Abstract: Disclosed is an oxide sensor in which a measuring electrode is arranged at a distance d to satisfy -3t.ltoreq.d.ltoreq.3t for a downstream end of an inner pumping electrode for a first chamber, i.e., the end located on a side of a second diffusion rate-determining section, provided that d represents a distance between the measuring electrode and the downstream end in a positive direction directed from the first chamber to a second chamber, and t represents a height of the first chamber. A partial pressure of oxygen in the first chamber is measured by using the measuring electrode. A main pumping cell is subjected to feedback control on the basis of a measured value so that the partial pressure of oxygen in the first chamber is controlled. After that, a measurement gas is introduced into the second chamber. Oxides contained in the measurement gas are decomposed by the aid of a detecting electrode or a catalyst.

Abstract: The present invention is drawn to a system to be used for measuring NO levels in exhaled breathing air. The system comprises: (i) a face mask that tightly covers the nose and/or mouth of the individual that the mask is intended to be used on; (ii) an inlet unit for inhaled breathing air, (iii) an outlet unit for exhaled breathing air, (iv) a non-rebreathing valve through which inhaled and exhaled breathing air, respectively, passes, and (v) a measuring unit for NO connected to the outlet unit. The present invention furthers encompasses a method for the diagnosis in mammals of inflammatory conditions in the airways. The characteristic feature is that nitric oxide NO is measured in exhaled breathing air and a found abnormal level is taken as an indication of an inflammatory condition in the airways.

Abstract: The excitation of the target nitrocompound with ultraviolet radiation ress in photodissociation yielding vibrationally excited NO with significant population of the v"=1 and v"=2 levels of the ground electronic state. As the population distribution of ambient NO favors the v"=0 level, discrimination between vibrationally excited NO and ambient NO is possible by probing the NO A-X (0,0),(1,1), and (2,2) bands near 226, 224, and 222 nm, respectively, employing (1+1) resonance-enhanced multiphoton ionization (REMPI). Many complex nitrocompounds cannot be photolyzed near 452 nm since their absorption cross sections are relatively small. Thus, the visible laser radiation is used to facilitate the detection of ambient NO and NO from NO.sub.2 by (2+2) REMPI and to discriminate these species from more complex nitrocompound analytes. The analytical utility of the present invention has been demonstrated at several photolysis/ionization wavelengths for NO/CH.sub.3 NO.sub.2 and NO.sub.2 /CH.sub.3 NO.sub.2 mixtures.

Abstract: Nitrosyl (FeII) hemoglobin can be detected in biological samples, using a method which involves injections of samples into a photolysis cell, prior to detection of chemiluminescence generated by the reaction between nitric oxide and ozone. This method is useful for monitoring the levels of nitric oxide bioactivity in both normal physiological states, and disease states, such as septic shock, atherosclerosis, thrombosis, hyperhomocysteinemia, pulmonary hypertension, malignancy, infections and central nervous system disorders.

Abstract: Non-invasive methods have been developed for the measurement of NO levels in a variety of fluid media, e.g., body fluids. The present invention embraces the use of a semi-permeable vessel wherein said vessel contains an NO reacting substance to trap NO diffusing thereinto, and a simple physical or chemical detection method to measure the levels of the end products. Since NO is a neutral gas molecule, it is capable of diffusing freely across a wide range of biocompatible polymer membranes which exhibit a high permeability to NO and other neutral gas molecules, such as O.sub.2 and CO.sub.2, but which are not permeable to charged molecules, such as NO.sub.3.sup.- or NO.sub.2.sup.-. The latter two compounds are ubiquitously present in body fluids and often interfere with the measurement of NO levels. The permeability of selected membranes to NO, but not to NO.sub.3.sup.- or NO.sub.2.sup.

Abstract: The invention comprises a novel sample introduction system which incorporates a venturi pump to convey a sample gas to an analytical instrument at atmospheric pressure. An APCI, ICP or MIP mass spectrometer is preferred as the analytical instrument. Using such an inlet with an APCI mass spectrometer, the real-time analysis of trace materials present in breath is facilitated, enabling, for example, the release of compounds responsible for aroma and taste to be analysed during eating and drinking. The invention can also be used for headspace analysis and for monitoring the release of fragrances from skin or clothing.

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: A nitrogen oxide detecting sensor, according to the present invention, incorporates a gas detecting portion including, as a main component thereof, an oxide compound having electric conductivity or semiconductivity, the oxide compound having a crystal structure of 2212 phase and expressed generally as: Bi.sub.2 Sr.sub.2 (Ca.sub.1-x Y.sub.x)Cu.sub.2 O.sub.8.+-..delta. where 0.6.ltoreq.x<1; 0.ltoreq..delta..ltoreq.1. Electrodes are electrically connected to the gas detecting portion. When the gas detecting portion is analyzed by X-ray diffraction using cuK.alpha. rays to obtain diffraction peak values thereof in the range of a diffraction angle between 5.degree. and 65.degree., the diffraction peak values having a sum .SIGMA. I?2212! expressed by one of the following:(a) .SIGMA. I?2212!/.SIGMA. I?T!>88.1%(b) {.SIGMA. I?2212!+.SIGMA. I?2201!}/.SIGMA. I?T!>94.8%(c) {.SIGMA. I?2212!+.SIGMA. I?Y.sub.2 O.sub.3 !} .SIGMA. I?T!>88.1%(d) {.SIGMA. I?2212!+.SIGMA. I?(Bi, Ca) O!}/.SIGMA. I?T! >88.8%where .

Abstract: In a first embodiment of the present invention, a control method and system are provided in an exhaust emission sampling system for controlling a flow controller in order to compensate for the effects of changing water vapor content in a diluted sample having a predetermined dilution ratio. A water measuring device such as a relative humidity sensor generates a water vapor signal based on the amount of water vapor in the diluted sample. The water vapor signal is then processed within a control unit to obtain a value for the amount of water in the diluted sample. A control signal is generated by the control unit based on the amount of water vapor, flow rate of the exhaust emissions, and also, on the type of fuel used in the combustion process to control the flow controller which is, preferably, a mass flow controller.

Abstract: The invention describes improved methods and reagent compositions employed therein to determine the existence of blood disorders such as hemolytic anemias in a blood sample obtained from an individual. The methods are preferably carried out on an automated flow cytometer and encompass determining if the individual's red blood cells have undergone a loss of membrane surface area by providing measurements of the surface area and the sphericity of the red blood cells in a whole blood sample as a function of osmolality. The method and reagent compositions used therein provide for the first time accurate measurements of the surface areas of both the mature red blood cell and the reticulocyte populations in a whole blood sample. The method and reagents of the invention promise to shed new insights into reticulocyte membrane remodeling in various red cell disorders.

Abstract: A nitrogen oxide sensor and a method of manufacturing the sensor are disclosed. The sensor has a gas detecting portion including sensitive material having electric property thereof subject to change in association with presence of nitrogen oxide in gas and a pair of electrodes electrically connected with the gas detecting portion. The gas detecting portion includes, as a main component thereof, metal oxide compound represented by a general formula:Bi.sub.2 Sr.sub.2 (Ca.sub.1-x Y.sub.x)Cu.sub.2 O.sub.8+y(0.8.ltoreq.x.ltoreq.1; 0.ltoreq.y.ltoreq.1)and having the 2212 phase crystal structure and crystalline size greater than 100 .ANG..

Abstract: An NOx sensor for an exhaust gas is made from .beta.-Nb.sub.2 O.sub.5 as a primary component and TiO.sub.2 as a subsidiary component. The TiO.sub.2 content is in a range of 0.1% by weight .ltoreq.TiO.sub.2 .ltoreq. 20% by weight. In place of TiO.sub.2, Ru may be used in the NOx sensor. The Ru content is in a range of 0.1% by weight .ltoreq.Ru.ltoreq. 10% by weight. Thus, the NOx sensor has an excellent NOx adsorbing ability and is higher in sensitivity to NOx in an exhaust gas.

Abstract: An apparatus for measuring nitric oxide exhaled from the lungs of a person comprises(a) a conduit for receiving the air exhaled by the person;(b) a resistor for increasing the pressure in the mouth of the person during exhalation to close the nasopharynx and to maintain a constant flow rate of said air exhaled by the person; and,(c) measuring means for measuring the nitric oxide concentration in said exhaled air.

Abstract: There is provided a test piece by which NO.sub.x, present in an environment may be visually observed apart from the influence of other gases, and with which qualitative and quantitative analysis may be performed. The test piece has a layered structure prepared by vacuum deposition a metal thin-film (Ag, Pt, Au, etc.) on a metal substrate (Cu, Zn, etc.). The rough amounts of NO.sub.x, SO.sub.x and NH.sub.3 in the environment are determined on the basis of the corrosion products (nitrates, etc.) produced when NO.sub.x, SO.sub.x and NH.sub.3 are collected after the test piece has been exposed to the environment for a prescribed period of time.

Abstract: A fiber optic chemical dosimeter system detects the presence of hydrazine fuels and nitrogen tetroxide and nitrogen dioxide gases that are used at rocket launch sites using colorimetric sensors that react selectively with the gases and then absorb laser light communicating through a fiber optic network having a conventional diode laser source transmitting interrogation pulses to a plurality of distributed sensors covering a wide area launch site, the sensor being reactive cladding or distal end types both providing optical reflective returns well suited for reflective near infra-red and visible-red laser interrogation by an optical time domain reflectometry monitor which compares the interrogated laser pulses with sensor returns to determine the extent and location of gas cloud exposures over the distributed wide area.

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: A gas sensor has a gas sensing component which permits measurement of a change in optical absorption and, optionally also a change in electrical conductivity on exposure to an environment containing certain gases. The gas sensing component comprises a metal bis aromatic macrocycle which may be a new mixed rare earth metal bis tetrabenzoporphyrin or tetrabenzoazaporphyrin.

Abstract: A method for the ultra-sensitive detection of atmospheric and surface adsorbed nitrocompounds such as propellants, explosives, and nitro-pollutants employs an excimer (ArF) laser operating at or near 193 nm to photofragment the target molecule and facilitate the detection of the characteristic NO fragment, formed from the dissociation of NO.sub.2, by resonance-enhanced multiphoton ionization (REMPI) and/or laser induced fluorescence (LIF) via its A-X, B-X, C-X, and/or D-X electronic transitions. In addition to NO, the detection of other fragments, such as C, CH, C.sub.2, NH and OH, by their ionization and/or prompt emission resulting from 193 nm excitation enhances the analyte identification. The analytical utility of this apparatus and method has been demonstrated on a number of compounds including dimethylnitramine (DMNA), nitromethane, nitrobenzene, orthonitrotoluene, para-nitrotoluene and trinitrotoluene (TNT).

Abstract: An NOx sensor has the sensor element made of an oxide, the resistance of which is varied in response to an NOx component in a gas to be measured, and a measuring portion for measuring a resistance variation of the sensor element and for detecting an NOx concentration in the gas to be measured. A catalyst is arranged at an upstream side of a flow of the gas to be measured with respect reach to the sensor element, which makes a partial pressure ratio of NO/NO.sub.2 reach to an equilibrium state and removes a CO component from the gas to be measured. A heater for adjusting a temperature is arranged at a position close to the sensor element, which maintains temperatures of the sensor element and the catalyst constant. An O.sub.2 sensor is arranged at a position close to the sensor element so that the measuring portion can detect accurately the concentration of Nox in the measurement gas by reference to the resistance of the sensor element.

Abstract: In order to prevent a catalyst for an internal combustion engine from experiencing decreased efficiency by deterioration after long time use of the catalyst, the decreased efficiency of the catalyst is determined, and the internal engine is controlled based on results of the determination so as to maintain high efficiency of the catalyst. The catalyst is installed in an exhaust pipe of the engine. Sensors for detecting conditions of exhaust gas both at a upstream side and a downstream side of the catalyst are provided, respectively. As for the sensor, for example, an oxygen sensor whose output varies stepwise at .lambda.=1, or a sensor whose output varies in proportion to air-fuel ratio can be used. Detected values of the sensors are taken into a control unit, catalyst efficiency and deteriorating degree of the catalyst are estimated by comparison of the detected values, and the engine is controlled so that the catalyst efficiency is maximized.

Abstract: A fiber optic chemical dosimeter system detects the presence of hydrazine fuels and nitrogen tetroxide and nitrogen dioxide gases that are used at rocket launch sites using colorimetric sensors that react selectively with the gases and then absorb laser light communicating through a fiber optic network having a conventional diode laser source transmitting interrogation pulses to a plurality of distributed sensors covering a wide area launch site, the sensor being reactive cladding or distal end types both providing optical reflective returns well suited for reflective near infra-red and visible-red laser interrogation by an optical time domain reflectometry monitor which compares the interrogated laser pulses with sensor returns to determine the extent and location of gas cloud exposures over the distributed wide area.

Abstract: Trace levels of molecular oxygen are measured by introducing a gas containing the molecular oxygen into a target zone, and impacting the molecular oxygen in the target zone with electrons at the O.sup.- resonant energy level for dissociative electron attachment to produce O.sup.- ions. Preferably, the electrons have an energy of about 4 to about 10 eV. The amount of O.sup.- ions produced is measured, and is correlated with the molecular oxygen content in the target zone. The technique is effective for measuring levels of oxygen below 50 ppb, and even less than 1 ppb. The amount of O.sup.- can be measure in a quadrupole mass analyzer. Best results are obtained when the electrons have an energy of about 6 to about 8 eV, and preferably about 6.8 eV. The method can be used for other species by selecting the appropriate electron energy level.

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: A method and apparatus for the chemiluminescent determination of NO/NO.sub.x in a sample gas is disclosed in which the NO.sub.x portion of the gas stream is catalytically converted in a preconditioned vitreous carbon bed at a relatively low temperature effective to catalytically convert NO.sub.x to NO and below 200.degree. C. The vitreous carbon is preconditioned by heating at a temperature of between 300.degree. C. and about 500.degree. C. for a sufficient period of time, on the order of two to five hours. The apparatus consists of a converter containing the preconditioned vitreous carbon in communication with a reaction cell consisting of a hollow cylindrical housing having an open end closed by an optical filter. A suitable photodetecter is disposed to detect light emitted through the optical filter. A chemiluminescent reaction between ozone and NO in the sample stream occurs in a reaction chamber defined by the interior of the housing. A reflector element may be disposed in the reaction chamber.

Abstract: A method for the control of the operation of an installation for the separation of air by cryogenic distillation comprising a double distillation column wherein the top of a medium pressure column and the base of a low pressure column are thermally interconnected by a vaporizer-condenser supplied with liquid oxygen from a bath of liquid oxygen in the base of the low pressure column. Liquid oxygen from the bath is continuously tested to detect the content of nitrous oxide in the bath, and upon the detection of a fall in the nitrous oxide content of the bath when the installation is operating under equilibrium conditions, the flow of liquid oxygen to the vaporizer-condenser is increased to raise the detected nitrous oxide content of the bath. But when the detected nitrous oxide level falls, then either a liquid oxygen purge line is opened farther, or else the operating time or pressure of switching adsorbers in the air supply is changed.

Abstract: A sensor is proposed for detecting nitrogen oxides (NO, NO.sub.2, N.sub.2 O.sub.4) in a test gas, having a semiconducting metal oxide layer (3) which is deposited on a ceramic substrate (10) and whose electrical resistance provides information about the concentration of nitrogen oxides (NO, NO.sub.2, N.sub.2 O.sub.4) in the test gas. The main components of the sensor are a converter layer (4) which is deposited on the metal oxide layer (3) and is made of a material which causes the oxidation of combustible components of the test gas and converts the nitrogen monoxide (NO) contained in the test gas into nitrogen dioxide (NO.sub.2) or dinitrogen tetroxide (N.sub.2 O.sub.4), which then reaches the metal oxide layer (3), as well as a heating device (5) which heats the metal oxide layer (3) and the converter layer (4). The converter layer is suitably constituted of titanium oxide (TiO.sub.2) and/or zirconium oxide (ZrO.sub.2) and/or silicon oxide (SiO.sub.2) and/or aluminum oxide (Al.sub.2 O.sub.

Abstract: The amount of smog formed in air and the smog concentration in air is determined by measuring the consumption of nitric oxide.

Abstract: A fiber optic chemical dosimeter system detects the presence of hydrazine fuels and nitrogen tetroxide and nitrogen dioxide gases that are used at rocket launch sites using colorimetric sensors that react selectively with the gases and then absorb laser light communicating through a fiber optic network having a conventional diode laser source transmitting interrogation pulses to a plurality of distributed sensors covering a wide area launch site, the sensor being reactive cladding or distal end types both providing optical reflective returns well suited for reflective near infra-red and visible-red laser interrogation by an optical time domain reflectometry monitor which compares the interrogated laser pulses with sensor returns to determine the extent and location of gas cloud exposures over the distributed wide area.

Abstract: A gas sensor for use in monitoring gases such as H.sub.2 S, NO.sub.2 or SO.sub.2 comprises a film or layer of non-protonated polyaniline as the gas sensing material.

Abstract: The present invention relates to a method and a device for the measurement of NO contents in liquids using an inert carder gas. The device consists of a micro reaction part FIG. 1 which is divided into an inert gas inlet nozzle 1, the microreaction vessel 2 with frit 3, at least one inlet nozzle for the injection of the liquid to be analyzed 4, as well as a cooled outlet nozzle for the inert gas loaded with NO 5, and a detector 6, with which the NO content of the inset liquid is measured and evaluated, and where the NO.sub.2 - ions present in the solution are reduced back to NO using a reaction mixture consisting out of 1,1'-dimethylferrocene in acetonitrile in an acidic medium, preferably perchloric acid.

Abstract: Nitric oxide, nitrosonium, S-nitrosothiols, and S-nitroso-proteins can be detected in biological samples, using a method which involves injection of samples into a photolysis cell, prior to detection of chemiluminescence generated by the reaction between nitric oxide and ozone. To detect S-nitrosothiols and S-nitroso-proteins separate aliquots of the same samples are subjected to pretreatment with mercurous ion, and a protein-precipitating agent, respectively, and the resulting nitric oxide signals are compared to those generated by untreated samples. This method is useful for monitoring the levels of nitric oxide bioactivity in both normal physiological states, and disease states, such as septic shock, atherosclerosis, thrombosis, hyperhomocysteinemia, pulmonary hypertension, malignancy, infections and central nervous systems disorders.

Abstract: A method for assaying superoxide (O.sub.2.sup.-) or nitric oxide (NO) in an aqueous sample includes an initial step of trapping O.sub.2.sup.- or NO in an emulsion or micellar suspension of a trapping solvent, then reacting the trapped analyte with an appropriate analytical reagent. A flow apparatus for carrying out the method is disclosed. Specific reaction conditions for using chemiluminescence to measure the analytes are also disclosed.

Abstract: An NO radical measuring method comprising the steps of mixing a test sample solution containing NO radicals with hydrogen peroxide or an analogous substance thereto and luminol or an analogous substance thereto, and measuring the intensity of chemiluminescence. The method enables a trace amount of NO radical to be measured with accuracy and in real time. An apparatus used for this method is also disclosed.

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: The present invention relates to a device for the measurement of NO contents in liquids using an inert carrier gas, where the device consists out of micro reaction part FIG. 1 which is divided into an inert gas inlet nozzle 1, the microreaction vessel 2 with frit 3, at least one inlet nozzle for the injection of the liquid to be analyzed 4, as well as a cooled outlet nozzle for the inert gas loaded with NO 5, and a detector 6, with which the NO content of the inlet liquid is measured and evaluated, and where the NO.sub.2.sup.- ions present in the solution are reduced back to NO using a reaction mixture consisting out of 1,1'dimethylferrocene in acetonitrile in an acidic medium, preferably perchloric acid.

Abstract: An apparatus and method for the sensitive detection of atmospheric and/or surface absorbed nitrocompounds has been developed. The apparatus and method may be employed to detect the presence or absence of propellants, explosives, and nitropollutants. The unique feature herein is that the apparatus and method employ one laser operating at or near 226 nm. The laser photofragments the target molecule and facilitates the detection of the characteristic NO fragment, by resonance-enhanced multiphoton ionization (REMPI) and/or laser-induced-fluorescence (LIF) via its A.sup.2 .SIGMA..sup.+ -X.sup.2 II.sub.i transitions. The analytical utility of this apparatus and method has been demonstrated on numerous compounds, such as, DMNA, nitromethane, nitro-benzene, TNT, and RDX. With the present system, a limit of detection of 8 and 24 ppb is obtained for RDX and TNT, respectively, using only 100 micro-Joules per pulse of laser energy.

Abstract: An NO.sub.x analyzer capable of reducing maintenance operations for removing solid substances from the analyzer, and for obtaining an analytical value of improved reliability for sample gases flowed through the analyzer is provided. A sample gas supply passage on the downstream side of an NO.sub.x convertor is provided with a first capillary therein; a sample gas supply passage between the first capillary and the NO.sub.x convertor is provided with an overflow passage having a second capillary branch connected therewith; a sample gas supply passage on a downstream side of the first capillary is provided with a diluent air supply passage having a third capillary therein and also branch connected with the sample gas supply passage. At least the confluence of the first capillary, the second capillary, and the diluent supply passage with the sample gas supply passage is arranged within a heating zone of the NO.sub.x analyzer.

Abstract: The amount of smog formed in air and the smog concentration in air is determined by measuring the consumption of nitric oxide.

Abstract: The invention relates to a method for measuring of the total content of organic carbon and of nitrogen in water. The total organic carbon value is obtained correctly as the sum of the liquid, dissolved, and solid materials of a sample of the water. The device comprises a non-dispersive infrared (NDIR) gas analyzer for the simultaneous measurement of the concentration of the gas components carbon dioxide CO.sub.2 and nitrogen oxide NO. The NDIR gas analyzer includes a phase separator (50), a thermal reactor (52), a double cooler (70), two valves (54, 56), as well as two amplifiers (58, 60) for the pneumatic signals of the receiver detectors (30, 36) with a display (62. 64) for the measured concentrations, total organic carbon and total nitrogen. The sample is split in a phase separator (50) into a gaseous and into a liquid part. The gaseous part, which comprises substantially the inorganic part of the carbon, the total inorganic carbon part in the form of carbon dioxide CO.sub.

Abstract: This invention is a process for detecting low levels of nitrogen oxides (NO.sub.x) in a flowing gas stream (typically an exhaust gas stream) and a catalytic NO.sub.x sensor which may be used in that process.

Abstract: A method for analyzing total bound nitrogen in a sample and providing an output data of total bound nitrogen and constituent compounds (nitrate and nitrite) is disclosed. The total nitrogen bound method provides a discrete sample through a furnace in the presence of continuous flow of water as carrier as well as oxygen carrier gas, resulting in the oxidation of the nitrogen compounds to nitric oxide. The nitrate method involves a discrete sample with water as a carrier provided to a sparge tank. The nitrite is catalytically reduced to nitric oxide in the presence of tartaric acid and ascorbic acid. The nitrate method involves a first conversion to change the nitrate to a nitrite. The first conversion occurs in the presence of a copper-cadmium catalyst causing the formation of the NO.sub.2. The nitrile is subsequently converted into NO. The nitric oxide produced in each of the three methods is measured in a chemiluminescent nitrogen detector.

Abstract: A method for measuring of the total content of organic carbon and of nitrogen in water. The total organic carbon value is obtained correctly as the sum of the liquid, dissolved, and solid materials of a sample of the water. The device comprises a non-dispersive infrared (NDIR) gas analyzer for the simultaneous measurement of the concentration of the gas components carbon dioxide CO.sub.2 and nitrogen oxide NO. The NDIR gas analyzer includes a phase separator (50), a thermal reactor (52), a double cooler (70), two valves (54, 56), as well as two amplifiers (58, 60) for the pneumatic signals of the receiver detectors (30, 36) with a display (62. 64) for the measured concentrations, total organic carbon and total nitrogen. The sample is split in a phase separator (50) into a gaseous and into a liquid part. The gaseous part, which comprises substantially the inorganic part of the carbon, the total inorganic carbon part in the form of carbon dioxide CO.sub.

Abstract: A method and apparatus are set forth for enhancing the concentration of oxides of nitrogen in the preferred embodiment. A permeable membrane is formed into a tube placed in a container. A sample containing bound nitrogen in placed in a container in contact with the tube. A carrier gas is swept through the tube in contact with the wall of the tube. This enables hydrophobic gases such as oxides of nitrogen to migrate through the wall of the tube and they are swept into a detection system. If desired, they can be permitted to accumulate in the wall for an interval and the carrier gas can be switched from off to on to achieve peak concentration for delivery to a bound nitrogen analytical device. Other hydrophobic gases such as oxides of sulfur can likewise be identified by sulfur analyzer. This enables an increase in trace concentration.

Abstract: NO.sub.2 and other electron acceptor gases can be detected at 5 volume parts per million by tetrathiafulvalene TTF. The TTF may be incorporated in a polystyrene film, which changes its infra-red spectrum and conductivity upon exposure to such gases.

Abstract: An integral multilayer analytical element for the analysis of an ammonia-forming substrate comprising:(I) a light-transmissive, liquid-impermeable support:(II) an ammonia indicator layer containing a reagent capable of undergoing a detectable change by gaseous ammonia;(III) a liquid barrier layer which allows gaseous ammonia passing therethrough;(IV) an ammonia-forming substrate reaction layer containing a reagent capable of reacting with an ammonia-forming substrate to form gaseous ammonia;(V) an intrinsic ammonia trapping layer containing a reagent which acts on intrinsic ammonia to convert it into a form which can not reach said reaction layer; and(IV) a porous spreading layer, in a laminate form.

Abstract: An apparatus for detecting or measuring the concentration of an analyte gas in a gas sample, which apparatus comprises a donor polymer and a halogen-containing compound positioned to contact the analyte gas and capable of reacting with the analyte gas to yield halogen; and a method for using the apparatus.

Abstract: An ion mobility spectrometer, ionization detector and mass spectrometer is described having a reaction region, and a region for introducing a sample gas, liquid or solid samples into the reaction region and an electrolyte in the reaction region of an alkali salt heated to a predetermined temperature, such as room temperature to 1000.degree. C., to provide a chemical reaction between the alkali atoms, cations or complement anions with the sample to provide product ions. The invention provides a non-radioactive ionization source for ionization of a broad class of compounds.

Abstract: The interference of ozone in the determination of nitrogen dioxide determinations by luminol chemiluminescence is eliminated by first passing the gas sample into contact with a selective reducing agent for ozone, particularly antimony trioxide.

Abstract: A method and apparatus for monitoring the physical and chemical properties of a sample fluid by measuring an optical signal generated by a fluorescent substance and modulated by an absorber substance. The emission band of the fluorescent substance overlaps the absorption band of the absorber substance, and the degree of overlap is dependent on the physical and chemical properties of the sample fluid. The fluorescent substance and absorber substance are immobilized on a substrate so that an effective number of molecules thereof are sufficiently close for resonant energy transfer to occur, thereby providing highly efficient modulation of the fluorescent emissions of the fluorescent substance by the absorber substance.

Abstract: A device for treating water to reduce the concentration of cations or anions therein includes a water-tight container (4) of flexible material, designed to be able to lie substantially flat (FIG. 3) when empty and having an aperture (5) for the introduction of liquid, a strainer (7) extending across the aperture, and a closure (6) for the aperture, and a quantity of ion-exchange material (b 8) occupying a minor proportion of the available interior volume of the container. A soil extraction outfit and a soil testing outfit are described, which incorporate the water treatment device.