Abstract: An improved device for monitoring the presence of toxic metals in workplace air comprises a base and a removable top assembly. The top assembly includes a test substrate, such as filter paper, having a first surface and a second surface. The first surface is supported by the top assembly and the second surface has an area that is sensitized with at least one chemical reagent for producing a reaction with at least one toxic metal. The base has an air inlet, an air outlet, and a channel connecting the air inlet and the air outlet, thereby enabling air entering the monitor from the air inlet to directly contact the area of the second surface of the test substrate prior to exiting the monitor through the air outlet.

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: Apparatus for chemical detection includes a cap for coupling with a sample vial containing a sample. The sample includes at least one chemical to be detected. The cap includes a reagent vial which contains a liquid reagent. The reagent vial includes a membrane which substantially retains the liquid reagent and which is substantially permeable to the chemical to be detected. The reagent vial can be opened to allow the chemical to permeate and enter the reagent vial and closed to substantially prevent the chemical from permeating the membrane and entering the reagent vial. In some embodiments, the reagent vial is opened and closed by movement of the reagent vial. In some other embodiments, the reagent vial remains stationary while a device moves to open and close the stationary reagent vial.

Abstract: This invention provides a fiber-optic sensor or analytical apparatus and associated method which utilizes the combination of (a) a solid, semi-solid or liquid sensor body which is capable of selectively dissolving the analyte compound to be detected and analyzed into the sensor body from the mixture or environment in which the compound is present and excluding undesired or interfering components, (b) a radiation source for directly radiating the analyte compound molecules to excite same to an elevated energy state, thereby causing the analyte compound itself to luminesce while dissolved in the sensor body, and (c) a radiation detector for detecting and measuring the light emitted from the excited analyte compound molecules when they return to a lower energy state. The selective dissolving sensor body provides a controlled environment in which both the source light directly excites the analyte molecules and the excited molecules emit light which is detected and measured.

Abstract: A method of optically measuring volatile impurities in contaminated medium using a combination of a distillation process with head space analysis. The method uses a hydrophobic extracting membrane at the surface of an internal reflection element (an optical fiber or an attenuated total reflection crystal). The hydrophobic analytes are extracted into the extracting membrane, from the contaminated medium. By heating the contaminated medium to form a vapor and cooling the sensor element surrounded by the extracting membrane this invention significantly reduces the limit of detection by between two and three orders of magnitude from the prior art. The distillation aspect of the method also serves to protect the extracting membrane surrounding the sensor from damage by the mechanical impurities in the contaminated medium.

Abstract: The adsorption of gas on a solid surface can produce considerable variation in the optical properties of the solid surface and eventually lead to the identification of the gas adsorbed. An optical waveguide having at least a portion of its length circumferentially coated with a transparent semiconductor material may function as a gas sensor. The sensor functions by exchanging electrons with a detectable gas brought in proximity with the coating material at reactive sites on the material's surface by the process of adsorption, thereby varying the refractive index of the transparent semiconductor material and altering the ellipticity of a light transmission through the optical waveguide. Substantially monochromatic polarized light is transmitted through the optical waveguide and then quantified by a light detector. A meter or other device connected to the light detector is adjusted to register a variation in the signal received by the light detector, indicating the presence of a detectable gas.

Abstract: A simplified, user-friendly method and apparatus for collecting and storing a human breath sample and for detecting and indicating whether the stored breath sample is a true alveolar sample. The invention includes in one embodiment thereof a preferably transparent container and a breath delivery device for directing a subject's breath into the container. A closure device is provided for accommodating the insertion of the breath delivery device into the container and for substantially sealing the container. A detector is provided for being positioned within the sealed container for detecting and indicating to an observer whether the breath sample stored in the container is a true alveolar sample.

Abstract: A multi-layer blood culture sensor includes two matrices. The first matrix is a polymer that is permeable to carbon dioxide and water, but impermeable to protons. A pH sensitive absorbance based dye is encapsulated or isolated in the polymer. The second matrix is a polymer with a pH insensitive fluorescent dye encapsulated or isolated in the polymer. The matrices are spectrally coupled and are useful for the determination of microorganisms in a blood culture bottle.

Abstract: A sensing chemistry for halogenated hydrocarbons includes pyridine or a pyridine derivative and a strong organic alkoxide base. The sensing chemistry may be in a nonaqueous organic solvent or in a solid state matrix. The base reacts with the halohydrocarbon to produce a carbene intermediate reaction product, which in the absence of water preferentially reacts with the pyridine to form a colored and/or fluorescent product.

Abstract: The present invention provides a unique fiber optic sensor which is able to provide a viewing zone for visual examination of a sample and its surrounding environment; and is able to conduct multiple assays concurrently using a plurality of different dyes immobilized at individual spatial positions within a dye sensing zone on the surface of the sensor. The present invention also provides apparatus for making precise optical determinations and measurements for multiple analytes of interest concurrently and provides methods of detection for multiple analytes of interest which can be correlated with specific parameters or other ligands for specific applications and purposes.

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 photometric detector is used to detect the presence of organic solvent vapors in the air. The detector need only be exposed to the air in the area to be tested. The optical density, i.e. darkness of the color of the detector determines the cumulative amount of solvent vapor exposure and the rate at which the dark color develops determines the concentration of solvent vapors in the air. This method can be used to quickly and easily test for harmful levels of toxic organic solvent vapors in the workplace or elsewhere.

Abstract: A fiber-optic sensor or analytical apparatus and associated method which utilizes the combination of (a) a solid, semi-solid or liquid sensor body which is capable of selectively dissolving the analyte compound to be detected and analyzed into the sensor body from the mixture or environment in which the compound is present and excluding undesired or interfering components, (b) a radiation source for directly radiating the analyte compound molecules to excite same to an elevated energy state, thereby causing the analyte compound itself to luminesce while dissolved in the sensor body, and (c) a radiation detector for detecting and measuring the light emitted from the excited analyte compound molecules when they return to a lower energy state. The selective dissolving sensor body provides a controlled environment in which both the source light directly excites the analyte molecules and the excited molecules emit light which is detected and measured.

Abstract: The present invention provides fiber optic sensors, apparatus, methods of optical detection, and methods of sensor manufacture for detection of organic analytes having a fixed polarity. The sensor requires an optical fiber strand; an immobilized polarity-sensitive dye; and an immobilized polymeric material which not only contains the polarity-sensitive dye but also absorbs and partitions the organic analyte of interest.

Abstract: The concentration of molecular oxygen in a sample is determined by exciting oxygen molecules of the sample from the electronic ground state to the excited .sup.1 .DELTA..sub.g state (excited singlet state), measuring a 1270-nm luminescence characteristic of the excited oxygen molecules (singlet oxygen) and correlating the luminescence characteristic measured with the concentration of molecular oxygen in the sample. Normally, the 1270-nm luminescence characteristic is the 1270-nm luminescence intensity. Preferably, the oxygen molecules are excited by being subjected to diffusion contact with a sensitizer such as a porphyrin or a porphyrin-related compound, e.g. a transition metal complex of a porphyrin. The sensitizer is brought into an oxygen-exciting electronic state by absorption of electromagnetic radiation such as light, the oxygen-exciting electronic state optionally being adapted to the measuring system employed by means of a quencher such as a substituted polyene.

Abstract: A method for measuring oxygen concentration using a probe comprising an immobilized polypyridine metal complex is disclosed, which can be used even in a case where the exciting ray to be used and luminescence are visible rays and which can stably be used even when it is directly immersed in a liquid to be examined without a protective membrane, which makes miniaturization of a probe possible.

Abstract: A method and apparatus are is disclosed for determining whether respiratory gas is present in a gaseous sample. The sample is brought into contact with an indicator which yields an indication within a diagnostically effective period of time of the presence in the sample of carbon dioxide in concentration of at least 2% while an indication of the presence of carbon dioxide or other trace acidic gas in a sample of ambient air is delayed beyond a predetermined period of time. The method and apparatus of the present invention have particular utility in determining the correct placement of an endotracheal catheter in a patient or in the direction of apnea.

Abstract: A gas testing apparatus of the type that directs a stream of gas to be tested through a tube containing reagent chemicals. The apparatus has a connector fitting to enable it to be connected to a closed system containing the gas to be tested, a base member having an orifice that reduces the pressure of the gas delivered to the testing tube to near atmospheric, a sliding cover that encloses the testing tube when it is positioned in the holder, and a rising stem indicator that indicates that gas flow has commenced through the tube. The apparatus also has tube seat seals for insuring that all gas entering the apparatus must flow through and not bypass the testing tube.

Abstract: The present invention relates to methods and materials for the detection of ketone and aldehyde analytes in fluid samples by means of reacting analyte containing samples with a first solid matrix material to which a nitroprusside salt is coupled and a second solid matrix material to which an amine is covalently coupled. Methods and devices are also provided for ascertaining the fat catabolism effects of a weight loss dietary regimen comprising determining the breath acetone concentration of the subject.

Abstract: The invention is directed to a testing and measuring device for colorimetrically detecting gases on a carrier which is impregnated with a solution of a moisture store and a detecting indicator. The testing and measuring device is improved in that the moisture on the indicator carrier needed for the detecting reaction is maintained over a longer time span during storage in the unused condition as well as during measurement under the action of the gaseous substance to be detected. For this purpose, the impregnating solution is composed of the detecting indicator and a mixture of sulfolane and diethylphthalate as a moisture store. For measuring hydride gases, the indicator comprises a palladium tetramine chloride. The impregnating solution is applied to a paper carrier or to a granular silica gel carrier.

Abstract: A passive gas sampling apparatus for detecting an analyte gas, which apparatus includes (1) a shell enclosing an adsorbent and (2) a diffusion tube extending through the shell and having (a) an inlet opening means outside the shell, through which the analyte gas may enter the diffusion tube, and (b) an outlet opening imbedded in the adsorbent inside the shell; and a method for using such apparatus.

Abstract: A method is disclosed for determining whether respiratory gas is present in a gaseous sample by which the sample is brought into contact with an indicator which yields an indication within a diagnostically effective period of time of the presence in the sample of carbon dioxide in concentration of at least 2% while an indication of the presence of carbon dioxide in a sample of ambient air would be delayed beyond a predetermined period of time. The method has particular utility in determining the correct placement of an endotracheal catheter in a patient or in the detection of apnea.

Abstract: Hydrogen peroxide stabilized in the presence of blood components by the addition of a metal oxide oxidant, an anionic chelating agent, particularly hydroxylic carboxylate and nitroprusside, and a catalase inhibitor. The composition finds particular application for stabilizing hydrogen peroxide in a diagnostic assay on a bibulous support.

Abstract: A method for measuring the concentration of hydroxides in alkaline solutions in a remote location using the tendency of hydroxides to absorb carbon dioxide. The method includes the passing of carbon dioxide over the surface of an alkaline solution in a remote tank before and after measurements of the carbon dioxide solution. A comparison of the measurements yields the absorption fraction from which the hydroxide concentration can be calculated using a correlation of hydroxide or pH to absorption fraction.

Abstract: A detector for enzymatically determining components in gases and aerosols and includes a porous filter disposed in a housing. The filler absorbs the aqueous reagent solution, the substrates and the enzymes and is brought into communication with a sample to be investigated. The detector of the invention is improved in that a separate preparation of the components needed for the detection takes place in the housing itself. The components combine without additional ancillary equipment or manual movements. The components are combined in that a porous filler is accommodated in a holder and is tightly held thereagainst and a filler tip projects outwardly therefrom. The filler tip is dipped in a supply vessel containing the reagent solution. A penetratable cover membrane which is impermeable to water is arranged between the filler tip and the supply vessel.

Abstract: The present invention provides a chemical indicator for the detection of hydrogen peroxide. A composition containing an aqueous solution of potassium dichromate is applied to a porous substrate. The reaction between the dichromate and chromate ions present in solution and hydrogen peroxide is accompanied by a dramatic color change which is visible to the naked eye. The initial color of the potassium dichromate solution may be enhanced by adjusting the pH of the solution to be basic. The rate of reaction between the dichromate and chromate ions and the hydrogen peroxide may be increased by the addition of the humectant urea to the potassium dichromate solution.

Abstract: The invention is directed to a dosimeter for detecting gaseous or aerosol substances. The dosimeter contains a collecting reagent in a tubular shell made of a membrane permeable for the substance to be detected. The dosimeter is improved so that also substances which cannot be absorbed by the collecting reagent can be made detectable. The dosimeter includes an outer shell wherein at least one additional inner shell is provided extending coaxially to the outer shell. The two shells conjointly define an intermediate space wherein a conversion reagent is accommodated for converting the substance to be detected into a conversion product. The inner shell defines an inner space wherein the collecting reagent is disposed for collecting the conversion product.

Abstract: A personal dosimeter for measuring the average concentration of undesirable contaminants gases such as nitrogen oxide includes a gas permeable web-like wafer formed of a material inert to polyamine. The wafer has a surface area having a numerical value at least one thousand times the value of the axial width of the wafer. The wafer is soaked in an absorptive medium not containing the ambient contaminant gas to be measured. The wafer, so soaked, is inserted within a gaseous impermeable housing from which the wafer may be selectively release and re-inserted. During an interval of release of the wafer, it is exposed for a predetermined interval of time to the ambient atmosphere. After re-insertion, the dosimeter is taken to an analysis site at which the wafer is removed and the molar concentration of products reaction with the atmospheric contaminant is measured.

Abstract: The invention is directed to an arrangement for measuring the concentration of gaseous or vaporous components of a gas mixture by using optically distinguishable reaction zones from gas test tubes which contain a substance reacting with the component to be detected. The change of the reaction zone is determined by means of direct observation and/or by means of an opto-electronic scanning device. This arrangement is improved in accordance with the invention in that the reacting substance is accommodated at least in one channel formed in a carrier. The channel has a cross section in the reaction zone which is less than 1 mm.sup.2.

Abstract: The invention is directed to a testing and measuring device for colorimetrically detecting hydride gases on a carrier which is impregnated with a solution of glycol and with a salt as an indicator. This measuring device is improved in that its long-term stability is increased and the detection of especially the smallest quantities is made possible by a clearly recognizable color change. For this purpose, only a salt, palladium chloride or palladium tetramine chloride, is present in the solution in addition to the glycol.

Abstract: A method and apparatus for the quantitative determination of an analyte in a liquid employs a liquid-permeable solid medium defining a liquid flow path. The medium includes a number of reaction-containing reaction zones spaced apart along the flow path and in which reaction occurs with the analyte or an analyte derivative (e.g., a labeled analyte) to result in the formation of a predetermined product. Detector means are employed to detect analyte, analyte derivatives, reactant or predetermined product in the reaction zones, the number of such zones in which such detection occurs indicating the amount of analyte in the liquid.

Abstract: A method and apparatus for testing for the presence and concentration of contaminants in a refrigerant. A sample of the refrigerant is withdrawn from a closed refrigeration, air conditioning or similar system and passed through a testing tube. Various sections of the tube contain provisions for the removal of oil entrained in the sample, for the removal of water contamination from the sample and for providing visual indications of the presence and concentration of a plurality of contaminants that may be present in the refrigerant.

Abstract: Methods and materials detect ketone and aldehyde analytes in fluid samples by reacting analyte containing samples with a first solid matrix material to which a nitroprusside salt is coupled and a second solid matrix material to which an amine is covalently coupled. Methods and devices are also provided for ascertaining the fat catabolism effects of a weight loss dietary regimen comprising determining the breath acetone concentration of the subject.

Abstract: There is provided a new and useful paper type G and or type V chemical agent detector comprising a paper base including, associated with the base, at least one dye chosen from 4-((4-(phenylazo)phenyl)azo)-phenol (D.Y. 23), p-ethoxyphenyl-azo-.alpha.-hydroxynaphthoic acid (PEN), or 3', 3", 5', 5"-tetrabromophenolphthalein ethyl ester (TBPE).

Abstract: A gas measuring and warning device includes a test tube which is traversed by the gas to be detected and with a photoelectric sampling means which contains an imaging optical system by which the test tube reaction image is projected onto the photo-sensitive row of the sensor elements. The imaging optical system contains a cylindrical lens having a cylinder axis which is parallel to the longitudinal axis of the test tube and to a row of sensor elements. Advantageously an achromatic lens as well as of an interference filter and of a pulse light source as used.

Abstract: A method of estimating a cumulative exposure to a component of a gas which comprises contacting a liquid reagent held by surface tension in a reservoir with a body of the gas through a conduit into which substantially only diffusional migration of the component from the body of gas occurs.

Abstract: The invention relates to a colorimetric detector tube having a porous charge. The charge contains an indicating region provided with an indicator ahead of which a pretreatment region is placed which carries a pretreatment substance. The material to be detected form products with the pretreatment substance which lead to a coloration in the indicating region. The detector tube is improved so that its indication is expanded to indicate higher detection concentrations. The detector tube is further improved so that even when the first pretreatment substance is exhausted, a colorimetric indication is made accessible to further quantities of the material to be detected. For this purpose, the charge contained in the tube includes a sequence of several pretreatment regions and indicating regions which alternate one with the other. In another configuration, the charge includes a mixture of pretreatment material and indicating material.

Abstract: A heat treatment device for the conversion of gaseous test samples into constituents determinable by a detector provides the possibility of obtaining the desired pyrolysis products even during the sampling, then feeding them directly to the detector. The device has a small structural shape, and is able to be carried and used easily and operated independently of an external energy supply. The heat treatment device is connectable to a number of different detectors. A container 1 through which the test gas can flow is provided with a chemical filler 5, 7, 8 capable of an exothermic reaction, and with a starter 4 initiating the reaction.

Abstract: A detector for rapid response, quantitative determination of carbon dioxide in a gas comprising one or more components, each of which comprises a carrier with a surface to be exposed to the gas, said surface including ane indicating element of a predetermined sensitivity which gives a rapid response signal when exposed to a given concentration of carbon dioxide, the response signals produced when the component or components are exposed to the gas providing a rapid and progresssive quantitative determination of the concentration of carbon dioxide or any change with time of said concentration in the gas.

Abstract: The invention relates to a colorimetric dosimeter including an indicator housing openable at one end and having a wall defining an interior space extending along the length thereof. The housing is partitioned into a first portion starting at the one end and a second portion following behind the first portion. A strip indicator defines a high-sensitivity region and is disposed in the first portion so as to conjointly define a clear through diffusion passage with the wall which extends to the second portion. A granular indicator defining a low-sensitivity region is disposed in the second portion.

Abstract: An apparatus for measuring the concentration of a component in a medium comprising:an optical sensor including at least one optical indicator for providing an optical signal which varies in response to the presence of a component in a medium;an optical signal fiber capable of transmitting the optical signal from the optical sensor; anda supply reservoir associated with the optical sensor and acting to provide additional optical indicator to the optical sensor.

Abstract: The invention is directed to a gas measuring device having a pretreatment device for converting the gas to be detected into a substance indicatable via a colorimetric indicator. The gas measuring device simplifies the detection of fluorine and includes a pretreatment device which has a chloride compound containing a metal of the first or second main groups of the periodic system and is exposed to the fluorine and has a chlorine indicator.

Abstract: A method and optrode for detecting gem polyhalogenated hydrocarbons in a sample fluid based on a single phase Fujiwara reaction as provided. The method comprises contacting a reaction mixture with a sample fluid which contains the gem-polyhalogenated hydrocarbons. The reaction mixture comprises an aqueous solution of pyridine or derivative thereof and a hindered nitrogen base. Upon contact a fluorescent and/or chromgenic reaction product forms whose fluorescence and/or absorbance is related to the concentration of gem-polyhalogenated hydrocarbons in the sample fluid.

Abstract: In a preferred embodiment, refrigerant together with oil, water and any other contaminants is drawn off from a high pressure refrigeration system. The drawn off refrigerant is reduced in pressure and serially, the oil is removed, the water is removed and the amount of water and acid present is determined.

Abstract: A sensor comprising a sensing element capable of sensing a component in an aqueous medium and an overcoating at least partially covering the sensing element. The overcoating comprises a water insoluble, component permeable, cross-linked cellulosic material and an effective amount of an opaque agent.

Abstract: The invention relates to a dosimeter wherein the substances to be detected color a chemical sensor layer. The degree of coloration of the chemical sensor layer is measured by a photometric diffusion-reflectance measuring device. This dosimeter is improved with respect to a measurement occurring during the time that the contaminant substance is effective. The foregoing is accomplished with the dosimeter of the invention in that the dosimeter has a measuring chamber which receives a diffusion element and with a light impermeable wall portion which closes off the diffusion element while at the same time being permeable to the substance to be detected. A light source and a photosensor are arranged in the measuring chamber.

Abstract: A diffusion sampler includes a vessel which has at least one inlet opening exposed to the gas to be investigated and which has a moderating zone. In its interior, the vessel has a collecting region provided with a collecting medium as well as a conversion region for converting the gas into substances which can be taken up by the collecting medium. The diffusion sample is improved in that its detection sensitivity is increased and that the collecting region as well as the converting region are provided with large areas in a manner adapted to the geometry of the vessel so that a smaller and more manipulable configuration is obtained. In addition, long-term dosimetry is made possible. For this purpose, the moderating zone is configured as a permeable barrier from which the converting region as well as the collecting region extend and determine the diffusion path in the entire interior of the vessel with each region being applied to a carrier.

Abstract: A system for detecting analytes in air or aqueous systems includes a permeation absorption preconcentrator sampler for the analytes and analyte detectors. The preconcentrator has an inner fluid-permeable container into which a charge of analyte-sorbing liquid is intermittently injected, and a fluid-impermeable outer container. The sample is passed through the outer container and around the inner container for trapping and preconcentrating the analyte in the sorbing liquid. The analyte can be detected photometrically by injecting with the sorbing material a reagent which reacts with the analyte to produce a characteristic color or fluorescence which is detected by illuminating the contents of the inner container with a light source and measuring the absorbed or emitted light, or by producing a characteristic chemiluminescence which can be detected by a suitable light sensor. The analyte can also be detected amperometrically.

Abstract: A sensor for determining the partial pressure of carbon dioxide in a liquid, which comprises a carbon dioxide - permeable, liquid and ion-impermeable membrane enveloping an aqueous medium containing an absorber, a fluorescer and a source of bicarbonate ions, which medium exhibits variations in pH as a function of the partial pressure of dissolved carbon dioxide, the ratio of absorber to fluorescer and the characteristics of the absorption spectrum of the absorber and the excitation and emission spectra of the fluorescer being such that the partial pressure of carbon dioxide in the liquid may be determined from the pH of the aqueous medium as measured by the intensity of the fluorescent emission of the fluorescer.

Abstract: An optical sensor which is a gas permeable silicone polymeric matrix having at least one optical indicator therein for providing an optical signal in response to excitation light. The optical indicator essentially comprises a mixture of non-polar derivatives of a polynuclear aromatic compound.