MXPA96003968A - Optical sensor for the determination of io - Google Patents

Abstract

The present invention relates to a composition comprising: (a) a transparent support, (b) which is coated on at least one side with a transparent coating comprising: (b1) a hydrophobic polymer free of plasticizer having a temperature of transition to Tg glass from -150øC to 50øC; (b2) counter-ions in the form of lipophilic salts; (b3) an ionophore that forms a complex with the ion to be determined, and (b4) a compound of the formula (I) ò (II) as fluorophore: wherein R1 and R3, and R1 and R6 are alkyl of 1 to 30 carbon atoms, or alkyl of 1 to 30 carbon atoms-CO-, and R2 and R5 are H or alkyl of 1 to 30 carbon atoms, with the proviso that the total number of carbon atoms in the alkyl groups is at least 5, or a salt thereof, with an inorganic or organic acid.

Description

OPTICAL SENSOR FOR THE DETERMINATION OF IONS The invention relates to a sensor for the optical determination of ions, for example, cations of the group consisting of metal and ammonium cations, or, for example, anions of the group consisting of anions of inorganic and organic acids, in samples aqueous by the fluorescence method, said sensor contains certain highly basic dyes from the group consisting of inas stem and acridines as fluorophores in the active coating, to a process for the quantitative or qualitative determination of cations, in particular in aqueous solutions, using the optical sensor, and a composition containing the fluorophores and polymers. The optical determination of ions has recently reached a greater importance, measuring the presence or concentration of ions, for example, by means of the change in the absorption or in the fluorescence of a suitable dye. The sensors, also known as optodes, generally comprise a transparent support material and an active coating. This active coating generally contains a transparent hydrophobic polymer and a lipophilic plasticizer to achieve adequate ion diffusion and a solubility of the active constituents. The active constituents are a specific ionophore as a complexing agent for ions, a counter-ion to maintain electrical neutrality, and an indicator substance that, due to a chemical change or a physical change in the environment, generates a signal measurable optics. Patent United States Number US-A-4,645,744 describes systems of this type, wherein the indicator substance is a neutral compound, for example a dye (p-nitrophenol), which interacts with a complex of ionophore / cation of metal, causing a color change as the optically measurable signal. The interaction can cause, for example, the elimination of a proton of the dye, causing a change in the electronic state. Suitable compounds include fluorescence compounds (e.g., fluorescein), whose fluorescence changes due to the change in the electronic state, and can be determined optically by means of fluorescence measurements. H. He and collaborators, in Chemical, Biochemical and Environmental Fiber Sensor II, SPIE, Volume 1368, pages 165-174 (1990), describe systems containing a carrier proton (Nile Blue) as indicator substance, wherein the potassium transport within the active coating by means of valinomycin as ionophore, causes the dissociation of the proton carrier and the diffusion of a proton to the aqueous phase. The proton carrier changes color from blue to red and, depending on the selection of the wavelength, either the reduction in fluorescence of the blue dye or the corresponding increase in the fluorescence of the red dye can be determined. Due to the higher sensitivity and selectivity, the measurement of fluorescence is preferred. A significant drawback of the process is the low sensitivity of the system, due to the low yield of fluorescence quantum of the indicator dye used. J.N. Roe in Analyst, Volume 115, pages 353-358 (1990), describes a system based on energy transfer system due to complex formation of the fluorescence dye used with the anionic form of a certain indonaftol, which itself forms a ternary complex with the ionophore loaded with potassium. Potassium is determined by measuring the change in absorption after loading with potassium, or from the change in fluorescence. The sensitivity and response rates of this system are considered unsatisfactory. Y. Kawabata, in Anal. Chem. Volume 62, pages 1528 to 1531 and 2054 to 2055, describes a membrane system for the optical determination of potassium using a hydrophobic ion exchanger, namely 3,6-bis bromide (dimethylamino) -10-dodecyl- or -10-hexadecylacridinium. A change in fluorescence is achieved by changing the polarity in the micro environment of the sample, since the acridinium salts diffuse at the interface with the aqueous phase, due to the exchange of ions with the potassium ion. W.E. orf and collaborators, in Puré & Appl. Chem. Volume 61, No. 9, pages 1613 to 1618 (1989), describe the use of pH-sensitive chromium and fluorine ionophores for the optical determination of cations, based on ion exchange reactions. The sensitivity of these systems is relatively low, measurement is hindered in optically dense systems, and relatively high concentrations of chromium or fluoro ionophore are required in the membrane. K. Wang et al., In Analytical Science, Volume 6, pages 715 to 720 (1990), discloses membranes containing an absorption dye (Nile Blue) as an indicator substance for the optical measurement of metal cations. The system is based on an ion exchange mechanism, which reduces absorption by the protonation of the dye. The sensitivity of the system is considered too low. So far, systems that have an ion exchange mechanism for the optical measurement of ions have not been described, and are based on the determination of the change in the fluorescence of a fluorophore, and have a high sensitivity, since the quantum yields of fluorescence and the basicities of known fluorophores sensitive to pH are too low. The systems described so far contain high molecular weight hydrophobic polymers in combination with a plasticizer in the active coating, in order to ensure rapid response times and adequate sensitivities.

In these membrane materials, long-term stability and repeated use are severely restricted, since the plasticizer and other low molecular weight constituents, eg, ionophores or fluorophores, wash out over time. In addition, substances of low molecular weight can penetrate the membrane and disable the sensor. It has now been discovered that certain acridine dyes and rhodamine dyes satisfy these high requirements in a surprising manner, and are lipophilic fluorophores, pH sensitive, and highly basic, which are highly suitable, in the neutral polymeric membrane, together with an ionophore. and a counter-ion, for the determination of ions by the mechanism of ion exchange, and have a fluorescence that depends a lot on the corresponding ion concentrations. These fluorophores are distinguished by a high fluorescence quantum yield, a high basicity, a large difference between the fluorescence signals of the protonated and deprotonated forms, a high lipophilicity, an adequate photostability, and suitable absorption and emission wavelengths. Highly sensitive systems can be provided for the optical determination of ions based on fluorescence measurements. In addition, surprisingly, it has been found that the service life and the frequency of use can be increased considerably, since the hydrophobic polymers free of plasticizer having a defined transition scale to the glass can be used as the polymers in the membrane. The invention relates to a composition comprising: (a) a transparent support; (b) coating on at least one side with a transparent coating comprising: (bl) a hydrophobic polymer free of plasticizer having a glass transition temperature Tg of -150 ° C to 50 ° C; (b2) counter-ions in the form of lipophilic salts; (b3) an ionophore that forms a complex with the ion to be determined, and (b4) a compound of Formula I or II as a fluorophore: wherein R ^ and R3, and R (and R) are alkyl of 1 to 30 carbon atoms, or alkyl of 1 to 30 carbon atoms-CO-, and R2 and R5 are H or alkyl of 1 to 30 carbon atoms. carbon, with the proviso that the total number of carbon atoms in the alkyl groups is at least 5, and salts thereof with inorganic or organic acids The total number of carbon atoms in the alkyl groups is preferably of at least 8, particularly preferably at least 10, and especially preferably at least 12. In a preferred embodiment, R2 is H. The alkyl groups may be linear or branched, and preferably contain from 1 to 22 carbon atoms, linear alkyl groups are preferred The alkyl examples are methyl, ethyl and the isomers of propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl, octadecyl, nonadecyl, eicosyl, heneic osilo, docosilo, tricosilo, tetracosilo and tricontilo. In a preferred embodiment, R? and R3 are alkyl of 6 to 24 carbon atoms or alkyl of 6 to 24 carbon atoms-CO-, particularly preferably alkyl of 10 to 24 carbon atoms or alkyl of 10 to 24 carbon atoms- CO-, and especially preferably alkyl of 14 to 22 carbon atoms or alkyl of 14 to 22 carbon atoms-CO-, while R2 is H. In another embodiment, R5 is preferably H, and R4 and R6 are preferably alkyl of 6 to 24 carbon atoms, particularly preferably alkyl of 10 to 24 carbon atoms, and especially preferably alkyl of 14 to 22 carbon atoms. In a further embodiment, R4 and R5 are preferably alkyl of 1 to 6 carbon atoms, particularly preferably alkyl of 1 to 4 carbon atoms, and especially preferably methyl or ethyl, and R6 is alkyl of 10 to 24 carbon atoms 6 alkyl of 10 to 24 carbon atoms-CO-, preferably alkyl of 14 to 22 carbon atoms or alkyl of 14 to 22 carbon atoms-CO-, and an especially preferred form alkyl of 16 to 22 carbon atoms or alkyl of 16 to 22 carbon atoms-CO-. The salts of the compounds of Formulas I and II can be derived, for example, from HF, HCl, HBr, Hl, H2SO3, HjSO, H3PO3. HjPOq, HN02, HNO3, HC104, HBF,, HB (C6H5) 4, HPF &;, HSbF6, CFjSOjH, toluenesulfonic acid, C 1 -C 4 -alkyl or phenyl-phosphonic acid, formic acid, acetic acid, propionic acid, benzoic acid, mono-, di- or tri-chloroacetic acid, or acid mono-, di-, or tri-fluoroacetic. Preference is given to HCl, HBr, HjSO, HC10, HBFQ, HB (C6H5) 4, HPF & and HSbF6. The compounds of Formulas I and II are novel, and can be prepared in a manner known per se from commercial 3,6-diaminoacridine by step alkylation, by means of different alkylating agents, or by alkylation using a alkylating agent or an acylating agent. Examples of suitable alkylating agents are dialkyl sulfates or onohaloalkanes, in particular chloro-, bromo-, and iodo-alkanes. Examples of suitable acylating agents are carboxylic anhydrides, and in particular, carboxylic acid halides, for example, carboxylic acid chlorides. This reaction can be carried out in the presence of inert and aprotic polar solvents, for example, ethers, alkylated acid amides, and lactams or sulfones, and at elevated temperatures, for example, from 50 ° C to 150 ° C. It is convenient to add a hydrogen halide scavenger, for example, alkali metal carbonates or tertiary amines, in particular sterically hindered tertiary amines. The compounds of Formula 11 can be obtained, for example, by the reaction of phthalic anhydride with 2 molar equivalents of 3-monoalkylaminophenol. Another possible preparation comprises reacting 3-monoalkylaminophenol with 1 molar equivalent of 2-hydroxy-4-dialkylamino-2'-carboxybenzo-phenone. These reactions are described, for example, in U.S. Patent No. US-A-4,622,400. The reaction is conveniently carried out in an inert solvent, for example, hydrocarbons or ethers. Conveniently, molar amounts of a condensing agent are added, for example, Lewis acids, concentrated sulfuric acid, perchloric acid or phosphoric acid. The reaction temperatures may be, for example, from 50 ° C to 250 ° C. The compounds of Formula I can be isolated in a conventional manner by precipitation, crystallization or extraction, and can be purified, if necessary, by recrystallization or chromatography. These are crystalline compounds, red, red-chestnut or red-violet. The compounds of Formulas I and II are highly suitable as fluorophoric coloring indicators for the optical determination of ions in an aqueous environment, in particular by measuring the change in fluorescence. The compounds of Formulas I and II preferably have a pK value, d of at least 8, in a particularly preferred way at least 10. The support can be formed, for example, from a plastic material, for example, laminated polycarbonate or acrylic, mineral materials or glass, and can have any desired shape, for example, plates, cylinders, tubes, tapes or fibers. Glasses are preferred. The thickness of the coating on the support can be, for example, from 0.01 to 100 microns, preferably from 0.1 to 50 microns, more preferably from 0.1 to 30 microns, and in a particularly preferable manner from 0.1 to 10 microns. Various types of hydrophobic polymer are suitable for the composition, wherein the hydrophobic term indicates that the water content in the polymers is at most 15 percent by weight, preferably at most 10 percent by weight, in a manner particularly preferably at most 5 percent by weight, and especially preferably at most 3 percent by weight, based on the polymer. Conveniently they have an average molecular weight of at least 5,000, preferably at least 10,000, and in a particularly preferred manner at least 20,000 daltons, for example, from 20,000 to 200,000 daltons, preferably 50, 000 to 200,000 daltons. The polymers must have an adequate solubility in organic solvents, in such a way that they can be mixed with the other components, and can be converted into coatings by conventional coating methods. In addition, they must be permeable to ions. The glass transition temperature is preferably -130 ° C to 0 ° C. The dielectric constant of the polymers is preferably from 2 to 25, particularly preferably from 5 to 15, at 100 Hz and room temperature. The optical transparency is preferably in the range of 400 to 1200 nanometers, particularly preferably 400 to 900 nanometers. Suitable polymers are known to the person skilled in the art. They can be homopolymers, copolymers, block polymers, graft polymers and polymer alloys. The components of a polymer alloy may be a combination of two or more polymeric components, these components having high and low glass transition temperatures. The transition temperature to the glass can be adjusted, for example, by means of the polarity and the chain length and the content of the structural units. The polymers can be selected, for example, from the group consisting of polyolefins, polyesters, polyamides, polyethers, polyimides, polyesteramides, polyamideimides, polyurethanes, polyureturethanes, polyesterurethanes, polyureas, polyurethanes and polysiloxanes, it being possible for the polymers to contain basic groups ionizable (eg, amino groups), or ionizable acid groups (eg, carboxyl or sulfonyl groups), which can be used as a replacement for the counter-ion of lipophilic salts, and can provide better ion transport. Some examples of monomers for the preparation of polyolefins are olefins of 2 to 12 carbon atoms, acrylic acid, methacrylic acid, maleic acid, maleic anhydride, esters of 1 to 30 carbon atoms of acrylic and methacrylic acid, amides of 1 to 30. carbon atoms of acrylic and methacrylic acid, acrylic amide and methacrylic amide, vinyl esters of carboxylic acids of 1 to 20 carbon atoms, acrylonitrile, butadiene, isaprene, chlorobutadiene, styrene, a-methylstyrene, vinyl chloride, vinyl fluoride, vinylidene chloride and vinyl ethers of alcohols of 1 to 30 carbon atoms. Polyesters, polyesteramides and polyamides are preferably synthesized from dicarboxylic acids of 2 to 12 carbon atoms, and diols or diamines of 2 to 18 carbon atoms. The polyimides are preferably synthesized from tetracarboxylic acids of 2 to 18 carbon atoms and diamines of 2 to 18 carbon atoms. The polyethers are preferably synthesized from diols of 2 to 12 aliphatic carbon atoms (1,2 or a-? Bond), or linear adducts of these diols and diglycidyl ethers of 8 to 30 carbon atoms. The polyurethanes and polyureas are preferably synthesized from diols or diamines of 2 to 18 carbon atoms and diisocyanates and / or tri-isocyanates of 2 to 20 carbon atoms. The polysiloxanes are preferably synthesized from dialkyls (from 1 to 4 carbon atoms) silyldichlorosilaps. In a preferred embodiment, the hydrophobic polymers are polyurethanes made from paly ethers of alkanediols of 3 to 6 carbon atoms and diisocyanates of 2 to 20 aliphatic, cycloaliphatic, cycloaliphatic-aliphatic, aro-aliphatic or aromatic carbon atoms, for example , from polytetrahydrofuran and bis (p-di-isocyanatocyclohexyl) methane (Tecoflex). In another preferred embodiment, the hydrophobic polymers are copolymers comprising: a) from 10 to 90 molar percent, preferably from 20 to 80 molar percent, particularly preferably from 30 to 70 molar percent, of identical structural units or different from Formula III. and from 90 to 10 mole percent, preferably from 80 to 20 mole percent, particularly preferably from 70 to 30 mole percent, based on the polymer, of identical or different structural units of Formula IV: ^ 10 C C- (IV).

RI3 Rl2 wherein R7 and R8, independently of one another, are H or alkyl of 1 to 4 carbon atoms, X is -0-6-NR1 -, R9 is alkyl of 6 to 20 carbon atoms, and R14 is H 6 alkyl of 1 to 20 carbon atoms; R10 and R1X, independently of one another, are H, F, Cl or alkyl of 1 to 4 carbon atoms, R12 and R13, independently of one another, are H, F, Cl, alkyl of 1 to 4 carbon atoms, -COOH, -COO-alkyl of 1 to 5 carbon atoms, -CONH-alkyl of 1 to 5 carbon atoms 6 -CON (R14) -alkyl of 1 to 5 carbon atoms, 6 R12 is H and R13 is - CN, phenyl, chlorophenyl, alkoxy of 1 to 12 carbon atoms, 6 acyloxy of 2 to 18 carbon atoms. R7 is preferably H or methyl, and R8 is preferably H. X is preferably -0-. R9 is preferably alkyl of 6 to 18 carbon atoms. Examples of R9 are hexyl, heptyl, octyl, 2-ethylhexyl, nonyl, decyl, dodecyl, tetradecyl, hexadecyl and octadecyl. R 10 is preferably H 6 methyl, R 2 is preferably H, and R 12 is preferably H. R 13 is preferably -CN, phenyl, -COO-alkyl of 1 to 4 carbon atoms, alkoxy of 1 to 4 carbon atoms. carbon, 6 acyloxy of 2 to 6 carbon atoms. Some examples of acyloxy are acetyloxy, propionyloxy, butyroyloxy, pentanoyloxy and hexanoyloxy. Examples of suitable salts with lipophilic anions are alkali metal, alkaline earth metal, and ammonium salts with substituted or unsubstituted tetraphenyl borates. The preferred cations with Li®, Na®, K®, Mg2®, Ca2®, NH4®, and the ammonium cations of primary, secondary and tertiary amines, and the quaternary ammonium cations which may contain from 1 to 60 carbon atoms. carbon. Some examples of ammonium cations are methyl, ethyl, propyl, butyl, hexyl, octyl, decyl, dodecyl, tetradecyl, hexadecyl, octadecyl, dimethyl, diethyl, dibutyl, butylmethyl, dioctyl, didodecyl, dodecylmethyl, trimethyl, triethyl, tripropyl, tributyl, trioctyl, tridodecyl, dodecyldimethyl, didodecylmethyl, tetramethyl, tetraethyl, tetrapropyl, tetrabutyl, tetrahexyl, tetraoctyl, tetradecyl, tetradodecyl, dodecyltrimethyl, octyltrimethyl, didodecyldimethyl, tridodecylmethyl, tetradecyltrimethyl and octadecyltrimethyl. The quaternary ammonium salts are preferred, in particular those having from 4 to 48, preferably from 4 to 24 carbon atoms. Other suitable salts with lipophilic anions are alkali metal, alkaline earth metal and ammonium salts of anionic surfactants, for example, of fatty acids of 12 to 22 carbon atoms or of alkyl acids of 12 to 22 carbon-sulfonic atoms, phosphates of alkyl of 12 to 22 carbon atoms, alkyl acids of 4 to 18 carbon atoms-benzoic acids, alkyl acids of 4 to 18 carbon atoms-phenylsulfonic acids, or alkyl acids of 4 to 18 carbon atoms-phenylphosphonic acids.

An example of a suitable borate anion is tetraphenyl borate, which phenyl groups can be substituted by one or more, preferably 1 to 3, particularly preferably 1 6 2 alkyl groups of 1 to 4 carbon atoms, alkoxy 1 to 4 carbon atoms, halogen, for example, F or Cl, or trifuoromethyl. Some specific examples are tetraphenyl borate, tetra (3,5-bistrifluoromethylphenyl) borate, and tetra (4-chlorophenyl) borate. The salts with lipophilic anions serve as a negative charge compensation for the metal cations that diffuse into the active coating, and to be measured therein in a complexed form. The salts with lipophilic anions can also be polymer salts containing acidic or basic groups, for example polysulphonic acids or polycarboxylic acids. These polymers can also be structural units (randomly distributed structural units or block elements) of the hydrophobic polymers. The amount of salts with lipophilic anions can be, for example, from 0.01 to 10 weight percent, preferably from 0.1 to 5 weight percent, particularly preferably from 0.1 to 2 weight percent, based on the amount of polymer. The polymer coating (also referred to as a membrane) contains an ionophore in, for example, an amount of 0.01 to 10 weight percent, preferably 0.1 to 5 weight percent, particularly preferably 0.1 to 2 weight percent. percent by weight, based on the amount of the polymer. Ionophores are natural or synthetic organic compounds which contain a plurality of electron-rich heteroatoms, normally alternating, for example, S, N and in particular 0, in the linear or cyclic carbon chains, and which are capable of selectively completing the ions that are going to be measured. Natural compounds are often macrocyclic compounds, for example, valinomycin, which is capable of selectively binding potassium cations. Another example is nonactin. A large group of ionophores comprises macrocyclic polyethers (crown ethers), which are capable of complexing different metal cations, depending on geometry and size. Other examples of ionophores are coronandenos, cryptandenos and calixarenos. The examples of the open chain ionophores are podandenos. These ionophores are described, for example, in U.S. Patent No. US-A-4,645,744. Examples of ionophores for anions are open chain or macrocyclic polyamines (mono- and polycyclic compounds, usually in a protonated form as polycations or as (poly) quaternary ammonium salts); open-chain or macrocyclic polyamides (mono- and poly-cyclic); open chain or macrocyclic polypyridinium (cyclic) compounds; calixarenos; cyclodextrins; metal porphyrin cobirinates and complexes; open-chain or macrocyclic metallocene compounds; mono- and polydentate ligand systems containing, for example, B, Si, Al or Sn as atoms of complexing ligands. The amounts of compounds of Formulas I and II can be, for example, 0.01 to 10 weight percent, preferably 0.1 to 5 weight percent, particularly preferably 0.1 to 2 weight percent, based on the amount of polymer. The fluorophores to be used according to the invention have very suitable absorption and emission wavelength ranges, which allow the use of known and economical light sources, for example, halogen or xenon lamps, or diodes light emitters. Examples of the detectors that can be used are photodiodes. The fluorophores also have high absorption coefficients and high quantum yields can be achieved. The high lipophilicity, the high basicity and the large dynamic scale of the change in fluorescence between the protonated and deprotonated forms, satisfy, in particular, the high requirements for the optical determination of ions, based on the fluorescence measurements. Both cations and anions can be determined. Examples of suitable cations are metal cations from the first to fifth major groups, and from the first to the eighth subgroups of the Periodic Table of the Elements, the lanthanides and the actinides. Some examples of metals are Li, Na, K, Rb, Cs, Mg, Ca, Sr, Ba, B, Al, Ga, In, TI, Sn, Pb, Sb, Bi, Cu, Ag, Au, Zn, Cd , Hg, Se, And, Ti, Zr, Hf, Cr, Mo, W, Mn, Fe, Co, Ni, Ru, Os, Rh, Go, Pt, Pd, The, Ce, Pr, Nd, Pm, Sm , Eu, Gd, Tb, Dy, Ho, Er, Yb, Lu, Ac, Th, Pa, U, Np and Pu. The preferred cations are the alkali metal and alkaline earth metal ions, in particular Li *, Na *, K *, Mg2 *, Ca2 *, Sr2 *, very particularly K *, Na * and Ca *. Examples of suitable ammonium cations are NH 4 *, and cations of primary, secondary and protonated tertiary and quaternary ammonium amines. The amines may contain from 1 to 40, preferably from 1 to 20, particularly preferably from 1 to 12 carbon atoms. The quaternary ammonium may contain from 4 to 40, preferably from 4 to 20, and particularly preferably from 4 to 16 carbon atoms. The anions to be measured can be derived from mineral acids, oxygen acids and inorganic complex acids. Examples are halides and pseudohalides F *, Cl *, Br *, I *, N3 *, CN *, OCN * and SCN *; the inorganic oxygen acid anions N02 *, N03 *, C032 *, P043 *, S042 *, C104 *, Mn04 * and C103 *; the inorganic complex acid anions Fe (CN) 64 * and Co (CN) 63 *; the anions of carboxylic acids, phenols and nucleotide anions, such as adenosine phosphate. The composition according to the invention is highly suitable as an optical sensor for the quantitative determination of ions, in particular cations, very particularly metal cations, for example, potassium cations, in an aqueous environment, preferably by means of spectrometry of fluorescence. The determinations can be made quickly with a high precision, even for low concentrations (for example, in the micromolar scale up to the nanomolar scale), since the equilibriums that depend on the pH of the complexing reactions and the proton exchange, get stabilized rapidly, and fluorophores are characterized by high fluorescence quantum yield and sensitivity. The analysis can be carried out, for example, directly in body fluids (blood, urine, serum), in natural water, or in wastewater, where it is possible that any cations that interfere are specifically linked or removed in advance. . The composition according to the invention is particularly suitable for the determination of physiological quantities, for example, for potassium on the scale of 0.5 to 10 millimoles, of cations in aqueous media. By means of the anionic compounds of Formula II, which generally have pK values less than 6, this property of the fluorophore can be used for the determination of anions, particularly halides, especially chloride, by the novel detection method, since a scale of pK less than 6 and, for example, up to about 4, is favorable for this detection. In addition to the preferred method of fluorescence spectroscopy, other methods of optical measurement can also be employed, for example, surface-plasmon resonance spectroscopy, absorption spectroscopy, reflex spectroscopy, interferometry or fluorescence spectroscopy or Ra an amplified surface spectroscopy. The invention further relates to a composition comprising: (a) a hydrophobic polymer free of plasticizer, having a glass transition temperature Tg of -150 ° C to 50 ° C, and (b) a compound of Formula I or II as fluorophore: wherein R ^ and Rj, and Rfl and Rj are alkyl of 1 to 30 carbon atoms or alkyl of 1 to 30 carbon atoms-CO-, and Rj and Rs are H or alkyl of 1 to 30 carbon atoms, with the condition that the total number of carbon atoms in the alkyl groups be at least 5, or salts thereof with inorganic or organic acids, ^ (c) an ionophore, which forms a complex with the ion leaving determine, and (d) counter-ions in the form of lipophilic salts. The aforementioned preferences and modalities 5 apply to this composition. The composition has a long shelf life, and is a coating composition for the production of sensors. The novel composition may additionally comprise inert solvents, wherein the concentration of the composition in C, the solution is from 1 to 50 weight percent, preferably from 5 to 40 weight percent, particularly preferably from 5 to 40 weight percent, 30 percent by weight, based on the solution. Examples of suitable inert solvents are protic-polar and aprotic solvents, which can be used alone or in mixtures of at least two solvents. Examples are: ethers (dibutyl ether, tetrahydrofuran, dioxane, ethylene glycol monomethyl ether and ethylene glycol dimethyl ether, ethylene glycol diethyl ether, diethylene glycol diethylene ether, triethylene glycol dimethyl ether), halogenated hydrocarbons (chloride) of methylene, chloroform, 1,2-dichloroethane, 1,1-trichloroethane, 1,2,2-tetrachloroethane), carboxylates and lactones (ethyl acetate, methyl propionate, ethyl benzoate, 2- acetate) methoxyethyl,? -butyrolactone, d-valerolactone, pivalolactone), carboxamides and lactams (formamide N, N-dimethyl, formamide N, N-diethyl, acetamide N, N-dimethyl, tetramethyl urea, hexamethylphosphoric triamide,? -butyrolactam, e- caprolactam, N-methyl pyrrolidone, N-acetyl pyrrolidone, N-methyl caprolactam), sulphoxides (dimethyl sulfoxide), sulfones (dimethyl sulfone, diethyl sulfone, trimethylene sulfone, tetramethylene sulfone), tertiary amines (piperid N-methyl, N-methyl morpholine), aliphatic and aromatic hydrocarbons, for example, petroleum ether, pentane, hexane, cyclohexane, methylcyclohexane, benzene or substituted benzenes (chlorobenzene, o-dichlorobenzene, 1,2,4-trichlorobenzene, nitrobenzene, toluene, xylene), and nitriles (acetonitrile, propionitrile, benzonitrile, phenylacetonitrile). The choice of a solvent depends essentially on the solubility of the individual components in the novel composition, which, as a coating for a sensor, must give a highly homogeneous mixture. Preferred solvents are polar aprotic solvents. The invention further relates to an optical sensor for the determination of cations in the aqueous measurement of samples, in particular by fluorescence spectrometry, which comprises: (a) a transparent support, (b) which is coated on at least one side with a transparent coating comprising: (bl) a hydrophobic polymer free of plasticizer having a glass transition temperature of -150 ° C to 50 ° C; (b2) a counter-ion in the form of a salt of a lipophilic anion; (b3) an ionophore that forms a complex with the ion to be determined, and (b4) a compound of Formula I or II as the fluorophore. The preferences and modalities mentioned above apply to the sensor. The novel sensor is produced by coating the support. For this purpose, conventional processes can be employed, for example, brush application, knife coating, dipping, spraying, pouring, curtain coating and centrifugal coating. In order to improve the adhesion, adhesion promoter layers can be provided to the support prior to coating, for example by its treatment with alkyl chlorosilanes. The invention also relates to a method for the optical determination of ions in aqueous measurement samples, wherein a composition according to the invention is contacted with the aqueous measurement sample, and then, in particular, the change in fluorescence of the fluorophore in the active polymer coating is measured. The process according to the invention can be carried out, for example, by immobilizing the composition according to the invention, comprising the support and the coating of active polymer, in an optical cell, wherein the active coating is placed in contact with the sample of 5 measurement. The optical cell contains a window, through which the active coating can be excited by irradiation, and the fluorescence radiation emitted can be measured by means of a spectrofluorometer. The wavelengths are adjusted in such a way that the absorption is at maximum lfc for irradiation, and the emission is at maximum for the fluorescence measurement. The intensity is measured as a function of time. The measurement system can be designed in such a way that the measurement is carried out in a discontinuous or continuous manner, for example, by pumping the measurement solution through the cell of measurement. In order to determine unknown cation concentrations, the system can be calibrated first by means of measurement samples of a known concentration, and the concentrations are plotted as a function of the fluorescence intensity. It is convenient to add pH regulators to the measurement sample, since the sensitivity of the measurement, and consequently also the fluorescence intensity of the fluorophore, depends on the pH of the measurement solution, due to the pH dependency of the Absorption spectrum. However, in another modality, this dependence on the pH can also be determined and taken into account in the calculation.

The pH scale of the measurement sample can be, for example, from 4 to 8, more preferably from 6.5 to 7.5. Examples of suitable regulators are citrate regulators and phosphate regulators. Other regulatory systems are described in U.S. Patent No. US-A-4,645,744, in particular including those that are incorporated directly into the active coating, in order to avoid addition to the measurement sample.

The following examples illustrate the invention in greater detail.

A) Preparation of fluorophores of Formulas I and II Example Al: Preparation of 3,6-bis (octyl normal-amino) acridine 6.33 grams of anhydrous potassium carbonate are added to a solution of 2.5 grams of 3,6-hydrochloride. diamino-acridine and 3.55 milliliters of 1-bromo-octapo in 50 milliliters of dimethyl sulfoxide, and the mixture is stirred at 80 ° C for 48 hours. The cooled reaction mixture is subsequently poured onto ice, and the brown suspension is extracted with methylene chloride. The organic phase is washed with a saturated aqueous solution of NaCl, and dried over sodium sulfate. After evaporation, the red-brown oil is chromatographed on silica gel using ethylene chloride / methanol (9: 1).

After evaporation of the solvent, the residue is taken up in diethyl ether / methanol (10: 1), and chromatographed on aluminum oxide. The eluate is recovered in methanol, 2N HCl is added, the mixture is extracted with diethyl ether, and the ether phase is dried and evaporated. The residue is dissolved in methylene chloride, normal hexane is added, and the formed red crystalline precipitate is filtered. Additional product can be isolated from the mother liquor after evaporation. The melting point of the title compound is 245 ° C. Absorption spectrum (ethanol):? Max = 472 nm; e = 51,400.

Example A2; Preparation of 3,6-bis (eicosyl norm-amino) acridine 2.53 grams of anhydrous potassium carbonate are added to a solution of 2.5 grams of 3,6-diamino-acridine hydrochloride and 2.95 grams of 1-eicosyl bromide in 20 milliliters of N, N'-dimethylethylene urea, and the mixture is stirred at 50 ° C for 86 hours. The cooled reaction mixture is subsequently poured into water, and the orange-brown suspension is extracted with methylene chloride. The organic phase is washed with water and dried over sodium sulfate. After evaporation, 2N HCl is added to the chestnut oil. The red precipitate formed is filtered, washed with water, and then dried in a high vacuum. The resulting red-brown crystals are recovered in methylene chloride / methanol (10: 1), and passed through chromatography on silica gel. After evaporation, the residue is taken up in diethyl ether / methanol (10: 1), and re-chromatographed on silica gel, giving the title compound as red crystals; absorption spectrum (ethanol):? ma? = 472 nm; e = 42,200.

Example A3: Preparation of 3,6-bis (hexyl normal-amino) acridine 298 milligrams of milled potassium hydroxide are added to a solution of 500 milligrams of N, N'-bistosyl-3,6-diaminoacridine and 797 milligrams of 1 -bromohexane in 25 milliliters of dimethyl formamide, and the mixture is stirred at 60 ° C for 22 hours. The cooled reaction mixture is subsequently poured into water, and extracted with ethyl acetate, and the organic phase is separated, washed with an aqueous solution of NaCl, and then dried over sodium sulfate. Evaporation gives a dark red oil, which is recovered in toluene / ethyl acetate (20: 1), and chromatographed on silica gel. Evaporation of the solvent gives a viscous yellow oil, which is dissolved in 11.5 milliliters of glacial acetic acid, 4.6 milliliters of 97 percent sulfuric acid are added with cooling with water, and then the mixture is stirred at room temperature for 15 minutes. hours. The red reaction mixture is poured into ice water, and adjusted to a pH of 11 by 30 percent NaOH. The mixture is extracted with ethyl acetate, and the organic phase is washed with 2N HCl and a saturated aqueous solution of NaCl, and then dried over sodium sulfate. After evaporation, the viscous dark red oil is recovered in methyl tertiary-butyl ether / methanol (5: 1), and chromatographed on silica gel, giving the title compound as orange-red crystals having a spot fusion >200 ° C (decomposition). ^ -RMN (CDC13): 8.1 [s, 1H, C (9)]; 7.44 [d, 2H, C (8)]; 6.93 [s, 2H, C (5)]; 6.82 [d, 2H, C (7)]; 3.20 [t, 4H, N-CH2]; 1.68 [m, 6H, CH3]. Example A4: Preparation of 3,6-bis (normal heptyl-ilanylamino) acridine 3.1 milliliters of heptanoyl chloride are slowly added dropwise to a suspension of 2.5 grams of hydrochloride 3,6-diaminoacridine in 50 milliliters of pyridine, and then the mixture is stirred for 30 minutes. The reaction mixture is subsequently poured into water. The yellow suspension is extracted with methylene chloride, and the organic phase is washed with a saturated aqueous solution of NaCl, and dried over sodium sulfate. After evaporation, the dark red oil is recovered in methylene chloride / methanol (10: 1), and chromatographed on silica gel. The evaporated eluate is recovered in methylene chloride, and added dropwise to cyclohexane. The yellow precipitate formed is filtered, washed with cyclohexane and dried in a high vacuum to give the title compound as yellow crystals having a melting point of 243-244 ° C. Absorption spectrum (ethanol):? Max = 384 nm; e = 2,300.

Example A5: Preparation of: a) A solution of 12.8 grams of phthalic anhydride and 13.2 grams of 3-N, N-diethylaminophenol is stirred at 110 ° C for 16 hours in 75 milliliters of toluene. The precipitated product is filtered and recrystallized from ethanol, giving red septum crystals of l-carboxy-l-hydroxy-3'-diethylaminobenzophenone (product A) having a melting point of 214 ° C. b) A solution of 5.5 grams of 3-aminophenol and 21.6 grams of 1-bromoeicosane in 250 milliliters of 1,4-dioxane is stirred at 100 ° C for 48 hours. The mixture is evaporated in vacuo, and the gelatinous brown residue is taken up in toluene / ethyl acetate (10: 1), and chromatographed on silica gel, giving 3-N-eicosylaminophenol as white crystals having a point of fusion of 80 ° C. c) 626 milligrams of product A and 790 milligrams of 3-N-eicosylaminophenol are stirred for 2 hours at 170 ° C in 5 milliliters of phosphoric acid (85 percent). After cooling, a solution of 1 milliliter of concentrated HCl in 1 milliliter of methanol is added, and the mixture is subsequently extracted with methylene chloride. After removing the solvent, the residue is taken up in methylene chloride / ethanol (85:15), and chromatographed on silica gel, giving the title compound as red-violet crystals having a melting point of 115. ° C. Absorption spectrum (ethanol):? = 532 nm; e = 90,000.

Example A6: Preparation of: a) A solution of 5.45 grams of 3-aminophenol and 11.6 grams of 1-bromo-octane in 250 milliliters of dioxane, stir at 100 ° C for 80 hours, then the solvent is evaporated, and the residue is then recovered in toluene ethyl acetate (10: 1), and chromatographed on silica gel, giving N-octylaminofonol as oeiges crystals, melting point of 75c C. b) 1.1 grams of N-octylaminophenol and 0.37 grams of phthalic anhydride are melted together at 100 ° C. 1 milliliter of phosphoric acid (85 percent) is added to the melt, which is then heated to 170 ° C. After 1 hour, the mixture is allowed to cool, and 2N HCl is added. The mixture is extracted with methylene chloride, the solvent is removed, and the red residue is recovered in methylene chloride / methanol (85:15). Chromatography on silica gel gives the title compound as red crystals having a melting point of 183 ° C. Absorption spectrum (ethanol); ? max = 522 nm: e = 73,700.

Example A7; Preparation of: a) 1.57 grams of product A of Example A5a, 0.55 grams of 3-aminophenol, and 10 milliliters of phosphoric acid (85 percent), are stirred for 30 minutes at 170 ° C. Then 6.7 milliliters of perchloric acid (50 percent) and 100 milliliters of methanol are added, the mixture is reheated, and the solvent is then removed in vacuo. The residue is recovered in methylene chloride, the solution is washed with water, and the solvent is removed again. The residue is taken up in methylene chloride / methanol (10: 1), and chromatographed on silica gel, giving red crystals of compound B of the formula: which has a melting point of 175 ° C. b) 0.1 gram of compound B is dissolved in 1 milliliter of methylene chloride and 0.3 milliliter of pyridine, and 100 milligrams of stearoyl chloride are added. After 3 hours, the mixture is evaporated to dryness in vacuo, and the residue is dissolved in methylene chloride / methanol (85:15), and chromatographed on silica gel, giving the title compound as red crystals which They have a melting point of 145 ° C. Absorption spectrum (ethanol); ? ma? = 560 nm: e = 10,900.

B) Preparation of polymers Examples B1 to B7: The monomers mentioned in Table 1 are introduced into an ampoule in the stated mixing ratios, together with 0.1 weight percent a, a'-azobisisobutyronitrile. In order to remove oxygen, the vial is evacuated and filled with nitrogen a number of times, then sealed, heated to 60 ° C and left at this temperature for 48 hours. The mixture is then cooled and dissolved in ten times the amount (based on the monomers) of tetrahydrofuran (THF). This solution is transferred to 20 times the amount of methanol, and then the precipitated polymer is filtered. The dried polymer is redissolved in tetrahydrofuran, and precipitated using methanol, separated, and then dried under vacuum for 48 hours. In Table 1 below, the following abbreviations are used; AN = acrylonitrile, DodMA = dodecyl methacrylate, EHA = ethylhexyl acrylate, MA = methyl methacrylate, VAC = vinyl acetate. The inherent viscosity (VI) is determined at 25 ° C in a 0.5 percent by weight solution of polymer in tetrahydrofuran.

TABLE 1 Examples B6 and B7 The procedure is as in Examples B1-B6, using ethyl acetate (EA), acrylonitrile (AN) and ethylhexyl acrylate (EHA). Results are shown in table 2.

TABLE 2 C) Production of coated supports Examples C1-C8: a) Support material.

The support material used is pre-treated glass. Circular glass plates (diameter 18 millimeters, thickness 0.17 millimeters) are immersed for one hour in a solution of 10 percent by volume of dimethyldodecylchlorosilane in isopropanol. Then the glass plates are washed each, one after the other, with 200 milliliters of isopropanol, ethanol and methanol, and dried at 110 ° C for 1 hour. The hydrophobic surface has a better adhesion of the membrane coating. b) Preparation of the coating solution. The following constituents are introduced into a 2 milliliter bottle, together with tetrahydrofuran (THF), and stirred until the components have dissolved. The fluorophore used is the compound of Example A5.

Example Cl: 125 grams of the polymer of Example Bl, 1.0 milligrams of fluorophore, 1.5 milligrams of valinomycin, 1.2 milligrams of tetrakis [3,5- (trifluoromethyl) phenyl] borate] of potassium, 3 milliliters of tetrahydrofuran.

Example C2: 100 milligrams of polymer of Example B2, 1.0 milligrams of fluorophore, 1.5 milligrams of valinomycin, 1.2 milligrams of tetrakis [3,5- (trifluoromethyl) phenyl] borate of potassium, 2 milliliters of tetrahydrofuran.

Example C3: 40 milligrams of polymer of Example B3, 1.5 milligrams of fluorophore, 1.5 milligrams of valinomycin, 1.2 milligrams of tetrakis [3,5- (trifluoromethyl) phenyl] borate] of potassium, 2 milliliters of tetrahydrofuran.

Example C4: 38 milligrams of polymer of Example B4, 1.5 milligrams of fluorophore, 1.5 milligrams of valinomycin, 1.2 milligrams of tetrakis [3,5- (trifluoromethyl) phenyl] borate] of potassium, 2 milliliters of tetrahydrofuran.

Example C5: 50 milligrams of polymer of Example B7, 1.5 milligrams of fluorophore, 1.5 milligrams of valinomycin, 1.2 milligrams of tetrakis [3,5- (trifluoromethyl) phenyl] borate] of potassium, 2 milliliters of tetrahydrofuran.

Example C6: 20 milligrams of Tecoflex polyurethane (Thermedics Inc., Woburn) having a Tg of -70 ° C, 0.5 milligrams of fluorophore, 0.24 milligrams of valinomycin, 0.2 milligrams of borate tetrakis [3,5- (trifluoromethyl) phenyl ] of potassium, 1 milliliter of tetrahydrofuran.

Example C7: 100 milligrams of Tecoflex * polyurethane (Thermedics Inc., Woburn) having a Tg of -70 ° C, 3 milligrams of fluorophore, 50 milligrams of N, N- [(4R, 5R) -4,5-dimethyl -l, 8-dioxo-3,6-dioxaoctamethylene) diethyl bis (12-methylamino) dodecanoate (calcium ionophore, Fluka 21102), 6 milligrams of potassium tetrakis [3,5- (trifluoromethyl) phenyl] borate, 2 milliliters of tetrahydrofuran. c) Production of coated glass supports. The glass supports are held in the chamber of a centrifugal coating apparatus (Optocoat OS 35var, Willer Company, CH-8484 Weisslingen). The chamber is rinsed with 10 milliliters of tetrahydrofuran and rotated for 2 minutes at 3,800 revolutions / minute. Then 50 microliters of the particular coating solution is pipetted onto the glass support, and the glass support is centrifuged for another 10 seconds. The glass support coated with a membrane is then removed and dried for 10 minutes in the air.

D) Determination of ion concentrations Examples DI to D6: The coated glass supports are held in an optical cell, where the membrane is in contact with the measuring liquid. The membrane can be excited optically in the optical cell, and the fluorescence radiation is measured. The optical cell is inserted in a spectrofluorometer (Perkin-Elmer LS-50). The wavelengths of absorption and emission are adjusted to the corresponding maximums of the fluorophores used in the membrane. The membrane is contacted with an aqueous solution of KCl, or a CaCl 2 solution of a defined concentration, pumping the solution through the cell at a rate of 1 milliliter / minute, and determining the change in fluorescence intensity. Before the measurement and after each measurement, the cell is rinsed with pH-regulating solutions free of potassium ion, and the fluorescence intensity is determined in order to define the baseline. The following tables show the fluorescence intensity (measured as the change in the photodiode voltage) as a percentage of the respective potassium concentration for the fluorophore of Example A5 (membrane Bl), and different compositions, as in Examples C1 -C7 Example DI (membrane C2): Potassium concentration (M) Fluorescence (volts) 0.00 4.32 0.1 3.96 0.5 3.67 1.0 3.52 3.0 3.46 5.0 3.33 7.0 3.23 10.0 3.15 Example D2 (membrane C6): Potassium concentration (mM) Fluorescence (volts) 0.00 5.30 0.1 3.20 0.5 1.70 1.0 1.20 3.0 0.50 5.0 0.40 7.0 0.30 10.0 0.20 Example D3 (Cl membrane): Potassium concentration (M) Fluorescence (volts) 0.00 6.89 0.5 4.00 4.0 2.89 10.0 1.89 Example D4 (C4 membrane): Concentration of Potassium (mM) Fluorescence (volts) 0.00 6.80 0.5 4.50 4.0 3.20 10.0 2.50 Example D5 (membrane C5): Potassium concentration (mM) Fluorescence (volts) 0.00 3.00 0.5 2.40 4.0 2.25 10.0 2.15 Example D6 (membrane C7): Potassium concentration (mM) Fluorescence (volts) 0.00 1.55 0.1 0.96 0.5 0.75 1.0 0.65 3.0 0.50 5.0 0.45 7.0 0.40 10.0 0.38

Claims (39)

1. A composition comprising: (a) a transparent support; (b) coating on at least one side with a transparent coating comprising: (bl) a hydrophobic polymer free of plasticizer having a glass transition temperature Tg of -150 ° C to 50 ° C; (b2) counter-ions in the form of lipofluoric salts; (b3) an ionophore that forms a complex with the ion to be determined, and (b4) a compound of Formula I or II as a fluorophore: where R | and Rj, and Rj and Rj are alkyl of 1 to 30 carbon atoms, or alkyl of 1 to 30 carbon atoms-CO-, and R2 and R are H or alkyl of 1 to 30 carbon atoms, with the proviso that the total number of carbon atoms in the alkyl groups be at least 5, or a salt thereof, with an inorganic or organic acid.

2. A composition according to claim 1, wherein R2 is H.

3. A composition according to claim 1, wherein the alkyl groups are linear alkyl groups.

4. A composition according to claim 1, wherein the alkyl groups contain from 1 to 22 carbon atoms.

5. A composition according to claim 1, wherein Rj and R are alkyl of 6 to 24 carbon atoms, or alkyl of 6 to 24 carbon atoms-CO-, and R2 is H.

6. A composition according to with claim 5, wherein Rj and R3 are alkyl of 10 to 24 carbon atoms or alkyl of 10 to 24 carbon atoms-CO-.

7. A composition according to claim 5, wherein R ^ and R are alkyl of 14 to 22 carbon atoms or alkyl of 14 to 22 carbon atoms-CO-.

8. A composition according to claim 1, wherein R5 is H, and R1 and R1 are alkyl of 6 to 24 carbon atoms.

9. A composition according to claim 8, wherein Rq and R6 are alkyl of 10 to 24 carbon atoms.

10. A composition according to claim 9, wherein RQ and R6 are alkyl of 14 to 22 carbon atoms.

11. A composition according to claim 1, wherein R | and R5 are alkyl of 1 to 6 carbon atoms, and R1 is alkyl of 10 to 24 carbon atoms or alkyl of 10 to 24 carbon atoms-CO-.

12. A composition according to the claim 11, wherein Rj and Rj are alkyl of 1 to 4 carbon atoms, and R ^ is alkyl of 14 to 22 carbon atoms or alkyl of 14 to 22 carbon atoms-CO-.

13. A composition according to the claim 12, wherein R ^ and Rj are methyl or ethyl, and R1 is alkyl of 16 to 22 carbon atoms or alkyl of 16 to 22 carbon atoms-CO-.

14. A composition according to the claim 1, wherein the salt of the compound of Formula I or II is derived from HF, HCl, HBr, Hl, H2S03, H2SO4, H3PO3, H3P0", HN02, HNO3, HClO ?, HBF ,,, HPF6, HSbF &; , CF3SO3H, HBtC ^ Q, toluenesulfonic acid, alkyl acid of 1 to 4 carbon atoms- or phenyl-phosphonic acid, formic acid, acetic acid, propionic acid, benzoic acid, mono- or tri-chloroacetic acid, or mono acid - di- or trifluoroacetic.

15. A composition according to claim 14, wherein the salt of the compound of Formula I or 11 is derived from HCl, HBr, H ^, HC10¡,, HBF4, HPF6, HB [C6H5]? or HSbF6.

16. A composition according to claim 1, wherein the compound of Formula I or II has a pK value. at least 8.

17. A composition according to claim 16, wherein the pKa value is at least 10.

18. A composition according to claim 1. 1, where the support is a glass.

19. A composition according to claim 1, wherein the thickness of the coating on the support is 0.01 to 100 microns.

20. A composition according to the claim 1, wherein the hydrophobic polymer has a molecular weight of at least 5,000 daltons.

21. A composition according to claim 1, wherein the hydrophobic polymer is selected from the group consisting of polyolefins, polyesters, polyamides, polyethers, poly-imides, polyesteramides, polyamides, polyurethanes, polyureturethanes, polyester-urethanes, polyureas, polyurethane-ureas and polysiloxanes.

22. A composition according to claim 21, wherein the polymers contain basic groups or ionizable acids.

23. A composition according to claim 21, wherein the hydrophobic polymers are polyurethanes made from polyethers of alkanediols of 3 to 6 carbon atoms and di-isocyanates of 2 to 20 aliphatic, cycloaliphatic, cycloaliphatic carbon atoms. -al isáticos, aromatic-aliphatic or aromatic.

24. A composition according to claim 21, wherein the hydrophobic polymers are copolymers comprising: a) from 10 to 90 molar percent of identical or different strual units of Formula III: R7 H -C C- (UI > ' C IOXR RIg and from 90 to 10 mole percent, based on the polymer, of identical or different structural units of Formula IV: - C- (IV). R 13 R wherein R7 and Rg, independently of one another, are H or alkyl of 1 to 4 carbon atoms. X is -0- or -NR,; .-. R0 is alkyl of 6 to 20 carbon atoms, and R,? is H or alkyl of 1 to 20 carbon atoms; R, d and R ^, independently of one another, are H, F, Cl or alkyl of 1 to 4 carbon atoms, R ^ and R--. independently of one another, are H, F, Cl, alkyl of 1 to 4 carbon atoms, -COOH, -COO-alkyl of 1 to 5 carbon atoms, -CONH-alkyl of 1 to 5 carbon atoms or -CO (R ^) -alkyl of 1 to 5 carbon atoms, or R1 is H and R ^ is -CN, phenyl, chlorophenyl, alkoxy of 1 to 12 carbon atoms, or acyloxy of 2 to 18 carbon atoms.

25. A composition according to claim 1, wherein the salt with a lipophilic anion is an alkali metal, alkaline earth metal or ammonium salt with a substituted or unsubstituted tetraphenyl borate.

26. A composition according to the claim 25, wherein the cation is Lie, Nad, K®, Mg2 ?, Ca2e, NH4e, or an ammonium cation of a primary, secondary or tertiary amine, or a quaternary ammonium cation containing from 1 to 40 carbon atoms .

27. A composition according to the claim 25, wherein the borate anion is tetraphenyl borate, whose phenyl groups are unsubstituted or substituted by one or more alkyl groups of 1 to 4 carbon atoms, alkoxy of 1 to 4 carbon atoms, halogen or trifluoromethyl.

28. A composition according to the claim 25, wherein the borate anion is tetraphenyl borate, tetra (3,5-bistrifluaromethylphenol) borate or tetra (4-chlorophenyl) borate.

29. A composition according to claim 16, wherein the amount of the salt with a lipophilic anion is 0.01 to 10 weight percent, based on the amount of polymer.

30. A composition according to claim 1, wherein the polymer coating contains an ionophore in an amount of 0.01 to 10 weight percent, based on the amount of polymer.

31. A composition according to claim 1, wherein the potassium ionophore is valinomycin.

32. A composition according to claim 1, wherein the amount of the compound of Formula I or II is 0.01 to 10 weight percent, based on the amount of polymer.

33. A composition according to claim 32, wherein the amount of the compound of Formula I or II is from 0.1 to 5 weight percent.

34. A composition according to the claim 32, wherein the amount of the compound of Formula I or II is from 0.1 to 2 percent by weight.

35. A composition according to claim 1, wherein the total number of carbon atoms in the alkyl groups is at least 10.

36. A composition according to claim 1, wherein the total number of carbon atoms. in the alkyl groups it is at least 12.

37. A composition comprising: (a) a hydrophobic polymer free of plasticizer, having a glass transition temperature Tg of -150 ° C to 50 ° C, and (b) a compound of Formula I or II as a fluorophore: wherein Rj and R3, and RQ and R1 are alkyl of 1 to 30 carbon atoms or alkyl of 1 to 30 carbon atoms-CO-, and R and R5 are H or alkyl of 1 to 30 carbon atoms, with the condition that the total number of carbon atoms in the alkyl groups be at least 5, or salts thereof with inorganic or organic acids, (c) an ionophore, which forms a complex with the ion to be determined , and (d) counter-ions in the form of lipophilic salts.

38. An optical sensor for the determination of ions in aqueous measurement samples, in particular by means of fluorescence spectrometry, which comprises: (a) a transparent support, (b) which is overlaid on at least one of a transparent coating comprising: (bl) a hydrophobic polymer free of plasticizer having a glass transition temperature Tg of -150 ° C to 50 ° C; (b2) the salt of a lipophilic anion, (b3) an ionophore that forms a complex with the ion to be determined, and (b4) a compound of Formula I or II as the fluorophore.

39. A method for the optical determination of ions in aqueous measurement samples, wherein a sensor according to claim 38 is brought into contact with the aqueous measurement sample, and then the change in fluorescence of the fluorophore in the active polymer coating. SUMMARY A composition comprising: (a) a transparent support; (b) coating on at least one side with a transparent coating comprising: (bl) a hydrophobic polymer free of plasticizer having a glass transition temperature Tg of -150 ° C to 50 ° C; (b2) counter-ions in the form of lipophilic salts; (b3) an ionophore that forms a complex with the ion to be determined, and (b4) a compound of Formula I or II as a fluorophore: wherein R and R3, and R4 and R ^ are alkyl of 1 to 30 carbon atoms, or alkyl of 1 to 30 carbon atoms-CO-, and R and R5 are H or alkyl of 1 to 30 carbon atoms, with the proviso that the total number of carbon atoms in the alkyl groups is at least 5, or a salt thereof, with an inorganic or organic acid. The composition is highly suitable for the qualitative or quantitative optical determination of ions by means of fluorescence detection. * * * * *