Abstract: The invention discloses an apparatus for detecting the presence of a chemical in a gaseous state, having:

Abstract: The invention relates to apparatus and a method for measuring NOx in biochemical processes, and to apparatus and methods for real time measuring the nitrification and/or denitrification rate of a liquid with or without suspended solids.

Abstract: A detection system for detecting contaminant gases includes a converter, a detector, a primary channel for delivering a target gas sample through the converter to the detector, and at least two scrubbing channels for delivering a reference gas sample through the converter to the detector. Each of the scrubbing channels includes a scrubber for removing basic nitrogen compounds from the reference gas sample, while the primary channel preferably transmits the target gas sample without scrubbing. The converter converts gaseous nitrogen compounds in the target gas sample to an indicator gas, such as nitric oxide (NO), and a control system directs the flow of a gas sample among the primary channel and the scrubbing channels. In accordance with one aspect of the invention, the basic-nitrogen-compound concentration can be measured by comparing the concentration of the indicator gas detected in the reference sample with the detected indicator-gas concentration in the target sample.

Abstract: An indicator system provides a visual indication of the cumulative level of an airborne contaminant. The indicator is a transparent sheath with support medium having an acidic surface and treated with a color pH indicator. As a basic contaminant is adsorbed by the medium, the medium color changes. As additional contaminant is adsorbed, the color front progresses the length of the indicator. The indicator system may be used with an adsorptive filter system to predict the life of adsorption bed assemblies. A sample flow is taken upstream of the adsorption beds and is passed through the indicator. Preferably, the flow rate is calibrated so that the rate of the color change in the indicator is proportional to the rate of depletion of the adsorption bed. By monitoring the indicator, an accurate prediction of adsorption bed life may be made.

Abstract: The present invention relates to apparatus and a method for measuring ammonia in biochemical processes, and more particularly to apparatus for real time measuring the amount of ammonia in a liquid with or without suspended solids.

Abstract: The present invention provides an ammonia sensor including a pH sensitive fluorophore immobilized in a hydrophobic polymer, wherein the fluorophore can react quantitatively with ammonia and the transducing moiety of the fluorophore is neutrally charged when deprotonated. The present invention also provides a method for detecting ammonia using the ammonia sensor and optical sensing devices comprising the ammonia sensor.

Abstract: A sensor for selective detection of ammonia in high-oxygen, NO.sub.x -containing gas. The sensor has a component part acting as the capacitor, and a gas-permeable sensitive layer as the dielectric, the sensitive layer being a hydrophobic, precious-metal-free zeolite of low acidity which has an ordered crystalline structure of primary-pores whose diameter is of the magnitude of the gas-kinetic diameter of NH.sub.3.

Abstract: The present invention provides an ammonia sensor having a pH sensitive fluorophore immobilized in a hydrophobic polymer, wherein the fluorophore can react quantitatively with ammonia and the transducing moiety of the fluorophore is neutrally charged when deprotonated. The present invention also provides a method for detecting ammonia using the ammonia sensor and optical sensing devices that include the ammonia sensor.

Abstract: Disclosed is a diagnostic apparatus for estimating an active Heliobacter pylori infectious agent in saliva, comprising in combination an immunoassay chamber in which a first portion of said saliva is subjected to serological test for antibody to said infectious agent and a chemical reaction chamber in which a second portion of said saliva is subjected to chemical analysis for an ammonia constituent thereof.

Abstract: An indicator system provides a visual indication of the cumulative level of an airborne contaminant. An indicator has a transparent sheath with support medium treated with acid and a pH indicator, as the contaminant is adsorbed, the color changes along the medium. The indicator system may be used with an adsorptive filter system to predict the life of adsorption bed assemblies. A sample flow is taken upstream of the adsorption beds and is calibrated with a flow meter and valve. By monitoring the indicator, an accurate prediction of adsorption bed life may be made.

Abstract: To estimate nitric acid ions and nitrous acid ions in a sample solution, a method is proposed which comprises the steps of (a) feeding both the sample solution and a reducing agent to an acidic solution which is flowing in a thin pipe; (b) positively mixing the sample solution and the reducing agent and thus reacting the same in a given portion of the pipe; (c) leading the reacted solution to a gas/liquid separator thereby to separate a gaseous phase from the reacted solution; and (d) estimating the nitric acid ions and nitrous acid ions in the gaseous phase.

Abstract: The present invention provides a creatinine sensor material having a first layer of a protonated pH sensitive fluorophore immobilized in a hydrophobic polymer, wherein the fluorophore can react quantitatively with ammonia and the transducing moiety of the fluorophore is neutrally charged when deprotonated; a second layer of creatinine deiminase and a polymer; and a third layer of a polymer. The present invention also provides a method for detecting creatinine using the creatinine sensor material and optical sensing devices that incorporate the creatinine sensor material.

Abstract: The present invention provides a urea sensor material having a first layer of a protonated pH sensitive fluorophore immobilized in a hydrophobic polymer, wherein the fluorophore can react quantitatively with ammonia and the transducing moiety of the fluorophore is neutrally charged when deprotonated; a second layer of urease and a polymer; and a third layer of a polymer. The present invention also provides a method for detecting urea using the urea sensor material and optical sensing devices that incorporate the urea sensor material.

Abstract: Ammonia monitor and method of use are disclosed. A continuous, real-time determination of the concentration of ammonia in an aqueous process stream is possible over a wide dynamic range of concentrations. No reagents are required because pH is controlled by an in-line solid-phase base. Ammonia is selectively transported across a membrane from the process stream to an analytical stream under pH control. The specific electrical conductance of the analytical stream is measured and used to determine the concentration of ammonia.

Abstract: A device for sensing ammonia (NH.sub.3) and nitrogen oxide (NO.sub.x) gases comprising: a sensor for detecting said ammonia and said nitrogen oxide gases, said sensor including a substrate and a layer consisting of cuprate material for detection of said ammonia and said nitrogen oxide gases, wherein said layer of cuprate material is selected from the group consisting of Y:Ba:Cu:O (YBCO) and Bi:Sr:Ca:Cu:O (BSCCO); a sensor holder for supporting said sensor; a perforated cap positioned over said sensor, said perforated cap having openings for passage of said ammonia and said nitrogen oxide gases to said sensor; a detection circuit communicating with said sensor for measuring output from said sensor; and a display or recording device connected to said detection circuit for displaying or recording a concentration of said ammonia and said nitrogen oxide gases based on the output from said sensor.

Abstract: Primary amines, ammonia, or mixtures thereof can be detected using a reagent comprising from about 650 ppm to about 25 percent by weight of phthalic dicarboxyaldehyde; from about 74 to about 99.88 percent by weight of an alkali metal borate; and, from about 550 ppm to about 22 percent by weight of a nucleophile.

Abstract: A method for continuously measuring particulate nitrate in a gas sample, comprising the steps of passing the gas sample through an inertial impactor with a 50% cut off at 2.5 microns, removing ambient pollutant gases from the gas with diffusion denuders, passing the gas through a first path so as to contact the gas with a coated filter so as to convert particulate nitrate to nitric acid vapor or passing the gas through a second path so as to contact the gas with coated filters to trap particulate nitrate and ammonia, and measuring nitric acid vapor and residual ambient pollutant gases produced from the first path and residual ambient pollutant gases produced from the second path with a chemiluminescent monitor, the difference in the signal produced from the gases from the two paths being a measurement of the particulate nitrate in the gas sample.

Abstract: The invention relates to a measurement apparatus (1) for analysing fluids, comprising a container (3) in the form of a syringe, into which a fluid may be taken in via an intake device (14) through at least one opening (5), and further comprising a sensor (7) which is either integrated in the container wall (9) or is attached to said container wall (9), the sensor(s) (7) being so disposed that it/they can come into contact with the fluid which may be taken up into the cavity (10).

Abstract: Viscous, liquid hexafluoroisopropanol-siloxane polymers having the basic structure: ##STR1## wherein R.sub.1 is a monovalent hydrocarbon radical selected from the group consisting of C.sub.1 -C.sub.6 alkyl groups; cyclohexyl groups and phenyl groups;R.sub.2 is ##STR2## wherein m=1 to 4; and n is an integer greater than 1, are useful for rapid, reversible vapor sorption, especially for hydrogen bond accepting vapors.

Abstract: A gas analyzer system for providing a spectroscopic analysis of the sample gas. This analysis is accomplished by first introducing the sample gas into the inlet of the system and transporting it to a spectral analyzer. The sample gas is then spectrally analyzed and the analyzer outputs a signal indicative of a radiation intensity spectrum associated with the analyzed sample gas. A processing unit uses the analyzer signal to detect the presence of one or more prescribed gases and to determine the concentration of each of the prescribed gases in the sample gas. Next, the reacting agent is supplied to the sample gas to convert one or more gases whose presence in the sample gas cannot be detected via spectral analysis due to the masking effects other gases present in the sample gas. The masked gases are converted to secondary gases at least one of which is readily detectable via spectral analysis.

Abstract: To estimate nitric acid ions and nitrous acid ions in a sample solution, a method is proposed which comprises the steps of (a) feeding both the sample solution and a reducing agent to an acidic solution which is flowing in a thin pipe; (b) positively mixing the sample solution and the reducing agent and thus reacting the same in a given portion of the pipe; (c) leading the reacted solution to a gas/liquid separator thereby to separate a gaseous phase from the reacted solution; and (d) estimating the nitric acid ions and nitrous acid ions in the gaseous phase.

Abstract: A method of monitoring compliance of a patient that has been placed on a medication maintenance program with a prescribed medication dosage by determining a normalized urine medication concentration. An unadulterated urine sample is obtained from the patient. The urine medication concentration and urine specific gravity are measured. The normalized urine medication concentration is calculated as a function of the measured medication concentration in the urine and the urine specific gravity. The calculated normalized urine medication concentration is compared with an expected medication concentration value for the patient for the maintenance program prescribed to determine any significant differences therebetween as an indication of noncompliance. Alternatively, a urinary-parameter normalized urine medication concentration is calculated as a function of the measured medication concentration in the urine, the urine specific gravity and at least one selected pharmacokinetic parameter of the medication.

Abstract: The invention relates to an absorptive support and a method for the determination of ammonium ions in aqueous solutions by the Berthelot method using one absorptive support. The absorptive support is impregnated with a phenol derivative.

Abstract: A sparingly soluble salt of a heteropoly acid is used for the determination of an analyte which is an aromatic amine rich in electrons or together with another substance leads to such an amine. The analyte is determined by means of the heteropoly blue color formed.

Abstract: The invention pertains to a method for generating the fluorescence of polyanionic fluorophores in low dielectric media with fluorescence activation produced by specific quaternary onium compounds. The method may be used for measuring an analyte and may be useful in sensor devices.

Abstract: In a device for determining the concentration of a reagent from a group consisting of gases with acid or alkaline reaction in aqueous environments, and volatile acids and bases in liquid or gaseous samples, a sample chamber is situated in a housing and a unit for pH measurement with a reaction space is separated from the sample chamber by an ion-impermeable, gas-permeable membrane. The feeding of the reaction space with buffer solution is facilitated by connecting the reaction space by means of an ion-permeable channel to a reservoir for a buffer solution located outside of the pH measuring unit.

Abstract: A sensor device is disclosed for identification of a gaseous component in a gaseous or liquid sample. The sensor device comprises an optode membrane having sensitivity for the gaseous component to be identified. The optode membrane incorporates two ionophores, at least one of which is a chromoionophore capable of changing absorption spectrum. The sensor device further comprises a hydrophobic gas-permeable membrane, one side of which is positioned upon the optode membrane to prevent direct contact of the optode membrane with the liquid or gaseous sample while still permitting passage of the gaseous component to be identified. As a result, ionic compounds incapable of passing through the lipophilic gas-permeable membrane do not interfere with the identification process leading to a highly sensitive sensor.

Abstract: The invention concerns a method for the colorimetric determination of NADH by means of enzymatic oxidation with benzyl alcohol dehydrogenase whereby an aromatic nitrosoaniline compound of the general formula I is reduced to a colored quinone diimine ##STR1## in which R.sup.1 denotes hydrogen, halogen, hydroxy, alkoxy, aryloxy, alkylthio, arylthio, alkyl or alkylene substituted if desired by carboxy, PO.sub.3 H.sub.2, dialkylphosphinyl or SO.sub.3 H, amino substituted if desired once or twice by alkyl which in turn can be substituted if desired by hydroxy, PO.sub.3 H.sub.2, SO.sub.3 H or carboxy and R denotes a residue which forms a color by electron conjugation with a quinone diimiine system. The invention also concerns a corresponding agent as well as a chromogenic nitroso compound of formula I as well as its use for the enzymatic colorimetric determination of an analyte.

Abstract: A method of detecting the presence or measuring the concentration, of a reactive gas in an inert ambient gas by (i) placing a silicon dioxide film derived from the oxidation of a hydrogen silsesquioxane resin in the inert ambient gas; (ii) passing the inert ambient gas over the film; (iii) monitoring a change in the current flow through the film at a voltage below and above a threshold voltage, as an indication of the presence in the inert ambient gas of a reactive gas; and (iv) determining the threshold voltage of the film as a measure of the concentration of the reactive gas in the inert ambient gas. The silicon dioxide film is characterized by a current-voltage curve which includes both linear and non-linear regions.

Abstract: A sparingly soluble salt of a heteropoly acid is used for the determination of an analyte which is an aromatic amine rich in electrons or together with another substance leads to such an amine. The analyte is determined by means of the heteropoly blue color formed.

Abstract: A device for detecting contaminants in returned bottles, particularly in a high-speed bottle line, is disclosed. In the preferred embodiment, a sample chamber is rotated on a carousel unit between top and bottom bulkheads. The surfaces of the bulkheads facing the chamber are flat and substantially parallel, and the chamber has two open ends which face the two bulkheads, respectively. A blast of air is directed into the mouth of the bottle to be sampled, forcing the contents of the bottle through an aperture in the lower bulkhead and into the sample chamber. In the preferred embodiment, the analyzer contains a UV absorption analyzer and a photoionization detector. The carousel unit contains four sample chambers which rotate between a sampling station, the two detectors, and a purge station. The analyzer is controlled by a computer which issues a reject instruction to a bottle reject mechanism if the level of contaminants detected by either detector exceeds a predetermined threshold.

Abstract: A sensor detects analytes in a fluid medium by measuring the conductivity of a layer on a carrier with the layer contacting an electrode pair. The layer interacts with the analyte and is improved in that the sensor has a long-term stability and the indication provided by the sensor is completely reversible. The layer is a fullerene layer.

Abstract: In a method for carrying out a surface plasmon resonance (SPR) measurement a beam of electromagnetic radiation is directed through a part transparent to it onto a surface of a material layer having been brought on its opposite side in contact with a test material. A change in the intensity of the reflected radiation, caused by the resonance phenomenon, is utilized for analyzing the test material. The material layer is of catalytic material, for example palladium, having a negative real part of the dielectric constant at the used wavelength of the electromagnetic radiation and being capable of catalyzing chemical reactions in which the test material takes part. The measurement is carried out at such a wavelength and angle of incidence of the radiation onto the surface that a change resulting from the material concentration accumulated on the opposite side of the material owing to the catalytic properties is detectable in the intensity of the reflected radiation.

Abstract: A paint or coating composition and method for detecting vapor or liquid reactants, such as ammonia. The composition is composed of ethyl cellulose as a binder, a filler, such as amorphous silica, and a dye, such as bromophenol blue. The composition serves as a passive detector for vapor or liquid reactants when applied to selected surfaces as a paint. The composition is capable of detecting extremely low concentrations of vapor. Further, the composition is capable of regenerating to its original color, thereby providing repeated detection capability.

Abstract: A device for detecting the presence or concentration of an analyte, a method of making the device, and a method of detecting the presence or concentration of an analyte. The invention features one or more supports, such as beads, which carry a thin film of polymer substrate. The polymer substrate has a sensing reagent and a porous matrix. The sensing reagent alters the optical properties of the polymer substrate in the presence of analyte.

Abstract: A chemical substance-sensing element of the invention has a sensor film on a substrate, the sensor film containing a dye and a compound sensitive to a chemical substance such as water, for example, a hydrophilic compound. The sensor film contains a dye and a chemical substance sensitive compound in a common layer or is composed of a dye film and a film of a chemical substance sensitive compound laminated thereto. The light reflectance of the sensor film changes when the chemical substance sensitive compound bonds with a chemical substance to be detected. The chemical substance can be detected and quantitatively measured by directing light from a light-emitting element toward the sensor film and detecting the reflectance of the sensor film by means of a light-receiving element.

Abstract: An ammonia sensor consisting of at least one pair of electrodes and an ammonia-sensing material comprising a polyaniline filling the space between the electrodes.

Abstract: An air sampling and analysis system has a plurality of air sampling tubes extending between an analytical laboratory and a number of remote locations where samples are taken. Means are provided for continually drawing air through the sampling tubes during times when they are not connected to a analytical instrument for measuring concentration of various gases. Means are also provided adjacent to the inlet of at least some of the sampling tubes for converting a vapor which may not travel the full length of the sampling tube, to a gas which will travel the full length of the tube. The concentration of the vapor can be found by measuring the composition of the air sample with conversion and subtracting a similar composition without conversion. Examples of vapors that are converted include hydrogen sulfide and ammonia.

Abstract: A sparingly soluble salt of a heteropoly acid is used for the determination of an analyte which is an aromatic amine rich in electrons or together with another substance leads to such an amine. The analyte is determined by means of the heteropoly blue color formed.

Abstract: An improved ion mobility spectrometer (IMS) and method for operating the same which enables analysis of ammonia in a mixture of gases when air is used as the carrier gas and the drift gas in the IMS. A controlled concentration of an ester such as Dimethyl methyl phosphonate (DMMP) is added to the air carrier gas stream prior to application of the carrier gas stream. The DMMP clusters with the ammonia, and the drift times of the ionized clusters differ from the drift times of the ions generated from the other constituents of the sample, thereby enabling identification and quantification of the ammonia.

Abstract: A method of detection of amino acids comprising the application, to the material being tested, of a reagent comprising the following basic formula: ##STR1## where X, Y and/or Z may be nitrogen C--H, C-alkyl or C-aryl and wherein A, B, C and/or D may be an alkyl or aryl substituent either alone or in combination.

Abstract: A paint or coating composition and method for detecting vapor or liquid reactants, such as ammonia. The composition is composed of ethyl cellulose as a binder, a filler, such as amorphous silica, and a dye, such as bromophenol blue. The composition serves as a passive detector for vapor or liquid reactants when applied to selected surfaces as a paint. The composition is capable of detecting extremely low concentrations of vapor. Further, the composition is capable of regenerating to its original color, thereby providing repeated detection capability.

Abstract: This invention relates to a process for the selective determination of the oncentration of a substance dissolved in a solvent by means of an osmosis cell. The osmosis cell according to the invention contains a substance not contained in the solution to be tested, which is either practically insoluble or is impermeable for the membrane. This substance reacts chemically with the substance permeating into the osmosis cell, with a product resulting from it in the cell or with a product resulting from the substance in the solution to be tested and permeating into the cell. Reaction products are thereby formed which produce a pressure in the osmosis cell, which is different from the osmotic pressure of the chemically converted portion of the substance. A pressure increase thereby occurs in the cell, from which the concentration of the substance in the solution to be tested can be determined on the basis of standard values.

Abstract: A nitrogen test kit for determining the relative level of nitrogen of a user who is involved in a health program where diet and exercise are monitored and adjusted for optimizing physical development, the kit including a plastic stick having a reagent zone on which is included a reactant such as urease, and a pH indicator such as bromthymol blue, used in conjunction with color chart blocks representing a range of urea nitrogen concentrations, wherein the user's urine nitrogen content can be determined by comparing the altered color of the reagent zone of an exposed test strip to the color chart and compared with a personal baseline level, developed from a number of tests under controlled conditions, for determining the present protein nitrogen turnover and approximate balance.

Abstract: A method for the multiplex sequencing on DNA is disclosed which comprises the electroblotting or specific base terminated DNA fragments, which have been resolved by gel electrophoresis, onto the surface of a neutral non-aromatic polymeric microporous membrane exhibiting low background fluorescence which has been surface modified to contain amino groups. Polypropylene membranes are preferably and the introduction of amino groups is accomplished by subjecting the membrane to radio or microwave frequency plasma discharge in the presence of an aminating agent, preferably ammonia. The membrane, containing physically adsorbed DNA fragments on its surface after the electroblotting, is then treated with crosslinking means such as UV radiation or a glutaraldehyde spray to chemically bind the DNA fragments to the membrane through said smino groups contained on the surface thereof.

Abstract: In a lasing dye sensor system, a stream of lasing dye freeflows across an ea open to the atmosphere. A chemical reaction between contaminants in the atmosphere and the lasing dye result in the change of emission spectra of the lasing dye. The change in emission spectra is detected and provides an improved apparatus and method for detecting low concentrations of chemical vapors in the atmosphere.

Abstract: The concentration of weak acid and weak base constituents, or their soluble salts, in liquids is determined by passing succeeding samples of constant volume to a separation zone wherein target constituents are volatilized by reagents, then volatilized analytes are stripped from the liquid matrix and carried to a detection zone at a constant flow rate, wherein signals proportional to the variations in individual target analyte concentrations between succeeding samples are generated.

Abstract: Apparatus for detecting the level of ammonia in air comprises a conduit through which air is flowed as an airstream past two ammonia sensors that straddle an ammonia absorber. The apparatus also comprises a signal processing circuit for comparing signals generated by the two ammonia sensors with the difference representing the level of ammonia present in the air.

Abstract: A multi-layer analysis element including an endogenous ammonia trapping layer, an ammonia producing layer containing a composition capable of reacting with an ammonia producing substance to produce gaseous ammonia, and at least one layer essentially incapable of trapping ammonia and essentially incapable of producing ammonia, and capable of preventing the diffusion of ammonia, disposed between the endogenous ammonia trapping layer and the ammonia producing layer. The unified multi-layer analysis element according to the invention is useful for the quantitative analysis of ammonia producing substances in aqueous biological food samples, with a high degree of sensitivity and accuracy, using a simple procedure.

Abstract: A sensor for detecting a chemical substance includes an insertion element having a structure which enables insertion of the chemical substance with a resulting change in the bulk electrical characteristics of the insertion element under conditions sufficient to permit effective insertion; the change in the bulk electrical characteristics of the insertion element is detected as an indication of the presence of the chemical substance.