Abstract: This invention provides a method for determining the concentration of a gas to be detected by a gas detector using a gas reactive pigment, wherein the dynamic range of the detectable concentration can be controlled. The method comprising bringing a gas to be detected such as a halogen gas, a hydrogen halide gas or the like into contact with a gas detector placed in a detection area and comprising a gas reactive pigment tetraphenylporphyrin or a derivative thereof represented by the general formula (1) or a metal complex of tetraphenylporphyrin or a derivative thereof represented by the general formula (2); and irradiating said gas detector with a detection beam and measuring a color change in said gas detector to determine the concentration of said gas to be detected, wherein the measurement is carried out in the temperature range from 40 to 80.degree. C. of said detection area; and a detection apparatus for carrying out the said method are disclosed.

Abstract: The present invention provides a method by which harmful trace gases in a gaseous mixture containing as such harmful halogen gases, halogenated hydrogen gases, acid gases, oxidizing gases, basic gases, organic acid gases, especially halogen gases or halogenated hydrogen gases, are detected by using tetraphenylporphyrin (TPP) and quantitated from a calibration curve constructed therefrom, where the range of detectable concentration is made adjustable so that harmful gas can be detected and quantitated over a broad range of concentration. Furthermore, this invention also provides a method for extending the accessible range of gas concentration by adjusting the sensitivity of the detector material via control of tetraphenylporphyrin concentration in matrix polymer of the detector material, by controlling the gas concentration range via measurement at a specific wavelength(s), and by the use of a plurality of detector materials with pre-set assay sensitivity.

Abstract: Acid/base measuring sensor systems consisting of arrays of basic sensor cells are described which are constructed based on the chemical/electrical response characteristics of poly(aromatic amines). Protonation (doping) or deprotonation (de-doping) of the --N.dbd.sites in the polymers leads to characteristic conductivity vs. concentration curves which can be calibrated to produce reliable, instantaneous readings of the acid/base concentrations at various points in the working environment.

Abstract: A composition, method, and test device for determining the total available chlorine concentration of a test sample are disclosed. The test device includes a test pad having a suitable carrier matrix incorporating an indicator reagent composition capable of converting combined available chlorine to free available chlorine and of interacting with free available chlorine to produce a detectable and measurable response for total available chlorine over a range of 0 to over 5000 ppm total available chlorine in the test sample. An indicator reagent composition contains: (a) an indicator dye that is responsive to free available chlorine, such as tetramethylbenzidine, (b) a buffer, (c) a surfactant, (d) an optional catalyst, and (e) an optional polymer. An indicator reagent composition is incorporated into a carrier matrix, like filter paper, to provide a test pad useful in a dry phase total available chlorine assay of a test sample, such as a sanitizing solution for a hemodialysis unit.

Abstract: The total base number of an oil sample of measured volume is determined by solvating the oil sample, adding a predetermined amount of acidic species to the solvated sample to react the acidic species with any basic species contained in the oil sample, extracting the remaining acidic species into an extractant phase, separating the extractant phase from the oil sample, and measuring the acidic species content of the extractant phase to determine the quantity of basic species in the oil sample. The same technique may be used to determine the total acid number of an oil sample by adding a predetermined amount of basic species to the sample and measuring the basic species content of the extractant phase.

Abstract: A process for measuring and controlling at an aim point the neutralization of an organic acid in an organic polymer solution using a near-infrared analyzer.

Abstract: A halogenated hydrocarbon (HHC) detector is formed from a silent discharge (also called a dielectric barrier discharge) plasma generator. A silent discharge plasma device receives a gas sample that may contain one or more HHCs and produces free radicals and excited electrons for oxidizing the HHCs in the gas sample to produce water, carbon dioxide, and an acid including halogens in the HHCs. A detector is used to sensitively detect the presence of the acid. A conductivity cell detector combines the oxidation products with a solvent where dissociation of the acid increases the conductivity of the solvent. The conductivity cell output signal is then functionally related to the presence of HHCs in the gas sample. Other detectors include electrochemical cells, infrared spectrometers, and negative ion mobility spectrometers.

Abstract: An apparatus and method for monitoring the product quality of chlorine in which a sample stream of chlorine is taken from a chlorine stream and a portion of the sample stream is passed to one of three different analyzers for detection of various contaminants. A common data acquisition network receives data from each analyzer for integration and output. The analyzers include a bromine in chlorine analyzer, a non-condensable gas in chlorine analyzer, and a halocarbon in chlorine analyzer.

Abstract: Safety apparel for use in harardous environments has an indicating material incorporated in the surface of the apparel. On exposure to hazardous materials, such as acids and bases, the surface changes color to indicate exposure and provide a warning. Further, a material and method is provided to treat surfaces to indicate exposure to hazardous materials. The treated surfaces may exhibit reversibility effective to indicate exposure over repetitive cycles.

Abstract: A method for real-time determination of the concentration of Lewisite in the ambient atmosphere, the method includes separating and collecting a Lewisite sample from the atmosphere in a collection chamber, converting the collected Lewisite to an arsenite ion solution sample, pumping the arsenite ion containing sample to an electrochemical detector connected to the collection chamber, and electrochemically detecting the converted arsenite ions in the sample, whereby the concentration of arsenite ions detected is proportional to the concentration of Lewisite in the atmosphere.

Abstract: An apparatus and method for monitoring the product quality of chlorine in which a sample stream of chlorine is taken from a chlorine stream and a portion of the sample stream is passed to one of three different analyzers for detection of various contaminants. A common data acquisition network receives data from each analyzer for integration and output. The analyzers include a bromine in chlorine analyzer, a non-condensable gas in chlorine analyzer, and a halocarbon in chlorine analyzer.

Abstract: A chemical switch device and method of sensing the presence of a chemical constituent in an ambient environment, the chemical switch device comprising a film which irreversibly reacts upon exposure to specific chemical components in the environment under the conditions of measurement. The reactions can lead to large changes in the physical and chemical properties of the film which are measurable electrically, optically or by other methods.

Abstract: A method is provided for precisely and concurrently measuring dynamic engine oil consumption and fuel consumption within an internal combustion engine on a real-time basis. Nonradioactive organo- bromine or chlorine compounds are added to the oil in small amounts in their natural isotopic abundance or enriched. Upon complete combustion, the bromine or chlorine is converted into hydrogen bromide (HBr) or hydrogen chloride (HCl), respectively. A tunable diode laser spectrometer is used to determine the trace amounts of the resultant HBr or HCl in the exhaust gases, which continuously flows through a sample cell by the use of a sample line that allows the unimpeded transport of samples, reduces the pressure of the exhaust gas and maintains it at a suitable level for analysis, and prevents the condensation of water vapor in the exhaust gas so as to prevent the dissolution of the tracer compounds in the water condensate.

Abstract: The total base number of an oil sample of measured volume is determined by solvating the oil sample, adding a predetermined amount of acidic species to the solvated sample to react the acidic species with any basic species contained in the oil sample, extracting the remaining acidic species into an extractant phase, separating the extractant phase from the oil sample, and measuring the acidic species content of the extractant phase to determine the quantity of basic species in the oil sample. The same technique may be used to determine the total acid number of an oil sample by adding a predetermined amount of basic species to the sample and measuring the basic species content of the extractant phase.

Abstract: A method is provided for accurately determining the complexing capacity (or free HF concentration) of a pickling liquor. A sample of pickling liquor is obtained and an excess of ferric ion is added thereto to complex with all of the free HF in the sample. A back titration is performed to determine the residual free ferric ion. The difference between the amount of ferric ion added and that found by the titration is related to the free HF in the original sample.The method is useful in conjunction with an automated, on-line system which periodically monitors a pickling bath and makes any necessary adjustments thereto.

Abstract: A method for optical measurement of bilirubin which comprises reacting a bilirubin-containing sample with a zinc compound, a coloring agent and bilirubin oxidase in a buffer, wherein a stable green pigment having a large molecular extinction coefficient is formed by the action of the zinc compound and thereby bilirubin in the sample can be measured specifically, and a reagent useful therefor. Said method and the reagent are useful for clinical test of total bilirubin and direct bilirubin in serum.

Abstract: Apparatus and method for qualitatively and quantitatively analyzing infrared emission from excited molecules in samples of interest is disclosed. Over the wavelength interval from 1 to 5 um, two strong emission bands are observed with a PbSe detector when organic compounds are introduced into an hydrogen/air flame. The band at 4.3 um (2326 cm.sup.-1 is due to the asymmetric stretch of carbon dioxide while the band at 2.7 um is due to both water and carbon dioxide emission. The carbon dioxide emission at 4.3 um is most intense at the tip of the flame, and increases with the amount of organic compound introduced into the flame. For chromatographic application, an optical filter can be used to isolate the 4.3 um emission band. The infrared emission detection system finds application in the determination of total inorganic carbon, chloride and available chlorine in aqueous samples.

Abstract: There is disclosed a method for measuring a glycosyltransferase, for measuring an activity or a concentration of the glycosyltransferase for a specific sugar, which comprises using a constitution containing a donor which is not labelled and a substance which is specifically bound only to a product.

Abstract: A triiodide-phosphoric acid stain when applied to either moist or dry fiber samples produces a range of colors indicative of the fiber species and the degree of refining of the fiber. The stain is made from an aqueous triiodide solution of about 0.6M in potassium iodide and about 0.1M in iodine and is mixed with an acid solution about 77 percent by weight of phosphoric acid in a ratio of about 1 to 100 v/v of triiodide to acid just prior to its application to the fiber samples to be stained.

Abstract: An HCl monitor is provided for the extractive analysis of high-temperature, high-pressure, coal-derived process streams. The monitor is capable of HCl concentration measurement in the presence of all known coal gasification products, with detection being based on the ability of HCl to protonate a high boiling alcohol (solvent) and, thus, enhance the conductivity of the alcohol. Conductivity is then related to HCl concentration. The observed high degree of sensitivity that can be achieved is a result of analyte preconcentration prior to the conductivity measurement due to the fast dissolution rate of HCl into the alcohol solvent, coupled with a large analyte gas-to-solvent ratio.