Abstract: This invention relates to an apparatus and method for the simultaneous and rapid determination of CoQ10 and CoQ10H2 concentrations in human samples using HPLC-EC. The electrochemical reactions are monitored at electrodes that measure the current produced by the reduction of the hydroquinone group of CoQ10 or by the oxidation of the hydroquinol group of CoQ10H2.

Abstract: A test sensor having a pair of electrodes and a reagent for electrochemically measuring the concentration of the analyte in a liquid sample. The test sensor comprises a capillary channel for collecting the liquid sample and a conductor disposed outside the capillary channel. The conductor is in fluid communication with the capillary channel. The liquid test sample is collected and moved through the capillary channel. The liquid test sample contacts the conductor when the capillary channel is substantially full to signal a full condition.

Abstract: An automated self-calibrating water quality monitoring sensor housing assembly includes a number of ion-selective electrodes combined in a single flow train to provide for the multi constituent analysis of a number of samples without direct intervention by a human operator. An operator can enter the laboratory, connect sample bottles to an intake manifold, activate the device, and download data once the analysis is complete. With the exception of periodic probe maintenance, the system is designed to be self-calibrating and self cleaning.

Abstract: A rotating electrode configuration lowers the detection limits of polyion-sensitive membrane electrodes. Planar potentiometric polycation and polyanion-sensitive membrane electrodes were prepared by incorporating tridodecylmethylammonium chloride and calcium dinonylnaphthalene sulfonate, respectively, into plasticized PVC or polyurethane membranes, and mounting discs of such films on an electrode body housed in a rotating disk electrode apparatus of the type used in voltammetry. Due to the unique non-equilibrium response mechanism of such sensors, rotation of the polyion-sensitive membrane electrodes at 5000 rpm resulted in an enhancement in the detection limits toward heparin (polyanion) and protamine (polycation) of at least 1 order of magnitude (to 0.01 U/ml for heparin; 0.02 ?g/ml for protamine) over that observed when the EMF responses of the same electrodes were assessed using a stir-bar to achieve convective mass transport.

Abstract: An ion sening circuit comprises a bridge sensing circuit and a differential amplifying circuit. The bridge sensing circuit detects the ion concentration of the solution in the operation mode of constant voltage and constant current. The differential amplifying circuit compares the output of the bridge sensing circuit and a floating reference voltage, thereby the delivered voltage to the bridge sensing circuit, such that the opeation mode of constant voltage and constant current is formed accordingly. The main features of the disclosed circuit are that it grounds the reference electrode and floats the source terminal. The drawbacks of not being manufactured with intergrated circuits by CMOS technology and low benefits when applied to sensor arrays are avoided by the disclosed circuit.

Abstract: A potentiometric measuring probe contains an electrolyte (110) as well as a primary reference element (106) and a secondary reference element (108) that are arranged so that the front (148) of an electrolyte deficiency advancing from an opening (112) of the measuring probe arrives at the secondary reference element before it arrives at the primary reference element. The potential difference existing between the primary reference element and the secondary reference element is monitored, and when a predefined tolerance criterion is found to be violated, the elapsed operating time from the point when the measuring probe was put into operation is determined and used as a basis for calculating the remaining operating time of the measuring probe.

Abstract: This invention relates to a method for analyzing the concentration of an analyte in a sample and to automatic analyzing apparatus. The invention will be described herein with particular reference to a method and apparatus for measuring the concentration of glucose or other analytes in blood but is not limited to that use.

Abstract: The present invention relates to a technique for measuring the concentration of a particular component in a sample liquid using a test tool (2). The test tool (2) includes a first through a third detection elements (31a-33a) arranged in the mentioned order in the moving direction of the sample liquid for measuring an electro-physical quantity. The present invention provides a concentration measuring method which includes a first detection step for detecting whether or not liquid conduction is established between the first and the second detection elements (31a, 32a), a second detection step for detecting whether or not liquid conduction is established between the second and the third detection elements (31a, 33a), a measurement step for measuring an electro-physical quantity by using the first through the third detection elements (31a-33a), and a concentration computation step for computing the concentration of the particular component based on the electro-physical quantity.

Abstract: A method and apparatus for measuring a target constituent of an electroplating solution using an electroanalytical technique is set forth. In accordance with the method, at least two electrodes are employed to execute the electroanalytical technique. Gasses that are trapped or generated at the surface of one or both of the electrodes of the pair are reduced and/or removed by directing a flow of solution toward the electrode surface. This flow of solution against the electrode surface acts to automatically flush the generated gasses (typically in the form of small bubbles) from the electrode surface and generally eliminates the need for manual purging by an operator. Elimination of these gasses reduces or eliminates variability in the open circuit potential, and concomitant noise that would otherwise occur in the electroanalytical measurements.

Abstract: The present invention provides microband electrode array sensors for detecting the presence and measuring the concentration of analytes in a sample. The microband electrodes of the invention have both a width and thickness of microscopic dimensions. Preferably the width and thickness of the microbrand electrodes are less than the diffusion length of the analyte(s) of interest. In general, both the thickness and width of the electrodes are less than about 25 micrometers. The electrodes are separated by a gap insulating material that is large enough that the diffusion layers of the electrodes do not overlap such that there is no interference and the currents at the electrodes are additive. Microband electrode arrays of this invention exhibit true steady-state amperometric behavior.

Abstract: A cartridge for analyzing a bodily fluid for use with an analytical device includes a base structure, a sensor arrangement, a pump arrangement, and a pump control arrangement configured to selectively operate the pump when the cartridge is operatively positioned in the analytical device. A system for analyzing a bodily fluid includes an analytical device with a cartridge-receiving receptacle and a cartridge operatively and removably mounted in the cartridge-receiving receptacle. The cartridge includes a sensor arrangement and a pump. The analytical device includes a pump control arrangement to selectively operate the pump. A method of analyzing bodily fluid includes inserting a cartridge into an analytical device, dispensing a sample into the cartridge, sensing the fluid with the cartridge, and allowing the analytical device to automatically pump a calibration fluid over sensors in the cartridge.

Abstract: A hand-held portable drug monitoring system to detect and quantitate cocaine and other organic drugs in saliva, sweat, and surface wipes by using an ion selective electrode or an array of ion selective electrodes. The ion selective electrode has a cast membrane reference electrode and a sensing electrode with a hydrophobic polymer, a plasticizer, and an ionophore selective for the organic drug to be tested. The ion selective electrode can be connected to a converter that coverts a voltage reading from the ion selective electrode to a quantitative drug concentration level. Also disclosed is the related method of using an ion selective electrode to detect an organic drug in saliva, sweat, and surface wipes, the method of testing electrical contact in an ion selective electrode, and the method of making a cast membrane reference electrode.

Abstract: A method for reducing interference caused by contaminants on the detection and/or measurement of an analyte in a biological sample includes providing a chemical sensor that contains carboxylated polyvinyl chloride (PVC—COOH) as a polymer component of the sensor's polymeric membrane. A biological sample containing the analyte of interest and a contaminant is placed in contact with the chemical sensor that includes PVC—COOH as a polymer component of the sensor's polymeric membrane. The analyte of interest in the biological sample is then measured and/or detected by the chemical sensor without interference by the contaminant.

Abstract: The present invention relates to methods and apparatus for determining concentrations of various inorganic or organic components in solder plating solutions, which include titration or parallel titration methods, direct potentiometry methods, calibration methods, and/or UV-Vis absorption analysis.

Abstract: Single-channel thin film devices and methods for using the same are provided. The subject devices comprise cis and trans chambers connected by an electrical communication means. At the cis end of the electrical communication means is a horizontal conical aperture sealed with a thin film that includes a single nanopore or channel. The devices further include a means for applying an electric field between the cis and trans chambers. The subject devices find use in applications in which the ionic current through a nanopore or channel is monitored, where such applications include the characterization of naturally occurring ion channels, the characterization of polymeric compounds, and the like.

Abstract: The present invention allows the determination of trace levels of ionic substances in a sample solution (ions, metal ions, and other electrically charged molecules) by coupling a separation method, such as liquid chromatography, with ion selective electrodes (ISE) prepared so as to allow detection at activities below 10−6M. The separation method distributes constituent molecules into fractions due to unique chemical and physical properties, such as charge, hydrophobicity, specific binding interactions, or movement in an electrical field. The separated fractions are detected by means of the ISE(s). These ISEs can be used singly or in an array. Accordingly, modifications in the ISEs are used to permit detection of low activities, specifically, below 10−6M, by using low activities of the primary analyte (the molecular species which is specifically detected) in the inner filling solution of the ISE. Arrays constructed in various ways allow flow-through sensing for multiple ions.

Abstract: The present invention relates to electrochemical cells including a first working electrode 32, a first counter electrode 34, a second working electrode 36, and a second counter electrode 38, wherein the electrodes are spaced such that reaction products from the first counter electrode 34 arrive at the first working electrode 32, and reaction products from the first and second counter electrodes 34, 38 do not reach the second working electrode 36. Also provided is a method of using such electrochemical cells for determining the concentration of a reduced or oxidized form of a redox species with greater accuracy than can be obtained using an electrochemical cell having a single working and counter electrode.

Abstract: The present invention relates to a substrate and a method for obtaining an electrophysiological measuring configuration in which a cell forms a high resistive seal (giga-seal) around a measuring electrode making it suitable for determining and monitoring a current flow through the cell membrane. The substrate is typically part of an apparatus for studying electrical events in cell membranes, such as an apparatus for carrying out patch clamp techniques utilised to study ion transfer channels in biological membranes. The substrate has a plurality or an array of measuring sites with integrated measuring and reference electrodes formed by wafer processing technology. The electrodes are adapted to conduct a current between them by delivery of ions by one electrode and receipt of ions by the other electrode and are typically silver/silver halide electrodes.

Abstract: Microanalytical systems based on a microfluidics/electrochemical detection scheme are described. Individual modules, such as microfabricated piezoelectrically actuated pumps and a microelectrochemical cell were integrated onto portable platforms. This allowed rapid change-out and repair of individual components by incorporating “plug and play” concepts now standard in PC's. Different integration schemes were used for construction of the microanalytical systems based on microfluidics/electrochemical detection. In one scheme, all individual modules were integrated in the surface of the standard microfluidic platform based on a plug-and-play design. Microelectrochemical flow cell which integrated three electrodes based on a wall-jet design was fabricated on polymer substrate. The microelectrochemical flow cell was then plugged directly into the microfluidic platform.

Abstract: A method consists in measuring ac impedance spectrum using gold, platinum or carbon working ultramicroelectrodes (1). The direct current DC potential pulse which overlaps with alternating current AC signal of an amplitude in the range from 0.005 to 0.015 V and frequency in the range from 10−2 to 106, Hz is applied at the electrode. The value of said DC potential pulse for a process of copper electrorefining is in the range from −0.4 to −0.9 V in relation to a platinum reference electrode (2). Resistance values characteristic of a given electrolyte (E) are obtained from said AC impedance spectrum and compared with standard characteristic obtained by standard additions method. A measuring system consist of electrodes (1, 2, 3) placed inside a measuring cell (4) filled with flowing industrial electrolyte.

Abstract: The present invention provide a method and an apparatus for detecting anions in water which does not require replacement of ion exchange resins and the like and can perform precise measurement at low cost in a simple operation.

Abstract: An alloy solute sensor probe, measurement system and measurement method are disclosed for directly measuring solute concentration profiles in conductive material components at elevated processing temperatures. The disclosed device and method permit direct, real-time non-destructive measurement of solute concentration profiles in treated surfaces in alloy components. In disclosed embodiments, a novel concentric carbon sensor and rod-shaped carbon sensor are disclosed which employ AC frequencies for probing the subsurface region of alloy samples to determine carbon concentration profiles at steel surfaces from measurements of alloy resistivity profiles. Results of carbon profile measurements obtained with the disclosed device and method compare favorably with conventional destructive analytical measurements made on post-processed samples.

Abstract: Method and apparatus for trace metal detection and analysis using bismuth-coated electrodes and electrochemical stripping analysis. Both anodic stripping voltammetry and adsorptive stripping analysis may be employed.

Abstract: The concentration of chloride ion in an acid copper electroplating bath is determined from the effect that chloride exerts on the copper electrodeposition rate in the presence of organic additives. A cyclic voltammetric stripping (CVS) rate parameter is measured, before and after standard addition of a plating bath sample, in an acid copper electrodeposition solution containing little or no chloride and at least one organic additive. Cross contamination and waste disposal issues associated with the reagents and reaction products involved in chloride titration analyses are avoided. The method may also be applied to analysis of other halides (bromide and iodide) and other solutions.

Abstract: Disclosed is a microchip-based differential-type potentiometric oxygen gas sensor, which comprises a working electrode and a reference electrode. The working electrode is composed of a cobalt-plated electrode, a buffered hydrogel, and an ion sensitive gas permeable membrane while the reference electrode is composed of an oxygen non-sensitive silver chloride electrode and the same ion-selective gas-permeable membrane of working electrode. By taking advantage of the corrosion potential, the microchip-based oxygen gas sensor can accurately and quickly detect the content of dissolved oxygen in a sample solution. With this structure, the oxygen gas sensor is applied to a microchip-based all potentiometric multi-sensor capable of detecting two or more ions and gas species on a single chip.

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 electrochemical sensor (A, A′) is specific for the detection of peroxyacetic acid in a solution which also contains hydrogen peroxide. A potential is applied between a reference electrode (120, 120′) and a working electrode (118, 118′). A read voltage (FIG. 7) is selectively pulsed across a counter electrode (122, 122′) and the working electrode. The current flowing between the working electrode and the counter electrode is dependent on the peroxyacetic acid concentration in the solution (FIG. 6). By careful selection of the read voltage, the contribution of hydrogen peroxide to the current flow is virtually negligible. The sensor effectively measures peroxyacetic acid concentrations in the range generally employed in sterilization and disinfection baths (100-3000 ppm.).

Abstract: A self-cleaning oxidation-reduction potential (“ORP”) probe system includes an ORP electrode (11), a flow cell (12) surrounding the ORP electrode, and a plurality of cleaning beads (17) contained in the flow cell in a manner in which they are free to contact the ORP electrode when fluid is passed through the flow cell. The self-cleaning probe system may also or alternatively include a pH probe electrode, or another fluid-testing probe, in the flow cell.

Abstract: The method consists in registering curves by cyclic voltammetry method in the range of copper ion concentration up to 20 g/l or alternately by chronoamperometric method in the range of concentration from 20 to 60 g/l. A platinum or gold microprobe of a diameter in the range from 1 to 50 um and a copper plate reference electrode are used. The value of current density read off from said curves is compared to the calibration curves previously determined by standard additions method. For high concentration in the range from 20 to 60 g/l the calibration curves obtained in the range of temperatures from 15 to 60° C. are registered.

Abstract: Systems and methods are provided herein for improving the selectivity and productivity of sensors via digital signal processing techniques. According to one illustrative embodiment, in an electrochemical method for monitoring of a select analyte in a mixed sample with an interfering analyte, an improvement is provided that includes applying a large amplitude potential stimulus waveform to the sample to generate a nonlinear current signal; and resolving a signal contribution from the select analyte in the generated signal by a vector projection method with an analyte vector comprising a plurality of real and imaginary parts of one or more Fourier coefficients at one or more frequencies of a reference current signal for the select analyte.

Abstract: An analytical system to determine the presence of specific constituents in a liquid stream. The analytical system is an automated system that facilitates the testing of one or more samples according to a variety of methods. The methods may be of varying levels of complexity and may be run either in parallel or sequentially.

Abstract: An ammonium selective ionophore for use in ion selective electrodes.

Abstract: An apparatus and method for the indirect determination of concentrations of additives in metal plating electrolyte solutions, particularly organic additives in Cu-metalization baths for semiconductor manufacturing. Plating potentials between the reference and test electrodes are measured and plotted for each of the solution mixtures, and data are extrapolated to determine the concentration of the additive in the sample. A multi-cycle method determines the concentration of both accelerator and suppressor organic additives in Cu plating solution in a single test suite.

Abstract: An electrical contact element for electrically connecting an electric device and providing current transmission in an electric device wherein the electrical contact element comprises a metallic body, and wherein at least one contact surface, present on the body, is completely or partially coated with a friction-reducing layer. The friction-reducing layer comprises a metal salt.

Abstract: The present invention includes a method and sensor that is easy to assemble and can operate to effectively detect an air borne or exogenously introduced analyte. In one embodiment, the assembled sensor includes a top cap capable of receiving a first electrolyte and a bottom cap capable of receiving a second electrolyte. The assembled sensor also includes a flexible boot that holds together the top cap, the bottom cap and a membrane. The membrane is located between the first electrolyte and the second electrolyte and enables an electrical device to detect an analyte (e.g., hazardous chemical) which originally entered the sensor through a passage in the top cap and interacted with the membrane.

Abstract: In order to regulate the metal ion concentration in an electrolyte fluid serving to electrolytically deposit metal and additionally containing substances of an electrochemically reversible redox system, it has been known in the art to conduct at least one portion of the electrolyte fluid through one auxiliary cell provided with one insoluble auxiliary anode and at least one auxiliary cathode, a current being conducted between them by applying a voltage. Accordingly, excess quantities of the oxidized substances of the redox system are reduced at the auxiliary cathode, the formation of ions of the metal to be deposited being reduced as a result thereof. Starting from this prior art, the present invention relates to using pieces of the metal to be deposited as an auxiliary cathode.

Abstract: A pH sensor is provided capable of readily determining the pH of a solution of a small amount. The pH sensor includes a semiconductor substrate, an oxide film provided on the semiconductor substrate, a solution storage part for holding a solution on the oxide film, and an electrode to be in contact with the solution in a vicinity of the oxide film. To determine the pH of a solution, a capacitance-voltage characteristic is initially monitored by the sensor between the electrode in contact with the solution and another electrode provided on the back surface of the semiconductor. Then the pH of the solution is derived from a flat band voltage which is obtained based on the capacitance-voltage characteristic.

Abstract: An improved membrane based biosensor incorporates sensing and reference electrodes and a dc electrical potential produced by a counter electrode. The biosensor incorporates ionophores. The conductivity of the membrane is dependent on the presence or absence of an analyte. A functional reservoir exists between the sensing electrode and a lipid membrane deposited on the sensing electrode. The invention also includes the method of detecting the presence or absence of the analyte by use of the biosensor.

Abstract: This invention relates to a method for analyzing the concentration of an analyte in a sample and to automatic analyzing apparatus. The invention will be described herein with particular reference to a method and apparatus for measuring the concentration of glucose or other analytes in blood but is not limited to that use.

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: Improved dry-operative ion-selective electrodes and their use are described. The dry-operative ion-selective electrodes include an internal reference electrode comprising a water-soluble salt dispersed in a polymer binder consisting essentially of a monomer having at least one carboxyl group and a hydrophobic monomer. The polymer provides reduced brittleness, good interlayer adhesion and high salt tolerance.

Abstract: The Applicant's invention comprises an apparatus and method for determining the amount of one or more components in a pulping liquor. At a first electrode, a varying voltage is supplied in a voltage range including the half-wave potential of each component of a liquor to be measured, and accounting for variations in the half-wave potential caused by changing process parameters. At a second electrode, which is roughly ⅓ to ¼ the size of the first electrode, the derivative of current intensity is monitored near the known half-wave potential for the various liquor components. Using curve-fitting means, the derivative of current intensity and selected other process condition data is used to determine concentrations of the various liquor components.

Abstract: A modular, in particular multidimensional system for the reagent-free, continuous detection of a substance is disclosed. The system is characterized by the presence of at least two measurements modules of preferably different types. The modules are robust and designed for a long-time operation. They have an exchangeable or replaceable selective layer structure. The system may also include appropriate modules for amperometry and optical sensors.

Abstract: A process for the examination of biocompartments (1), having a micro-flow chamber (2) which contains a biocompartment (1) which is continually or intermittently subjected to the through-flow of a culture medium. In a culture medium zone proximal to the biocompartments (1), an electrical potential is applied in such a manner, that from a substance in the culture medium which is released or consumed by the biocompartments (1), OH− and/or H+ ions are formed. During the application of the potential, a first measurement (pH−1, pH−3) for the pH value of the culture medium is measured. The potential is then switched off or changed in such a manner that the formation of OH−0 and/or H+ ions from the said substance is stopped. Before or after the measuring of the first measured value, (pH−1, pH−3) with switched off electrical potential, a second measured value (pH−2, pH−4) is measured for the pH value of the culture medium.

Abstract: The present invention relates to chloride-selective electrodes which comprise insoluble metal salt layer and a protecting membrane formed of hydrophilic polyurethane thereon, wherein the hydrophilic polyurethane coated chloride-selective electrodes show fast activation and response time and are usefully employed to accurately measure the chloride by reducing the interference from bromide and iodide or preventing the surface of the electrode from protein adsorption.

Abstract: A method of screening a water soluble gold complex for use as a sensitizer in a silver halide photographic element comprised of experimentally measuring the electrochemical potential of the gold complex and then determining if the electrochemical potential falls within a predetermined utility window.

Abstract: An apparatus and a method for determining concentration of fluorine ions in aqueous solutions are provided. In the apparatus, a pH sensor is provided for sensing a pH value of an aqueous solution to be determined. A pH controller is then used to compare the pH value determined with stored pH data to determine whether the aqueous solution is acidic or alkalinic. An acid dispenser or a base dispenser is then used to dispense either an acid or a base into the pH adjustment tank for adjusting the pH value of the aqueous solution to within a desirable range. For instance, for the detection of fluorine ions, a suitable pH range is between about 4 and about 10. After the pH value is stabilized in the aqueous solution, a fluorine ion sensor may be used to sense the fluorine ion concentration in the aqueous solution. A common acid and base which may be used to bring the pH value within the desirable range may be H2SO4 and NaOH.

Abstract: An apparatus and a method of characterising liquids employ liquid sensors of different types of technology, in order to generate characterisation data from the whole of the output signals originating from these sensors when they are soaked in a sample of the liquid. The set of sensors may comprise: lipid sensors, quartz microbalances, ion-selective electrodes, biosensors, chemical microelectrodes or even, in certain particular applications, fiber optic based-sensors. The output signals originating from the different sensors are normalized with respect to values which are determined in a prior standardization operation during which the sensors were soaked in at least one sample reference liquid.

Abstract: An apparatus and method for the indirect determination of concentrations of additives in metal plating electrolyte solutions, particularly organic additives in Cu-metalization baths for semiconductor manufacturing. The apparatus features a reference electrode housed in an electrically isolated chamber and continuously immersed in the base metal plating solution (without the additive to be measured). An additive concentration determination method comprises electroplating a test electrode at a constant or known current in a mixing chamber wherein the base metal plating solution is mixed with small volumes of the sample and various calibration solutions containing the additive to be measured. Plating potentials between the electrodes are measured and plotted for each of the solution mixtures, and data are extrapolated to determine the concentration of the additive in the sample.

Abstract: An electronic sensor is described that includes a sample receptacle and a data storage device. The data storage device is powered by a pair of half cells on the sensor. The half cells contain ion solutions that are also used to calibrate the sensor. As the sensor is placed within a sensor data reader, the data stored on the data storage device is transferred to the reader along with measurements of the voltage potential between the half cells. The reader thereafter calculates a calibration slope curve for the sensor. The calibration slope curve is then used to determine the exact ion concentration of any sample that is placed in the sample receptacle.