38 results about "Coulometry" patented technology

A sensor designed to determine the amount and concentration of analyte in a sample having a volume of less than about 1 μL. The sensor has a working electrode coated with a non-leachable redox mediator. The redox mediator acts as an electron transfer agent between the analyte and the electrode. In addition, a second electron transfer agent, such as an enzyme, can be added to facilitate the electrooxidation or electroreduction of the analyte. The redox mediator is typically a redox compound bound to a polymer. The preferred redox mediators are air-oxidizable. The amount of analyte can be determined by coulometry. One particular coulometric technique includes the measurement of the current between the working electrode and a counter or reference electrode at two or more times. The charge passed by this current to or from the analyte is correlated with the amount of analyte in the sample. Other electrochemical detection methods, such as amperometric, voltammetric, and potentiometric techniques, can also be used. The invention can be used to determine the concentration of a biomolecule, such as glucose or lactate, in a biological fluid, such as blood or serum. An enzyme capable of catalyzing the electrooxidation or electroreduction of the biomolecule is provided as a second electron transfer agent.

A sensor, and methods of making, for determining the concentration of an analyte, such as glucose or lactate, in a biological fluid such as blood or serum, using techniques such as coulometry, amperometry, and potentiometry. The sensor includes a working electrode and a counter electrode, and can include an insertion monitoring trace to determine correct positioning of the sensor in a connector.

A sensor utilizing a non-leachable or diffusible redox mediator is described. The sensor includes a sample chamber to hold a sample in electrolytic contact with a working electrode, and in at least some instances, the sensor also contains a non-leachable or a diffusible second electron transfer agent. The sensor and / or the methods used produce a sensor signal in response to the analyte that can be distinguished from a background signal caused by the mediator. The invention can be used to determine the concentration of a biomolecule, such as glucose or lactate, in a biological fluid, such as blood or serum, using techniques such as coulometry, amperometry, and potentiometry. An enzyme capable of catalyzing the electrooxidation or electroreduction of the biomolecule is typically provided as a second electron transfer agent.

<heading lvl="0">Abstract of Disclosure< / heading> A small volume sensor, and methods of making, for determining the concentration of an analyte, such as glucose or lactate, in a biological fluid, such as blood or serum, using techniques such as coulometry, amperometry, and potentiometry. The sensor includes a working electrode and a counter electrode, and can include an insertion monitoring trace to determine correct positioning of the sensor in a connector. In one embodiment, the sensor determines the concentration of the analyte by discharging an amount of charge into the sample, determining the time needed to discharge the charge, and determining the current used to electrolyze a portion of the analyte using the amount of charge and the amount of time.

An apparatus and method make use of a single shunt and two or more instrumentation amplifiers, switchably measuring voltages at the shunt. This permits current measurement. At times each instrumentation amplifier has its input shorted, which permits zeroing out many sources of offset in the signal path of that amplifier. Dynamic range is several orders of magnitude better than known current measurement approaches, permitting coulometry.

A method and system are provided for estimating state of charge of a cell having a positive electrode, for example of a lithium phosphate type, the charge profile of which includes a range of state of charge between about 30 and about 90% in which variation of voltage is 10 times less rapid than for a state of charge higher than 90%. Determination of state of charge for a state of charge greater than 90% is based on either the use of a calibration relationship between cell voltage and state of charge when a current is passing through the cell that is less than a predetermined threshold value and its voltage has stabilized, or on the use of coulometry the result of which is corrected taking into account the accuracy of the current sensor.

The invention discloses a method for determining the total concentration of organic gas in environmental gas by a photocatalytic fuel cell (PFC) photoelectrocatalysis method. The PFC photoelectrocatalysis method particularly comprises a PFC saturation photocurrent method and a PFC coulometry. The method for determining the total concentration of the organic gas in the environmental gas comprises the following steps of: manufacturing a PFC three-in-one electrode; assembling a PFC determining device; and recording the saturation photocurrent or electric quantity of organic gas of a light anode chamber, and calculating the total concentration of the organic gas in the environmental gas according to the corresponding formula. The total content of the organic gas in the environmental gas is determined by using a PFC device, electric signals of PFC photoelectrocatalysis on oxidizing reaction of the organic gas are recorded by using an electrochemical workstation, and the total content of the organic gas in the gas is calculated according to the theories of the saturation photocurrent method and the coulometry. The technology solves the problems of complex conventional processes of acquisition, desorption, pre-treatment and the like, and a sample can be directly used for determination without pretreatment; and the method is short in determination time, and quick and convenient and avoids secondary pollution and is suitable for environment monitoring and laboratory analysis.

The invention discloses a device and a method for the determination of trace moisture content of sulfur hexafluoride gas. The method comprises the following steps: A, inhaling a certain amount of sulfur hexafluoride gas at a constant speed; B, electrolyzing the inhaled sulfur hexafluoride gas in a coulombmeter electrolytic tank; C, collecting relevant data, and determining the moisture content in the sulfur hexafluoride gas according to the Karl-Fischer coulometry method. The method is easy for measurement, consumes less time and has accurate results; and the device has simple structure and low cost, and is applicable to popularization and use.

The invention discloses a method of detecting the content of organic chlorine in crude oil containing free water. The detection method comprises the following steps: primarily separating oil and water, measuring the viscosity at a temperature of 60 DEG C; when the viscosity is less than 300 mPa.s, carrying out dehydration in an enclosed space at a temperature of 60 DEG C, measuring the organic chlorine content of crude oil by a micro-coulometry method; when the viscosity is greater than 300 mPa.s, adding No.120 solvent oil into crude oil, removing water by a distillation and reflux mode; reading the volume of separated water; adding distilled No.120 solvent oil into crude oil again, putting crude oil in a distillation instrument, measuring the organic chlorine content of the crude oil by amicro-coulometry method; recording related data, and substituting the data into a formula to carry out calculation. Crude oil containing free water is divided into low density and low viscosity crudeoil and high density and high viscosity crude oil based on the viscosity and density; different dehydration and measuring modes are adopted to solve the difficulty in measuring the content of organicchlorine in crude oil containing free water; when the standard content of organic chlorine is more than 3 [mu]g / g, the detection credibility is high, and the relative error is within 10%.

The invention relates to a preparation method of a water content standard material. The method comprises the steps of: weighing the mass of a dried glass volumetric flask, adding propylene carbonate, 1-butanol and xylene in proportion, and weighing the mass of the mixed solution; measuring water in the mixed solution, and calculating the mass of water needing to be added according to a preparation target value; adding deionized water into the volumetric flask and mixing the solution well; shifting part of the mixed solution into an ampoule bottle, adjusting the humidity of a constant temperature and humidity chamber, monitoring water content variations over time under different humidity conditions; recording the humidity within the constant temperature and humidity chamber when the solution water content varies minimally; under a humidity condition with stable solution water content, charging ampoule bottles with the mixed solution separately, and sealing the ampoule bottles; taking the mean of the results measured by Coulometry and volumetric methods as the water content of a standard material; and evaluating the water uncertainty. The water content standard material prepared by the method of the invention is beneficial for improving the accuracy of a Karl Fischer water titrator measuring result.

The invention belongs to the technical field of biosensor construction and particularly discloses a method for constructing an electrochemical nucleic acid sensor recognition element through an insertion method. The insertion method specifically comprises the following steps of inserting a sulfhydrylated capture probe into a diluent sulfydryl layer to construct an electrochemical nucleic acid sensor recognition element. Compared with an existing backfilling method, the electrochemical nucleic acid sensor recognition element prepared by adopting the insertion method can improve uniformity of the recognition element and maintain hybridization activity of the probe so that the electrochemical nucleic acid sensor recognition element has better analysis performance; meanwhile, thermodynamic and kinetic parameters of a hybridization reaction process between the capture probe and target nucleic acid in a solution are analyzed in combination with a timing coulometry, and the insertion method disclosed by the invention is more beneficial to understanding a mechanism of an interface hybridization reaction on a molecular level.

The invention belongs to the technical field of water environment chemical analysis, and in particular relates to a local coulometric method for measuring biochemically degradable organic matter in water bodies. The present invention finds a unique way to select the fastest point of voltage drop as the cut-off point of voltage collection. The cut-off point is easy to find and can greatly shorten the measurement time and improve the work efficiency. Moreover, the local Coulomb method of the cut-off point selection method is used. Oxygen BOM Q1 The linear correlation between the value and the concentration of GGA standard solution for cultivating electrogenic microorganisms is better, which provides a more scientific, reasonable and accurate test method for the determination of biodegradable organic matter in water by microbial fuel cells, and provides a new method for scientific control of water environmental pollution. The idea and direction of this paper have great promotion value and broad application prospects.

The invention provides a method for testing trace moisture in dimethyl sulfoxide. Prepared ethanol water is divided into two parts; a first part of the ethanol water is used for preparing a uniform transparent mixed system of dimethyl sulfoxide, hydroxylamine hydrochloride, the ethanol water and a Karl Fischer's reagent; and a second part of the ethanol water is used for comparison of moisture content with the uniform transparent mixed system of dimethyl sulfoxide, hydroxylamine hydrochloride, the ethanol water and the Karl Fischer's reagent. In the system where dimethyl sulfoxide and the Karl Fischer's reagent coexist, dimethyl sulfoxide has the capability of oxidizing I<-> ions and is reduced to be dimethyl thioether. According to the invention, since hydroxylamine hydrochloride in the Karl Fischer's reagent containing dimethyl sulfoxide is pre-oxidized by dimethyl sulfoxide, it is guaranteed that the I<-> ions are completely converted into I2 through an electrode, testing results are real, reliable and stable, and deficiency in testing of trace moisture in a dimethyl sulfoxide solution by using Karl Fischer coulometry is overcome.

The invention relates to an analysis and detection method for the amount of tritium produced by liquid lead-lithium alloy neutron irradiation, including sampling, sample dissolution, separation and purification of lead and lithium, transformation of lithium-containing solution medium system, coulomb analysis, mass spectrometry analysis and data processing. step. The invention has the advantages of simple sample pretreatment procedure, high analysis result precision and the like. Since tritium is not directly measured, it is not necessary to extract and release tritium from the liquid lead-lithium alloy, which avoids the problem that tritium is closely combined with the liquid lead-lithium alloy and difficult to release. The main measurement value of the present invention is the isotope abundance ratio of lithium, and the diffusion, dissolution and retention of lithium atoms in the system space will not affect the measurement results of the tritium production of the liquid lead-lithium alloy, so the present invention overcomes the traditional direct measurement method that cannot be measured Problems with tritium entrapment and permeation in liquid lead-lithium alloy cladding systems for fusion reactors.