Abstract: Sodium ion selective compositions which comprise an ion carrier, a compound capable of solvating the ion carrier, and a supporting matrix are disclosed.The ion carriers of this invention are hemispherand compounds represented by the formula ##STR1## wherein R.sup.1, R.sup.2, R.sup.3, and R.sup.4 are independently hydrogen, alkyl, alkenyl, cycloalkyl, aryl or a heterocyclic group and R represents Z-decyl, Z-octyl, 3-octyl, and cyclohexyl methyl.

Abstract: An ion-selective polymeric membrane for an electrochemical sensor for use in analytical chemistry, comprisinga) a supporting matrix e.g. of PVC, andb) an ionophore selected from calixarene or oxacalixarene derivatives of the formula IV ##STR1## wherein n+m=3-8;m=0-8;n=0-8;a, which may be the same or different on each aryl group, is 0 or 1;R.sup.2 is alkyl, aryl, alkaryl, alkoxy, alkoxyalkoxy, aryloxy, alkaryloxy, alicyclic, alkylthio, arylthio, alkarylthio, or a substituted derivative thereof;R.sup.3 is --H, alkyl or alkenyl;X is --OH or a group containing an acrylate or methacrylate functional group;provided that when X is --OH, n is at least 1/2(n+m);and provided that when m=0, n=4, a=0 and R.sup.3 is alkyl or allyl, R.sup.2 is not alkoxy having 4 or more carbon atoms in the alkyl group;and provided that when m=0, n=4, a=0 and R.sup.3 is t-butyl, R.sup.2 is not methoxy or ethoxy;or of the formula V ##STR2## wherein R.sup.

Abstract: A process for obtaining a multifunctional, ion-selective-membrane sensor is disclosed, which process comprises the following steps:a) preparation of a siloxanic prepolymer, followed by one or more deposition(s) of said siloxanic prepolymer on a device of MOS or ISFET type;b) preparation of a solution containing an ionophore, a monomer of a polymerisable olefin, 2,4-toluenediisocyanate and a dialcohol or a diamine or a glycol or a trialcohol or a triamine, which preparation is followed, after that said solution has been kept stirred for at least 48 hours at room temperature, by the deposition thereof on the siloxanic prepolymer, which deposition is carried out by means of a spinner;c) photochemical treatment in the presence of a photoinitiator by means of UV light, with a suitable mask being used, which allows the exposure to UV light to take place on one gate only;d) chemical washing of the sensor, by means of an organic solvent;e) thermal treatment ("thermal curing"), so as to complete the reactions of polym

Abstract: In order to reduce the measuring volume in a device for measuring chemical and physical parameters of liquid or gaseous media by means of optical sensor elements whose optodes may be replaced easily, a measuring unit with a sample channel is provided which may be inserted into a supporting frame of the device and which may be connected to ingoing and outgoing sample lines via capillary bores. The measuring unit contains a sensor carrier forming the boundary of the sample channel on one side, which sensor carrier has bores holding the optodes. The indicator film of each individual optode is situated in the plane of the sensor carrier facing the sample channel.

Abstract: Cyclic molecules having oriented groups are capable of forming stable complexes with cations.

Abstract: An electrochemical detection system is described comprising in combination:(a) a multielement, microelectrode array detector containing means for acquiring a plurality of signals;(b) electronic means for receiving said signals and converting said signals into a readout or display providing information with respect to the nature and concentration of elements present in a solution being tested.Also described is the means of making the above described microelectrode detector.

Abstract: A luminescent probe complex for measuring pH comprising, polypyridine ligands having ion dissociable substituents on their carbon rings and a transition metal ion selected from the elements of the VIII group of the periodic table.Also disclosed is a luminescent probe membrane for measuring pH wherein the probe complex is contained in a macromolecular membrane. Further disclosed is a device for measuring pH wherein the probe membrane is immobilized at the tip of an optical fiber.A method for measuring pH using the above are also disclosed. The present invention enables measurement of pH of microenvironments.

Abstract: An anion-selective electrode of the present invention comprises, as anion sensitive substance, a tetraalkyl type, quaternary phosphonium salt having four alkyl radicals, each having 8 to 24 carbon atoms; a combination of a tetraalkyl onium salt having four alkyl radicals each having 10 to 24 carbon atoms, and an onium salt having one alkyl radical with 1 to 20 carbon atoms and three alkyl radicals with the proviso that the number of carbon atoms contained in the three alkyl radicals each is larger than that contained in the one alkyl radical; or a tetraalkyl type, quaternary onium salt having an asymmetrical molecular structure. The anion-selective electrode has good properties including selectivity and measurement accuracy. An anion-selective, field effect transistor or a chemical analysis apparatus, provided with the anion-selective sensitive substance, is suitable for measuring an anion concentration with a high accuracy.

Abstract: A method and apparatus for measuring a characteristic which is a function of the concentration of one or more chemical species in a sample fluid, examples being the concentration of sodium ion or potassium ion in blood, makes use of a discardable or disposable measuring device comprising one or more sensors, an example of a relevant type of sensor being a potentiometric electrode, one or more conditioning (e.g. calibration) fluid chambers and, optionally, a sample fluid chamber, the sensor(s) being movable relative to the chamber(s), or vice versa, so as permit conditioning of the sensor(s) in a conditioning fluid chamber and exposure of a sensing surface part of the sensor(s) to a sample fluid.

Abstract: The present invention provides an ion selective electrode for anions such as Cl.sup.- and cations such as Ca.sup.2+ which has a sensitive membrane comprising a polymer material and containing an ion sensitive material and a plasticizer. In thins ion selective electrode, the ion sensitive material is an ion exchanger such as a quaternary ammonium salt, a quaternary phosphonium salt or an organic phosphate and the plasticizer is a compound having the formula (1): ##STR1## wherein X represents an alkyl group, a phenyl group or a phenyl group to which a functional group bonds. As the plasticizer there may also be used a mixture of the compound of the formula (1) with an alcohol compound such as an alcohol having a dielectric constant of 10 or less and containing 10 or more carbon atoms or an ester compound.

Abstract: This invention relates to a semiconductor substrate having a porous surface nd to the amperometric receptor-based sensors formed with the substrate. More specifically, this invention pertains to the substrate in the form of a bipolar junction transistor having a porous hydrophilic surface directly on its base wherein the surface forms a support for an amperometric sensor. The invention also pertains to the methods of making and using the substrate and sensor.

Abstract: A solid state pH sensor having an indicator electrode of metal/metal oxide and a reference electrode of metal/metal salt applied to electrically conductive conductors, such as electrically conductive cermet conductors and electrically conductive metal pins, imbedded in an electrically non-conductive substrate, such as electrically non-conductive ceramic substrates including S-glass substrates. The sensing portion of the sensor preferably has a coating of an annealed perfluorocarbon copolymer. Alternatively, the indicator or reference electrodes may be formed on separate electrically non-conductive substrates with each having an electrically conductive conductor imbedded therein. These indicator or reference electrodes may be utilized with each other or with prior art indicator or reference electrodes.

Abstract: A silicone matrix is employed to form a substance-sensitive membrane which is particularly suited for installation on a solid state sensor. The ionophore may be a potassium ionophore, an ammonium ionophore or any other ionophore. The membrane may be coupled to the molecule of interest through a bioactive agent, such as an enzyme, an immunochemical, bacteria, antibody, virus, or antigen. The resulting substance-sensitive membrane has electrochemical properties which compare favorably to those of conventional PVC membranes, and exhibit significantly greater adhesion to glasses and semiconductor substrate materials. The improved adhesion will prolong the life of the sensors and prevent the formation of electrolyte shunts which have been known to render solid state sensors inoperative.

Abstract: A calcium ion selective electrode having a sensitive membrane comprising an organic polymeric substance, a plasticizer and a calcium ion sensitive substance of neutral carrier type, wherein the dielectric constant of the plasticizer is 10 or less, thus remarkably improving the responsiveness and stability of the electrode.

Abstract: A chemical sensor includes a field effect-type transistor. An extended gate electrode is connected to a gate electrode of the transistor. A sensitive membrane is provided on at least a part of the extended gate electrode. The sensor also includes a reference electrode. Both the extended gate and reference electrodes are formed on a substrate different from the substrate on which the transistor is formed. Divided parts for the chemical sensor wherein the parts of the sensor except for the reference electrode are made independent are also disclosed and claimed. Sensors for simultaneously sensing a number of different chemical substances in a single sample are also disclosed and claimed.

Abstract: The surface of an electrically conductive substrate (1) is provided with a redox layer (5) by an electrolytic polymerization process, and the surface of the resulting member is further provided with an ion carrier membrane (6) which includes polyvinyl chloride, a plasticizer and an ion carrier, thereby forming an ion sensor. Used as the plasticizer is one selected from among phthalate plasticizers, maleate plasticizers, adipate plasticizers, carboxylate plasticizers and polycaprolactone plasticizers, or one selected from among plasticizers comprising modified ethylene-- vinyl acetate copolymer. The ion sensor obtained has low solubility in the plasticizer of the redox layer and therefore is highly stable. Since the ion sensor has little toxicity, it can be used in vivo.

Abstract: An electroanalytical electrode assembly includes an electrically conductive working electrode having a body of electrolyte material thereupon and separated from the analytical environment by a hydrophobic membrane. The membrane has an electrical conductivity greater than the electrical conductivity of the remainder of the measuring circuit and is selectably permeable for a preselected and ionic species, so as to provide a stable membrane potential. Use of an assembly of this type allows for placement of a reference electrode external of the membrane.

Abstract: The sensor comprises a chip of a semiconductor material wherein a field-effect transistor is formed the drain and source regions whereof are provided on a first face of the chip, onto which an ion-selective membrane is applied which is coupled to said field-effect transistor.The membrane covers said first face of the chip completely, and terminals are provided in addition which comprise conductive elements applied to the other face of the chip and being connected to said drain and source regions by connections which extend through the chip.These connections are formed by a method providing for the formation in the chip of buried layers of semiconductor material.

Abstract: An electrode, preferably of a conductive polymer, has on its surface, preferably over all of its surface, an ion exchange material, preferably of significant thickness. Such a coated electrode may be used for sensing the presence of measuring the concentration of an ionic species, or for removal from or release of an ionic species into an electrode.

Abstract: A plurality of uniform microfabricated sensing devices are produced by establishing a plurality of base sensors on a substrate wafer, forming over at least a portion of each base sensor a permselective layer, superimposing a photoformable proteinaceous photoresist layer over a substantial portion of the permselective layer, and forming a topmost layer of an immobilized ligand receptor. The ligand receptor and corresponding ligand may be immunoreactive species.

Abstract: The surface of a gate insulating membrane of an ion-selective field-effect transistor (ISFET) (10) is coated with a carbon thin membrane (4), and the surface of the latter is coated with an electrolytic polmerization membrane (3) of 2,6 xylenol. The ISFET obtained exhibits hydrogen-ion selectivity, little drift, high stability and little response to light. If the surface of the electrolytic polmerization membrane (3) of 2,6 xylenol is coated with another ion-selective membrane or enzyme-active membrane, various ions and the concentration of a biological substrate can be measured.

Abstract: A method for monitoring for the presence of an electrolyte and for locating the electrolyte upon its presence uses a system comprising an electrically conductive locating member and an electrically conductive source member, between which an electrical connection is made upon the presence of the electrolyte. The locating member and/or the source member comprises (i) an electrode and (ii) an ion exchange material which is in electrical and physical contact with and substantially entirely surrounds all surfaces of the electrode; the ion exchange material having an ionic resistance which depends upon the concentration of a chemical species in the electrolyte. Upon the presence of the electrolyte, a connection to the locating member is made effective at a first point whose location is defined by the presence of the electrolyte.

Abstract: An electrode, preferably of a conductive polymer, has on its surface, preferably over all of its surface, an ion exchange material, preferably of significant thickness. Such a coated electrode may be used for sensing the presence or measuring the concentration of an ionic species, or for removal from or release of an ionic species into an electrode.

Abstract: A method of forming a conductive lamina for use with and to form a bio-medical electrode device comprising the steps of providing a non-conductive base structure, providing a mixture of an electrically conductive substance and a media component, depositing the mixture onto the base structure, and curing the mixture. The method further comprises the step of mixing the electrical conductant and the media component in a closed cell, positive pressure kinetic mixer. The method further comprises the steps of combining a urethane base and a polyhydric alcohol to form the media component and delaying the mixing of the media component and the electrical conductant for a predetermined time period. In another embodiment, the method comprises the steps of combining a photo-initiator, a cross-linking agent, and low pH acrylic monomers to form a precomponent, and mixing the precomponent with the glycol to form the media component.

Abstract: An ion sensor is disclosed, together with the relevant process for preparing it, which contains a polymeric organic matrix, a ionophore, a device based on semiconductors of EMOS or ISFET (CHEMFET) type containing at its surface silicon oxide adhering to said polymeric organic matrix by means of a polysiloxanic matrix, characterized in that the polysiloxanic matrix is selected from the organosilanes of general formula ##STR1## wherein: R.sup.II, R.sup.III, R.sup.IV, which may be either equal to, or different from, one another, are alkyl or alkoxy groups containing from 1 to 10 carbon atoms,R.sup.I is equal to (CH.sub.2).sub.p X (CH.sub.2).sub.q wherein:X is CH.sub.2, or an either mono- or polycondensed aromatic group, or NH or O,p and g, which may be either equal to, or different from, one another, are integers which can have values comprised within the range of from 0 to 10, with value 0 being excluded when X is either NH or O,Y is --NH.sub.

Abstract: Several types of new microelectronic devices including diodes, transistors, sensors, surface energy storage elements, and light-emitting devices are disclosed. The properties of these devices can be controlled by molecular-level changes in electroactive polymer components. These polymer components are formed from electrochemically polymerizable material whose physical properties change in response to chemical changes, and can be used to bring about an electrical connection between two or more closely spaced microelectrodes. Examples of such materials include polypyrrole, polyaniline, and polythiophene, which respond to changes in redox potential. Each electrode can be individually addressed and characterized electrochemically by controlling the amount and chemical composition of the functionalizing polymer. Sensitivity of the devices may be increased by decreasing separations between electrodes as well as altering the chemical environment of the electrode-confined polymer.

Abstract: A disposable, inexpensive electrode for an electrochemical sensor includes a laminated anode and a laminated cathode. The anode is a film substrate with anodic material such as platinum deposited on the substrate. The cathode is also a film substrate with cathodic material such as silver deposited on the substrate. The anode and cathode can be laminated with an intermediate layer of dielectric material. A working surface is provided on the electrode and defined, in part, by the anode and cathode. One procedure for defining the working surface is to fabricate spaced openings in the cathode film and the layer of dielectric material. The openings in the cathode film and dielectrical layer are aligned and the exposed surfaces of the anode and cathode define the working area. An enzyme, such as glucose oxidase, is bonded to the exposed anode and a membrane is applied over the working area and enzyme. The membrane is preferably a silicone water-based elastomer.

Abstract: An ion-selective electrode comprises a non-conductive support, an inner reference electrode and an ion-selective layer mounted in this order. A surface of the ion-selective layer is covered with a material which forms a contact angle of at least 90.degree. with water. By this material, the surface area over which a test liquid comes into contact with the ion-selective layer is reduced.

Abstract: A testing module is provided having units which can be arranged seriatim to provide narrow through passageways linked to each other for quantitative determination of analytes passing through the units as by electrical testing with electrodes. Auxiliary passageways are preferably used in one unit to allow flushing of a first sample chamber without contamination from a second sample chamber. An electrode holder carries a membrane backed by a gel to aid in electrically linking the membrane to an electrode and to support the membrane in a substantially planar condition in use.

Abstract: An electrode, preferably of a conductive polymer, has on its surface, preferably over all of its surface, an ion exchange material, preferably of significant thickness. Such a coated electrode may be used for sensing the presence or measuring the concentration of an ionic species, or for removal from or release of an ionic species into an electrode.

Abstract: An electrode assembly of the flow-through type comprising as a key element a porous and a preferably microporous tubular material impregnated with a matrix of an organic plastic material containing a nonvolatile solvent plasticizer and an ion-active material dissolved in the plasticizer, the plasticizer not being a solvent for the tubular material. There is also disclosed an electrode assembly involving a membrane material in which the membrane material communicates electrically directly through a metal conductor.

Abstract: A dip electrode assembly comprising as a key element a porous and a preferably microporous membrane support impregnated with a membrane matrix of an organic plastic material containing a nonvolatile solvent plasticizer and an ion-active material dissolved in the plasticizer, the plasticizer not being a solvent for the membrane support. There is also disclosed an electrode assembly involving a membrane material in which the membrane material communicates electrically directly through a metal conductor.

Abstract: An electrode, preferably of a conductive polymer, has on its surface, preferably over all of its surface, an ion exchange material, preferably of significant thickness. Such a coated electrode may be used for sensing the presence or measuring the concentration of an ionic species, or for removal from or release of an ionic species into an electrode.

Abstract: An electrochemical reference element is proposed having a metal electrode such as silver coated with the tetraphenyl (TPB) salt of the metal. The element may form the internal reference of an ion selective electrode with an ion selective membrane carried directly upon the TPB coating. The element provides a thermodynamically reversible couple suitable for use in a non-aqueous environment.

Abstract: The surface of an electrically conductive substrate (1) is provided with a redox layer (5) by an electrolytic polymerization process, and the surface of the resulting member is further provided with an ion carrier membrane (6) which includes polyvinyl chloride, a plasticizer and an ion carrier, thereby forming an ion sensor. Used as the plasticizer is one selected from among phthalate plasticizers, maleate plasticizers, adipate plasticizers, carboxylate plasticizers and polycaprolactone plasticizers, or one selected from among plasticizers comprising modified ethylene - vinyl acetate copolymer. The ion sensor obtained has low solubility in the plasticizer of the redox layer and therefore is highly stable. Since the ion sensor has little toxicity, it can be used in vivo. A preferred plasticizer is benzopohenon-tetracarboxylic under cyclic acid.

Abstract: Membrane for barium ion selective electrodeThe solution pertains to a membrane for barium ion selective electrode formed by the film of suitable polymeric material, for example, high-molecular weight poly(vinyl chloride), with an ion exchanger based on a neutral carrier, namely N,N'-diphenyl-N,N'-di-(2-n-butyloxycarbonylphenyl)diamide of 3,6,9-trioxaundecandioic acid ##STR1##

Abstract: The present invention provides a stabilized potassium ion-selective membrane comprising lysine-substituted valinomycin covalently bound to a polymeric substrate. The membrane of the invention exhibits improved stability and is used either on ISEs or on solid-state coated wire or semiconductor devices.

Abstract: A potentiometric electrochemical analysis method, which comprises placing by capillary action an aqueous sample liquid to be tested for the presence of a quantity of an analyte in the sample liquid, in each of two compartments of an electrochemical analysis cell, wherein the aqueous sample liquid so placed in each compartment is in electrochemical contact with one of two electrodes forming part of the cell, wherein the electrodes are insensitive to the analyte, and wherein the compartments are separated by an electroactive barrier which is sensitive to or selective for the analyte, the barrier not being in electrical contact with either electrode except through the medium of the sample liquid, the method further comprising changing the amount of the analyte material in a selected one of the compartments by adding thereto a predefined standard quantity of analyte, measuring the resulting cell potential and determining the concentration of the analyte in the sample liquid, the predefined standard quantity of an

Abstract: An ion-sensitive composition and an ion-selective electrode is disclosed in which the ionophore is an organotin having the formulaR.sub.x.sup.1 Sn(SR.sup.2).sub.4-xorR.sub.y.sup.1 Sn(SR.sup.3 --X--R.sup.3 S).sub.4-y SnR.sup.1whereinx is 0 or an integer from 1 to 3;y is 2 or 3;each R.sup.1 independently is substituted or unsubstituted alkyl or substituted or unsubstituted aryl;each R.sup.2 independently is substituted or unsubstituted alkyl.each R.sup.3 independently is substituted or unsubstituted alkylene; and,X is a single chemical bond or a linking group.

Abstract: According to the invention organic monolayer films are applied to an electrically conductive substrate, resulting in an electrode which can be used in electrochemical processes. The said film serves as ultrathin membrane and allows certain selected species to approach the substrate and be detected. The film comprises active species which are selective towards specific species contained in mixture with others and a blocking surface sealing component. It is also possible to use one compound serving both purposes. The components of the film are attached to the substrate by a variety of means: adsorption, chemisorption, electro-chemical deposition.

Abstract: The ultramicroelectrode comprises a wire or filament of noble metal and/or carbon on which an insulating layer is provided. The insulating layer is made from a cross-linked alkenyl-substituted poly(1,4-phenylene) ether, poly(1,4-phenylene) thioether or poly(1,4-aniline). This ultramicroelectrode can be used as a disk, cylindrical, bipolar or shielded electrode and may be used as a stimulating electrode, amperometric or potentiometric microsensor or as an electrode for analytical measurement, e.g. for inverse voltammetry.

Abstract: A coated-wire electrode for potentiometrically titrating surfactant molecules having more than ten carbon atoms includes an electrically-conductive core coated with a semipermeable membrane. The membrane matrix included a polymer, a plasticizer and an ion-exchange material consisting essentially of dimidium bromide or disulphine blue in suitable proportions to be surfactant selective. The membrane is responsive to anionic, cationic and amphoteric surfactants as well as alkoxylated nonionic surfactants.

Abstract: A disposable, inexpensive electrode for an electrochemical sensor includes a laminated anode and a laminated cathode. The anode is a film substrate with anodic material such as platinum deposited on the substrate. The cathode is also a film substrate with cathodic material such as silver deposited on the substrate. The anode and cathode can be laminated with an intermediate layer of dielectric material. A working surface is provided on the electrode and defined, in part, by the anode and cathode. One procedure for defining the working surface is to fabricate spaced openings in the cathode film and the layer of dielectric material. The openings in the cathode film and dielectrical layer are aligned and the exposed surfaces of the anode and cathode define the working area. An enzyme, such as glucose oxidase, is bonded to the exposed anode and a membrane is applied over the working area and enzyme. The membrane is preferably a silicone water-based elastomer.

Abstract: A liquid film type, chloride ion-selective electrode is provided with the present invention, which comprises a sensitive film containing a polymeric material as a support film material, a tetraalkyl ammonium salt with four alkyl group each having 10-24 carbon atoms as a chloride ion-sensitive substance, and a mixture of a linear alcohol having a low dielectric constant with at leastg 10 carbon atoms and an organic compound having a dielectric constant higher than that of said linear alcohol as plasticizer. This electrode has a high selectivity over lipophilic anions and hydrophilic anions, high accuracy ion measurements, and a long life.

Abstract: Ion-selective compositions which comprise an ion carrier, a compound capable of solvating the ion carrier, and a supporting matrix are disclosed. The ion carrier according to the invention is a lipophilic hemispherand compound. These compositions are particularly useful in ion-selective electrodes. Such an electrode is capable of selectively transporting a first ion in preference to a second ion. Particularly useful hemispherands have a .DELTA.G of complexation with the first ion which is at least 0.3 Kcal/mole greater than the .DELTA.G of complexation with the second ion. Dry-operative electrodes using these ion-selective compositions as membranes are also disclosed.

Abstract: This invention relates to fluoride ion-selective electrodes which employ, as the active membrane component, a ternary compound of the type M.sub.x Ln.sub.y F.sub.3-x, where M is an alkaline earth metal ion such as calcium, strontium or barium, and Ln is a lanthanide metal ion such as lanthanum, cerium, prosiodymium, neodymium, promethium, samarium and europium.

Abstract: Electrochemical devices constructed according to the present invention can be used to convert an ion flux into an electric current for determination of ion concentration. The devices are operated without the need for a reference electrode and are specific based on known ion transfer agents. Operation of the devices involves the use of pairs of electrodes modified with electroactive redox materials overlaid with ion selective coatings. An applied potential between a pair of appropriately modified electrodes results in the flow of an electric current between the electrodes which is dependent on the concentration of the ion to be sensed.Devices constructed by combining electrodes overlaid with electroactive polymers and different ion selective films allow simultaneous determination of diverse ions. For example, these devices are useful for measuring the concentration of total cations, total anions, H.sup.+, Li.sup.+, K.sup.+, Ca.sup.2+, Na.sup.+, HCO.sub.3.sup.-, Cl.sup.

Abstract: An ion sensor includes an ion sensitive membrane formed from a vinyl polymer based compound containing a hydroxyl and/or carboxyl group. The membrane is provided on an extended gate electrode on a gate electrode of a field-effect type transistor. The ion sensor also includes a reference electrode arranged in opposition to the extended gate electrode. The extended gate electrode and reference electrode are formed on a substrate different from the substrate on which the field-effect type transistor is formed. A divided part for an ion sensor is also provided and includes the portions of the ion sensor discussed above except for the reference electrode. The divided part is used with a separate reference electrode.

Abstract: A functional membrane is provided for proton-driven ion transport. It consists essentially of a blend of two components. The first component is an active polymer having cation-binding sites, the cation binding sites being provided, e.g., by a crown ether, a cryptand or an acyclic complexone with an ionizable acidic site, e.g., a carboxylic acid, a sulfonic acid and a phenol, such active polymer being incorporated into a polymer backbone via a spacer component. The second component is a support polymer, e.g. a polyaramide, a polysulfone, or a polypip-erazine-fumaramide.

Abstract: An improved phosphate selective membrane electrode using bis(p-chlorobenzyl)tin dichloride as the membrane active component. In addition to this tin compound, the membrane contains N,N-dimethylformamide (DMF), a strong complexing agent for tin compounds.