MXPA96005329A - Optical sensor system to determine ph values and ioni concentrations - Google Patents

Abstract

A method for the independent and reversible optical determination of the pH value and the ionic concentration of an aqueous sample, with the help of two different sensors according to the fluorescence method, in this method two optical sensors are contracted, which are each composed of polymers of different structures, but each containing the same fluorescent dye, and each consisting of a coated material composed of: a) a carrier material, to which are applied: b) at least one water-insoluble layer of a polymer comprising at least one hydrophilic monomer (A) from the group of substituted olefins, and c) a fluorescent proton-sensitive dye that is bonded directly or via a bridge group to the polymer backbone b), or that is incorporated into the polymer b) with an aqueous test sample irradiated with exciting light, the fluorescence is measured and the pH values and the values are calculated. ionic concentrations from the measured fluorescence intensities, with reference to calibration curves

Description

OPTICAL SENSOR SYSTEM TO DETERMINE PH VALUES AND ION CONCENTRATIONS The invention relates to an optical method for determining the pH value and the ionic concentration of an electrolyte solution, to optical sensors for carrying out the method, to polymers and to a polymerizable composition, and to fluorescent dyes. 10 It is known that the value pK. of an indicator changes with the ionic concentration of a solution, and that change depends on the level of load on the indicator. Accordingly, it has already been proposed in German Patent Number DE-A-3,430,935 to use, in the determination of the pH value, the difference between the measured values of two sensors M < and Mn that have different dependencies of ionic concentration, which is a complex function _, of ionic concentration J, after calibration with known standard solutions by calculation using a process control computer. The optical determination of the ionic concentration at a pH value, given according to the fluorescence method using two optical sensors, is described in German Patent Number DE-A-3,430,935. In that case, the fluorescent dye of the sensors, which is the same for each sensor, is immobilized by means of bridging groups directly on the surface of glass carriers, with a sensor containing additional charges to achieve a high polarity and dependence of ionic concentration, and the other sensor being modified in such a way that it is substantially non-polar, hydrophobic and independent of the ionic concentration. A very considerable disadvantage of these sensors is that the fluorescent dye is directly exposed to the external effects of the measuring solutions, and has influence both of a physical nature (for example, dissolution of the dye, deposits on the surface) and of a chemical nature (decomposition of the dye), which quickly / make sensors useless. In addition, in the case of excitation in an evanescent field, the interference between the evanescent measurement field and the fluorescence of the test sample can not be completely eliminated, which reduces the accuracy of the measurement. However, the response time of these sensors is short, since the fluorescent dye bound to the surface immediately comes into contact with the electrolyte solution, the sensitivity is considered adequate. International Patent Number WO 93/07483, used as pH indicators, carriers coated with hydrophilic polymers containing a polymer-bound dye, based on the optical measurements in the absorption method, fluorescence detection is not mentioned. that the service life and usable life of the sensors to determine the concentration ^ * ion and the pH value can be increased considerably, the sensitivity is not reduced, but actually increases, and the response times are not reduced, but even increase slightly when the 5 measurements are performed with sensors wherein the fluorescent dye is embedded in a polymeric membrane, and the membrane layers of the two sensors used for the measurement have different polymer compositions. These different compositions cause, for example, differences in the hydrophilicity, polarity and / or dielectric constant, and with the same, a different dependence of the ionic concentration, without it being necessary to make a provision for high loads in, at least, one sensor. Surprisingly, it was shown that it is not necessary to use charged sensors, but that it is possible to even measure in an environment * _ ** virtually not loaded. The embedding of the indicator dye in the sensor membrane causes effective protection against damage and interference from the measurement medium, so that the service life also extends. In addition, in sensors that measure in an evanescent field of the substrate, the membrane maintains the sample solution geometrically remote from the detection zone on the surface of the waveguide, which, in contrast to the sensors described in the German Patent Number DE- A-3,340,935, prevents interference with the fluorescence of the sample solution. The photostability is surprisingly high, which ensures a longer life. Response times and conditioning times correspond, despite embedding of the fluorophore, to the short time periods required for the optical measurement systems, these parameters depending substantially on the thickness of the membrane. The sensitivity and resolution in the measurement scale are improved even a little, like a *; result of the displacement of the pH between the calibration curves. Also, in a surprising way, it has discovered that the p < 3 to other pH scales by selecting the polymer, in such a way that a considerably larger pH measurement scale is covered in the use of the same fluorophore. The change in the environment of the fluorophore, by For example, the local dielectric constant can be used to • • the purpose of adjusting the dependence on the ionic concentration that can be substantially influenced by the selection and nature of the polymer, and the concentration of the fluorophore. Using the discovered measurement method, you can determine Both the ionic concentration and the pH value of a solution. The sensors can be used in a repeated manner, optionally after cleaning, for example, in continuous determinations. The invention relates to a method for the independent and reversible optical determination of the pH value and the ionic concentration of an aqueous sample with the aid of two different sensors according to the fluorescence method, in which method two optical sensors are brought into contact, which are each composed of polymers of different structure, but each containing the same fluorescent dye, and each consisting of a coated material composed of: a) a carrier material, to which apply: b) at least one water insoluble layer of a polymer comprising, at least, a hydrophilic opomer (A) from the group of substituted olefins, and c) a proton-sensitive fluorescent dye that is bonded directly or by means of a bridging group to the central structure of polymer b), or which is incorporated in the polymer b) , with an aqueous test sample, irradiated with exciting light, measuring the fluorescence and calculating the pH values and the ionic concentrations from the measured fluorescence intensities, with reference to calibration curves. Hydrophilic can mean a solubility in water of at least 1 percent by weight, preferably at least 10 percent by weight, more preferably at least 20 percent by weight, most preferably at least 40 percent by weight , and at least 50 percent by weight is particularly preferred, whereby, the percentages by weight they are related to the solution. In detail, a procedure can be performed wherein, after calibration with samples of a known ionic concentration and a known pH, the fluorescence intensity in contact with an electrolyte solution of unknown composition is measured, and the contributions are separated of the ionic concentration and the pH at the measured fluorescence intensity, one of the other, by means of a calculation. The measurement data obtained from the calibrations are evaluated by calculation, for example, using a pattern recognition algorithm. Using the calculation method, the pH and the ionic concentration can then be determined from the measurement data obtained. You can perform both pre-calibration, as a direct calibration. The sensors are put in contact with the calibration solutions or with the test samples. This can be done manually (for example, using pipettes), or with a suitable automatic transverse flow system, rigidly mounting the sensors in a flow cell. These cross flow cells are known to the person skilled in the art, and can simply be adapted to the particular intended use. As the light sources to excite the fluorescence, it is possible to use ultraviolet lamps (for example, mercury vapor lamps, halogen lamps), laser, diode laser devices and light emitting diodes.

It may be convenient to use filters to filter the light of the wavelength, to which the fluorescent dye has a maximum absorption. The fluorescent light emitted by the sensors is can collect, for example, using a lens system, and then is guided to a detector, for example, a secondary electron multiplier or a photodiode. The lens system , and can also be configured in such a way that the fluorescence radiation is measured through the transparent carrier, on the edges of the carrier, or through the analysis sample. Conveniently, the radiation is guided in a manner known per se, by means of a dichroic mirror. The fluorescence of the sensors, preferably are measured while they are in contact with the solutions of calibration or sample. The sensors wherein the fluorophore is incorporated into the polymer are generally suitable for use only once. If the polymeric membrane is provided with a permeable and hydrophilic protective layer, it is possible that these Sensors such as sensors that have fluorophores bonded with polymer in general (which may similarly have a protective layer on the membrane) are used repeatedly or in continuous measurements. The geometric shape of the carrier material may vary to a very large degree; for example, it may be in the form of fibers, cylinders, spheres, cuboids or cubes. Transverse flow systems are also possible, where continuous measurements or successive measurements can be made. Flat sensors are preferred. The carrier material is preferably transparent. It can be, for example, inorganic glass or transparent plastic, such as polycarbonate, polyesters, polyamides or polyacrylates or polymethacrylates. In another preferred form, the carrier material of the optical sensors is transparent and preferably consists of glass or a transparent polymer. The flat sensor can have any desired external shape, for example, it can be square, rectangular or round. It can have a surface area of 0.01 to about 50 cm, conveniently 0.02 to 10 c. The measuring region of the sensor can have an area of, for example, less than 5 mm, preferably less than, or equal to 2 m. The measurement region can be identical to a fully coated sensor surface. Conveniently, a coating provided on both sides, but locally separated, can be used. The polymers of layer b) preferably comprise at least 50 mole percent of monomer (A), based on the polymer. The hydrophilic monomer (A) is preferably an olefinic monomer which can correspond to Formula XX: Z? CR = CR2 (XX) wherein each R independently of the others is hydrogen or a hydrophobic substituent, and Zx is a hydrophilic radical The hydrophobic substituents may be, for example, alkyl of 1 to 12 carbon atoms, alkoxy of 1 to 12 carbon atoms , haloalkyl of 1 to 12 carbon atoms, phenyl, halophenyl, alkyl of 1 to 4 carbon atoms-phenyl, alkoxy of 1 to 4 carbon atoms-phenyl, carboxylic acid ester groups having a total of 2 to 20 carbon atoms. carbon atoms, -CN, F or Cl- The hydrophilic radicals can be, for example, -OH, -O- (alkylene of 2 to 12 carbon atoms) -OH, -C (0) -NH2, -C ( O) -NH- (alkylene of 2 to 12 carbon atoms) -OH, -C (0) -N- (alkylene of 2 to 12 carbon atoms) 2-0H, -C (0) -NH-alkyl of 1 to 12 carbon atoms, -C (O) -N- (alkyl of 1 to 12 carbon atoms) 2, pyrrolidonyl, or C- (O) -O- (alkylene of 2 to 12 atoms - "2") - carbon) -OH The thickness of the polymer layer b) can be, for example, 0.01 at 50 microns, preferably from 0.1 to 25 microns, and especially from 0.1 to 10 microns. Being composed of different polymers means that the differences between the dependencies of the sensors on the ionic concentration are determined by the composition of the polymer and the properties of the membrane. Structural differences can be achieved, for example, through a different content of fluorophores. the incorporation or immobilization thereof within or on the polymer, different amounts of monomers, different monomers involved in the polymer structure, and / or different crosslinking agents and / or different polymers blended with the polymerizable monomers. One of the sensors must always exhibit a dependence on the ionic concentration, while the other sensor does not have dependence on the ionic concentration, or has a different dependence on the ionic concentration. Accordingly, the sensors are coated with different polymer membranes, in such a way that they have different dependencies in the ionic concentration. For the method according to the invention, it is better to select polymers where there is a large difference in the dependence on the ionic concentration. Advantageously, the difference in the dependence on the ionic concentration is at least 0.1, preferably at least 0.15, and especially at least 0.2, measured as the displacement of pK, between the calibration curves in buffer solutions of an ionic concentration of 0.1M and 0.3M. A convenient practical scale of ion concentration difference is 0.1 to 0.15. Combinations of polymers based on polyvinyl pyrrolidone are polyhydroxyethylmethacrylic acid-based polymers, or based on polyacrylic amides, have been proven to be suitable, for example, in measurements on the physiological scale (for example, determination of the pH value of blood or serum). The sensor may have one or more membrane layers 5 locally spaced apart; in the latter case, parallel measurements can be made with the same or different test samples. The polymers of layer b) may be crosslinked, for example, with 0.01 to 50 mole percent, preferably from 0.1 to 20 mole percent, and especially from 0.5 to 10 mole percent, of a crosslinking agent, based on the polymer. Suitable crosslinking agents are, for example, esters of acrylic or methacrylic acid or polyol amides, preferably diols to tetroles, or polyamines, preferably diamines to tetramines. These crosslinking agents are known and many are described in the literature. Some examples of polyols are ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,6-hexanediol, diethylene glycol, 1,1-trihydroxymethyl-ethane or propane, pentaerythritol and dipentaerythritol. Some examples of Polyamines are ethylenic diamine, 1,3-prophane diamine, 1,4-butane diamine, 1,6-hexane diamine, diethylene triamine and triethylene tetramine. Another known crosslinking agent is, for example, divinyl benzene. Other suitable crosslinking agents are alkylene bis-dialkylmelanimidyl compounds, such as bis- (dimethyl) maleinimidyl of ethylene.

The polymers b) can be partially completely composed of at least one hydrophobic monomer (A) and optionally, a hydrophobic monomer. The polymers b) d preferably comprise at least 20 mole percent, more preferably at least 30 mole percent especially at least 40 mole percent, more especially at least 50 mole percent, preferably at least 80 mole percent. molar percent of the monomer (A), and in accordance with the above, at most 80 mole percent, more preferably at most 70 mole percent especially as much 60 mole percent, most especially as much 50 mole percent , and preferably at most 20 mole percent of a hydrophobic comonomer (B), based on the polymer. The polymer b) can comprise, for example, from 20 to 100 mole percent, preferably 20 to 80 molar rupnt of at least one structural unit of Formula III and from 80 to 0 mole percent, preferably from 80 to 20 mole percent of at least one structural unit of Formula 5 IV: wherein: Ra is hydrogen, alkyl of 1 to 6 carbon atoms, or -COORg, and Rg is hydrogen, alkyl of 1 to 6 carbon atoms, hydroxyalkyl of 1 to 6 carbon atoms, or an alkali metal cation, for example, Na8 or K®, Rb is pyrrolidonyl, -OH, hydroxyalkoxy of 2 to 6 carbon atoms, -CONR7R8 or -C00R9, R7 and R8 are each independently of the other, hydrogen, alkyl of 1 to 6 carbon atoms , or hydroxyalkyl of 2 to 6 carbon atoms, and R9 is hydrogen or hydroxyalkyl of 1 to 6 carbon atoms, Rc is hydrogen or alkyl of 1 to 6 carbon atoms, Rd is hydrogen, alkyl of 1 to 6 carbon atoms, F or Cl, Re is hydrogen or alkyl of 1 to 6 carbon atoms, or Re and Rf are together -C0-0-C0-, and Rf is hydrogen, alkyl of 1 to 6 carbon atoms, -CN, F or Cl. In a preferred form, the layer is composed of polymers having 100 mole percent of structural units of Formula III, especially Ra hydrogen wherein Rc is hydrogen or methyl, and Rb is pyrrolidonyl, -CONR7R8 or -COOR9, where R7 and R8 are each independently of the other, hydrogen, alkyl of 1 to 6 carbon atoms, or hydroxyalkyl of 2 to 6 carbon atoms, and R9 being hydrogen or hydroxyalkyl of 2 to 6 carbon atoms. In a preferred subgroup, the polymer layer is formed by polymers comprising from 20 to 80 mole percent of at least one structural unit of the Illa Formula: and from 80 to 20 mole percent of at least one structural unit of Formula IIIb: wherein: R and R are each independently of the other, hydrogen or methyl, preferably hydrogen; R ^ is di (C 1-6 alkyl) amino, preferably di (C 1-4) alkyl amino, and especially dimethylamino or diethylamino; and R.- is amino, preferably mono (C 1-6) alkyl amino, and especially mono (C 1-6) alkyl amino, for example, tertiary butyl amino. These polymeric membranes (with the exception of those where R.- = amino) are especially suitable for pH measurements on the physiological scale around about 7.4. Although they are very hydrophobic, they still have adequate response times, but they are not soluble in water and, therefore, do not need to crosslink, and can be prepared from solutions of the corresponding monomers, for example, by pouring centrifugation. The water-insoluble layer having hydrophilic monomers (A) can be, for example, especially a layer that can be obtained by the following process: solution polymerization of at least one hydrophilic monomer (A), from the group of substituted olefins in the presence of a carrier polymer comprising at least one hydrophilic monomer (A) from the group of substituted olefins that are identical to, or different from, the former.

These polymers are preferably crosslinked, for example, with diolefinic crosslinking agents. The amount of crosslinking agent may be from 0.1 to 30 weight percent, preferably from 0.5 to 20 weight percent, and especially from 1 to 10 weight percent, based on the monomer (A) and the carrier polymer . The polymers thus prepared form polymer networks in which the carrier polymer is embedded. These polymer membranes are distinguished by good mechanical properties and high durability, which ensure a long service life. A special advantage is its ease of manufacture and the control of the thickness of the layer by means of the processes of emptying by centrifugation, since the viscosity of the solutions of emptying can be established in an objective way by means of the content and the selection of the carrier polymer. The carrier polymer is preferably hydrophilic. An additional advantage is the polymerization and / or crosslinking directly on the carrier by the action of heat and / or actinic radiation. Suitable carrier polymers are, for example, those having an average molecular weight of 10,000 to 500,000 daltons, preferably 20,000 to 350,000 daltons, determined by the gel permeation method, using standard polymers of a known molecular weight. Suitable mixing ratios between the monomer (A) and the carrier polymer are, for example, from 5 to 95 percent by weight, preferably from 30 to 70 percent by weight of carrier polymer, and 95 to 5 percent by weight, preferably 70 to 30 percent by weight of monomer A, based on the total mixture of monomer and carrier polymer. The hydrophilic carrier polymers can be selected, for example, from the group of homo- and copolymers of pyrrolidone vinyl; of hydroxyalkyl acrylates and methacrylates; of vinyl alcohol; of vinylhydroxyalkyl ethers; of acrylic amides and methacrylic amides; or of acrylic amides and methacrylic hydroxyalkyl amides. These polymers are known and are to some extent commercially available or can be prepared according to analogous processes. The hydroxyalkyl groups may contain from 2 to 12, preferably from 2 to 6, carbon atoms. The desired degree of hydrophilicity can be adjusted using hydrophobic olefinic comonomers. The N atoms of the acrylic amides and the methacrylic amides may be mono- or di-substituted by alkyl of 1 to 6 carbon atoms. In a convenient form, the carrier polymer is composed of the monomer (A), and the monomer (A) is used simultaneously with that carrier polymer for the preparation of the membrane. Examples of hydrophilic carrier polymers are polyvinyl pyrrolidone, acrylates and methacrylates of poly (hydroxyalkyl 2 to 6 carbon atoms), for example polyhydroxyethyl methacrylate, polyhydroxypropyl methacrylate, methacrylate polihidroxibutilo methacrylate of polihidroxihexilo, polyhydroxyethyl acrylate, acrylate polyhydroxypropyl acrylate polihidroxibutilo, or acrylate polihidroxihexilo, amide polyacryl amide or polymethacrylic amide polyacrylic mono (alkyl having 1 to 6 carbon atoms or amide polymethacrylic mono- (C1 to 6 carbon atoms), polyacrylic amide of di- (alkyl of 1 to 6 carbon atoms) or polymethacrylic amide of di (alkyl of 1 to 6 carbon atoms) In an especially preferred form, the polymer layer comprises at least a monomer (a) from the group: pirrolidonavinílica methacrylate, 2-hydroxyethyl methacrylate, 3-hydroxypropyl acrylate, 4-hydroxybutyl acrylate, 5-hydroxypentyl, 6-hydroxyhexyl acrylate, acrllica amide, amide N, N- dimethyl acrylic, and tertiary butyl acrylic amide, or a polymer obtainable by the solution polymerization of a monomer (A), from the group: pyrrolidonavinyl, methacrylate 2- hydroxyethyl methacrylate, 3-hydroxypropyl acrylate, 4-hydroxybutyl acrylate, 5-hydroxypentyl acrylate, 6-hydroxyhexyl and amide acrylic, in the presence of a carrier polymer of a monomer (A) from the group consisting of pyrrolidone vinyl, 2-hydroxyethyl methacrylate, 3-hydroxypropyl methacrylate, 4-hydroxybutyl acrylate, and acrylic amide. The fluorescent dye may be present, for example, in an amount of 0.01 to 10 percent by weight, of preference of 0.1 to 5 percent by weight, and especially 0.5 to 3 percent by weight, based on the polymer. The fluorescent dye is preferably covalently linked to the central structure of the polymer by means of a bridge group. Suitable proton-sensitive fluorescent dyes are, for example, those xanthenes group and benzoxanthenes (for example fluorescein, halogenated fluoresceins, luoresceinas seminaftof, luoros is inaftorrodaf, 2,3-benzofluoresceina, 3,4-benzofluorescelna, isomers benzorhodamine and substituted derivatives, the isomers of benzocrogen and substituted derivatives); acridines (for example, acridine, 9-amino-6-chloroacridine); acridones (e.g., 7-hydroxyacridone, 7-hydroxybenzacridone); pyrenes (for example, 8-hydroxypyren-1, 3,6-trisulfonic acid), cyanine coloring materials; and coumarins (e.g., 7-hydroxycoumarin, 4-chloromethyl-7-hydroxycoumarin). Fluorescent dyes can be made functional to bond with a central structure of the polymer. Suitable bridging groups for linking the fluorescent dye to the polymer backbone are, for example, -0-C (0) -, -C (0) -0-alkylene of 2 to 12 carbon atoms-0-C (0) -, -NH-C (0) -0- and -NH-C (0) -0-alkylene of 2 to 12 carbon atoms-OC (O) -, -C (0) -0- ( alkylene of 2 to 6 carbon atoms-0) t bis i2- '~ "c (0) -0 ~ (alcluylene of 2 to 6 carbon atoms-0) ^ bis ^ ~ alkylene of 2 to 6 carbon atoms- NH-, -C (0) -NH- (alkylene from 2 to 6 carbon atoms-O) x bis 12-alkylene of 2 to 6 carbon atoms-NH-, -C (O) -NH- (alkylene of 2 to 6 carbon atoms -O) 1 biß i2 ~ H2 ~ (0) ~ NH ~ # E1 alkylene in the alkylene-O- repeat residues may be, for example, ethylene or 1,2-propylene. The bridge group of the fluorescent dye is preferably a group - (CO) S-NH- (alkylene of 2 to 12 carbon atoms -O) r-C0- or - (CO) β-0- (alkylene of 2 to 12 carbon atoms-0) r-CO- or -CtOJ-NH- CHjCH ^ O)! bis 6-CH2C (O) -NH-, the group (C0) 8 or the NH group being linked to the fluorescent dye, and each being rys 0 or 1. The alkylene preferably contains from 2 to 6 carbon atoms , and it is especially ethylene. The fluorescent dye bonded to the central structure of the polymer can be, for example, a dye of Formula I, II or Ha: where Rj ^ and R2 are each independently of the other, hydrogen, alkyl of 1 to 4 carbon atoms, alkoxy of 1 to 4 carbon atoms, alkoxy of 1 to 4 carbon atoms, carbonyl, alkyl of 1 to 4 carbon atoms-S02- or halogen, and R3 is hydrogen and R4 is -NH-CO-, -CO-NH- (alkylene of 2 to 12 carbon atoms-O) -CO-, -CO-NH- (alkylene of 2 to 12 carbon atoms-NH) -CO- or -C (0) -NH- (CH2CH2-0)? bis 6-CH2C (0) -NH-, or R3 is -NH-CO-, -CO-NH- (alkylene of 2 to 12 carbon atoms- *** 0) -CO-, -CO-NH- ( alkylene of 2 to 12 carbon atoms-NH) -CO- or-C (0) -NH- (CH2CH2-0) 1 bis 6-CH2C (0) -NH- and R4 is hydrogen; or wherein R5 is hydrogen and R6 is -NH-C (O) -, -CO-NH- (alkylene of 2 to 12 carbon atoms -O) -CO-, -CO-NH- (alkylene of 2 to 12 carbon atoms-NH) -CO- or -C (O) -NH- (CH2CH2-0)? bis 6- CH2C (0) -NH-, or R5 is -NH-C (O) -, -CO-NH- (alkylene of 2 to 12 carbon atoms-O) -CO-, -CO-NH- ( alkylene of 2 to 12 carbon atoms-NH) -CO- or -C (0) -NH- (CH2CH2-0) 1 bi8 6-CH2C (0) -NH-, and R6 is hydrogen, in each case in free form or in salt form, and the alkyl esters of 1 to 20 carbon atoms thereof. The compounds of Formulas I, II and especially Ia are distinguished by an excitation absorption in the visible scale, by a longer wavelength fluorescence and by an excellent photo-stability, in such a way that the sources can be used. of radiation commercially available for the fluorescence excitation, which satisfies the excitation wavelengths. 10 It has also been discovered, in a surprising manner, that the pK value. of the fluorophore can be varied symmetrically and coupled with the desired pH measurement scale, if the hydrophilicity of the polymers composed only of acrylic amides or methacrylic amides and acrylic amides or amides -J.5 N-substituted methacrylics, or only at least two different acrylic amides or N-substituted methacrylic amides, is established by its composition, and the fluorophore is covalently bonded to the polymer. It has also been found that the viscosity of the coating compositions comprising These polymers can be adjusted in such a way that economically convenient and economical coating methods can be employed, such as, for example, centrifugal casting. Accordingly, the invention also relates to a copolymer comprising at least one structural unit recurring Formula VII: optionally at least one recurring structural unit of Formula VIII: and the recurring structural units of Formula IX: wherein: Rk is hydrogen or methyl, Rm is hydrogen or alkyl of 1 to 12 carbon atoms, phenyl or benzyl, Rn and RQ are each independently of the other, alkyl of 1 to 12 carbon atoms, phenyl or benzyl, or Rn and R0 they are together tetramethylene, pentamethylene, - (CHj ^ -O-ICHj ^ - or - (CH2) 2_ - (alkyl of 1 to 6 carbon atoms) - (CHj ^ -. and F is the radical of a directly bound fluorophore or by means of a bridging group to the N atom, with the proviso that at least two different recurring structural units of Formula VII are present, or at least one structural unit of Formula VII, and at least one structural unit of Formula VIII. Rβ, Rn and RQ as alkyl preferably contain from 1 to 6 carbon atoms. Preferred copolymers are those having structural units of Formula VII and structural units of Formula VIII, with Ra preferably being alkyl of 1 to 12 carbon atoms, more preferably alkyl of 1 to 6 carbon atoms. The structural units of Formula VII may be present in an amount of 10 to 80 molar percent, preferably 20 to 70 molar percent, and the structural units of Formula VIII in an amount of 90 to 20 molar, preferably from 80 to 30 mole percent, based on the polymer. The polymer can additionally be crosslinked, especially when it is desired to prevent a possible water solubility, or too high a solubility in water. Suitable crosslinking agents have been mentioned above. The divalent structural units of the crosslinking agent may be present, for example, in an amount of 0.1 to 30% by weight percent, preferably 0.5 to 20 weight percent, r and especially 1 to 10 weight percent, based on the polymer. The fluorophore radical F can be derived from the fluorophores mentioned above, and is especially a fluorophore of Formula I, II or Ha. The structural unit of Formula IX can be present in an amount of 0.1 to 10 molar percent , preferably from 0.5 to 5 mole percent, based on the polymer. In an especially preferred form, the polymer comprises structural units of Formula VII and structural units of Formula VIII, Rk is hydrogen, R-, is alkyl of 3 to 6 carbon atoms, Rn and R0 are alkyl of 1 or 2 carbon atoms, and F is a radical of Formula I, II or Ha. The invention also relates to a polymerizable composition comprising: a) an acrylic amide or methacrylic amide of Formula X: b) optionally an acrylic amide or amide • Methacrylic of Formula XI: H R, (XI), H CÍOH ^ R. c) an acrylic amide or methacrylic amide of Formula XII: and d) optionally at least one crosslinking agent > . r and diolefinic, wherein Rk, W ^, Rn and R0, and also F, are as defined above, with the proviso that at least two different monomers of Formula X are present, or at least one structural unit of the Formula XI, and at least one structural unit of Formula X. The composition is subject to the same preferences and has the same shapes as those given above for the corresponding polymers. The compositions may comprise other additives, for example, solvents, thermal polymerization initiators, such as, for example, radical formers, photoinitiators for photopolyzing, processing aids and stabilizers, such as, for example, antioxidants and / or light-protecting agents. The invention also relates to a sensor comprising a material coated with a water-insoluble and hydrophilic polymer, the polymer containing an indicator dye, wherein: a) it is applied to a carrier material: b) a water-insoluble layer of a polymer comprising at least one hydrophilic monomer (A) from the group of substituted olefins, and c) a proton-sensitive fluorescent dye is covalently linked in a direct manner or by means of a bridge group to the central structure of the polymer b ), or is incorporated in the polymer b). "Incorporated" means the presence of a homogeneous preference mixture. The forms and preferences indicated above apply to the sensors. In a convenient form, an adhesion promoter layer is formed between the carrier material and the polymeric layer. The polymeric layer may be provided with a protective proton-permeable layer. The sensors are also suitable for measuring the pH at physiological temperatures, and are especially suitable for measurements on the physiological pH scale of about 6 to 8, and especially of 6.4 to 7.6. The response times may be less than 30 seconds, and a first measurement is possible after less than about 5 minutes. The sensors are also distinguished by a high degree of storage stability. The sensors can be prepared according to the coating techniques known per se. In order to improve adhesion, the carrier materials can be treated in advance with adhesion promoters. For the same purpose, it is also possible to carry out a plasma treatment of the carrier material, in order to generate functional groups on the surface. The surface can also be provided with copolymerizable groups in order to achieve an especially high degree of adhesion. The adhesion promoters known for glass are, for example, triethoxy-glycidyloxysilane, 3-azidopropyltriethoxysilane, or 3-aminopropyltriethoxysilane. The surfaces thus treated can be further modified, for example, with O- (N-succinimidyl) 6- (4'-azido-2'-nitrophenylamino) -hexanoate. It has proven to be especially advantageous to treat the surfaces with ethylenically unsaturated carboxylic acid ester silanes, such as, for example, 3-trimethoxysilylpropyl ester of methacrylic acid, because, in the polymerization, the layer can be anchor covalently to the surface. Known coating techniques are, for example, spreading, dipping, knife application, spraying, casting, curtain casting, or centrifugal casting. For the coating, it is possible to use either polymerization solutions according to the invention, or hydrophilic monomers (A) optionally mixed with a hydrophilic carrier polymer and / or a crosslinking agent, containing a copolymerizable fluorescent dye, in the second if the polymerization is carried out after the coating. The polymerization can be thermally initiated, for example, with initiators such as a.a'-azobisisobutyronitrile or ammonium peroxodisulfate, or by the action of radiation, such as, for example, ultraviolet light with the concomitant use of photoinitiators and optionally sensitizers. Examples of photoinitiators are benzophenones, xanthones, thioxanthones and secondary-acetophenones. The copolymerizable fluorescent dyes contain, for example, an ethylenically unsaturated group (vinyl, crotonyl, methallyl) which is bonded directly or by means of a bridging group to the fluorescent dye. The monomers (A) and the carrier polymers are known. A known copolymerizable fluorescent dye is, for example, 3- or 4-acryloylami-nofluorescein. Polymers that contain fluorescent dyes that have the bridging groups -0-C (0) - and -C (0) -0-alkylene of 2 to 12 carbon atoms-OC (O) - can be obtained, for example, by esterification with fluorescent dyes containing carboxy or hydroxy groups. Polymers containing fluorescent dyes having the bridging groups -NH-C (0) -0- and -NH-C (0) -0-alkylene of 2 to 12 carbon atoms-OC (O) - can be obtained , for example, by means of fluorescent dyes made functional with isocyanate and polymers containing a hydroxy group. The reactions described above can be carried out in a manner known per se, for example, in the absence or in the presence of a suitable solvent, the reactions being carried out, as necessary, with cooling, at room temperature, or with heating, example, on a temperature scale of from about 5 ° C to about 200 ° C, preferably from about 20 ° C to 120 ° C, and, if necessary, in a closed vessel, under pressure, in an inert gas atmosphere , and / or under anhydrous conditions. The starting materials mentioned hereinabove and hereinafter, which are used for the preparation of the polymers are known or can be prepared according to methods known per se. The reactants can be reacted with each other as such, that is, without the addition of a solvent or diluent, for example, in the molten state. It is generally convenient, However, add a solvent diluent or a mixture of solvents. Examples of these solvents and diluents that may be mentioned are: water; esters, such as ethyl acetate; ethers, such as diethyl ether, dipropyl ether, di-isopropyl ether, dibutyl ether, tertiary butyl methyl ether, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol dimethyl ether, di ethoxy ethyl ether, tetrahydrofuran or dioxane; ketones, such as acetone, methyl ethyl ketone or methyl isobutyl ketone; alcohols, such as methanol, ethanol, propanol, isopropanol, butanol, ethylene glycol or glycerol; amides, such as N, N-dimethyl formamide, N, N-diethyl formamide, N, N-dimethyl acetamide, N-methyl pyrrolidopa, or hexa-ethyl-phosphoric acid triamide; nitriles, such as acetonitrile or propionitrile; and sulfoxides, such as dimethyl sulfoxide. By selecting the monomers and polymers to be used according to the invention, it is possible, in an objective manner, to vary the properties of the sensor membranes, such as, for example, the hydrophilicity, the degree of swelling or polarity, within a wide range. As a result, it is possible to prepare, using the same indicator dye, sensor membranes, which can be optimized for different pH scales, and react in a different way to the ionic concentration of the solution (see also Tables 4 and 5). In addition, the method for preparing the sensor membrane allows industrially applicable processes (eg, spin coating) to be used for the coating of flat glass or plastic carrier materials for economical mass production of flat sensors. The invention also relates to compounds of the formulas la, lie and lid: where: R? and R2 are each independently of the other hydrogen, alkyl of 1 to 4 carbon atoms, alkoxy of 1 to 4 carbon atoms, alkoxycarbonyl of 1 to 4 carbon atoms, alkyl of 1 to 4 carbon atoms-S02- or halogen , and R3 or R5 is hydrogen and R4 or R6 is a group - (CO) s-0- (alkylene of 2 to 12 carbon atoms -O) r-CO-CRk = CH_, - (C0) S-NH- (alkylene of 2 to 12 carbon atoms-NH) rC0-CRk = CH2, -NH (CO) - (alkylene of 2 to 12 carbon atoms -NH) r -CO- CRk = CH2, - (CO) s-0- (alkylene of 2 to 12 carbon atoms -O) r-CO-CRk = CH2, - (C0) s-0- (alkylene of 2 to 12 carbon atoms-O) - alkylene of 2 to 6 carbon atoms-NH-CO-CRk = CH2, -NH- (alkylene of 2 to 12 carbon atoms) carbon-O) r-alkylene of 2 to 6 carbon atoms-NH-CO-CRk = CH2, or -NH-C (O) -CH2-0- (alkylene of 2 to 12 carbon atoms -O) r- alkylene of 2 to 6 carbon atoms-NH-CO-CRk = CH2, or R3 or R5 is a group - (CO) a-NH- (alkylene of 2 to 12 carbon atoms -O) r-C0-CRk = CH2, - (CO) S-NH- (alkylene of 2 to 12 carbon atoms-NH) rC0-CRk = CH2, -NH-C (0) - (alkylene of 2 to 12 carbon atoms-NH) r-CO-CRk = CH2, or -C (0) s-0- (alkylene of 2 to 12 carbon atoms -O) rC0-CRk = CH2, -C (0) s-0- (alkylene of 2 to 12 carbon atoms-O) r-alkylene of 2 to 6 carbon atoms-NH-CO-CRk = CH2, -NH- (alkylene of 2 to 12 carbon atoms -O) r-alkylene of 2 to 6 carbon atoms-NH-CO-CRk = CH2, or -NH-C (0) -CH2-0- (alkylene of 2 to 12 carbon atoms-O) r-alkylene of 2 to 6 carbon atoms-NH -CO-CRk = CH2, and R4 and R6 are hydrogen, r and s are each 0 or 1, and Rk is methyl or hydrogen; with the proviso that R x and R 2 are different from hydrogen, when R 3 or R 4 is acryloyl; in each case in free form or in salt form, and the alkyl esters of 1 to 20 carbon atoms thereof. The alkylene in the alkylene-O- residue preferably contains from 2 to 6 carbon atoms, preferably is linear, and is especially ethylene. In the case of R3 and R4, in the group - (C0) s-NH- (alkylene of 2 to 12 carbon atoms -O) r-C0- CRh = CH2, preferably s, and also preferably r is 0 In the case of R5 and R6, in the group - (CO) s-NH- (alkylene of 2 to 12 carbon atoms -O) r-C0-CRh = CH2, preferably s, and also preferably r is 1. Unless defined otherwise, the general terms used hereinbefore and hereinafter have the following preferred meanings: Halogen is fluorine, chlorine, bromine or iodine, especially fluorine, chlorine or bromine, more especially chlorine or bromine. Unless otherwise defined, groups or carbon containing structural units each contain 1 up to and including 4, preferably 1 or 2 carbon atoms. carbon. Alkyl - as a group by itself and as a structural unit of other groups, such as alkoxy and alkoxycarbonyl - is, giving due consideration to the number of carbon atoms present in the group or compound in question, whether straight chain, that is, methyl, ethyl, propyl or butyl, or branched, for example, isopropyl, isobutyl, secondary butyl or tertiary butyl. Examples of R3 or R and R5 or R6 are the acryloyl amine group -NHC0CH = CH2, the methacryloyl amine group -NHCOC (CH3) = CH2, and the 2- (methacryloyloxy) -ethylaminocarbonyl group -CONHCH2CH2OCOC (CH3 ) = CH-. Preferred forms within the scope of the invention, taking into consideration the condition mentioned above are: (1) A compound of Formula la, wherein Rx is hydrogen, alkyl of 1 to 2 carbon atoms, alkoxy of 1 to 2 atoms carbon, alkoxy of 1 to 2 carbon atoms, carbonyl or halogen, preferably hydrogen or alkyl of 1 to 2 carbon atoms, especially hydrogen or methyl. (2) A compound of the formula la, wherein R2 is hydrogen, alkyl of 1 to 2 carbon atoms, alkoxy of 1 to 2 carbon atoms, alkoxy of 1 to 2 carbon atoms-carbonyl or halogen, preferably hydrogen or alkyl of 1 to 2 carbon atoms, especially hydrogen or methyl, more especially hydrogen. (3) A compound of Formula la, wherein R3 is hydrogen and R4 is acryloylamino or methacryloylamino, especially acryloylamino, or R3 is acryloylamino or methacryloylamino, especially acryloylamino, and R4 is hydrogen. A special preference is given within the scope of the invention to 4-acryloylamino-4 ', 5 * -dimethyl fluororescein and 5-acryloylamino-4', 5'-dimethyl fluororescein as compounds of the invention.

-Formula I. A very special preference is given within the scope of the invention to 4-acryloylaminofluorescein. The compounds according to the invention can be prepared according to processes known per se or analogous processes, for example, by the reaction of a compound of Formula V, VI or Via.

A- they are known or can be prepared in a manner analogous to the known compounds, and wherein R 'and R2 are as defined for Formulas la, II and Ha, and R7 is hydrogen, and R8 is -NH2 or - (CO) s-NH-alkylene of 2 to 12 carbon atoms-OH or - (CO) s-0-alkylene of 2 to 12 carbon atoms-OH, or R7 is NH2 or - (C0) s-NH- alkylene of 2 to 12 carbon atoms-OH or - (CO) B-0-alkylene of 2 to 12 carbon atoms -OH, and R8 is hydrogen, in free form or in salt form, optionally in the presence of a base, with - - an acrylic or methacrylic acid derivative of the formula CH2 = C (Rh) C0X, where Rh is hydrogen or methyl, and X is an leaving group, for example, halogen, especially chloro. Another possibility for manufacturing the compounds of the Formula Ia, He and Hd is the reaction of CH2 = C (Rh) CO-W1-C (?) X with compounds of Formulas V, VI or Via, where R7 and R5 or R8 and R5 are -OH or - NH2, whereby, Wx means one of the linking groups defined for R3 to R5 in Formulas a, He and Hd.

The reaction can be carried out in a manner known per se, for example, in the presence of a suitable solvent or diluent, or a mixture thereof, the reaction being carried out, as necessary, with cooling, at room temperature. , or with heating, for example, on a temperature scale from about -10 ° C to the boiling temperature of the reaction medium, preferably from about 0 ° C to about 25 ° C, and if necessary, in a vessel closed, under pressure, in a gas atmosphere inert and / or under anhydrous conditions. Particularly convenient reaction conditions can be found in the Examples. The starting materials used for the preparation of the compounds, in each case in free form or in salt form, are known or can be prepared in accordance with the methods known per se. The reactants can be reacted with each other as such, that is, without the addition of a solvent or diluent, for example, in the molten state. However, it is usually convenient to add an inert solvent or diluent, or a mixture of at least two solvents. Examples of these solvents and diluents which may be mentioned are: aromatic, aliphatic and alicyclic hydrocarbons and halogenated hydrocarbons, such as benzene, toluene, xylene, mesitylene, tetraline, chlorobenzene, dichlorobenzene, bromobenzene, petroleum ether, hexane, cyclohexane, dichloromethane, trichloromethane, tetrachloroethane, dichloroethane, trichloroethene or tetrachloroethene; ethers, such as diethyl ether, dipropyl ether, di-isopropyl ether, dibutyl ether, tertiary butyl methyl ether, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol dimethyl ether, dimethoxy ethyl ether, tetrahydrofuran or dioxane; ketones, such as acetone, ethyl ketone, or methyl isobutyl ketone; amides, such as N, N-dimethyl formamide, N, N-diethyl formamide, N, N-dimethyl acetamide, N-methyl pyrrolidone, or tria-ida of hexamethylphosphoric acid; nitriles, such as acetonitrile or propionitrile; and sulfoxides, such as dimethyl sulfoxide. If the reaction is performed in the presence of a base, it is also possible that bases, such as triethyl amine, pyridine, N-methyl morpholine, or N, N-diethyl aniline in excess, are used to act as a solvent or diluent. The reaction is conveniently carried out on a temperature scale from about -10 ° C to about + 40 ° C, preferably from 0 ° C to about + 20 ° C. In a preferred form, a compound of Formula V is reacted from -10 ° C to + 40 ° C, preferably at 0 ° C, in a ketone, preferably acetone, with acryloyl chloride. The invention also relates to the use of two sensors according to the invention, which have different polymer compositions in layer b) in the optical determination of the ionic concentration and the pH value of a solution of electrolyte by means of fluorescence detection.

The following Examples serve to illustrate the invention. Temperatures are given in degrees Celsius.

A) Preparation of polymerizable fluorescent dyes Example Al: 4-Acryloylaminofluorescein 1.26 milliliters of freshly distilled acryloyl chloride that have been dissolved in 1.5 milliliters of acetone, are added dropwise at 0 ° C, with stirring, to a solution of 5 grams of 4-aminofluorescein in 150 milliliters of acetone. acetone.

After one hour, the crystalline product that forms is filtered with suction and washed twice with each of acetone and ether. The product is then dried overnight under a high vacuum at room temperature. The dye breaks down from 200 ° C. H-NMR (S0DM-d6): 10.9 (s, 1H); 8.47 (d, 1H); 7.96 (dxd, 1 HOUR); 7.25 (d, 1H); 6.25-6.75 (, 6H); 6.35 (dxd, 1H); 5.85 (dxd, 1H); IR (KBr): 2100 - 3650s (wide), 1705m, 1690m, 1675m, 1630s 1600s cm "1; MS: M + = 402; absorption spectrum (EtOH): lm = 442 nm, e = 9 970; (EtOH + 2% = 0.1N NaOH):? Bav = 500 nm, e = 89 100. S0DM-d6 = deuterated dimethyl sulfoxide; EtOH = ethanol.

Example A2: 5-Acryloylaminofluorescein 180 milligrams of freshly distilled acryloyl chloride which have been dissolved in 2 milliliters of acetone, are added dropwise at 0 ° C, with stirring, to a solution of 300 milligrams of 5-aminofluorescein in 10 milliliters of acetone. After 2 hours, 5 milliliters of ether are added to the reaction mixture, and the precipitate is filtered with suction. After washing twice with ether, the yellowish-orange product is dried at room temperature under a high vacuum. ^ -RMN (S0DM-d6): 10.65 (s, 1H), 7.75 (d, 1H); 7.65 (dxd, 1H); 7.5 (broad s, 1H); 65.5 (broad s, 2H); 6.2 - 6.45 (m, 4H); 6.0 (dxd, 1H); 5.57 (dxd, 1H); IR (KBr): 2200 - 3650m (broad), 1693m, 1637m, 1591s cm "1; MS: M + = 402; absorption spectrum (EtOH):? max = 445 nm, e = 3 450; (EtOH + 2% = 0.1N NaOH):? max = 500 nm, e = 71 600.

Example A3: 4-Acryloylamino-4 ', 5'-dimethylfluorescein A mixture of 24.8 grams of 2-methylresorcinol and 21.8 grams of 4-nitrophthalic anhydride is heated at 200 ° C for 15 minutes. The cooled solid crude product is boiled in ethanol, filtered while hot, and filtered with suction. The red crystalline mixture of 4 •, 5'-dimethyl-4 (5) -nitrofluorescein is further processed immediately. 8.7 grams of sodium sulfide hydrate and 4.1 grams of sodium acid sulfur hydrate, are added to a solution of 3.7 grams of 4 ', 5'-dimethyl-4 (5) -nitrofluorescein in 150 milliliters of water, and the mixture is refluxed for 2 hours. After cooling, 15 milliliters of glacial acetic acid are added, and the resulting product is filtered with suction. The crude product is heated in 300 milliliters of 2N hydrochloric acid, and filtered while hot. The filtrate is cooled to room temperature, and produces a crystalline precipitate which, after filtering with suction, is again dissolved in 350 milliliters of a 0.5 percent sodium hydroxide solution. After the addition of 7 milliliters of glacial acetic acid, the title compound is precipitated and filtered with suction. The product is dissolved in 100 milliliters of diethyl ether, and washed twice using 20 milliliters of water each time. The dried ether phase is concentrated, and the residue is chromatographed on silica gel first with methylene chloride / methanol (85:15), then with normal hexane / ethyl acetate (1: 1), and ethyl acetate. ethyl as eluent only, with the result that the mixture of the title compound is separated. 4-Amino-4 ', 5'-dimethyl-fluorescein: lH-NMR (S0DM-d6): 9.9 (broad s, 2H); 7.05 (s, 1H); 7.0 (dxd, 2H); 6.65 (d, 2H), 6.5 (d, 2H); 5.8 (s, 2H); 2.35 (s, 6H); IR (KBr): 2300-3650s (broad), 1755s, 1710s, 1625s, 1605s cm "1; MS: M + = 376; absorption spectrum (EtOH):? -a? = 470 nm, e = 6,500; EtOH + 2% = 0.1N NaOH):? "A? = 510 nm, e = 88,000. 5-Amino-4 ', 5' -dimethyl-fluorescein: lH-NMR (S0DM-d6): . 05 (s, 2H); 7.73 (d, 1H); 6.9 (dxd, 1H); 6.8 (d, 2H), 6.7 (d, 2H); 6.4 (s, 2H); 6.25 (d, 1H); 2.45 (s, 6H); IR (KBr): 2100 -3650m (broad), 1720m, 1700m, 1630s, 1660s cm "1; MS: M + = 376: absorption spectrum (EtOH): Ba? = 471 nm, e = 1 940; (EtOH + 2% = 0.1N NaOH):? | A? = 510 nm, e = 85 200. 4-Acryloylamino-4 ', 5'-dimethylfuorescein A solution of 36 milligrams of acryloyl chloride is added dropwise to a solution of 100 milligrams of 4-amino-4 ', 5'-dimethylfuorescein in 4 milliliters of acetone After stirring at room temperature for 1.5 hours, the reaction mixture is concentrated to 0.5 milliliters, and the crystalline precipitate is triturated in ether. Filtration with suction and drying under a high vacuum produce the pure title compound in the form of yellow crystals that decompose from 200 ° C. * H-NMR (S0DM-d6): 10.85 (s, 1H); 8.4 ( d, 1H), 7.9 (dxd, 1H), 7.2 (dxd, 1H), 6.7 (d, 2H), 6.55 (d, 2H), 6.3 (dxd, 1H), 5.8 (dxd, 1H), 2.3 (s) , 6H), IR (KBr), 2200 - 3650m (broad), 1690m, 1630m, 1600s cm "1; MS: M + = 429; absorption spectrum (EtOH):? | a? = 454 nm, e = 12300; (EtOH + 2% = 0.1N NaOH):? Aa? = 514 nm, e = 77 700.

Element A4: 5-Acryloylamino-4 ', 5'-dimethylfuorescein In a manner analogous to that described in Example Al, the title compound is prepared in the form of crystals. yellows from 100 milligrams of 5-amino-4 ', 5'-dimethylfluorescein. -NMR (SODM-d6): 10.6 (s, 1H), 7.8 (d, 1H), 7.6 (d, 1H); 7.5 (broad s, 1H); 6.45 (d, 2H); 6.3 (d, 2H); 6.2 (d, 1H), 5.7 (d, 1H), 2.3 (s, 6H); IR (KBr): 2000 - 3700m (wide), 1685m, 1635m, 1600s, 1585s cm-1; MS: M + = 429; absorption spectrum (EtOH):? ^ = 454 nm, e = 15 100; (EtOH + 2% = 0. ÍN NaOH):?, ^ = 514 nm, e = 77 100.

Example A5; Acid 4 (5) - (2-methacryloyloxy) -ethylaminocarbonyl) -2- (11-hydroxy-3-oxo-3 H -dibenzo [c, h] xanthen-7-yl) benzoic acid. 100 milligrams (0.17 millimoles) of 4 (5) -carboxy-2- (1-hydroxy-3-oxo-3H-dibenzo [c, h] xanthen-7-yl) -benzoic acid are added to a solution of 32 milligrams of 2-aminoethyl methacrylate hydrochloride and 41 milligrams of 1,8-bis (dimethylamino) naphthalene in 5 milliliters of tetrahydrofuran (THF) After 48 hours of stirring at room temperature, another 32 milligrams of 2-aminoethyl methacrylate hydrochloride and 41 milligrams of 1,8-bis (dimethylamino) naphthalene are added, and the mixture is stirred for a further 48 hours. The reaction mixture is concentrated and the residue is chromatographed on silica gel first with methylene chloride / methanol (10: 1) as eluent, yielding the title compound in the form of purple crystals. "H-NMR (CDCL3): 8.6 (d, 4H); 8.45 (s, 1H); 8.2 (dxd, 1H), 8.1 (dxd, 1H); 8.05 (dxd, 1H); 7.5 (s, 1H), 7.3 - 7.4 (m, 8H); 7.2 (d, 1H); 6.15 (d, 1H); 5.95 (s, 1H), 5.65 (m, 1H), 5.45 (m, 1H); 4.4 (t, 2H); 4.2 (t, 2H); 3.8 (t, 2H); 3.6 (t, 2H); 2.0 (s, 3H); 1.8 (s, 3H); IR (KBr): 2400 - 3650m (broad), I750m, 1725s, 1650s c "1; EM: m + 587.

Example A6; In a manner analogous to that described in Examples Al to A6, it is also possible to prepare the other compounds of Formula I mentioned in Table 1.

Table 1 or. F-! R. R3 R_ 1 H H H NHCOC (CH3) = CH2 H H NHCOC (CH 3) = CH 2 H 3 CH 3 H H NHCO-HC = CH 2 4 CH3 H NHCO-HC = CH2 H 5 CH3 H H NHCO- (CH3) C = CH2 6 CH3 H NHCO- (CH3) C = CH2 H7H CH3H NHCO-HC = CH2 8 H CH 3 NHCO-HC = CH 2 H 9 H CH 3 H NHCO- (CH 3) C = CH 2 H CH 3 NHCO- (CH 3) C = CH 2 H 11 CH 3 CH 3 H NHCO-HC = CH 2 12 CH3 CH3 NHCO-HC = CH2 H 13 CH3 CH3 H NHCO- (C__3) C = CH2 14 CH3 CH3 NHCO- (CH3) C = CH2 H 15 Cl H H NHCO-HC = CH2 16 Cl H NHCO-HC = CH 2 H 17 Cl H H NHCO- (CH 3) C = CH 2 18 Cl H NHCO- (CH 3) C = CH 2 H 19 H Cl H NHCO-HC = CH 2 H Cl NHCO-HC = CH 2 H 21 H Cl H NHCO- (CH 3) C = CH 2 22 H Cl NHCO- (CH 3) C = CH 2 H 23 Cl Cl H NHCO-HC = CH 2 24 Cl Cl NHCO-HC = CH 2 H 25 Cl Cl H NHCO- (CH 3) C = CH 2 Cl Cl NHCO- (CH 3) C = CH 2 H Br H H NHCO-HC = CH 2 Br H NHCO-HC = CH2 H Br H H NHCO- (CH3) C = CH2 Br H NHCO- (CH3) C = CH2 H H Br H NHCO-HC = CH2 H Br NHCO-HC = CH 2 H H Br H NHCO- (CH 3) C = CH 2 H Br NHCO- (CH3) OCH2 H Br Br H NHCO-HC = CH2 Br Br NHCO-HC = CH2 H Br Br H N? CO- (CH3) C = CH2 Br Br NHCO- (CH 3) C = CH 2 H CH 3 O H H NHCO-HC = CH 2 CH3O H NHCO-HC = CH2 H CH3O H H NHCO- (CH3) C = CH2 CH3O H NHCO- (CH3) C = CH2 H H CH3O H NHCO-HC = CH2 H CH3O NHCO-HC = CH2 H H CH3O H NHCO- (CH3) C = CH2 H CH3O NHCO- (C? 3) C = CH2 H CH3OCO H H NHCO-HC = CH2 CH3OCO H NHCO-HC = CH2 H CH3OCO H H NHCO- (0_3) C = CH2 CH3OCO H NHCO- (CH3) OCH2 H H CH3OCO H NHCO-HC = CH2 H CH3OCO NHCO-HC = CH2 H H CH3OCO H NHCO- (CH3) C = CH2 H CH3OCO NHCO- (CH3) C = CH2 H Example 7: Preparation of: a) H3N + - (CH2) u-C (0) -0-CH3 (a). 10 grams of 12-aminododecanoic acid are suspended and 200 milliliters of absolute methanol and 2.48 milliliters of sulfuric acid (97 percent) are added. The clear solution is heated overnight under reflux. The pale yellow solution is evaporated to dryness, and the white crystals obtained are washed with diethyl ether and subsequently dried. Yield: 15.4 grams of a white powder, m.p. 73 ° C. b) CH2 = CH-C (0) -NH- (CH2) ll-C (0) -0-CH3 (b). 3.25 grams of (a) are dissolved in 50 milliliters of CHjC ^, and 1 equivalent of triethyl amine is added. The reaction mixture is cooled to 5 ° C, and equivalent drops of acryloyl chloride dissolved in 10 milliliters of CH 2 Cl 2 are added dropwise. After a reaction time of 4 hours at 0 ° C, the mixture is filtered, and the filtrate is evaporated to dryness. The crude product is dissolved in ethyl acetate, washed with water SP separates the organic phase, and pvapnra until dry. I chromatographed on silica gel using ethyl acetate as the eluent yielding 1.31 grams (46 percent) of white crystals, melting point: 65 ° C.! H-NMR (CDC1): 3.18 ppm (OCH). c) CH2 = CH-C (0) -NH- (CH2) p-C (0) -OH (c). Compound (b) is treated for 30 minutes with HCl (20 percent) at 60 ° C in water. The reaction mixture is extracted after cooling with ethyl acetate. The organic phase is washed with water and brine, and then dried. The solvent evaporates producing 80 percent of the crude product, which is pure according to the NMR analysis. The product is used directly in the next step of the process. d) Title compound. Compound (c) is dissolved in 15 milliliters of tetrahydrofuran (THF), and 2.1 millimoles of carbonyldiimidazole are added. After stirring (2 hours), 2 millimoles of 4-amipofluorescein dissolved in 60 milliliters of tetrahydrofuran are added, and stirring is continued overnight. The solvent is evaporated and the residue is chromatographed on silica gel. The fractions containing the product are combined, dissolved in IN NaOH, and acidified with IN HCl to precipitate the product. The product is isolated by centrifugation, washed twice with water, and then centrifuged. Yield of the title compound: 350 milligrams (30 percent); MS (BRA +): 599.

Example 8: Preparation of: H2CH2) 3-NH-C (0) -CH-CH, a) N3- (CH2CH2-0-) 3-H (a) 0.2 mol of triethylene glycol chlorohydrin, and 0. 3 moles of sodium azide, heated for 16 hours at 110 ° C. The reaction mixture is cooled and filtered through a sintered glass funnel (P3). The filtrate is distilled and produces 86 percent of the product; boiling scale from 100 to 115 ° C / 0.1 mm / Hg. b) N3- (CH2CH2-0-) 3-CH2-C (0) -0-C (CH3) 3 (b) 0.35 moles of (a) are slowly added to a suspension of 0.385 moles of sodium hydride in tetrahydrofuran with cooling in an ice bath. After shaking for 1 hour at room temperature, 0.42 moles of tertiary 2-bromobutyl acetate are added dropwise. The agitation is continued overnight. The solvent is evaporated, the residue is taken up in diethyl ether, washed three times with water, and once with brine. The solution is dried, the solvent is evaporated, and the residue is distilled at 0.1 mm / Hg at 120-160 ° C. 30 percent of compound (b) is obtained; ^ -NMR (CDC13): 1.48 ppm (tertiary butyl), 4.05 ppm (0CH2C (0) 0).

C) N3- (CH2CH2-0-) 3-CH2-C (0) -OH (c). 6.9 mmol of the compound (b) are dissolved in 30 milliliters of dioxane, 100 milligrams of Pd / C (5 percent) are added, and the mixture is stirred for 6 hours under a hydrogen atmosphere. After filtration and evaporation of the solvent, 99 percent of the compound (c) is produced. 1 H-NMR (CDC13): 1.50 ppm (tertiary butyl). d) CH2 = CH-C (0) -NH- (CH2CH2-0-) 3-CH2-C (0) -0-C (CH3) 3 (d). 17.5 millimoles of compound (c) are dissolved in 50 milliliters of CH2C12, and treated first with 21 millimoles of triethyl amine, and secondly with 26.2 millimoles of acryloyl chloride dissolved in 20 milliliters of CH2C12 over a period of 40 minutes. The mixture is kept for 3 hours at 0 ° C, then water is added, the organic phase is separated, dried and the solvent is evaporated. The raw product is used directly for the next step of the reaction. e) CH2 = CH-C (0) -NH- (CH2CH2-0-) 3-CH2-C (0) -0H (e). 16.4 mmol of the compound (d) in 25 milliliters of CHjCln are treated for 5 hours at room temperature with 25 milliliters of trifluoroacetic acid. The solvent and the acid are removed by distillation to give the compound (e), H-NMR (CDC13): 4.25 pp (0CH2C (0) 0), 5.75-5.85 and 6.3-6.4 (olefinic protons of the acrylic amide group) . f) Composite of the title. 1.15 mmol of the compound (e) are dissolved in 5 milliliters of tetrahydrofuran, and 1 equivalent of carbonyldi-imidazole is added. After 3 hours of stirring, 4-aminofluorescein dissolved in 30 milliliters of tetrahydrofuran is added, and the resulting mixture is stirred for 48 hours. The solvent is expelled, and the residue is purified by chromatography on silica gel. 37 percent of the title compound is produced; MS (BRA ": 589, MS (BRA +): 591.

B) Manufacture of flat sensors Example Bl: First, glass substrates (sheets of 18 millimeters in diameter) are cleaned with a sodium hydroxide solution when percent, and then activated in 65 percent nitric acid. The activated sheets are then silanized with 3-trimethoxysilylpropyl methacrylic acid ester. 150 microliters of hydroxyethyl methacrylate, 5 milligrams of 5 N, N-methylenebiscacrylic acid amide, 2 milligrams of 4-acryloylaminofluorescein, and 20 milligrams of ammonium peroxydisulfate are added to 4 milliliters of a solution taken from a solution of 4 milligrams. grams of polyhydroxyethyl methacrylate in 60 milliliters of dimethyl formamide. 50 microliters of the mixture The resultant is transferred by pipette to a sheet that remains on top of a centrifugal coater, and the sheet is centrifuged for 30 seconds at a rate of 5000 revolutions per minute. For the polymerization, the coated sheets are then kept in an oven at 64 ° C for 2 a / --_. 15 3 hours. Transparent substrates are obtained which have a polymer layer of about 1 micron thick. The polymeric layer has a good mechanical stability.

Example B2: 20 First the glass substrates are cleaned (sheets of 18 millimeters in diameter) with a 30 percent solution of sodium hydroxide, and then activated in 65 percent nitric acid. Then the activated sheets are silanized with 3-trimethoxysilylpropyl ester of methacrylic acid. 150 are added microliters of hydroxyethyl methacrylate, 5 milligrams of amide of N, N-methylenebisacrylic acid, 2 milligrams of 4-acryloylaminofluorescein, and 10 milligrams of "Irgacure 651 I" (photoinitiator, Ciba-Geigy AG) to 4 milliliters of a solution taken from a solution of 4 grams of polyhydroxyethyl methacrylate in 60 milliliters of dimethyl formamide. 50 microliters of the resulting mixture are transferred by pipette to a sheet that remains on top of a centrifuge coater, and the sheet is centrifuged for 30 seconds at a rate of 5,000 revolutions per minute. For polymerization, the coated sheets are then irradiated with ultraviolet light (365 nanometers, 1,300 μW / cm) for 10 a minutes at room temperature. Transparent substrates having a polymeric layer of about 1 miera of thickness. The polymeric layer has a good mechanical stability. __________________: In a manner analogous to that described in Examples Bl and B2, it is also possible to prepare the other membranes mentioned in Table 2 ("pseudo-penetration networks").

Table 2 polyhydroxyethyl methacrylate, PHPMA: pyridium methacrylate ih idroxy pr op i 1, PHBA: polyhydroxybutyl acrylate. 2UliPD: - pyrrolidonavillin, AA: acrylic amide, HEMA: hydroxyethyl methacrylate, HPMA: hydroxypropyl methacrylate, HBA: hydroxybutyl acrylate. 34-acryloylaminofluorescein. 'N, N-methylenebisacryl acid amide. 5-ammonium peroxodisulfate. 6 Irrcure 651. sol = solvent DMF = dimethyl formamide.

Example B4: The N-dimethylacrylic amide and tertiary-acrylic butyl amide in the desired ratio are placed in an ampoule and dissolved in dimethyl sulfoxide, so that a 30 percent solution is formed. After the addition and dissolution of a.a'-azoisobutyronitrile and 4-acryloyl-aminofluorescein, the ampule is repeatedly frozen, evacuates, and is gasified with nitrogen in order to remove the oxygen. The polymerization is carried out at 60 ° C for 48 hours in a water bath. A highly viscous transparent yellow mass is obtained, which, with stirring and if necessary with heating, dissolves in twice the amount of methanol (based on the amount of dimethyl sulfoxide used). The solution is added dropwise, with vigorous stirring, to 20 times the amount of distilled water or diethyl ether, the polymer formed being precipitated in the form of yellow wicks which agglutinate rapidly. The polymer is filtered, Dry at 100 ° C for 24 hours, then dissolve again in methanol, and precipitate in water or diethyl ether. After removing the mother liquor, the product is dried at 100 ° C for 48 hours. The resulting brittle yellow solid is very hygroscopic. The copolymer composition is determined by measurement of FT-IR, and the concentration of the dye is determined by ultraviolet spectroscopic measurement at the maximum Dye absorption (pure dye: 442 nanometers, copolyzed bristle dye: 454 nanometers). In a manner corresponding to that described, it is possible to prepare the copolymer membranes mentioned in Table 3. First the glass substrates are cleaned (sheets of 18 millimeters in diameter) with a 30 percent solution of sodium hydroxide, and then activated in 65 percent nitric acid. The activated sheets are then syllable with trimethoxysilane 3-aminopropyl. The silanated sheets are allowed to react for 1 hour at room temperature in a solution of 6- (4'-azido-2'-nitrophenylamino) -hexanoate of 0- (N-succinimidyl) in a pH regulator of dimethyl formate / borax (5: 1) The polymer (5 percent) is dissolved in methanol at 20 ° C to 25 ° C, and applied to the sheet, which has become functional with azido groups, in the form of a thin film, by means of a spin coating. at a rate of 500 revolutions per minute for 20 seconds, it is irradiated for 15 minutes, and then dried under nitrogen for 12 hours at 60 ° C. The layer thickness of the membranes is approximately 1 miera.

Table 3 1 N, N-dimethylacrylic amide 2 tertiary-acrylic butyl amide 3 4-acryloylaminofluorescein N, N-dimethylacrylic amide content 0.5 wt% tetrahydrofuran at 25 ° C 6 concentration of 4-acryloylaminofluorescein, determined by ultraviolet spectroscopy. 7 estimated Example B5: 35 milligrams (0.058 millimoles) of the compound of Example A7, 2.19 grams of N, N-dimethylacrylic amide, 2.81 grams of tertiary-acrylic butyl amide, and 25 milligrams of azobisisobutyronitrile are dissolved in 16.7 grams of sulfoxide of dimethyl, are placed in an ampoule and then frozen in liquid nitrogen. The ampoule is evacuated and then heated to room temperature. Nitrogen is introduced, and the mixture is frozen by liquid nitrogen. The procedure is repeated three times. The ampoule is kept for 5 days at 60 ° C. The yellow viscous product is dissolved in 25 milliliters of hot methanol, and the product is precipitated by the addition of 1.5 liters of diethyl ether. The residue is dissolved again in 25 milliliters of hot methanol, and precipitated by the addition of 1.5 liters of diethyl ether. The orange-red product is dried at room temperature in a high vacuum. The yield is 1.83 grams (36.6 percent), the glass transition temperature is 147.9 ° C, the inherent viscosity (0.5 percent solution in methanol at 25 ° C) is 2.06 deciliters / gram. The concentration of the dye material in the polymer is 0.53 weight percent.

Example B6: Example B5 is repeated using the compound of Example A8 in place of the compound of Example A7. The yield is 4.05 grams (81 percent), the glass transition temperature is 150.8 ° C, the inherent viscosity (0.5 percent solution in methanol at 25 ° C) is 1.34 deciliters / gram. The concentration of the dye material in the polymer is 0.44 percent by weight.

C) Application Examples Example Cl: Two sensors are mounted one behind the other in two flow cells. Calibration solutions or sample solutions are introduced and transported through the cells using pumps. The concentration of the measurement is controlled in a thermostatic manner. The light of a halogen lamp (white light, excitation wavelength of 480 nanometers) is conducted through an excitation filter, and reflected on a dichroic mirror, and focused on the flat sensors using lenses. The fluorescent light (at 520 nanometer) emitted by the sensors is collected using the same lens system, and is guided by the dichroic mirror through an emission filter to a photodiode. The fluorescence of the sensors is recorded while they are being actuated by the calibration or sample solutions. The measurement data obtained from the calibrations are evaluated with a partial least squares pattern recognition algorithm; The calculation method is then able to determine the pH and the ion concentration from the measurement data obtained from the sample. The following Tables give the effects of the different membrane compositions on the properties of embedded fluorescent dyes. Since the variation in ionic concentration alters not only the pKa of the dye, but also the pH of the measurement solution, and in turn the latter has influence on the maximum dye fluorescence intensity, in order to measure the pH using the sensor system described, it is necessary to know the dependence of the ionic concentration both in the pKa of paint as in pH of calibration buffer solution. Tables 4 and 5 show examples of fluorescent dyes, their pKa / and the dependence of the ionic concentration on the pKa and on the pH with different membrane compositions of the sensor. The sensors of the following tables that have different dependencies of ionic concentration can be selected for pH determination.

Table 4 1 for the abbreviations, see Table 2 2 A: 4-acryloylaminofluorescein, B: 4-acryloylamino-4 ', 5'-dimethylfuorescein. 3 at an ionic concentration of 0.1M 4 displacement of the pKa between the calibration curves in the regulatory solutions of an ionic concentration of 0.1M and 0.3M. 5 displacement of the pH between the calibration curves in the regulatory solutions of an ionic concentration of 0.1M and 0.3M.

Table 5 1 prepared from dimethylacrylic amide and tertiary-acrylic butyl amide (tBuAA). 2 A: 4-acryloylaminofluorescein (1 weight percent) 3 at an ion concentration of 0.1M displacement of the pKa between the calibration curves in the regulatory solutions at an ionic concentration of 0.1M and 0.3M. 5 displacement of the pH between the calibration curves in the regulatory solutions of an ionic concentration of 0.1M and 0. 3M.

Table 6

Claims (39)

1. To a method for the independent and reversible optical determination of the pH value and the ionic concentration of an aqueous sample, with the aid of two different sensors according to the fluorescence method, in said method two optical sensors, which are each composed of polymers of different structure, but each containing the same fluorescent dye, and each consisting of a coated material composed of: a) a carrier material, to which are applied: b) at least one water-insoluble layer of a polymer comprising, at least, a hydrophilic monomer (A) from the group of substituted olefins, and c) a proton-sensitive fluorescent dye that is bonded directly or via a bridge group to the central structure of the polymer b ), or which is incorporated in the polymer b), are brought into contact with an aqueous test sample irradiated with exciting light, the fluorescence is measured and the values of the pH and ionic concentrations from the fluorescence intensities measured with reference to calibration curves.

2. A method according to claim 1, wherein the carrier material of the optical sensors is transparent, and consists of glass or a transparent polymer.

3. A method according to claim 1, wherein the carrier material is planar.

4. A method according to claim 1, wherein the polymers of layer b) comprise at least 20 mole percent of the monomer (A), based on the polymer.

5. A method according to claim 1, wherein the hydrophilic monomer (A) is an olefinic monomer corresponding to Formula XX: Z? CR = CR2 (XX) wherein each R independently of the others, is hydrogen or a hydrophobic substituent, and Z? It is a hydrophilic radical.

6. A method according to claim 5, wherein the hydrophobic substituents are selected from alkyl of 1 to 12 carbon atoms, alkoxy of 1 to 12 carbon atoms, haloalkyl of 1 to 12 carbon atoms, phenyl, halophenyl, alkyl of 1 to 4 carbon atoms-phenyl, alkoxy of 1 to 4 carbon atoms-phenyl, carboxylic acid ester groups having a total of 2 to 20 carbon atoms, -CN, F and Cl.

A method according to claim 5, wherein the hydrophilic radicals are selected from -OH, -0- (2-alkylene of 2 to 12 carbon atoms) -0H, -C (0) -NH2, - C (0) -NH- (alkylene of 2 to 12 carbon atoms) -0H, -C (0) -N- (alkylene of 2 to 12 carbon atoms) -0H, -C (0) -NH-alkyl from 1 to 12 carbon) 2, pyrrolidonyl, and C- (O) -O- (alkylene of 2 to 12 carbon atoms) -OH.

8. A method according to claim 1, wherein the thickness of the polymeric layer is 0.01 to 50 microns.

9. A method according to claim 1, wherein the difference in the dependence on the ionic concentration of the sensors is at least 0.1, measured as the displacement of pKa between the calibration curves in regulatory solutions of an ion concentration of 0.1 M and 0.3M.

10. A method according to claim 1, wherein the polymers of layer b) are crosslinked.

11. A method according to claim 1, wherein the polymers of layer b) comprise at least 20 mole percent of the monomer (A) and, according to the same, at most 80 mole percent of a hydrophobic comonomer (B), based on the polymer.

12. A method according to claim 1, wherein the polymer b) comprises from 20 to 100 molar percent of at least one structural unit of Formula III: and from 80 to 0 mole percent of at least one structural unit of Formula IV: wherein: Ra is hydrogen, alkyl of 1 to 6 carbon atoms, or -COORg, and R ^ is hydrogen, alkyl of 1 to 6 carbon atoms, hydroxyalkyl of 1 to 6 carbon atoms, or an alkali metal cation , for example, Na * or K®, Rb is pyrrolidonyl, -OH, hydroxyalkoxy of 2 to 6 carbon atoms, -CONR7R8 or -COOR9, R7 and R8 are each independently of the other, hydrogen, alkyl of 1 to 6 atoms carbon, or hydroxyalkyl of 2 to 6 carbon atoms, and g is hydrogen or hydroxyalkyl of 1 to 6 carbon atoms, Rc is hydrogen or alkyl of 1 to 6 carbon atoms, Rd is hydrogen, alkyl of 6 carbon atoms , F or Cl, Re is hydrogen or alkyl of 1 to 6 carbon atoms, R_, and Rf are together -CO-O-CO-, and Rf is hydrogen, alkyl of 1 to 6 carbon atoms, -CN, F or Cl.

13. A method according to claim 12, wherein the layer it is composed of polymers having 100 mole percent of structural units of Formula III, wherein Ra is hydrogen, Rc is hydrogen or methyl, and Rb is pyrrolidonyl, -CONR7R8 or -C00R9, R7 and R8 are each independently of the another, hydrogen, alkyl of 1 to 6 carbon atoms, or hydroxyalkyl of 2 to 6 carbon atoms, and R9 is hydrogen or hydroxyalkyl of 2 to 6 carbon atoms.

A method according to claim 1, wherein the polymer layer comprises from 20 to 80 mole percent of at least one structural unit of the Formula Illa. and from 80 to 20 mole percent of at least one structural unit of the Formula Illb: wherein: Rg and R are each independently of the other, hydrogen or methyl, preferably hydrogen; Rh is di (C 1-6 alkyl) amino, preferably di (C 1-4) alkyl amino, and especially dimethylamino or diethylamino; and R is amino, preferably mono (C 1-6 alkyl) amino, and especially mono (C 1-6) alkyl amino, for example, tertiary butyl amino.

15. A method according to claim 1, wherein the hydrophilic polymers of layer b) are polymers comprising a polymerization of at least one hydrophilic monomer (A) from the group of substituted olefins, where it is homogeneously distributed when minus a carrier polymer comprising at least one hydrophilic monomer (A) from the group of substituted olefins that is identical to, or different from, the first.

16. A method according to claim 15, wherein the polymerized is crosslinked, and the carrier polymer is embedded in the polymer network.

17. A method according to claim 15, wherein the hydrophilic carrier polymer is a vinyl pyrrolidone homopolymer or copolymer; of an acrylate or hydroxyalkyl methacrylate; of vinyl alcohol; of a vinylhydroxy-alkyl ether; of an acrylic amide or methacrylic amide, or of an acrylic amide or methacrylic hydroxyalkyl amide.

18. A method according to claim 15, wherein the carrier polymer is composed of the monomer (A), and the monomer (A) is simultaneously used together with that carrier polymer for the preparation of the membrane.

19. A method according to claim 15, wherein the hydrophilic carrier polymer is polyvinyl pyrrolidone, a poly (hydroxy alkyl 2-6 acrylate) acrylate or methacrylate, for example, polyhydroxyethyl methacrylate, polyhydroxypropyl methacrylate, methacrylate of polyhydroxybutyl, polyhydroxyhexyl methacrylate, polyhydroxyethyl acrylate, polyhydroxypropyl acrylate, polyhydroxybutyl acrylate, or polyhydroxyhexyl acrylate, polyacrylic amide or polymethacrylamide, mono-polyacrylic amide (C 1-6 -alkyl or mono-poly-amide acid amide) alkyl of 1 to 6 carbon atoms), polyacrylic amide of di (C 1-6 alkyl) or polymethacrylic amide of di (C 1-6 alkyl)

20. A method according to claim 15 , wherein the polymer of layer b) comprises at least one monomer (A) from the group: pyrrolidonavinyl, 2-hydroxyethyl methacrylate, 3-hydroxypropyl methacrylate, 4-hydroxybutyl acrylate, 5-hydroxypentyl acrylate, 6-hydroxyhexyl acrylate, acrylic amide, N, N-dimethylalkyl amide, and tertiary butyl acrylic amide, or a polymer obtainable by the solution polymerization of a monomer (A), from the group: pyrrolidone-vinyl, methacrylate 2- hydroxyethyl, 3-hydroxypropyl methacrylate, 4-hydroxybutyl acrylate, 5-hydroxypentyl acrylate, 6-hydroxyhexyl acrylate and acrylic amide, in the presence of a polymer carrying a monomer (A) from the group consisting of pyrrolidone -vinyl, 2-hydroxyethyl methacrylate, 3-hydroxypropyl methacrylate, 4-hydroxybutyl acrylate, and acrylic amide.

21. A method according to claim 15, wherein the ratio of the mixture between the monomer A and the carrier polymer is from 5 to 95 weight percent of the carrier polymer, and from 95 to 5 weight percent of the monomer A, based on the total mixture of the monomer and carrier polymer.

22. A method according to claim 1, wherein the polymers of layer b) are crosslinked with 0.01 to 50 mole percent of a crosslinking agent, based on the polymer.

23. A method according to claim 22, wherein the crosslinking agent is an ester of acrylic or methacrylic acid, or amide of a polyol or polyamine.

24. A method according to claim 1, wherein the fluorescent dye is present in an amount of 0.01 to 10 weight percent, based on the polymer.

25. A method according to claim 1, wherein the proton-sensitive fluorescent dye is selected from the group of fluorescein, xanthenes and benzoxanthenes.; acridines; acridones; pyrenes and coumarins, which optionally they link in a covalent manner directly or by means of a bridge group to the polymer.

26. A method according to claim 1, wherein the bridging group of the fluorescent dye is the group - (CO) a-NH- (alkylene of 2 to 12 carbon atoms -O) r-C0- or - ( C0) s-0- (alkylene of 2 to 12 carbon atoms-O) r-C0- or -C (0) -NH- (CH2CH2-0)! bi8 6-CH2C (0) -NH-, the group (C0) 8 or the NH group being linked to the fluorescent dye, and each being rys 0 6 1.

27. A method according to claim 1, wherein where the fluorescent dye is a dye of Formula I, II or Ha: wherein Rj ^ and R2 are each independently of the other, hydrogen, alkyl of 1 to 4 carbon atoms, alkoxy of 1 to 4 carbon atoms, alkoxy of 1 to 4 carbon atoms-carbonyl, alkyl of 1 to 4 atoms of carbon-S0 - or halogen, and R3 is hydrogen and R is -NH-CO-, -CO-NH- (alkylene of 2 to 12 carbon atoms-O) -CO-, -CO-NH- (alkylene of 2 to 12 carbon atoms-NH) -CO- or -C (0) -NH- (CH2CH2-0) 1 big 6-CH2C (0) -NH-, or R3 is -NH-CO-, -CO- NH- (alkylene of 2 to 12 carbon atoms-O) -CO-, -CO-NH- (alkylene of 2 to 12 carbon atoms-NH) -CO- or -C (O) -NH- (CH2CH2- °) bis 6"2 (°) ~ NH" R 4 is hydrogen; or wherein R5 is hydrogen and R6 is -NH-C (O) -, -CO-NH- (alkylene of 2 to 12 carbon atoms-O) -CO-, -CO-NH- (alkylene of 2 to 12 carbon atoms-NH) -CO- or -C (0) -NH- (CH2CH2-0)? bis 6-CH2C (0) -NH-, or R5 is -NH-C (O) -, -CO-NH- (alkylene of 2 to 12 carbon atoms-O) -CO-, -CO-NH- ( alkylene of 2 to 12 carbon atoms-NH) -CO- or -C (0) -NH- (CH2CH2-0) 1 bis 6 -CH2C (0) -NH-, and R6 is hydrogen, in each case in the free or in salt form, or an alkyl ester of 1 to 20 carbon atoms thereof.

28. A copolymer comprising at least one recurring structural unit of Formula VII: optionally at least one recurring structural unit of Formula VIII: and the recurring structural units of Formula IX: wherein: R is hydrogen or methyl, R-, is hydrogen or alkyl of 1 to 12 carbon atoms, phenyl or benzyl, Rn and R0 are each independently of the other, alkyl of 1 to 12 carbon atoms, phenyl or benzyl, or Rn and RQ are together tetramethylene, pentamethylene, - (CH) -0- (CH2) - or - (CH2) 2 -N- (alkyl of 1 to 6 carbon atoms) - (CH2) -, and F is the radical of a fluorophore linked directly or by means of a bridging group to the N atom, with the proviso that at least two different recurring structural units of Formula VII are present, or at least one structural unit of Formula VII, and at least one structural unit of Formula VIII.

29. A copolymer according to claim 28, wherein B, Rn and R0 as alkyl contain from 1 to 6 carbon atoms.

30. A copolymer according to claim 28, wherein structural units of Formula VII and structural units of Formula VIII are present.

31. A copolymer according to claim 30, wherein the structural units of Formula VII are present in an amount of 10 to 80 mole percent, and the structural units of Formula VIII are present in an amount of 90 to 20. mole percent, based on the polymer.

32. A copolymer according to claim 28, wherein the polymer is crosslinked, and the divalent structural units of the crosslinking agent are present in an amount of 0.1 to 30 weight percent, based on the polymer.

33. A copolymer according to claim 28, wherein the fluorophore radical F is selected from the fluorophores of the formulas I, II and Ha.

34. A copolymer according to claim 28, wherein the polymer comprises structural units. of Formula VII and structural units of Formula VIII, Rk is hydrogen, R-, is alkyl of 3 to 6 carbon atoms, Rn and R0 are alkyl of 1 or 2 carbon atoms, and F is a radical of the Formula I, II or Ha.

35. A composition comprising: a) an acrylic amide or methacrylic amide of Formula X: b) optionally an acrylic amide or methacrylic amide of Formula XI: H (XI), H C ^ -NR ^ R. c) an acrylic amide or methacrylic amide of Formula XII: and d) optionally at least one diolefinic crosslinking agent, wherein Rk, R-, Rn and R0, and also F, are as defined above, with the proviso that at least two different monomers of Formula X are present, or at least one structural unit of the Formula X, and at least one structural unit of Formula XI.

36. An optical sensor comprising a material coated with a water-insoluble and hydrophilic polymer, the polymer containing an indicator dye, wherein: a) is applied to a carrier material: b) a water-insoluble layer of a polymer comprising at least one hydrophilic monomer (A) from the group of substituted olefins, and c) a proton-sensitive fluorescent dye is linked in a covalent manner directly or by means of a bridging group to the central structure of the polymer b), or it is incorporated in the polymer b).

37. A sensor according to claim 15, wherein the thickness of the polymer layer b) is 0.01 to 50 microns.

38. A compound of Formula I, He or lid: where: R? And R2 are each independently of the other hydrogen, alkyl of 1 to 4 carbon atoms, alkoxy of 1 to 4 carbon atoms, alkoxycarbonyl of 1 to 4 carbon atoms, or halogen, and R3 or R5 is hydrogen and R4 or R6 is a group - (C0) s-0- (alkylene of 2 to 12 carbon atoms -O) r-CO-CRk = CH2, - (C0) 8-NH- (alkylene of 2 to 12 carbon atoms-NH) r-CO-CRk = CH2, -NH (CO) - (alkylene of 2 to 12 carbon atoms-NH) r-CO- CRk = CH2, - (C0) s-0- (alkylene of 2 to 12 carbon atoms-O) r-CO-CRk = CH2, - (C0) 8-0- (alkylene of 2 to 12 carbon atoms-O) - alkylene of 2 to 6 carbon atoms-NH-CO-CRk = CH2, -NH- (alkylene of 2 to 12 carbon atoms) carbon-O) - alkylene of 2 to 6 carbon atoms-NH-CO-CRk = CH2, or -NH-C (O) -CH2-0- (alkylene of 2 to 12 carbon atoms -O) r- alkylene of 2 to 6 carbon atoms-NH-CO-CRk = CH2, or R3 or R5 is a group - (C0) S-NH- (alkylene of 2 to 12 carbon atoms -O) r-CO-CRk = CH2, - (CO) g-NH- (alkylene of 2 to 12 carbon atoms-NH) r-CO-CRk = CH2, -NH-C (O) - (alkylene of 2 to 12 carbon atoms-NH) r-CO-CRk = CH2, -C (O) g-0- (alkylene of 2 to 12 carbon atoms -O) r -CO-CRk = CH 2, -C (O) s-0- (alkylene of 2 to 12 carbon atoms -O) - C 2 -C 6 -alkylene-NH-CO-CRk = CH 2, -NH- (C 2 -C 12 -alkylene) - C 2 -C 6 -alkylene-NH-CO-CRk = CH2, or -NH-C (O) -CH2-0- (alkylene of 2 to 12 carbon atoms -O) r- alkylene of 2 to 6 carbon atoms-NH-CO-CRk = CH2, and R4 and R6 are hydrogen, r and s are each independently of the other, 0 or 1, and Rk is methyl or hydrogen; with the proviso that R and R2 are different from hydrogen, when R3 or R4 is acryloylamino; in each case in free form or in salt form, or an alkyl ester of 1 to 20 carbon atoms thereof.

39. The use of two sensors according to claim 36, having different polymer compositions in layer b) in the optical determination of the ionic concentration and the pH value of an aqueous electrolyte solution by means of fluorescence detection. SUMMARY A method for the independent and reversible optical determination of the pH value and the ionic concentration of an aqueous sample, with the help of two different sensors according to the fluorescence method, in this method two optical sensors are brought into contact, which are each composed of polymers of different structures, but each containing the same fluorescent dye, and each consisting of a coated material composed of: a) a carrier material, to which are applied: b) at least one insoluble layer in water of a polymer comprising, at least, a hydrophilic monomer (A) from the group of substituted olefins, and c) a proton-sensitive fluorescent dye that is bonded directly or via a bridge group to the central structure of polymer b), or that is incorporated in polymer b), with an aqueous test sample irradiated with exciting light, the fluorescence is measured and the values of the pH and ionic concentrations from the measured fluorescence intensities, with reference to calibration curves. * * * * * - • - I, ANA ELENA FERRER RAMÍREZ, translator member of the Mexican Organization of Translators, A.C., with address at Av. Clavería 224-205, Col. Clavería, México, D.F. 02080, Tels. 396 2669 and 396 5201, I certify that the preceding document is, to the best of my knowledge, a faithful and accurate translation of the original document in English that I had in view. Mexico, D.F., September 21, 1996.