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: 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: A test instrument for uniformly spreading a collected specimen on a reagent layer has a first opening for collecting the specimen, a specimen spreading layer having an upper surface a portion of which is exposed to the first opening, the reagent layer provided so that an upper surface thereof is in contact with the lower surface of the specimen spreading layer, and a support layer provided on a lower surface of the reagent layer. Even if the specimen does not attached itself in a uniform distribution over the large area of the first opening, it will be evenly distributed at the second opening, the opening area of which is smaller than that of the first opening at which measurement is performed. When an absorbing layer provided in the proximity of the edge portion of the first opening is supplied with an excess amount of the specimen, a direct path to the absorbing layer is blocked by the inner peripheral region of the first opening so that the absorbing layer is soaked via the spreading layer.

Abstract: A system for detecting trace concentrations of an analyte in air includes a preconcentrator for the analyte and an analyte detector. The preconcentrator includes an elongated tubular container comprising a wettable material. The wettable material is continuously wetted with an analyte-sorbing liquid which flows from one part of the container to a lower end. Sampled air flows through the container in contact with the wetted material with a swirling motion which results in efficient transfer of analyte vapors or aerosol particles to the sorbing liquid and preconcentration of traces of analyte in the liquid. The preconcentrated traces of analyte may be either detected within the container or removed therefrom for injection into a separate detection means or for subsequent analysis.

Abstract: A rapid and direct assay for detecting of a virus having a characteristic enzyme in clinical samples in which (1) the clinical sample is contacted in solution with a substrate for the enzyme which includes a chromogen that is cleaved from the substrate by the enzyme and a precipitating agent that reacts with the liberated chromogen to form a precipitate (2) filtering the solution to concentrate the precipitate and (3) visually observing the concentrated precipitate for the characteristic color of the chromogen.

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: A test device having the following meritorious effects is obtained in accordance with the present invention by using at least one composition selected from the group consisting of ink compositions for detecting glucose, for detecting protein, for detecting urobilinogen, and for detecting occult blood in a body fluid, and for detecting the pH thereof:a) The test device is stable during storage in atmospheric air for a long period of time, presenting no discoloration phenomenon;b) The test device has high sensitivity coupled with excellent measurement performance;c) The regions for detecting glucose and the other body fluid ingredients and the pH can be formed directly on the surface of the test device by printing, allowing the test device to be formed by mass production and the process steps to be reduced; andd) The ink compositions for detecting glucose, etc. are stable, and can be handled easily.

Abstract: A system for detecting trace concentrations of an analyte in air includes a preconcentrator for the analyte and an analyte detector. The preconcentrator includes an elongated tubular container comprising a wettable material. The wettable material is continuously wetted with an analyte-sorbing liquid which flows from one part of the container to a lower end. Sampled air flows through the container in contact with the wetted material with a swirling motion which results in efficient transfer of analyte vapors or aerosol particles to the sorbing liquid and preconcentration of traces of analyte in the liquid. The preconcentrated traces of analyte may be either detected within the container or removed therefrom for injection into a separate detection means or for subsequent analysis.

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: 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: A blood aerator comprises an aerating vessel having a vessel body provided with ports for a gas- and liquid-tight connection to a blood hose and at least one gas hose. A simplified and reliable handling is permitted in that a port for the blood hose and a port for a lower gas hose are separately provided on the bottom portion of the vessel body, the port for the lower gas hose contains a hydrophobic filter element, which is impermeable to blood and permeable to gas, and the port for a second gas hose is provided on the top portion of the vessel body.

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: A system for detecting trace concentrations of an analyte in air and includes a preconcentrator for the analyte and an analyte detector. The preconcentrator includes an elongated tubular container in which is disposed a wettable material extending substantially the entire length of the container. One end of the wettable material is continuously wetted with an analyte-sorbing liquid, which flows to the other end of the container. Sample air is flowed through the container in contact with the wetted material for trapping and preconcentrating the traces of analyte in the sorbing liquid, which is then collected at the other end of the container and discharged to the detector. The wetted material may be a wick comprising a bundle of fibers, one end of which is immersed in a reservoir of the analyte-sorbing liquid, or may be a liner disposed on the inner surface of the container, with the sorbing liquid being centrifugally dispersed onto the liner at one end thereof.

Abstract: A system for analysis of trace concentration of contaminants in air includes a portable liquid chromatograph and a preconcentrator for the contaminants to be analyzed. The preconcentrator includes a sample bag having an inlet valve and an outlet valve for collecting an air sample. When the sample is collected the sample bag is connected in series with a sorbing apparatus in a recirculation loop. The sorbing apparatus has an inner gas-permeable container containing a sorbent material and an outer gas-impermeable container. The sample is circulated through the outer container and around the inner container for trapping and preconcentrating the contaminants in the sorbent material. The sorbent material may be a liquid having the same composition as the mobile phase of the chromatograph for direct injection thereinto.

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 system for analysis of trace concentrations of contaminants in air includes a portable liquid chromatograph and a preconcentrator for the contaminants to be analyzed. The preconcentrator includes a sample bag having an inlet valve and an outlet valve for collecting an air sample. When the sample is collected the sample bag is connected in series with a sorbing apparatus in a recirculation loop. The sorbing apparatus has an inner gas-permeable container containing a sorbent material and an outer gas-impermeable container. The sample is circulated through the outer container and around the inner container for trapping and preconcentrating the contaminants in the sorbent material. The sorbent material may be a liquid having the same composition as the mobile phase of the chromatograph for direct injection thereinto.

Abstract: The disclosure relates to improvements in the art of gas chromatography, and gas chromatographs containing a detector operated on the thermal conductivity principle. In the conventional gas chromatograph, a pair of resistance filaments constitutes an opposite arm of a Wheatstone bridge, and each of two pairs of filaments provides a reference side and a measuring side, respectively, across which a carrier gas can be flowed and the bridge balanced. A moisture-containing sample can be input and transported via carrier gas through a circuit to a substrate filled column and the moisture and other components of the sample separated according to their different affinities for the column substrate. The sample constituents elute from the column in characteristic sequence as elution bands diluted with carrier gas.