Abstract: The present invention is directed to a reversible electrochemical sensor for polyions. The sensor uses active extraction and ion stripping, which are controlled electrochemically. Spontaneous polyion extraction is suppressed by using membranes containing highly lipophilic electrolytes that possess no ion-exchange properties. Reversible extraction of polyions is induced by constant current pulse of fixed duration applied across the membrane. Subsequently, polyions are removed by applying a constant stripping potential. The sensors provide excellent stability and reversibility and allow for measurements of heparin concentration in whole blood samples via protamine titration. The sensors can also monitor a polyion concentration and an enzyme activity, wherein the polyion decomposition is directly proportional to the enzyme activity in a sample. Additionally, the sensors can monitor an enzyme inhibitor activity.

Abstract: In vitro electrochemical sensors that provide accurate and repeatable analysis of a sample of biological fluid are provided. Embodiments include sensors that include a sample chambers having overhangs extending therefrom.

Abstract: A biosensor system determines analyte concentration from an output signal generated from a light-identifiable species or a redox reaction of the analyte. The biosensor system adjusts a correlation for determining analyte concentrations from output signals or determined analyte concentrations with one or more complex index function extracted from the output signals or from other sources. The complex index functions determine at least one slope deviation value, ?S, or normalized slope deviation from one or more error parameters. The slope-adjusted correlation between analyte concentrations and output signals may be used to determine analyte concentrations having improved accuracy and/or precision from output signals including components attributable to bias.

Abstract: An analyte test element for determining the concentration of at least one analyte in a physiological sample fluid having a first and a second surface in a predetermined distance opposite from each other, said both surfaces are provided with two substantially equivalent patterns forming areas of high and low surface energy which are aligned mostly congruent, whereby the areas with high surface energy create a sample distribution system with at least two detection areas, characterized in that the detection areas of first and second surface are also provided with two corresponding patterns of working and reference electrodes of electrochemical detection means.

Abstract: Among others, techniques and systems are disclosed for detecting trace levels of heavy metal ions in a sample liquid. A voltage is applied to a sample liquid that includes metal complexes. A current signal associated with the metal complexes is measured. The measured current signal is processed to simultaneously detect a presence of two or more metal ions associated with the metal complexes.

Abstract: A liquid chromatographic system is provided including catalytically combining hydrogen and oxygen gases in the chromatography eluent stream in a catalytic gas elimination chamber, to form water and thereby reduce the gas content in the eluent stream. Also, a liquid ion chromatographic system in which the effluent from the detector is recycled to a membrane suppressor and then is mixed with a source of eluent for recycle to the chromatographic column.

Abstract: An improved combination ion-selective electrode has a thin ion-sensing body extending from an outer reference body. The exposed portion of the ion-sensing body is encompassed by a sleeve which effectively forms an extension of the reference body and also provides mechanical stability to the ion-sensing body. One or more fluid channels are formed interior to the sleeve to provide an electrically conductive path from the reference solution within the reference body to the tip of the electrode.

Abstract: A sensor for biomolecules or charged ions includes a substrate; a first node, a second node, and a third node located in the substrate; a gate dielectric located over the substrate, the first node, the second node, and the third node; a first field effect transistor (FET), the first FET comprising a control gate located on the gate dielectric, and the first node and the second node; and a second FET, the second FET comprising a sensing surface located on the gate dielectric, and the second node and the third node, wherein the sensing surface is configured to specifically bind the biomolecules or charged ions that are to be detected.

Abstract: A water quality analyzer comprises: sensor electrodes 1a, 1b made of different metals from each other, the electrodes in a liquid of inspecting object generating a sense voltage in proportion to the liquid's impurities concentration; an operational amplifier OP1 amplifying the sense voltage without inverting to provide for a CPU 3; a resistor R0 whose one end is connected to the electrode 1a; and a voltage divider 2 applying a voltage obtained by dividing the sense voltage by a prescribed division ratio to R0's another end. The CPU 3 calculates input signal from OP1 to obtain chlorine concentration and displays the calculated result on a LCD 4 in a measurement mode, and sets the division ratio of the divider 2 so that sense voltage across electrodes 1a, 1b soaked in a liquid including prescribed concentration chloride approximately agrees with a reference voltage of prescribed concentration in a sense-voltage calibration mode.

Abstract: An electrochemical method for measuring the concentration of an anionically-charged and non-electroactive polymer in an aqueous solution is provided. The method comprises immobilizing a cationic dye material on an electrically conductive substrate form a working electrode; contacting the working electrode with the aqueous solution including the anionically-charged and non-electroactive polymer to be measured, and transmitting electrical power to the working electrode; measuring a current of the working electrode under a determined electric potential; and calculating a concentration or quantity of the anionically-charged polymer in the aqueous solution according to the measured current of the working electrode.

Abstract: A suppressed ion chromatographic apparatus using a regenerant recycle loop, comprising (a) an ion separation device, (b) a membrane suppressor, (c) a detector, (d) a container for regenerant solution, (e) a first conduit between the ion separation device and the suppressor, (f) a second conduit between the regenerant solution container and the suppressor, (g) a third conduit between the suppressor and the regenerant solution container, and (h) a regenerant solution recycle loop out of fluid communication with the detector outlet.

Abstract: The invention relates to a method of determining a charged particle concentration in an analyte (100), the method comprising steps of: i) determining at least two measurement points of a surface-potential versus interface-temperature curve (c1, c2, c3, c4), wherein the interface temperature is defined as a temperature of the interface between a measurement electrode and the analyte (100), wherein the surface-potential is defined at the interface, and ii) calculating the charged particle concentration from locations of the at least two measurement points of said curve (c1, c2, c3, c4).This method, which still is a potentiometric electrochemical measurement, exploits the temperature dependency of a surface-potential of a measurement electrode. The invention further provides an electrochemical sensor and electrochemical sensor system for determining a charged particle concentration in an analyte. The invention also provides various sensors which can be used to determine the charged particle concentration, i.e.

Abstract: In order to realize an accurate electrochemical measurement without a peak caused due to a silver chloride complex ion, an electrochemical measurement electrode of the present invention which measures an electrochemical active substance in a sample solution containing a chloride ion includes (i) a working electrode, (ii) a reference electrode made of silver and silver chloride, and (iii) a silver ion capturing material which captures a silver ion out of a silver chloride complex ion generated in the reference electrode.

Abstract: A method for operating an ion-sensitive sensor with a measurement circuit which includes an ion-sensitive electrolyte-insulator-semiconductor structure (EIS); wherein the measurement circuit is embodied to issue an output signal which is dependent on ion concentration, especially a pH value, of a measured liquid; wherein the method comprises steps of: Introducing the ion-sensitive electrolyte-insulator-semiconductor structure into a measured liquid; accelerating charging processes in the region of an insulator layer of the ion-sensitive electrolyte-insulator-semiconductor structure by operating the sensor over a predetermined time span at least a first working point, dynamically adapting the working point to set a second working point, and registering and processing the output signal of the measurement circuit at the second working point.

Abstract: An oxide-ion sensor includes an oxygen electrode, a sense electrode and a saturated (reference) electrode. The sense electrode is operated at a substantially constant current for determining an instantaneous value of a dissolved oxide-ion concentration in the molten salt electrolyte. The saturated electrode is used to determine a reference value of the dissolved oxide-ion concentration in the molten salt electrolyte. A dissolved oxide-ion concentration in the molten salt electrolyte is continuously monitored in-situ during the molten-salt based electrochemical reduction process by determining an equilibrium potential between the sense electrode and the saturated electrode with the sense electrode carrying a small current in a circuit that is completed using the oxygen electrode.

Abstract: Method for measuring the global ion concentration of a body fluid that comprises application of a stable DC voltage between first and second electrodes of a cell for measuring the global ion concentration of a body fluid so as to cause electrochemical hydrolysis reactions of the body fluid water to occur at the level of said first and second electrodes, measurement of a hydrolysis current generated by said electrochemical hydrolysis reactions of the water and determination of the global ion concentration of the body fluid by comparison with a previously defined calibration curve. The measuring cell comprises a fluid channel having an internal cross-section smaller than or equal to 1.5 mm.

Abstract: An ion concentration measurement system is provided. The ion concentration measurement system has: at least an end system having a sensing unit for measuring the ion concentration of a test solution to generate at least a sensing signal; a control unit for controlling the acquisition of the sensing signal; a display unit for displaying the sensing signal in real time; and an end wireless transmission interface for transmitting the sensing signal wirelessly.

Abstract: A sampling system for measuring the presence and concentration of inorganic ion species, including, metals, metalloids and non-metals, in a liquid solution including a first sampling unit. The first sampling unit includes a potentiometric subsystem configured to gather environmental metrics of the liquid sample, a preparation subsystem, coupled to the potentiometric module, the preparation subsystem being configured to prepare and isolate contaminants of concern in a flow of a liquid sample into metal, metalloid, or non-metal ionic forms; and a voltammetric subsystem selectively coupled to the preparation subsystem, potentiometric subsystem and a sample source, the voltammetric subsystem being configured to identify and determine a concentration of metal, metalloid, or non-metal ionic species through stripping voltammetry. The system is configured to compare a value of a stripping signal of the sample with a predetermined value to determine if dilution of the sample is required.

Abstract: An ion analyzing apparatus includes a sensor; a counter electrode having openings, the counter electrode being positioned so as to substantially surround the sensor; and a bias generating circuit coupled to the sensor, wherein the sensor includes quartz crystal and a pair of electrodes positioned on surface of the quartz crystal, and one of the pair of electrodes is coupled to the bias generating circuit.

Abstract: An ion concentration sensor produces a signal reflective of the ion concentration within a solution. The ion concentration sensor is based on an ion sensitive transistor having a solution input, a reference input, a diffusion input, and a diffusion output. The ion sensitive transistor is connected as a pass transistor, such that the diffusion output provides an electrical signal indicating an ion concentration in a solution contacting the solution input.

Abstract: A method and device for the quantitative determination of an ion in a fluid which comprises subjecting the fluid to voltammetry using a sensing electrode which comprises an electrically conducting support having a surface which is coated with a support matrix, the support matrix containing an electroactive species capable of being oxidised or reduced to form a charged species, and an ionophore.

Abstract: Methods and devices for point of care determination of heparin concentration in blood are described. Cartridges including protamine ion sensitive electrodes (ISEs) and reference electrodes and systems for automatically determining heparin concentration in the cartridges are provided. Some systems add blood to a protamine bolus sufficient to bind all heparin, leaving excess protamine. The excess protamine concentration can be determined by measuring the initial slope of the electrode potential rate of change, and comparing the slope to known protamine concentration slope values In some cartridges, an oscillating pressure source moves the blood-protamine mixture back and forth across the protamine ISE. Some systems also use a second blood sample having the heparin removed or degraded to create a blank reference sample. Protamine ISEs can include polyurethane polymer, DNNS ionophore, and NPOE plasticizer.

Abstract: An electrochemical suspended element-based sensor system includes a solution cell for holding an electrolyte comprising solution including at least one electrochemically reducible or oxidizable species. A working electrode (WE), reference electrode (RE) and a counter electrode (CE) are disposed in the solution. The CE includes an asymmetric suspended element, wherein one side of the suspended element includes a metal or a highly doped semiconductor surface. The suspended element bends when current associated with reduction or oxidation of the electrochemically reducible or oxidizable species at the WE passes through the suspended element. At least one measurement system measures the bending of the suspended element or a parameter which is a function of the bending.

Abstract: Provided are the preparation, characterization, and application of a nanopore membrane device. The nanopore device comprises a thin membrane prepared from glass, fused silica, ceramics or quartz, containing one or more nanopores ranging from about 2 nm to about 500 nm. The nanopore is prepared by a template method using sharpened metal wires and the size of the pore opening can be controlled during fabrication by an electrical feedback circuit. The nanopore device is particularly useful for counting and analyzing nanoparticles of radius less than 400 nm.

Abstract: A signal processing circuit includes an ion sensitive field effect transistor, a reference electrode for the ion sensitive field effect transistor, a metal oxide semiconductor transistor having its gate coupled to the reference electrode, and a biasing circuit. The biasing circuit is configured to bias the ion sensitive field effect transistor and the metal oxide semiconductor field effect transistor to operate in a weak inversion region and to provide an output current signal.

Abstract: A barrier structure for use in an electrochemical stochastic membrane sensor for single molecule detection. The sensor is based upon inorganic nanopores having electrically tunable dimensions. The inorganic nanopores are formed from inorganic materials and an electrically conductive polymer. Methods of making the barrier structure and sensing single molecules using the barrier structure are also described.

Abstract: Method for microanalyzing ions with the following steps: placing a volume of an ionic liquid (2) inside a cavity (1) having an internal volume, where the volume of said liquid is smaller than said internal volume; placing inside said internal cavity (1) a solution (4) containing said ions (C+, A?) to be analyzed, where the solvent of the solution (4) and the ionic liquid (2) are chosen for being immiscible and allowing an ion transfer (C+, A?) from said solution (4) to said ionic liquid (2); and detecting the presence of said ions (C+, A?) in said ionic liquid (2) using an analysis means (3) for analysing at least one type of ion in solution in said ionic liquid (2), in a free state or in a complex, said analysis means (3) being contacted with said ionic liquid (2). A device and a system for carrying out this method are also provided.

Abstract: Apparatus and method for detecting current or potential generated in a liquid sample suitable for use in a chromatography or other liquid sample analytical system. One embodiment is an electrolytic ion transfer device with a signal detector in communication with the electrodes of the transfer device. Another is a combination ion transfer device/electrolyte generator. Another substitutes a detector for the ion transfer device in the combination.

Abstract: An electrolyte analyzing apparatus according to the present invention includes an A/D converter which converts analogue data output from an ion selective electrode into digital data. The electrolyte analyzing apparatus also includes a data processor which calculates a median of multiple pieces of the digital data converted from multiple pieces of the analogue data output from the ion selective electrode and outputs the median as measurement data of an electrolyte; and a calculator which calculates a concentration of the electrolyte contained in a specimen based on the measurement data of the electrolyte output from the data processor.

Abstract: A method for identifying biological samples that are collected using the wrong anticoagulant for subsequent analytical testing. The method also provides for identification of certain analytical test results that are substantially or partly adversely affected.

Abstract: The present invention is directed to a reversible electrochemical sensor for polyions. The sensor uses active extraction and ion stripping, which are controlled electrochemically. Spontaneous polyion extraction is suppressed by using membranes containing highly lipophilic electrolytes that possess no ion-exchange properties. Reversible extraction of polyions is induced by constant current pulse of fixed duration applied across the membrane. Subsequently, polyions are removed by applying a constant stripping potential. The sensors provide excellent stability and reversibility and allow for measurements of heparin concentration in whole blood samples via protamine titration.

Abstract: An apparatus, system and method maximizes efficiency and accuracy of measuring an ion concentration of a measured fluid by varying a flow of ions within a measuring cell (1006) in accordance with an output signal of a sensor cell. The pump current through a pump cell is switched between a constant positive current and a constant negative current when upper and lower thresholds of the output signal are reached. The pulse width ratio of the square wave produced by the varying current is compared to a pulse width ratio function derived from a calibration procedure to determine the ion concentration of the measured fluid. In one embodiment, the functions of the pump cell and sensing cell are performed by a single electrochemical cell. In an embodiment where a concentration of a compound is determined, a primary electrochemical cell system pumps an ion of an element of the compound into and out from a measuring chamber.

Abstract: An electrochemical sensor system for sensing free radicals or materials which generate free radicals in solution includes a working electrode coated with a plurality of cerium oxide nanoparticles and a counter electrode. A solution to be analyzed provides electrolytes to electrically couple the working electrode to the counter electrode. Electronics are connected to at least one of the working and counter electrodes for measuring and amplifying an electrical current signal generated by reduction or oxidation occurring at the working electrode, wherein in a presence of free radicals an electrical current signal flows between the working electrode and the counter electrode. The system can be used to sense the presence of hydrogen peroxide.

Abstract: A suppressed ion chromatographic apparatus using a regenerant recycle loop, comprising (a) an ion separation device, (b) a membrane suppressor, (c) a detector, (d) a container for regenerant solution, (e) a first conduit between the ion separation device and the suppressor, (f) a second conduit between the regenerant solution container and the suppressor, (g) a third conduit between the suppressor and the regenerant solution container, and (h) a regenerant solution recycle loop out of fluid communication with the detector outlet.

Abstract: A method and apparatus for cleaning and disinfecting a milk line system and for determining the extent to which a milk line system is rinsed with a cleaning fluid, whereby in one or more places in the milk line system the electric conductivity if the cleaning fluid is determined. More in particular, according to the invention, the electric conductivity is measured in places which are difficult for the cleaning fluid to reach or at places in the milk line system which are more likely to harbor undesirable microbes. The cleaning solutions may be an alkali, detergent, hydrogen peroxide, or acid including peracetic acid, ozone, an alcohol, an aldehyde including formaldehyde, phenol and ethylene oxide, to the extent that these substances do not adversely affect materials such as the compositions of the teat cups.

Abstract: An apparatus for a continuous, automated quantitation of tin compounds in liquid samples and a method for quantitative analysis based on the said apparatus are provided herein. The inventive apparatus acidifies liquid samples and in case organotin compounds are present in the sample, a selective UV irradiation converts the organotin compounds into inorganic tin. The inventive apparatus quantitates this inorganic tin by means of electrochemical methods. The apparatus and method of the present invention allow quantitative analyses of trace amounts of organic and inorganic tin compounds present in liquid samples by converting organotin, a form unsuited for measurement, into inorganic tin, a form amenable to measurements and performing electrochemical analysis. Above all, the present invention affords the construction of an automated, continuous analysis system, making unnecessary additional manual operations and reducing labor costs.

Abstract: A disposable, self-administered electrolyte test is affixed to the label of a commercially available electrolyte supplement, is available in the pharmacy section of a retail store, or is distributed by a physician or a clinic.

Abstract: An apparatus and method for detecting ionic materials includes a sensing electrode which contacts a liquid sample and detects a sensing voltage corresponding to a surface potential which is changed by a concentration of ionic materials in the liquid sample, a first switching transistor having a first terminal connected to the sensing electrode and a second terminal connected to a first node, a second switching transistor having a first terminal connected to a reset voltage and a second terminal connected to the first node, and a sensing transistor having a gate connected to the first node.

Abstract: A chloride selective electrode membrane comprises a polymeric matrix wherein the matrix comprises an epoxy resin, and an amine agent selected from the group consisting of polyamides, amidoamines and mixtures thereof. The amine agent is present in stoichiometric excess and functions as both curing agent and chloride selective agent.

Abstract: A liquid chromatographic system is provided including catalytically combining hydrogen and oxygen gases in the chromatography eluent stream in a catalytic gas elimination chamber, to form water and thereby reduce the gas content in the eluent stream. Also, a liquid ion chromatographic system in which the effluent from the detector is recycled to a membrane suppressor and then is mixed with a source of eluent for recycle to the chromatographic column.

Abstract: An object of the present invention is to suppress an electric potential drift as described above and improve pH measurement precision in order to obtain practical measurement precision in the dry-type multilayered film-type pH electrode. The present invention provides a complex pH electrode which has at least two ion-selective electrodes comprising a non-conductive support, a pair of electrode layers, an electrolytic layer and an ion-selective membrane where at least one of the ion-selective electrode is a hydrogen ion-selective electrode, wherein the hydrogen ion-selective membrane is saturated with carbon dioxide gas.

Abstract: The present invention relates generally to any electrolyte and methods for monitoring the constituents contained therein. More specifically, the present invention relates to plating baths and methods for monitoring the constituents contained therein based on chemometric analysis of voltammetric data obtained for these baths. More particularly, the method of the present invention relates to application of numerous chemometric techniques of modeling power, outlier detection, regression and calibration transfer for analysis of voltammetric data obtained for various plating baths.

Abstract: In accordance with the present invention a measuring device compares the current generated by two working sensor parts and gives an error indication if they are too dissimilar, i.e., the current at one sensor part differs too greatly from what would be expected from considering the current at the other. Not only can this method detect when one of the sensor parts has not been properly covered with sample liquid, but it can also detect if there is a manufacturing defect in either sensor part or if either has been damaged after manufacture, since even with complete coverage of the working sensor parts, an anomalous current will be generated at the affected sensor part under such circumstances.

Abstract: An electrode for use in analytical voltammetry, wherein the electrode has a uniform composition and contains an alloy in a solid state, the alloy containing a pure metal or compound having a low overvoltage for hydrogen and a few percent of at least one second metal or compound, wherein the electrode is a non-toxic electrode with a sufficiently high overvoltage for hydrogen allowing detection of a metal or compound to be detected. Also provided is an apparatus containing the electrode for performing analytical voltammetry involving a redox reaction at an electrode surface, and a method for increasing the utility of voltammetric analyses, by conducting the analyses with an electrode system containing the electrode.

Abstract: Methods and systems are provided for determining whether a volume of biological sample is adequate to produce an accurate electrochemical analyte concentration measurement. Certain such methods and systems provide the additional function of compensating for a sample volume determined to be less than adequate in order to proceed with an accurate analyte concentration measurement. The present invention is employed with a biosensor, such as an electrochemical test strip to which the sample volume of biological solution is deposited, and a meter configured to receive such test strip and to measure the concentration of selected analytes within the biological sample.

Abstract: Ion-selective electrode sensor systems, and methods of fabricating such systems, may be utilized to analyze microfluidic sample volumes, i.e., sample volumes on the order of 1 to 1000 microliters.

Abstract: An ionic conductive wire and method of forming an electrochemical cell in which an electric insulate tube is filled with an ionic conductive material. Terminals proximate the ends of the electric insulate tube are sealed with a fine porous material that is electric-insulate. The ionic conductive wire is movable such that it selectively connects at least two electric conductive materials to form an electrochemical cell.

Abstract: Techniques are provided for measuring chloride ion concentration in a medium. The techniques allow measurements to be made in dry or alkaline media, or both. For alkaline conditions, a sensor includes a pair of electrodes and a polymer film imprinted for uptake of chloride ions under alkaline conditions. The film is deposited to be in contact with at least one electrode and the medium. For dry conditions, a sensor includes a pair of electrodes and a conductive polymer film imprinted for uptake of chloride ions. The film is in contact with the pair of electrodes, and is positioned for contact with the medium. An electrical conductivity of the film depends on an amount of chloride ions taken up by the film. Some techniques allow chloride ion measurements over years at sensors embedded in concrete. Such measurements allow the determination of the progress of rebar corrosion in concrete infrastructure.

Abstract: The subject invention comprises electrochemical methods and devices for in vitro detection of an ischemic event in a patient sample. Following addition of a known amount of a transition metal ion to the patient sample, electrodes are used to measure the current or potential difference of non-sequestered transition metal ion in the sample. The amount of non-sequestered transition metal ion in the sample reflects the degree of modification to albumin that is the result of an ischemic event.

Abstract: Dental amalgam as an electrode material in voltammetry is provided having a very high overpotential to hydrogen. Accordingly, trace analyses can be carried out at potentials sufficiently negative to allow determination of e.g. zinc, cobalt, nickel and iron at trace levels. Such analyses have not previously been possible except by using a mercury or a mercury film electrode. Such determinations are very important for field and online analyses of pollutants in soil and groundwater, and the electrode can be used repeatedly.