WO1998022816A1

WO1998022816A1 - Apparatus for the analysis of liquid and gaseous media

Info

Publication number: WO1998022816A1
Application number: PCT/GB1997/003207
Authority: WO
Inventors: Sean Keeping; Dieter Binz; Albrecht Vogel
Original assignee: Abb Instrumentation Limited
Priority date: 1996-11-22
Filing date: 1997-11-21
Publication date: 1998-05-28
Also published as: AU5229798A; DE19648441A1; AU744898B2

Abstract

The invention relates to a device for examining liquid or gaseous media (100), having at least one measuring cell (5) to which the medium (100) to be examined and liquids for the analysis can be fed via feed flow lines (10, 11, 12, 13, 14, 15, 16) and pumps (30, 31, 32, 33, 34, 35, 36). In order to achieve simple storage of the liquids required for the analysis, and also to be able to dimension the device (1) to be as small as possible, measuring units (4) are provided, to which the measuring cells (5), the feed lines (10, 11, 12, 13, 14, 15, 16) and the pumps (30, 31, 32, 33, 34, 35, 36) are assigned. The measuring units (5) are integrated into a flat component (2). The latter is detachable, arranged on or in a container (3). Supply bags and/or storage containers (310) for the liquids necessary for the analysis are installed in this container (3).

Description

APPARATUS FOR THE ANALYSIS OF LIQUID AND GASEOUS MEDIA

The invention relates to apparatus for the analysis of liquid and gaseous media, in particular environmentally sensitive media such as, treated and untreated sewage and river water. The invention particularly relates to such apparatus which is designed to measure a plurality of parameters, such as for example measuring a number of different features of the chemical composition.

Thus for example, in the field of environental waste control, it is usual to monitor water sources for the presence of nitrate, ammonia and phosphates and to monitor the biological oxygen demand.

Devices are already known for determining the biological oxygen demand, in which the oxygen consumption of the water sample is measured. These methods may be subdivided into laboratory methods and on-line measuring methods. The laboratory methods are standardized and described in DIN 38409 Part 51 . A typical procedure is a so-called dilution method with which the content of biological degradable substances in the water sample is determined. In the laboratory this test can take five days to complete.

Another technique is based upon use of a fermentation calorimeter, which measures the heat production of metabolic processes. In this method, the heat product of the fermentation material is compensated for by appropriate cooling. The cooling rate determined is proportional to the metabolic heat produced and hence is also proportional to the metabolic activity of the biomass. However, the cost outlay on apparatus is high, and corresponding devices are too expensive for use as a process measuring device.

Also known are enzyme thermistors which measure the heat which is produced when an immobilized layer of enzymes reacts with an organic substance. This is measured, for example, by means of two absolute temperature sensors that are located in the feed or discharge lines of the reaction vessel having the immobilized enzymes. In so-called "flow systems" using this method, the sample under test flows through an enzyme column and, the temperature is measured determined at the end of the column. An uncoated column is used as reference. The difference between the signals from the two temperature sensors is a measure of the reaction heat.

Known devices of this type need to operate for a very long time without having to be maintained. However, the need for storage of the bacteria and enzymes which are needed for the analysis causes problems, as these only have a limited lifetime, they have to be renewed frequently. In the cases of known devices, this is not so simple since the biocomponents need to be located in reaction chambers, and these are not easily accessible.

In the case of apparatus for carrying out analyses on bodies of water, such as the treatment tanks, holding tanks and discharge channels of a waste water treatment plant, known apparatus is bulky and is installed adjacent the body of water to be analysed. Apparatus is also known in which the analysis apparatus is designed as a buoy which floats in the body of water. See e.g. WO94/25875 andWO94/25876. Such buoys require the necessary reagents to be stored within the buoy and the buoy is provided with means for taking on board samples of water to be analysed, performing the required analyses and transmitting data relating to the analysis results.

In known apparatus, especially of the type designed to float on the body of water to be analysed, problems have been encountered in devising a design which is economical to produce, is robust with a relatively low number of moving parts, can be maintained easily with long intervals between maintenance times and in which replaceable components and stores of reagents can be readily interchanged.

The present invention has as one of its objects to provide apparatus for the analysis of liquid and gaseous media which ovecomes the above problems and in addition allows simple storage of the reagents necessary for the analysis. In addition apparatus can be designed in accordance with the invention which is compact, i.e. with the entire apparatus and its components having very small dimensions.

According to one aspect of the invention, there is provided apparatus for analysing liquid or gaseous media, said apparatus having at least one component for performing one or more unit operations selected from fluid transport, reagent addition, reaction between reagent and analyte, detection of reaction product and fluid discharge, characterised in that at least one of said components, in particular one which consists of a pump or measuring device, is at least partly integrated within a flat component. Preferably, at least one pump or measuring device is at least partly integrated within the flat component, and in such a case, preferably one or both of the pump and the measuring device are themselves designed as flat components. Apparatus may be constructed according to the invention which includes at least one measuring cell to which medium to be analysed and reagents carrying out the analysis can be fed via feed lines, characterised in that said measuring cell is at least partly integrated within a flat component.

Conveniently one or more measuring cells and pumps are arranged in recesses in the surface of the flat component.

The invention further provides apparatus for analysing liquid or gaseous media, said apparatus having at least one component for performing a unit operations selected from fluid transport, reagent addition, reaction between reagent and analyte, detection of reaction product and fluid discharge, characterised in that at least one of said components consists of a measuring cell which is at least partly integrated within a flat component.

In accordance with the invention, there is further provided apparatus for analysing liquid or gaseous media, said apparatus having at least one component for performing one or more unit operations selected from fluid transport, reagent addition, reaction between reagent and analyte, detection of reaction product and fluid discharge, characterised in that at least one of said components consists of a pump which is at least partly integrated within the flat component. Also optionally provided are component or components for fluid transport which comprise flow channels formed integrally within said flat component.

The term "flat component" as used herein, refers to a component which may be generally plate like, i.e. it is bounded by one or preferably two generally planar surfaces. The transverse dimension of such a component would generally be substantially greater than its thickness, i.e. the ratio of transverse dimensionrthickness would normally be in the range 500: 1 -10: 1 , preferably 200: 1 -1 0: 1 , more preferably 1 00: 1 -10: 1 and most preferably 50: 1 -1 0: 1 .

In terms of absolute dimensions, the maximum transverse of the flat component would normally be in the range 5-50 cm and typically in the range 5-30 cm. The thickness would primarily depend upon the material from which the flat component was manufactured and would normally be less than 1 0 cm in thickness, preferably less than 5 cm in thickness and most preferably less than 2 cm in thickness. The minimum thickness of the flat component would generally be dictated by the rigidity of the material from which the component was constructed and the requirement for one or more functional components to be at least partly integrated therein. Normally the flat component would be greater than 0.2 cm in thickness and preferably greater than 0.5 cm in thickness.

Conveniently, the flat component is formed from a sheet, slab or wafer of a material which has sufficient rigidity to be self-supporting. The material should be chosen to allow the various functional element of the apparatus according to the invention to be at least partly integrated with the flat component. Thus the functional elements (which include flow components such as bores, measuring cells, reaction chambers and pumps) may be integrated within the flat component itself. Certain of the aforementioned functional elements may be accommodated within flow channels or recesses formed in one or both of the planar surfaces of the flat component, or such channels or recesses may form one or more boundaries or side walls of the functional elements themselves.

In addition to channels and recesses formed in the planar surfaces of the flat component, the flat component may be provided with bores extending through its full thickness. Such bores would, in use, be connected to flow lines connected to other elements of the apparatus according to the invention. Conveniently such bores may be terminated with suitable connection devices, for example hollow needles arranged to pierce and enter into fluid communication with sealable elements of other parts of the apparatus. Thus, for example, such sealable elements may consist of diaphrams or septums of other parts of the apparatus adapted to matingly engage with the flat component.

As indicated, the overall size and shape of the flat component will normally be dictated by the size and shape of the remaining parts of the appartus with which it is designed to interact. Thus to fit within a cylindrical casing, the flat component may, for example, be circular in cross-section.

The apparatus of the invention may further be defined in terms of a device for analysing samples of liquid which are taken continuously or intermittently from a body of liquid in which the device is at least partially immersed, the device comprising a casing and conduit means for transferring samples of liquid to the interior of the casing where a plurality of analysis operations are carried out at separate analysis stations, each of which includes a set of devices for performing unit operations selected from fluid transport, reagent addition, reaction between reagent and analyte, detection of reaction product and fluid discharge, characterised in that a plurality of said reaction stations are provided at respective spaced locations on a carrier element having at least one substantially planar surface, and a plurality of said devices for performing unit operations selected from fluid transport, reagent addition, reaction between reagent and analyte, detection of reaction product and fluid discharge are integrated into said carrier element and/or positioned in recesses in said carrier element, whereby a removable cartridge assembly charged with reagents may be matingly engaged with said substantially planar surface of the carrier element so as enable reagents to be transferred to conduits leading to said devices.

In a preferred construction, the flat component is in the form of a wafer, and flow conduits for transporting fluid to one or more of said component for performing a unit operations selected from fluid transport, reagent addition, reaction between reagent and analyte, detection of reaction product and fluid discharge are provided in the form of channels in said wafer. The apparatus may be arranged so that a plurality of analysis operations may be performed at separate analysis stations, each of which includes a set of devices for performing unit operations selected from fluid transport, reagent addition, reaction between reagent and analyte, detection of reaction product and fluid discharge. Thus a plurality of said reaction stations may be provided at respective spaced locations on a carrier element having at least one substantially planar surface, and a plurality of said devices for performing unit operations selected from fluid transport, reagent addition, reaction between reagent and analyte, detection of reaction product and fluid discharge are integrated into said carrier element and/or positioned in recesses in said carrier element.

Desirably, a removable cartridge assembly charged with reagents is arranged to be matingly engaged with said substantially planar surface of the carrier element so as enable reagents to be transferred to conduits leading to said devices.

The flat component is preferably produced from a material which is mechanically stable, corrosion-resistant and reaction-free in relation to the medium to be analysed and to the analysis reagents. Examples include silcon, corrosion- resistant metals such as stainless steel and plastics material. Silicon is preferred, because it allows fabrication of the flat component from a silicon wafer using production techniques developed in the semiconductor industry. The apparatus according to the invention preferably includes at least one measuring cell and at least two pumps combined in a single measuring unit or module. Further, the flat component or module preferably has at least one, and most preferably a plurality of measuring units or modules entirely integrated into the surface thereof.

The or each measuring unit or module is connected to a feed line for the medium to be analysed and the or each measuring unit or module can be fed reagents via respective feed lines. A chamber may be provided to accommodate a filter which is integrated into each feed line, preferably directly downstream of the inlet end. Each feed line may then be connected to a main line that is connected to the measuring cell of the measuring unit. A pump and a flow sensor may be connected downstream of the pump, integrated into each feed line, downstream of the chamber. Further, each feed line and each main line of each measuring unit may be formed by a U-shaped recess in the surface of the component, and a cover plate is arranged on the surface of the flat component by means of which the entire surface is tightly sealed to the outside.

Each measuring unit or module may be equipped with one or more piezoelectric pumps, and flow sensors and the electric contacts of the pumps may be installed on the surface of a cover plate. Each pump and each flow sensor are preferably arranged to be connected individually to and disconnected individually from an associated measuring unit.

Measuring cells may be assigned to respective measuring devices which are operated optically, chemically or electrochemically, to monitor the reactions in the measuring cell. Thus, for example, each measuring cell and the associated measuring device may be arranged directly adjacent to each other in a common recess in the flat component. When an optical measuring device is used, this recess may be provided with reflecting side walls and the cover plate may be of transparent design. Then each optical measuring device may be divided into a light emitting module and a light-receiving module, the first module being installed at the first end and the second unit at the second end of a measuring cell.

Various methods of feeding fluids to the flat component may be adopted, but preferably at least one feed line is provided, one end of which is connected to a bore that passes through the flat component. The bore may then be connected to a line in the form of a hollow needle.

The apparatus according to the invention may be constructed with the flat component adapted to be attached to a component in the form of a container for holding one or more of the following: supply bags and/ar storage containers for reagents, a water treatment system, at least one storage container for a biocomponent, and a reaction chamber having two oxygen sensors, as well as at least one cooling device for the reagents and a heating element for the biocomponent. The container may be partly of double-wall design. The storage containers for the reagents, water treatment system, storage container for a biocomponent, and reaction chamber having two oxygen sensors, as well as at least one cooling device for the reagents and a heating element for the biocomponent, may then be arranged between the lateral outer and inner wall of the container.

A hollow needle may be inserted into each supply bag and/or storage container, through which the medium to be examined can be fed from outside, via a feed line, into the container, and a distributor, may be connected to each bore on the underside of the component, plugged onto the end of the feed line.

Flow lines are preferably provided so that the contents of a measuring cell can be fed to a respective reaction chamber, the contents of which can then be led out of the container via a flow line, and the contents of the other measuring cells can be led into the interior of the container via another respective line. The apparatus may also have connected to each storage container, a flow line onto which one flow line of the flat component can be plugged The medium to be examined can then be led from outside, via a feed line, into the container, the feed line being connected to a distributor chamber that is provided with flow lines to which the flow lines of the flat component are attached. Similarly, the apparatus may be arranged so that the contents of a measuring cell can be fed to a reaction chamber, and in the contents of the measuring cells and of the reaction chamber can be led out of the container via flow lines.

The invention will be explained in more detail below using schematic drawings, in which:

Fig. 1 shows one embodiment of apparatus for analyzing liquids in accordance with the invention.

Fig. 2 shows a top view of the flat component of the apparatus of Fig. 1 , Fig. 3 shows a portion of the flat component illustrated in Fig. 2, Fig. 4 shows a variant of the apparatus illustrated in Fig. 1 .

The apparatus 1 illustrated in Fig. 1 is essentially formed by a flat component 2 and a container 3 which is open at its upper end. In the case of the exemplary embodiment illustrated here, four measuring units or modules 4 are integrated into the flat component 2. These measuring units are illustrated only schematically. The flat component 2 is shown in more detail in Fig. 2. Fig. 3 shows a detail of the flat component 2, in which only one of these measuring units 4 illustrated.

Each measuring unit or module 4 is designed in such a way that each of its components can be connected and disconnected as required. For this reason, it is possible to use measuring units or modules 4 of identical construction, so that each measuring unit or module 4 has the same number of pumps and flow sensors. In the case of the exemplary embodiment illustrated here, four measuring units or modules 4 of identical construction are used. They are therefore provided with the same reference symbols. Each measuring unit or module 4 is equipped with a measuring cell 5, to which a maximum of six liquids to be used for the analysis i.e. reagents (not illustrated) and the liquid to be analyzed can be fed. If fewer reagents are required for the analysis, then correspondingly fewer pumps and flow sensors need to be activated by the microprocessor (the function of which will be described below). If required, it is also possible for a greater or less number of measuring units or modules 4 to be used. The number is not restricted to four.

All the measuring units or modules 4 are integrated (e.g. embedded) into the surface 2S of the flat component. For this purpose, the surface 2S is provided with recesses (not illustrated) whose dimensions are selected such that all the components of the measuring units 4 have adequate space to be accommodated therein. These recesses may be formed using known etching or milling methods. These methods are not described in more detail here, since they are well known in the art.

According to the invention, flat component 2 may be produced from a material in the form of a metalloid, a metal, a metal alloy or a plastic. Care should be taken during the selection of the material that this has a very good mechanical stability and does not react with the reagents used for the analysis. In the case of the exemplary embodiment illustrated here, the flat component 2 is of disc shaped design and has a diameter of 10 cm. Its thickness depends on the depth of the recesses which have to be constructed for the measuring units 4. In the embodiment shown, it is about 0.8 cm. Since all the components of the measuring units 4 are arranged in recesses, it is possible for a cover plate 2D to be placed onto the surface 2S, as is illustrated in Fig. 2. This plate rests on a flat surface, so that the flat component 2 is sealed tightly at its upper surface. The size of the cover plate 2D is selected so that it covers the surface 2S completely, i.e. as far as the rim of the component 2. The cover plate 2D may be permanently connected to the flat component 2. The cover plate 2D may be produced from an electrically nonconducting material. When optically operating measuring devices are used, a transparent cover plate 2D may be used.

Each measuring unit or module 4 has a measuring cell 5 to which the gaseous or liquid medium 100 to be examined can be fed. The measuring cell 5 has a capacity of about IpL. If required, it can also be designed to be larger or smaller. Each measuring cell 4 is provided with a feed line 1 0, whose first end opens into a bore 10B in the flat component 2, via which bore the medium 100 to be examined can be fed. The feed line 10 is formed by a U-shaped recess (not illustrated) which, just like the abovementioned recesses for the components of the measuring unit 4, is etched or milled into the surface 2S. The bore 10B extends as far as the underside 2U of the component 2.

The bores 10B of all the measuring units 4 are connected at the underside 2U of the component 2 to a common distributor 3K. As Fig. 3 shows, a chamber 20, in which for example a filter (not illustrated) can be arranged, is firstly integrated into each feed line 10, directly downstream of the bore 10B. In addition, a pump 30 and a flow sensor 40 are incorporated into each feed line 10, downstream of the chamber 20. The second end of each feed line 1 0 is connected to a main line 50, which opens into the measuring cell 5. In the case of the exemplary embodiment illustrated here, the measuring cell 5 can be fed with six liquid reagents (not illustrated) necessary for the analysis, in addition to the medium 100 to be examined. For this purpose, six further feed lines 1 1 , 1 2, 1 3, 14, 1 5, 1 6 are provided. The first end of each of these feed lines 1 1 , 1 2, 1 3, 14, 1 5, 1 6 opens in each case into a bore MB, 1 2B, 1 3B, 1 4B, 1 5B, 1 6B. These are all designed like the bore IOB. By appropriate modification of the connections to each measuring cell 5 (not illustrated), further liquids for the analysis (i.e. reagents) can also be provided. At the underside 2U, all the bores 1 1 B, 1 2B, 1 3B, 1 4B, 1 5B, 1 6B are connected to lines 60, which in the case of the exemplary embodiment illustrated here are designed as hollow needles. Each feed line 1 1 , 1 2, 1 3, 1 4, 1 5, 1 6 opens on the upper side 2S directly downstream of the bore 1 1 B, 1 2B, 1 3B, 14B, 1 5B, 1 6B, firstly into a chamber 21 , 22, 23, 24, 25, 26, which contains a filter (not illustrated).

Furthermore, in this case a pump 30, 31 , 32, 33, 34, 35, 36 and a flow sensor 40, 41 , 42, 43, 44, 45, 46 are also integrated into each feed line 1 1 , 1 2, 1 3, 1 4, 1 5, 1 6. All the feed lines 1 1 , 1 2, 1 3, 14, 1 5, 1 6 open into the main line 50. With the aid of the pumps 30, 31 , 32, 33, 34, 35, 36, the medium 100 to be examined, the reagents and/or liquids which are required for the analysis, can be sucked up via the feed lines 1 0, 1 1 , 1 2, 1 3, 14, 1 5, 1 6 and transported to the measuring cells 5. Flow sensors 40, 41 , 42, 43, 44, 45, 46, ensure that the desired amounts of liquid reagents reach the respective measuring cell 5.

The pumps 30, 31 , 32, 33, 34, 35, 36 and the flow sensors 40, 41 , 42, 43, 44, 45, 46 are connected via signal lines (not illustrated) to a microprocessor (not illustrated), which controls the pumps 30, 31 , 32, 33, 34, 35, 36 and the flow sensors 40, 41 , 42, 43, 44, 45, 46. Also stored in this microprocessor is a program through which the analyses are controlled. In the case of the measuring unit 4 illustrated in Fig. 3, each measuring cell 5 is assigned a measuring device 5M, operating optically, chemically or eiectrochemically. Using the measuring devices 5M, the reactions progressing in the measuring cells 5 can be registered. The optically operating measuring devices 5M comprises two modules 50M and 51 M. As Fig. 3 shows, in each case one module 50M, 51 M is installed at the first and at the second end of the measuring cell 5 in such a way that light from one module 50M in each case can be radiated into the measuring cell 5. The light which passes through the measuring cell 5 is registered by the second module 51 M for the evaluation. The flat component 2 is designed in such a way that one measuring cell 5 and the associated measuring device 5M can be arranged lying directly alongside each other in a common recess (not illustrated) .

Recesses which are provided to accommodate a measuring cell 5 having an optically operating measuring device 5M have reflecting side walls (not illustrated) . The measured signals produced by each measuring device 5 are forwarded via a signal line (not illustrated) to the microprocessor (not illustrated) to be stored and evaluated. The electric supply to the pumps 30, 31 , 32, 33, 34, 35, 36, flow sensors 40, 41 , 42, 43, 44, 45, 46 and the measuring devices SM is carried out via flat lines (not illustrated), which are either laid within the flat component 2 or, to the extent necessary, led over the cover plate 2D. According to the invention, the measuring units 4 can be equipped with piezoelectric pumps 30, 31 , 32, 33, 34, 35, 36 (not illustrated) . The electric contacts which are necessary for this are in this case installed on the surface of the cover plate 2D.

In operation of the apparatus 1 according to the invention, the flat component 2 is placed onto the open end 3A of the container 3. In the case of the exemplary embodiment illustrated here, the latter is of cylindrical design, since the flat component 2 has a circular cross-section. The outer diameters of the two components 2 and 3 are matched to each other. According to the invention, the two components 2 and 3 may also be provided with different cross-sections. Arranged within the container 3 are supply bags 3V and/or storage containers for the reagents (not illustrated) . With the aid of cooling devices 3F, which are arranged alongside the supply bags 3V, the reagents are kept at a predefined temperature. The capacity of the supply bags 3V is dimensioned so as to contain sufficient reagent suffice for about 10,000 measurements. When the reagents are used up, the flat component 2 may be removed from the container 3 and placed onto a new container 3 having filled supply bags 3V. The exchanging of the container 3 is possible in a simple way, since all the connections between the component 2 and the container 3 are merely plugged into one another. This form of connection is enabled by the fact that all the connections of the bores 1 1 B, 12B, 1 3B, 14B, 1 5B, 1 6B on the underside of the component 2 are designed as pluggable hollow needles 60, and the bores 10B are connected to a common pluggable distributor 3K. During the connection of the two components 2 and 3, a hollow needle 60 is in each case stuck into a supply bag 3V. Each supply bag 3V is closed on the side facing a hollow needle 60 by an elastic covering (not illustrated) . This covering can be pierced by any hollow needle 60. The hollow needles 60 are enclosed in a leakproof manner by the coverings. During the connection of the two components 2 and 3, the distributor 3K is plugged onto the end of a feed fine 3Z, which is led from below in a leakproof manner into the container 3. Via this feed line 3Z, the medium 100 to be examined is introduced into the container 3. Via the distributor 3K, the medium 100 to be examined is distributed uniformly to the lines 1 0 of the measuring units 4, and is fed from there to the measuring cells 5 with the aid of the pumps 30. The outflow 5F of each measuring cell 5 opens into a bore 58 which, at the underside 2U of the component 2, is connected to a line 90. Three of these flow Iines90 open into the interior of the container 3. With the aid of the liquid 101 which collects in the container 3, pressure is exerted on the supply bags 3V, so that the latter empty more easily. Should the liquid 101 , which flows out of the flow Iines90 into the container 3, not be sufficient, then additional liquid can be introduced into the container 3 via the feed line 3Z (not illustrated) . The emptying of the supply bags 3V can also be aided using a gas (not illustrated) which, for this purpose, is introduced into the container 3. However, this measure in only possible if the container 3 is closed in a gastight manner by the component 2.

According to the invention, one of the four flow lines 90 may be plugged onto the connecting line 91 L of a reaction chamber 91 , which is likewise arranged within the container 3. This reaction chamber 91 is provided in order to determine the biological oxygen demand.

According to the invention, the said chamber 91 may contain a biocomponent in the form of microorganisms or enzymes. Supply bags 92, which are arranged directly alongside the reaction chamber 91 , contain buffer solution and/or calibration solution. These can be introduced into the reaction chamber 91 (not illustrated) . Pure water, to dilute a liquid to be examined, can likewise be introduced into the reaction chamber 91 . The pure water is produced by a water treatment system which is explained in more detail below.

With the aid of a heating element 3H, which is installed alongside the supply bag 92, the biocomponent can be kept at a defined temperature. The reaction chamber 91 has an oxygen sensor 93 connected upstream and an oxygen sensor 94 connected downstream. Also installed in the container 3 is a water treatment system 3W. If the analysis of waste water 1 00 is carried out using the device according to the invention, then pure water can be produced with the apparatus. The pure water is then mixed with the waste water 1 00 to be examined before it is introduced into the measuring cells 5, in order to lower the concentration of the pollutants contained in the waste water to a value which is suitable for the measurement (not illustrated) . Using the apparatus 1 according to the invention, it is possible, for example, to check waste water 100 from a sewerage treatment plant (not illustrated) for its content of ammonium, nitrate and phosphate. At the same time, the biological oxygen demand of the waste water 1 00 can be determined. For this purpose, the waste water 1 00 is fed to the four measuring cells 5

Three of the measuring units or modules 4 are provided for the detection of phosphate, nitrate and ammonium. In each measuring unit 4, the detection of in each case one of the three chemical compositions in the form of phosphate, nitrate or ammonium is carried out. The liquid 1 00 to be examined, in this case the waste water, is therefore precisely mixed on the way into a measuring cell with reagents for the detection of phosphate, nitrate or ammonium (not illustrated) .

With the aid of the measuring device 5M, it is established whether a reaction has taken place in the associated measuring cell 5. If this is the case, a measuring signal is output by the measuring device 5M to a microprocessor (not illustrated). In order to determine the biological oxygen demand, the waste water 100 is led into the measuring cell 5 without the addition of a reagent. For this, the line 90, which is connected to the bore 5B of this measuring cell 5, is plugged into the feed fine 91 L of the reaction chamber 91 during the connection of the two components 2 and 3. The waste water 100 then flows from the measuring cell 5 past the oxygen sensor 93, which measures the oxygen content of the waste water 100 and sends its measuring signal to the microprocessor. In the reaction chamber 91 , the biologically degradable substances contained in the waste water 100 are converted into heat and biomass, for example by bacteria which are filled from the storage container 92 into the reaction chamber 91 or are already contained therein. During this procedure, oxygen is consumed. The oxygen proportion in the waste water 1 00, which is led out of the reaction chamber 91 to the outside via the line 95, is determined with the oxygen sensor 94. In the microprocessor (not illustrated), the amount of biologically degradable substances in the waster water 100 is determined from the measured signals from the two oxygen sensors 93 and 94. If ammonium, nitrate or phosphate are contained in the waste water 100, then an appropriate signal from the microprocessor is passed to an indicating device (not illustrated) .

As Fig. 4 shows, the flat component 2 can also be arranged in the interior of a container 3 open on one side. In the case of the exemplary embodiment illustrated here, the container 3 has a diameter of 1 6 cm. Its height is 1 2 cm. The distance between the lateral outer wall 3A and the lateral inner wall 38 is selected to be sufficiently large that storage containers 3V for reagents can be arranged in the space 3R remaining in between. Furthermore, cooling devices 3F for the reagents are provided. Connected to each storage container 3V is a line 70. The flow lines 70 are led at the bottom of the cylindrical component 3 as far as the underside the component 2, specifically such that the flow lines 60 that are connected at the underside 2U of the component 2 to bores 1 1 B, 12B, 13B, 14B, 1 5B, 1 6B can be plugged onto the flow lines 70 when the component 2 is inserted into the cylindrical component 3. Before the insertion of the component 2, the flow lines 70 are closed at their ends by a film or a diaphragm (not illustrated), so that no reagents flow out of the storage containers 3V before the connection to the flow Iines60 has been produced. The capacity of the storage containers 3V is dimensioned such that the reagents suffice for about 10,000 measurements. When the reagents are used up, the flat component 2 is removed from the cylindrical component 3, and inserted into a new component 3, whose storage containers 3V are filled. The exchanging of the component 3 is possible in a simple way, since all the connections between the component 2 and the component 3 are only plugged in.

As Fig. 1 shows, a feed line 3Z is led from below into the component 3. Via the feed line 3Z, the medium 100 to be examined is introduced into a distributor chamber 3K that is arranged underneath the component 2. Instead of using the feed line 3Z, the medium 100 can also be sucked up directly into the distributor chamber 3K via a diaphragm (not illustrated) . The distributor chamber 3K has connections 80 onto which the flow linesl OL arranged on the underside 2U of the component 2 can be plugged. From the distributor chamber 3K, the medium 100 can be fed to the measuring cells 5 with the aid of the pumps 30. The outflow 5F of each measuring cell 5 is connected to a bore 52, which is connected on the underside 2U of the component 2 to a line 90 which is led out of the cylindrical component 3. According to the invention, at least one line 90 can be connected to a reaction chamber 91 that is arranged in the space 3R. This reaction chamber 91 is provided in order to determine the biological oxygen demand.

Biocomponents, for example in the form of bacteria, can be fed to this reaction chamber 91 from a storage container 92. The reaction chamber 91 has an oxygen sensor 93 connected upstream and an oxygen sensor 94 connected downstream. Furthermore, the cylindrical component 3 has, also in the case of this exemplary embodiment, a water treatment system 3W. Using this apparatus 1 , the same measurements can be carried out and also evaluated as in the case of the apparatus 1 illustrated in Figs. 1 -3 and explained in the associated description.

Claims

1 . Apparatus for analysing liquid or gaseous media, said apparatus having at least one component for performing a unit operation selected from fluid transport, reagent addition, reaction between reagent and analyte, detection of reaction product and fluid discharge, characterised in that at least one of said components consists of a pump or measuring device which is at least partly integrated within the flat component.

2. Apparatus according to Claim 1 characterised in that at least one of said components consists of a pump which is at least partly integrated within the flat component.

3. Apparatus according to Claim 2 in which the pump is itself designed as a flat component.

4. Apparatus according to any preceding claim characterised in that at least one of said components consists of a measuring cell which is at least partly integrated within the flat component.

5. Apparatus according to Claim 5 in which the measuring cell is itself designed as a flat component.

6. A device according to any preceding claim wherein said device includes at least one measuring cell to which medium to be analysed and reagents carrying out the analysis can be fed via feed lines, characterised in that said measuring cell is at least partly integrated within a flat component.

7. Apparatus according to any preceding claim, characterized in that at least one measuring cell and at least one pump are arranged in recesses in the surface of the flat component.

8. Apparatus for analysing liquid or gaseous media, said apparatus having at least one component for performing a unit operation selected from fluid transport, reagent addition, reaction between reagent and analyte, detection of reaction product and fluid discharge, characterised in that at least one of said components consists of a measuring cell which is at least partly integrated within the flat component.

9. Apparatus according to Claim 8 in which the measuring cell consists of a flat component

10. Apparatus for analysing liquid or gaseous media, said apparatus having at least one component for performing a unit operation selected from fluid transport, reagent addition, reaction between reagent and analyte, detection of reaction product and fluid discharge, characterised in that at least one of said components consists of a pump which is at least partly integrated within the flat component.

1 1 . Apparatus according to any preceding claim wherein said component or components for fluid transport comprise flow channels formed integrally within said flat component.

1 2. Apparatus according to any preceding claim wherein the flat component is produced from a material which is mechanically stable, corrosion-resistant and reaction-free in relation to the medium to be analysed and to the analysis reagents

1 3. Apparatus according to any preceding claim characterized in that at least one measuring cell and at least two pumps are combined in a single measuring unit or module

14. Apparatus according to Claim 1 3 characterised in that the flat component has at least one measuring unit or module entirely integrated into the surface thereof.

1 5. Apparatus according to Claim 1 4 characterised in that the flat component has a plurality of said measuring units or modules entirely integrated into the surface thereof.

1 6. Apparatus according to any of Claims 1 3 to 1 6 characterized in that the or each measuring unit or module is connected to a feed line for the medium to be analysed and the or each measuring unit or module can be fed reagents via respective feed lines

1 7. Apparatus according to Claim 1 6 characterised in that a chamber to accommodate a filter is integrated into each feed line, preferably directly downstream of the inlet end.

8. Apparatus according to Claim 1 6 or Claim 1 7, characterized in that each feed line is connected to a main line that is connected to the measuring cell of the measuring unit, and in that a pump and a flow sensor connected downstream of the pump are integrated into each feed line, downstream of the chamber.

9. Apparatus according to any of Claims 1 6 to 1 8, characterized in that each feed line and each main line of each measuring unit are formed by a U- shaped recess in the surface of the component, and a cover plate is arranged on the surface of the flat component by means of which the entire surface is tightly sealed to the outside.

20. Apparatus according to any preceding claim, characterized in that each measuring unit or module is equipped with piezoelectric pumps, and in that the electric contacts of the pumps are installed on the surface of the cover plate.

21 . Apparatus according to any preceding claim characterized in that each pump and each flow sensor can be connected individually to and disconnected individually from a measuring unit.

22. Apparatus according to any preceding claim, characterized in that each measuring cell is assigned at least one measuring device, operating optically, chemically or electrochemically, to monitor the reactions in the measuring cell.

23. Apparatus according to any preceding claim characterized in that each measuring cell and the associated measuring device are arranged directly adjacent to each other in a common recess, and in that when an optical measuring device is used, this recess is provided with reflecting side walls and the cover plate is of transparent design.

24. Apparatus according to Claim 23 characterized in that each optical measuring device is divided into a light-emitting module and a light-receiving module, and in that the first module is installed at the first end and the second unit is installed at the second end of a measuring cell.

25. Apparatus according to any preceding claim, characterized in that at least one feed line one end of which is connected to a bore that passes through the flat component

26. Apparatus according to Claim 25 characterized in that the underside of the flat component, the bore is connected to a line in the form of a hollow needle.

27. Apparatus according to any preceding claim, characterized in that the flat component is attached to a component in the form of a container for holding supply bags and/ar storage containers for reagents, a water treatment system, at least one storage container for a biocomponent, and a reaction chamber having two oxygen sensors, as well as at least one cooling device for the reagents and a heating element for the biocomponent, are arranged.

28. Apparatus according to Claim 27, characterized in that the container is partly of double-wall design, and storage containers for the reagents, a water treatment system, a storage container for a biocomponent, and a reaction chamber having two oxygen sensors, as well as at least one cooling device for the reagents and a heating element for the biocomponent, are arranged between the lateral outer and inner wall of the container.

29. Apparatus according to Claim 27 or Claim 28 characterized in that a hollow needle is inserted into each supply bag and/or storage container, in that the medium to be examined can be fed from outside, via a feed line, into the container , and in that a distributor, which is connected to each bore on the underside of the component, can be plugged onto the end of the feed line.

30. Apparatus according to any preceding claim, characterized in that the contents of a measuring cell can be fed to the reaction chamber, whose content can be led out of the container via a line, and in that the contents of the other measuring cells can be led into the interior of the container via a respective line.

31 . Apparatus according to any preceding claim, characterized in that connected to each storage container is a line onto which in each case one line of the flat component can be plugged, in that the medium to be examined can be led from outside, via a feed line, into the container, the feed line being connected there to a distributor chamber that is provided with flow lines onto which the flow lines of the flat component can be plugged.

32. Apparatus according to any preceding claim characterized in that the content of a measuring cell can be fed to the reaction chamber, and in that the content of the measuring cells and of the reaction chamber can be led out of the container via lines.

33. A device according to any preceding claim, wherein said flat component is in the form of a wafer, and flow conduits for transporting fluid to one or more of said component for performing a unit operations selected from fluid transport, reagent addition, reaction between reagent and analyte, detection of reaction product and fluid discharge are provided in the form of channels in said wafer.

34. A device according to Claim 33 wherein said wafer is formed by silicon.

35. Apparatus according to any preceding claim adapted to perform a plurality of analysis operations at separate analysis stations, each of which includes a set of devices for performing unit operations selected from fluid transport, reagent addition, reaction between reagent and analyte, detection of reaction product and fluid discharge

36. Apparatus according to Claim 35 characterised in that a plurality of said reaction stations are provided at respective spaced locations on a carrier element having at least one substantially planar surface, and a plurality of said devices for performing unit operations selected from fluid transport, reagent addition, reaction between reagent and analyte, detection of reaction product and fluid discharge are integrated into said carrier element and/or positioned in recesses in said carrier element

37. Apparatus according to Claim 36 in which a removable cartridge assembly charged with reagents is arranged to be matingly engaged with said substantially planar surface of the carrier element so as enable reagents to be transferred to conduits leading to said devices.

38. A device for analysing samples of liquid which are taken continuously or intermittently from a body of liquid in which the device is at least partially immersed, the device comprising a casing and conduit means for transferring samples of liquid to the interior of the casing where a plurality of analysis operations are carried out at separate analysis stations, each of which includes a set of devices for performing unit operations selected from fluid transport, reagent addition, reaction between reagent and analyte, detection of reaction product and fluid discharge, characterised in that a plurality of said reaction stations are provided at respective spaced locations on a carrier element having at least one substantially planar surface, and a plurality of said devices for performing unit operations selected from fluid transport, reagent addition, reaction between reagent and analyte, detection of reaction product and fluid discharge are integrated into said carrier element and/or positioned in recesses in said carrier element, whereby a removable cartridge assembly charged with reagents may be matingly engaged with said substantially planar surface of the carrier element so as enable reagents to be transferred to conduits leading to said devices.

39. Apparatus for analysing liquid or gaseous media, said apparatus having at least one component for performing a unit operation selected from fluid transport, reagent addition, reaction between reagent and analyte, detection of reaction product and fluid discharge, characterised in that at least one of said components is at least partly integrated within the flat component.

40. Apparatus according to Claim 39, including the feature or features of any of Claims 1 to 38.