Abstract: Electrolytic eluent recycle systems for ion chromatography using a multi-channel electrolytic ion exchange device which integrates suppression, eluent generation, and eluent recycle. The systems recycle the eluent into the analytical system without passing the eluent through the electrode chambers. Also, such systems with a channel for electrolytic removal of ions from the suppression effluent before recycle.

Abstract: A monitoring method of metal ions or oxygen ions applicable to a high concentration non-aqueous electrolyte includes: applying a potential in a non-aqueous electrolyte to obtain current information with respect to the potential; varying the potential applied in the non-aqueous electrolyte containing metal ion concentration or oxygen ion concentration such that the metal ion concentration or the oxygen ion concentration is maintained in spite of the potential being applied; detecting a linear relationship among the concentration, the current, and passed charges in the non-aqueous electrolyte by repeatedly performing the obtaining step and the varying step, while changing the concentration; and calculating metal ion concentration or oxygen ion concentration of the non-aqueous electrolyte in pyroprocessing of the non-aqueous electrolyte by using the linear relationship.

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: A measuring arrangement for registering a measured variable representing concentration of an analyte in a measured medium, includes: a first electrode modified with a redoxly active substance, a second electrode, and a measuring circuit, which comprises a voltage source for applying at least one predetermined voltage between the first electrode and a reference, and an apparatus for registering electrical current flowing, in such case, between the first electrode and the second electrode or for registering a variable correlated with the electrical current flowing between the first electrode and the second electrode, wherein the second electrode is modified with the same redoxly active substance as the first electrode.

Abstract: Methods and apparatuses relating to large scale FET arrays for analyte detection and measurement are provided. ChemFET (e.g., ISFET) arrays may be fabricated using conventional CMOS processing techniques based on improved FET pixel and array designs that increase measurement sensitivity and accuracy, and at the same time facilitate significantly small pixel sizes and dense arrays. Improved array control techniques provide for rapid data acquisition from large and dense arrays. Such arrays may be employed to detect a presence and/or concentration changes of various analyte types in a wide variety of chemical and/or biological processes.

Abstract: Methods and apparatuses relating to large scale FET arrays for analyte detection and measurement are provided. ChemFET (e.g., ISFET) arrays may be fabricated using conventional CMOS processing techniques based on improved FET pixel and array designs that increase measurement sensitivity and accuracy, and at the same time facilitate significantly small pixel sizes and dense arrays. Improved array control techniques provide for rapid data acquisition from large and dense arrays. Such arrays may be employed to detect a presence and/or concentration changes of various analyte types in a wide variety of chemical and/or biological processes.

Abstract: Methods and apparatuses relating to large scale FET arrays for analyte detection and measurement are provided. ChemFET (e.g., ISFET) arrays may be fabricated using conventional CMOS processing techniques based on improved FET pixel and array designs that increase measurement sensitivity and accuracy, and at the same time facilitate significantly small pixel sizes and dense arrays. Improved array control techniques provide for rapid data acquisition from large and dense arrays. Such arrays may be employed to detect a presence and/or concentration changes of various analyte types in a wide variety of chemical and/or biological processes.

Abstract: Methods and apparatuses relating to large scale FET arrays for analyte detection and measurement are provided. ChemFET (e.g., ISFET) arrays may be fabricated using conventional CMOS processing techniques based on improved FET pixel and array designs that increase measurement sensitivity and accuracy, and at the same time facilitate significantly small pixel sizes and dense arrays. Improved array control techniques provide for rapid data acquisition from large and dense arrays. Such arrays may be employed to detect a presence and/or concentration changes of various analyte types in a wide variety of chemical and/or biological processes.

Abstract: Provided are an apparatus and method for detecting biomolecules. The apparatus includes a FET having a substrate, a source electrode, a drain electrode, a channel region between the source and drain electrodes, and probe molecules fixed to the channel region, wherein the source and drain electrodes are separated on the substrate, a microfluid supplier selectively supplying one of a reference buffer solution of low ionic concentration and a reaction solution of high ionic concentration containing target molecules, to the channel region of the FET to which the probe molecules are fixed, and a biomolecule detector detecting the target molecules by measuring a first current value of the channel region of the FET, and a second current value of the channel region of the FET to which the target molecules and the probe molecules that bind to each other in the reaction solution of high ionic concentration are fixed.

Abstract: The presence of a select analyte such as glucose in the sample is evaluated in an electrochemical system using a conduction cell-type apparatus. A potential or current is generated between the two electrodes of the cell sufficient to bring about oxidation or reduction of the analyte or of a mediator in an analyte-detection redox system, thereby forming a chemical potential gradient of the analyte or mediator between the two electrodes after the gradient is established, the applied potential or current is discontinued and an analyte-independent signal is obtained from the relaxation of the chemical potential gradient. The analyte-independent signal is used to correct the analyte-dependent signal obtained during application of the potential or current.

Abstract: Methods and apparatus relating to very large scale FET arrays for analyte measurements. ChemFET (e.g., ISFET) arrays may be fabricated using conventional CMOS processing techniques based on improved FET pixel and array designs that increase measurement sensitivity and accuracy, and at the same time facilitate significantly small pixel sizes and dense arrays. Improved array control techniques provide for rapid data acquisition from large and dense arrays. Such arrays may be employed to detect a presence and/or concentration changes of various analyte types in a wide variety of chemical and/or biological processes. In one example, chemFET arrays facilitate DNA sequencing techniques based on monitoring changes in the concentration of inorganic pyrophosphate (PPi), hydrogen ions, and nucleotide triphosphates.

Abstract: A gas sensor includes a housing having disposed therein a membrane electrode assembly comprising a sensing electrode, a counter electrode, and a polymer membrane disposed between the sensing electrode and the counter electrode. The polymer membrane comprises an ionic liquid retained therein. The sensor also includes a catalyst support that can be stable in a range of potentials to allow for detection mode and catalyst regeneration mode to be operative. The sensor further includes a circuitry and algorithm to implement the catalyst regeneration mechanism electrochemically. The sensor further includes a chamber for reference gas to which the counter electrode is exposed, and a chamber for test gas to which a gas to be tested is exposed. The sensor also includes a pathway for test gas to enter the chamber and a measured electrical circuit connecting the sensing electrode and the counter electrode.

Abstract: Methods and apparatus relating to very large scale FET arrays for analyte measurements. ChemFET (e.g., ISFET) arrays may be fabricated using conventional CMOS processing techniques based on improved FET pixel and array designs that increase measurement sensitivity and accuracy, and at the same time facilitate significantly small pixel sizes and dense arrays. Improved array control techniques provide for rapid data acquisition from large and dense arrays. Such arrays may be employed to detect a presence and/or concentration changes of various analyte types in a wide variety of chemical and/or biological processes. In one example, chemFET arrays facilitate DNA sequencing techniques based on monitoring changes in hydrogen ion concentration (pH), changes in other analyte concentration, and/or binding events associated with chemical processes relating to DNA synthesis.

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: Potentiometric sensor comprising an ion selective electrode and the latter, on its part, containing a membrane characterized in that it comprises: a thermoplastic material; an electroactive substance based on a salt wherein the cation is the protonated form of the analyte to be determined and the anion is a cluster which comprises boron atoms; and a plasticizing agent. In addition, the invention further relates to the use of said sensor for the detection and/or quantification of a compound containing at least one nitrogen atom.

Abstract: The present invention aims to simplify the structure and a fabrication method of an ion-selective electrode in an ion concentration measuring device that measures an anion, particularly a chloride ion, in a biological component. To this end, in a potential difference measuring unit, a quaternary ammonium salt derivative serving as a ligand for an anion is immobilized to the surface of a gold electrode by using as a linker an insulative molecule forming a self-assembled monolayer. The potential difference measuring unit measures an electromotive force generated with anion binding, as an interface potential change on the surface of the gold electrode. In order to reduce the influence of adsorption of impurities on the electrode surface, a high-molecular weight polymer is physically adsorbed on the gold electrode and thus used when a biological component is measured.

Abstract: Provided are devices and methods for performing multi-point analysis on biological materials, such as cells. In one embodiment, the devices simultaneously collect information related to a characteristic of a cell membrane and a characteristic of the interior of the cell.

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: Disclosed herein is a method of correcting erroneous measurement results in a biosensor. The method includes the steps of: (a) applying a first voltage from a voltage generator 12 to a test strip 10 when a blood sample is applied on the test strip 10, and measuring an electric current generated from the test strip within one second of applying the first voltage by a microcontroller unit (MCU), and then calculating a hematocrit value of the blood sample using the measured electric current value! (b) applying a second voltage from the voltage generator to the test strip after calculating the hematocrit value of the blood sample, and measuring an electric current generated from the test strip within a predetermined time of applying the second voltage, and then calculating a glucose level using the measured electric current value; and (c) correcting the glucose level in (b) by using the calculated hematocrit value in (a).

Abstract: Methods and apparatus relating to FET arrays for monitoring chemical and/or biological reactions such as nucleic acid sequencing-by-synthesis reactions. Some methods provided herein relate to improving signal (and also signal to noise ratio) from released hydrogen ions during nucleic acid sequencing reactions.

Abstract: A crown ether derivative that acts as cation capturing ligand and alkanethiol having a longer carbon chain than a linker are immobilized, coexisting together, on the surface of a gold electrode, by using as the linker an insulating molecule (e.g., alkanethiol) that forms self-assembled monolayers. Electromotive force produced in association with cation coordination is measured by a potentiometer through a change in interfacial potential on the surface of the gold electrode. Further, an insulated gate field effect transistor formed on the same substrate as the gold electrode is used as the potentiometer. Furthermore, a straight-chain polymer physically adsorbed on the gold electrode is used in order to reduce the influence of the adsorption of impurities on the surface of the electrode during biological sample measurement.

Abstract: A method for operating a sensor for biomolecules or charged ions, the sensor comprising a first field effect transistor (FET) and a second FET, wherein the first FET and the second FET comprise a shared node includes placing an electrolyte containing the biomolecules or charged ions on a sensing surface of the sensor, the electrolyte comprising a gate of the second FET; applying an inversion voltage to a gate of the first FET; making a first electrical connection to an unshared node of the first FET; making a second electrical connection to unshared node of the second FET; determining a change in a drain current flowing between the unshared node of the first FET and the unshared node of the second FET; and determining an amount of biomolecules or charged ions contained in the electrolyte based on the determined change in the drain current.

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: A method of microanalyzing ions, which includes: placing in a cavity having an internal volume, a volume of an ionic liquid that is smaller than the internal volume; placing in the cavity a solution containing the ions that are to be analyzed, a solvent of the solution and the ionic liquid being selected so as to be immiscible and so as to enable the ions to be transferred from the solution to the ionic liquid; and detecting a presence of the ions in the ionic liquid with an analyzer that analyzes at least one of cations or anions of the ions in the ionic liquid, in a free state or in a complexed state, the analyzer being in contact with the ionic liquid.

Abstract: An electrochemical sensor for the presence or concentration of an analyte has at least one electrode and at least one electrochemically active species able to undergo electrochemical reaction in response to electrical potential applied to the electrode, where the said reaction is modified by the presence of the analyte. This sensor has the novel characteristic that at least one said electrochemically active species is encapsulated within polymer particles. These particles are preferably formed from an amorphous polymer with a glass transition temperature above the temperature of the fluid to which the sensor is exposed. The encapsulating polymer protects the analyte species from degradation, but a small analyte such as a hydrogen or bisulfide ion can pass through the polymer and undergo reaction at the active species.

Abstract: A method is provided to sample a sensor array. The method can include measuring a waveform associated with a chemical event occurring on the sensor array. The waveform can include at least one region associated with expected measured values and at least one region associated with unpredictable measured values. The method can also include applying a first frame averaging to the at least one region associated with the expected measured values. Here, a first number of frames can be included in the first frame averaging. Further, the method can include applying a second frame averaging to the at least one region associated with the unpredictable measured values, where a second number of frames can be included in the second frame averaging. The second number of frames can be less than the first number of frames.

Abstract: In a method and a device for determining the concentration of one or more oxidizing agents in an aqueous solution flowing in a main stream, a partial flow of the aqueous solution is diverted to a bypass, wherein the difference between the potential of the aqueous solution before and after at least partial and/or selective breakdown of any oxidizing agents is measured. The bypass is for diverting and returning the partial flow of the aqueous solution, and has at least one elimination unit through which the aqueous solution flows for at least partial and/or selective breakdown of the oxidizing agent(s), and two measuring electrodes for determining the difference between the potentials of the aqueous solution before and after it passes through the elimination unit.

Abstract: A method of determining an analyte concentration employs a biosensor that includes a molecularly imprinted polymer film formed on a metal layer. The biosensor is connected to a charge/discharge circuit and charged and discharged during exposure to a solution containing an analyte. Voltage values during discharge are measured, and a characteristic parameter of the voltage values, which is associated with a concentration of the analyte detected by the biosensor, is determined. An unknown concentration of the analyte is determined by comparing the characteristic parameter to reference data representing a relation between known concentration of the analyte and the characteristic parameter of the biosensor. A biosensor, such as an anesthetic biosensor, is also disclosed.

Abstract: A system and method for voltammetric analysis of a liquid sample solution.

Abstract: Methods are described for reading a chemically-sensitive field-effect transistor (chemFET) with an improved signal-to-noise ratio. In one embodiment, a method is described for reading a chemFET having a first terminal and a second terminal, and a floating gate coupled to a passivation layer. The method includes biasing the first terminal of the chemFET to a first bias voltage during a read interval. The second terminal of the chemFET is coupled to a data line during the read interval. A current is induced through the chemFET via the data line. An output signal proportional to an integral of a voltage or current on the data line is generated in response to the induced current through the chemFET during the read interval.

Abstract: Method and apparatus to measure electrolytes. The apparatus has a measuring portion for measuring electromotive forces generated by a reference fluid and the sample fluid, respectively, by the use of an electrode portion. A dilution vessel for preparing the sample solution by diluting a sample fluid with a diluting fluid. A control portion for providing control such that the reference fluid and the sample solution are alternately supplied to the electrode portion from the dilution vessel and that a given amount of the diluting fluid is supplied to and wasted from the dilution vessel prior to the preparation of the sample solution.

Abstract: The present disclosure relates to various methods for measuring the amount of an analyte present in a biological fluid using an electrochemical testing process. Various embodiments are disclosed, including the use of AC test signals and the performance of tests having a Total Test Time within about 3.0 seconds or less, and/or having a clinically low Total System Error.

Abstract: A system capable of detecting low-level releases of bio-agents and other harmful substances contained in air concentrates and recycles exhaust air from a collector in order to entrain and retain more particles from an aerosol release event. The system ensures that particles that were not initially entrained or subsequently retained will have successive opportunities to be entrained within the collection solution. The system also optionally utilizes concentrators in series and a collector to ensure that the particle content of air entering the collector is maximized.

Abstract: The present invention provides methods and apparatuses for analyte detection.

Abstract: Disclosed herein is an electrochemical measurement system for analyzing heavy metals in organic compound-containing samples, comprising: a lower plate; a flow channel plate; an upper plate; an organic compound-decomposing electrode and a heavy metal analysis electrode; and a flow changeover portion. The disclosed system can continuously perform a pretreatment process for organic compound decomposition and a process for heavy metal analysis, thus making it possible to achieve the selective analysis and separation of heavy metals in wastewater. Also, it can substitute for expensive spectrophotometric analysis equipment and makes it possible to monitor trace heavy metals on-line in situ. In addition, it may include a small-sized battery as a power source, such that it is easy to carry and use.

Abstract: A potentiometric sensor includes a housing, in which a reference half cell space and a therefrom separated, measuring half cell space are formed. The reference half cell space contains a reference electrolyte and at least one part of a first potential sensing electrode for sensing a reference potential, and the measuring half cell space is liquid-tightly sealed by a measuring membrane, especially a pH-sensitive glass membrane, and contains an inner electrolyte and at least one part of a second potential sensing electrode for sensing a measuring half cell potential. A passageway extends through a wall of the housing, opens into the reference half cell space, and is sealed relative to a medium surrounding the housing, and wherein the potentiometric sensor has means for producing through the passageway an electrolytic contact between the reference electrolyte and the medium surrounding the housing.

Abstract: The invention is to devices and method for rapid determination of analytes in liquid samples by various assays including immunoassays incorporating a sample dilution feature for forming a diluted sample for analysis. The devices and methods also include a dilution verification feature for verifying the degree of dilution of the diluted sample. The devices preferably are capable of being used in the point-of-care diagnostic field is provided.

Abstract: A sensing device for the determination of ions in a thin layer sample (32) comprising: a first (12) and second (14) ion selective electrode, each having a first (16) and second layer (20); the first layer (16) of the first ion selective electrode (12) being a polymeric membrane layer in electrical contact with the second layer (20) of the first ion selective electrode (12), and the first layer (18) of the second ion selective electrode (14) being a polymeric membrane layer in electrical contact with the second layer (20) of the second ion selective electrode (14); the first and second ion selective electrodes being positioned in opposing arrangement such that, the respective polymeric membrane layers are in direct contact with a thin layer sample (32) containing ions, located between the first and second electrodes; and a detector (28) in electrical connection with the first (12) and second (14) ion selective electrodes.

Abstract: The invention relates to a device and method for non-invasive detection of an analyte in a fluid sample. In one embodiment, the device comprises: a collection chamber containing an absorbent hydrogel material; a fluidic channel connected to the collection chamber; a sensing chamber connected to the fluidic channel, wherein the device is comprised of a compressible housing that allows transfer of fluid collected by the collection chamber to be transferred to be extracted and withdrawn to the sensing chamber upon compression of the device, wherein the sensing chamber contains a material that specifically detects the analyte and wherein the sensing chamber is operably linked to a processor containing a potentiostat that allows detection of the analyte using electrochemical sensing.

Abstract: The purpose of the invention is to provide a method for quantifying a chemical substance with high accuracy using substitutional stripping voltammetry and a sensor chip used therefor. A sensor chip comprising a stripping electrode which is covered with stripping gel and a method utilizing the sensor chip. A reaction represented by the following formula (III) occurs at the stripping electrode. [Chem.

Abstract: A method for operating a measuring device comprising the following steps: providing a first sample of the liquid; ascertaining an updated calibration function by means of a standard addition method, wherein the first sample is supplemented at least once with a standard solution, which has a known concentration of the measured ion; determining a measured value of concentration of the measured ion in the first sample; providing a second sample of the liquid; ascertaining a measured value of concentration of the measured ion in the second sample as a reference measured ion concentration (cref) by means of a reference method; and determining a difference (cdisturb) between the apparent measured ion concentration (capparent) and the reference measured ion concentration (cref) and deriving a correction value (ckorr) therefrom for future measured values of concentration of the measured ion in the liquid, as ascertained with the measuring device.

Abstract: The chloride concentration in an acid copper plating bath is determined from the chloride oxidation current measured under controlled hydrodynamic conditions at a noble metal electrode using specific voltammetric parameters. The measurement is made directly on the undiluted plating bath so that the chloride measurement is fast and no waste stream is generated.

Abstract: Internally calibrated pH and other analyte sensors based on redox agents provide more accurate results when the redox active reference agent is in a constant chemical environment, yet separated from the solution being analyzed in such a way as to maintain electrical contact with the sample. Room temperature ionic liquids (RTIL) can be used to achieve these results when used as a salt bridge between the reference material and the sample being analyzed. The RTIL provides the constant chemical environment and ionic strength for the redox active material (RAM) and provides an electrolytic layer that limits or eliminates direct chemical interaction with the sample. A broad range of RAMs can be employed in a variety of configurations in such “Analyte Insensitive Electrode” devices.

Abstract: Method for determining ion concentration or concentration of a substance in a solution by means of an ion selective, field effect transistor or an ion sensitive sensor having an EIS structure. The method comprises steps as follows: at least at a predetermined point in time of a first measuring phase, the potential lying on the electrode is sensed relative to a reference potential; before beginning a sterilization- and/or cleaning phase following the first measuring phase, the last voltage sensed during the first measuring phase is stored; and at the beginning of a second measuring phase following the sterilization- and/or cleaning phase, is the voltage stored during the sterilization phase is applied on the electrode.

Abstract: Methods and apparatus relating to very large scale FET arrays for analyte measurements. ChemFET (e.g., ISFET) arrays may be fabricated using conventional CMOS processing techniques based on improved FET pixel and array designs that increase measurement sensitivity and accuracy, and at the same time facilitate significantly small pixel sizes and dense arrays. Improved array control techniques provide for rapid data acquisition from large and dense arrays. Such arrays may be employed to detect a presence and/or concentration changes of various analyte types in a wide variety of chemical and/or biological processes. In one example, chemFET arrays facilitate DNA sequencing techniques based on monitoring changes in hydrogen ion concentration (pH), changes in other analyte concentration, and/or binding events associated with chemical processes relating to DNA synthesis.

Abstract: Air quality in a workplace can be monitored to ensure worker safety.

Abstract: In order to provide a method of electrochemically detecting a target substance, a method of electrochemically detecting an analyte, and a detection set which have a theoretical advantage in the measurement sensitivity obtained by a conventional electrochemical detection method using a working electrode with a trapping substance immobilized, can reuse the working electrode, and can detect an analyte regardless of the size thereof, there is provided a method including: attracting the target substance containing a labeling substance in a liquid sample to a working electrode in which a trapping substance for trapping the target substance containing a labeling substance is not present; and electrochemically detecting the target substance containing a labeling substance.

Abstract: A method for electrochemical impedance spectroscopy uses interdigitated electrodes functionalized with a first species and nanoparticles functionalized with a second species that preferentially attaches to the first species. The nanoparticles are composed of a material with a dielectric constant (k value) greater than 2. The chemically functionalized electrodes are then exposed to a solution containing the chemically functionalized nanoparticles which then become immobilized on the electrodes through the attachment of the first species to the second species. The impedance spectrum is measured and an amount of the first species is then determined from the measured spectrum. Because the high-k dielectric nanoparticles increase the double-layer capacitive impedance, the sensitivity of determining the amount of the first species attached to the second species is enhanced.

Abstract: An apparatus and methods are provided for the accurate determination of hydrogen content in fluid media at elevated temperatures. The apparatus consists of a proton conducting solid electrolyte in contact with an internal metal/hydrogen reference standard, in which the electrolyte and the reference material are in a chemically stable contact. The electrical signal generated is a function of the hydrogen concentration on the measuring side.

Abstract: An ion chromatography apparatus comprising: (a) a first chromatography column, (b) a second chromatography column, the volume of the second column being no greater than 0.9 times the volume of the first; and (c) valving disposed between said first and second columns permitting selective transfer of separated ionic species from first chamber to second chamber for further analysis.