than or equal to 1.5, in which a laser beam, in particular at least one beam of a quantum cascade laser, preferably, be coupled with a wavelength in the middle infrared range. A measuring unit comprising the ATR body, for example may be in the urinal itself or mounted in the conventional drain pipe of the urinal, but is preferably in a separate or diverted from the discharge pipe line. It is sufficient for this embodiment regularly been at least two or three, in particular at least six or seven attenuated on the boundary wall to the medium totally reflected measuring beams for a reliable result.

In order to obtain reproducible data, the measuring cell is equipped as zweclanäßigerweise flow cell with a reversibly closable inlet and outlet. In addition, it has proven to be advantageous if the measuring unit or casting cell can be for example the corresponding channel systems, thermostatically controlled. Furthermore, it is advantageous if a means for cleaning the measuring unit with, for example, cleaning liquid and / or water and optionally a means for drying the measuring unit, for example, are provided a blower.

Further, another embodiment of the invention has a water closet to the object, comprising a toilet bowl, comprising at least one ATR body with at least two levels, in particular substantially parallel boundary surfaces, which is transparent to the measuring radiation and has a refractive index which is greater than the an at least one boundary surface adjoining the medium to be examined, in particular greater than or equal to 1.5, in which a laser beam, in particular at least one beam of a quantum cascade laser, preferably with a wavelength in the mid-infrared region, can be coupled; and / or at least one drain line, in which a measuring unit, in particular measuring cell comprising at least one ATR body with at least two levels, in particular substantially parallel boundary surfaces, which is transparent to the measuring radiation and has a refractive index which is greater than the an at least one boundary surface adjoining the medium to be examined, in particular groE than or equal to 1-5, in which a laser beam, in particular at least one beam of a quantum cascade laser, preferably, be coupled with a wavelength in the middle infrared range. It is sufficient for this embodiment regularly been at least two or three, in particular at least six or seven attenuated on the boundary wall to the medium totally reflected measuring beams for a reliable result. The infrared measuring device according to the invention or a measuring unit can eg. either be integrated into the drain pipe of the toilet or, preferably, present in a separate or diverted from the discharge pipe line. As with the previously described urinal can be thermostated the measuring cell used in the lavatory. The feces analysis described above can be as characteristic information determined in view of the present fats and their grades. In the two above-described Ausfubrungsfonnen the measuring unit preferably is connected to a controllable via a valve supply line for cleaning liquid in connection with the after each measurement, the measuring unit / measurement cell, in particular, the ATR body, is cleaned.

Further, the present invention in a further embodiment, a urinal, comprising a urinal basin, comprising at least one ATR body with at least two levels, in particular substantially parallel boundary surfaces, which is transparent to the measuring radiation and has a refractive index which is greater than the one at least one boundary surface adjoining to be examined medium, in particular greater than or equal to 1.5, in which a light beam, in particular at least one beam of a continuous spectrum or a multi-wavelength spectrum, in particular in the middle infrared range emitting IR-light source can be coupled; and / or at least one drain line, in which a measuring unit, in particular measuring cell comprising at least one ATR body with at least two levels, in particular substantially parallel boundary surfaces, which is transparent to the measuring radiation and has a refractive index which is greater than the one at least one boundary surface adjoining to be examined medium, in particular greater than or equal to 1.5, in which a light beam, in particular at least one beam of a continuous spectrum or a multi-wavelength spectrum, in particular in the middle infrared range emitting IR-light source can be coupled. A measuring unit comprising the ATR body, for example may be in the urinal itself or mounted in the conventional drain pipe of the urinal, but is preferably in a separate or diverted from the discharge pipe line. It is sufficient for this embodiment regularly been at least two or three, in particular at least six or seven attenuated on the boundary wall to the medium totally reflected measuring beams for a reliable result. In order to obtain reproducible data, the measuring cell is equipped as zeckmäßigerweise flow cell with a reversibly closable inlet and outlet. In addition, it has proven to be advantageous if the measuring unit or - cell, may be for example the corresponding channel systems, thermostatically controlled. Furthermore, it is advantageous if a means for cleaning the measuring unit with, for example, cleaning liquid and / or water and optionally a means for drying the measuring unit, for example, are provided a blower.

Further, another embodiment of the invention has a water closet to the object, comprising a toilet bowl, comprising at least one ATR body with at least two levels, in particular substantially parallel boundary surfaces, which is transparent to the measuring radiation and has a refractive index which is greater than the an at least one boundary surface adjoining to be examined medium, in particular greater than or equal to 1.5, in which a light beam, in particular at least one beam of a continuous spectrum or a multi-wavelength spectrum, in particular in the middle infrared range emitting IR-light source can be coupled; and / or at least one drain line, in which a measuring unit, in particular measuring cell comprising at least one ATR body with at least two levels, in particular substantially parallel boundary surfaces, which is transparent to the measuring radiation and has a refractive index which is greater than the an at least one boundary surface adjoining to be examined medium, in particular greater than or equal to 1.5, in which a light beam, in particular at least one beam of a continuous spectrum or a multi-wavelength spectrum, particularly in the mid-infrared region, emitting infrared light source, can be coupled. The infrared measuring device according to the invention or a measuring unit can be, for example, either integrated into the drain pipe of the toilet or, preferably, present in a separate or diverted from the discharge pipe line. It is sufficient for this embodiment regularly been at least two or three, in particular at least six or seven attenuated on the boundary wall to the medium totally reflected measuring beams for a reliable result. As with the previously described urinal can be thermostated the measuring cell used in the lavatory. The feces analysis described above can be as characteristic information determined in view of the present fats and their grades. In the two above-described embodiments, the measurement unit preferably having a controllable via a valve supply line for cleaning liquid in connection with the after each measurement, the measuring unit / measurement cell, in particular, the ATR body, is cleaned.

According to the invention further comprises a hollow body, in particular a needle, a tube or an immersion probe, with non-transparent sidewalls, in particular with a tapered end, provided, in which in an end region or at one end, in particular in the tapering end, of the hollow body ATR body is sealingly attached, the at least two planar, substantially parallel boundary surfaces comprises, which is transparent to the measuring radiation and has a refractive index which is larger than the one adjacent to at least one boundary surface, to be examined medium, in particular greater than or equal 1.5, said attenuated through the interior of the hollow body at least one laser beam, in particular a quantum cascade laser, can be coupled to the ATR Közper and at least one infrared measuring beam to at least one of the flat, parallel delimiting surfaces of the ATR body at least six times along a measuring path is totalreflektierbar. In an alternative embodiment of the hollow body, in particular the needle, tube or immersion probe, an ATR body is sealingly, additionally or exclusively, mounted in a side wall, eg in a lateral surface of a needle.

Such hollow articles are particularly suitable as a measuring cell or as a component in particular an IR Meßvornchtung invention. For example, said tube or said needle for invasive determination of components in the blood are used by living things. Due to the small size of the present at the needle / tube top miniature ATR body real-time measurements can be made with such a hollow body, such as stress testing of athletes.

Another embodiment of the invention relates to a cannula, in particular stent, comprising at least one IR-measuring cell, in particular a flow cell, comprising at least one ATR body with at least two plane, substantially parallel boundary surfaces, which is transparent to the measuring radiation and has a refractive index which is greater than that of an adjacent at least one boundary surface, to be examined medium, in particular greater than or equal to 1.5, in which a laser beam, in particular at least one beam of a quantum cascade laser, preferably with a wavelength in the mid-infrared region, can be coupled and at least one IR measurement beam at least one of the flat, parallel delimiting surfaces of the ATR body at least six times along a measuring section is weakened totalreflektierbar; and / or at least a hollow body described above.

It is provided that the ATR body of the cannula, which in particular comprises an infrared measuring device described above, is in operative connection with at least one quantum cascade laser and / or a detector and / or an evaluation unit. Thus, a laser beam in the ATR body are coupled.

Even with this cannula succeeds in quantitative and / or qualitative determination of components, especially of saccharides, urea, creatinine and / or triglycerides, such as in body fluids of living organisms.

According to the invention it is further provided a measuring unit / measuring cell containing at least one ATR body for the automated analysis operation, for example by means of an automatic analyzer or -roboters. This analysis unit comprises besides said measuring cell a Spülsowie a Trockenvonichtung for the ATR body. In this way, for example, can be cleaned a flow cell or a closable flow cell or an immersion probe after the measuring and prepared for the subsequent measurement. The automated measurement method previously described allows very short measuring cycles. For example, rich per measuring already about 10 seconds, for example to allow six ingredients, for example in the blood or urine to determine can. Thus, using the measuring device according to the invention, a plurality of samples automatically by infrared spectroscopy to be measured.

According to a further aspect of the invention, an ATR body is provided, comprising a first ATR body and a second ATR body, wherein the first and the second ATR body, at least in such a way to be in contact in that a measurement beam via the first ATR body in the second ATR body of this measuring beam in the first ATR body can be coupled and from the second again coupled out, wherein the second ATR body comprises at least two planar, substantially parallel boundary surfaces, of which the first boundary surface is a medium to be analyzed exposable and the second boundary surface facing the first ATR body and filled with this at least one sealed, in particular evacuated or gas cavity is formed. With this embodiment of an ATR body, it is possible the use of expensive, more sensitive or more resistant and / or non-toxic or restrict in the medium to be analyzed not soluble ATR materials to that surface area which comes into contact with the medium. Thus it is possible, an ATR base body made of, for example, zinc selenide, which is generally toxic, or sodium chloride, which dissolves in aqueous media, where appropriate.

The FT-IR measuring device according to the invention and the inventive ATR / quantum cascade laser-IR measuring device are particularly suitable in particular for the determination of components, especially in food analysis, medicine or veterinary medicine. For example, can be detected qualitatively and / or quantitatively from body fluids such as blood, urine, saliva or lymph ingredients Thus, conditions for rapid diagnosis are created. For example, using a flow cell, if the blood such as glucose, urea, creatinine or triglycerides, as well as alcohols, such as ethanol, are desired even on-line, that is in real time mode, determined. Accordingly, the infrared measuring device according to the invention is suitable for example for use in dialysis. The replaced blood can continually examined for particular other critical components and the time at which the blood is sufficiently purified can be accurately determined. This eliminates unnecessarily long dialysis times. Also due to the small dimensionable ATR body, it is no problem to access for use in dialysis to disposable or recyclable flow cells. Expediently, such a flow cell is configured as a module that can be readily integrated into a test section, eg in a blood conducting cannula.

Information on the status of being cleaned in dialysis blood may also provide by the distinction made by means of the infrared measuring device according to the invention spectroscopic study of the costs incurred in the blood purification washing or replacement fluid. According to the invention said measuring means is also used for the determination of components in this wash liquid. Hereby the advantage is associated, that the measurement no longer has to take place under sterile conditions, however fast information about the state of the purified blood are made possible.

The detectors for the registration of the measuring radiation can be used on all standard, coming in Infrarotmeßvorrichtungen used systems. In a further embodiment, detectors may be as known in the photoacoustic spectroscopy, are used. Details of the photoacoustic spectroscopy are well known in the art and are, for example, in "<nplcit id="ncit0003" npl-type="b"><text>Optical Spectroscopy ", VCH, Weinheim, 1994</text></nplcit>Chap. 6 will be described.

With the measuring devices according to the invention, particularly the ATR / quantum cascade laser-IR measuring apparatus, it is possible to miniaturize the measuring apparatus considerably, without having to accept losses in the measurement accuracy, or quality, even in the analysis of aqueous multi-component systems. Here also the very distinctive water bands in the infrared shows no deterioration. For example, with the inventive devices wavelength specific signals detectable and distinguishable, which differ in their intensities by a multiple or even to one or more orders of magnitude, for example, a factor of 1000. Consequently, as can be multicomponent systems analyze causing a strong noise with these devices. Moreover, with these devices manage a very high light throughput.

For detection of a substance measuring radiation of a specific wavelength in each case already enough. Regardless of how many substances are analyzed, it is always sufficient to use only one Referenzmeßstrahl for an exact qualitative and quantitative determination. Thus, if for example n substances with n measuring beams, each differing in their wavelength analyzed, a single Referenzmeßstrahl enough to complete the measurement, so that a total of only n + 1 shall be used beams.

Finally, with the inventive devices already on the basis of rvellenlängenspezifischen Intensitätsinforroationen all information necessary for a full analysis available, there being no need in the present case the evaluation of the measuring radiation Polarisationseigenschafterz.

Further embodiments of the invention are described with reference to the following figures in detail, without the invention to these particular embodiments to be limited. Show it<dl id="dl0001"><dt>figure 1</dt><dd>an infrared measuring device according to the invention with flow cell in a schematic representation;</dd><dt>figure 2</dt><dd>a measuring unit according to the invention in a schematic representation in longitudinal section;</dd><dt>figure 3</dt><dd>an infrared measuring device according to the invention with flow cell in a schematic representation; and</dd><dt>figure 4</dt><dd>a longitudinal section durcch a coated ATR body.</dd></dl>

As Figure 1 reveals, a Infrarotmeßvozzichtung invention may be provided in one embodiment with a flow cell. 1 A longitudinal wall 5a of the flow cell 1 is formed from an ATR body 2 having a trapezoidal cross-section. The flat boundary surface 5a is opposite to a rear side of the ATR body delimiting parallel wall surface 5b. The flow cell 1 is equipped with a cylindrical channel 3, which is present in a straight line through the flow cell first A beam of light is introduced via the quantum cascade laser 4 over the narrow side of the ATR body 2 and is incident on the flat bounding surface 5a, to which is adjacent the medium under investigation. After several, preferably at least six or seven times, attenuated total reflection along the measurement path of the emitted light beam is registered by a detector 6 and passed the signal to an evaluation unit. 7 Not shown in the radiation source or the detector is in each case a mirror optics, with the aid of for example the beam guide is optimized and controlled. However, suitable mirror optics are well known to those skilled, in particular in connection with infrared spectrometers. The flow of the sample medium is supported by a pump 8, which may be a peristaltic pump or piezo example. can via a control valve 9 optionally either the material to be analyzed or a rinsing or reference solution, which can also come from a separate container 10, are passed through the flow cell. If the test sample is to be measured quantitatively, it is recommended that a fan (not shown) provided to blow dry especially the ATR body before each new measurement.

In a particular embodiment may be in the flow cell 1 to one that substituted, ie by another flow cell, for example, replaced with a different ATR body, can be. Interchangeable flow cells are in particular always used when you want to ensure that sterile conditions are maintained and / or the measurement result to be falsified in no case by possibly adhere to the surface of the ATR body remaining residues of previously measured sample, for example in dialysis. The replaced flow cells can be either disposed of or recycled.

Further, 17 can be provided according to a preferred embodiment of an optical multiplexer for wavelength-specific the radiation sequence bzw- the radiation pattern and / or the intensity of the measurement radiation of the Quantenkaskandenlasers 4 controls and is in operative connection with this and on the other hand also wavelength-specific detector 6 and / or the evaluation unit 7, for example, the simultaneous and / or sequential detection of the measuring radiation, regulates.

Figure 2 is shown a measuring unit 11, in a coated, two-part ATR body 12 from embedded substantially zinc selenide in a holder. 13 The ATR-base body 12 of zinc selenide is provided with a layer or a separate ATR body, in particular in plate form, 14 of diamond whose one flat boundary surface 5a with the medium to be analyzed comes in contact and whose parallel thereto boundary surface 5b in the interior of ATR body an evacuated or filled with air or gas cavity 15 defines. The ATR-base body 12 has a plurality of planar boundary surfaces at which the incident infrared ray is reflected. The holder 11 may have a channel or a channel system 16 for thermostatting the measuring cell. The infrared beam, in turn, increases its output, the light source 4 ', for example in the form of a quantum cascade laser, and is on the detector unit 6' registered. That and the detected signals are analyzed and processed in the evaluation unit 7 '. In order to make with the measurement unit shown sufficiently accurate infrared spectrometric examinations, it is sufficient if the side length or the diameter of the medium facing limiting surface, that the measuring section of the diamond layer is in the range of about 4 to 5 mm. Sample volumes &lt;100 ul, and even those in the range of 5 to 50 .mu.l, so z. B. 10 uL, can readily be examined with the illustrated measuring cell for the presence of one or more substances. Several substances can be determined simultaneously side by side. Of course, also a multiplexer be provided 17 of Figure 1 (not shown).

The infrared measuring device according to the invention allows for the first time a simple reliable and inexpensive access for the analysis and characterization of particular polar substances, for example those having hydroxyl functions, even in aqueous systems with high accuracy advantage, furthermore, that even the smallest sample quantities can be detected continuously in particular. As advantageously has also proved that the infrared measuring device according to the invention, in particular the unit used and the combination of measuring unit and quantum cascade lasers, possibly also including a detector or optical multiplexer, is extremely insensitive to vibration and furthermore allows a miniaturized design.

As the figure is given in 3, corresponds to the embodiment of the invention an infrared measuring device that a measuring radiation with a continuous spectrum uses, essentially the structure shown in FIG. 1. In this case, a light beam on the IR light source 4a, also containing an interferometer, with the aid of which interference-modulated light can be generated, inserted over the narrow side of the ATR body 2 and is incident on the flat bounding surface 5a, to which is adjacent the examined medium. After several, especially at least six or seven times, attenuated total reflection of the outgoing light beam is registered by a detector 6 and the signal passed to an evaluation unit 7, with the aid of the Fourier transform is performed.

In a particular embodiment may be in the flow cell 1 to one that substituted, ie by another flow cell, for example, replaced with a different ATR body, can be.

According to FIG 4, a measuring unit 1.11 one ATR body 12, in particular of trapezoidal cross-section, include that is, provided on that plane boundary surface 5a which is exposed to the sample medium with a coating 14, in particular a diamond layer. a space 13 for receiving sample liquid connects to the coating, which can also be designed as a tube or conduit, with which the measuring unit 11 may also be a flow cell. Figure 4 is also possible to infer a detail in the area of ​​the coated boundary surface in an enlarged view.

The features disclosed in the foregoing description, in the claims and in the drawings features of the invention can be essential to implementing the invention in its various embodiments both individually and in any combination.

LIST OF REFERENCE NUMBERS

<dl id="dl0002" compact="compact"><dt>1</dt><dd>Measuring cell, flow cell</dd><dt>2</dt><dd>ATR body</dd><dt>3</dt><dd>cylindrical channel</dd><dt>4, 4 '</dt><dd>Quantum Cascade Lasers</dd><dt>4a</dt><dd>IR light source, comprising an interferometer</dd><dt>5a</dt><dd>parallel flat delimiting surface of the ATR body 2</dd><dt>5b</dt><dd>planar boundary surface of the ATR body 2</dd><dt>6, 6 '</dt><dd>detector</dd><dt>7, 7 '</dt><dd>evaluation</dd><dt>8th</dt><dd>pump</dd><dt>9</dt><dd>control valve</dd><dt>10</dt><dd>Separate container for rinsing and / or reference solution</dd><dt>11</dt><dd>measuring unit</dd><dt>12</dt><dd>coated ATR body</dd><dt>13</dt><dd>holder</dd><dt>14</dt><dd>Coating, diamond coating</dd><dt>15</dt><dd>Cavity in the ATR body 12</dd><dt>16</dt><dd>Channel system for thermostating the measuring unit 11</dd><dt>17</dt><dd>Optical multiplexer</dd></dl>