Abstract: Single or multi-cell reservoir sensors with single illumination sources and one or more detectors per cell unit have an arrangement whereby a gaseous, vapor or liquid sample enters the cell body and interacts with a sensing solution to detect and quantify a given species. Entrance of the sample into the sensor is through an opening in the cell body which may be covered with a membrane to contain the sensing reagent and to presort the species entering the cell. Reservoir cells can be used with organic, inorganic or biochemical sensing materials. A variety of sensors as alcohol, drugs of abuse, organic halides, cyanide and inorganic ions are provided.
Type:
Grant
Filed:
June 27, 1990
Date of Patent:
May 26, 1992
Assignee:
FiberChem Inc.
Inventors:
Stanley M. Klainer, Johnny R. Thomas, Marcus S. Butler
Abstract: A method capable of detecting low concentrations of a pollutant or other component in air or other gas, utilizing a combination of a heating filament having a catalytic surface of a noble metal for exposure to the gas and producing a derivative chemical product from the component, and an electrochemical sensor responsive to the derivative chemical product for providing a signal indicative of the product. At concentrations in the order of about 1-100 ppm of tetrachloroethylene, neither the heating filament nor the electrochemical sensor is individually capable of sensing the pollutant. In the combination, the heating filament converts the benzyl chloride to one or more derivative chemical products which may be detected by the electrochemical sensor.
Type:
Grant
Filed:
March 23, 1990
Date of Patent:
October 8, 1991
Assignee:
ARCH Development Corporation
Inventors:
Joseph R. Stetter, Solomon Zaromb, Melvin W. Findlay, Jr.
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.
Type:
Grant
Filed:
March 6, 1989
Date of Patent:
October 1, 1991
Assignee:
Environmental Technologies Group, Inc.
Inventors:
Kishore N. Vora, Donald N. Campbell, Robert C. Davis, Jr., Glenn E. Spangler, Julio A. Reategui
Abstract: Process for the detection of a chemical warfare agent, in which a detection reagent able to fluoresce is brought into contact with the chemical warfare agent, which reacts with the chemical warfare agent so that the fluorescent light emitted by the detection agent changes. A detection reagent is used which undergoes this change because of solvent effects. The advantages of the process reside especially in the fact that, not only, as in the prior art, can LOST be detected but now also VX can be detected.
Abstract: The present invention provides a general assay methodology suitable for the detection of organic analytes which are neither aldehydes nor ketones and for inorganic substances. The methodology utilizes prepared sensitized films of derivatizing agents and specific developer solutions for the selective and controlled formation of light scattering crystals whose presence serves as a qualitative and/or quantitative measure of the individual analyte of interest in the sample.
Abstract: The present invention is a method for determination of dicyanodiamide in a plant matrix, i.e. in a plant or a part of a plant. It involves a series of steps including extracting any dicyanodiamide from the plant matrix as well as purifying the dicyanodiamide obtained of interfering substances. Next, the dicyanodiamide obtained is reacted with 3-hydroxy-2-butanone in a non-aqueous, alcoholic hydrochloric acid medium to form 2-guanidino-4,5-dimethyloxazole, and then any 2-guanidino-4,5-dimthyloxazole formed is isolated using liquid-liquid extraction. Finally, any isolated 2-guanidino-4,5-dimethyloxazole is purified by reverse phase high pressure liquid chromatography (HPLC) and the amount of 2-guanidino-4,5-dimethyloxazole is determined spectrophotometrically at a wavelength of 260 nm.
Abstract: Method and apparatus are provided for analyzing a sample for nitrogen. The method combusts a nebulized sample in an oxygen-rich atmosphere and then analyzes the combustion gases for nitrogen.The apparatus employs a nebulizer operatively connected to a combustion tube and employs an appropriate nitrogen detector to analyze the combustion gases from the combustion tube for nitrogen.
Abstract: Primary and secondary amines in biological fluids are selectively derivitized by reaction with esters of N-hydroxysuccinimide or N-hydroxysulfosuccinimide to form an N-acylated derivative. Those N-acylated derivatives may then be extracted into a polar organic phase and extracted. Non-electroactive amines may be made suitable for coulometric analysis by selecting the ester used so as to attach an electroactive group to the amine. For example, histamine may be reacted with the Bolton-Hunter reagent to form a suitable derivative in high yield.
Type:
Grant
Filed:
December 27, 1988
Date of Patent:
March 13, 1990
Assignee:
The United States of America as represented by the Department of Health and Human Services
Inventors:
Kenneth A. Jacobson, Kenneth L. Kirk, Markku I. Linnoila, Thomas Miller, Kazunori Mine
Abstract: A solution of various benzaldehyde derivatives dissolved in suitable solvents are used in impinger sampling or as a coating on substrates to provide passive, real-time visual colorimetric indication of the presence of hydrazine and its derivatives.
Type:
Grant
Filed:
June 2, 1988
Date of Patent:
February 13, 1990
Inventors:
Patricia A. Taffe, Susan L. Rose-Pehrsson
Abstract: Methods and apparatus for monitoring the reaction between a metal, and/or metal oxide, reactive with nitrous oxide wherein a mixture of nitrous oxide and a diluent is passed through a bed of a material containing the metal, or metal oxide, and the time to a marked change in the exit gas composition is determined. The procedure is of particular utility for metal surface area determination.
Abstract: A colorimetric test reagent composition is presented for determining the amount of cyanuric acid in water. Cyanuric acid is added to outdoor swimming pool water to stabilize the chlorine added as a sanitizer. Basically the test composition utilizes melamine and an indicator material which responds to a change in pH of the test environment caused by the action of cynanuric acid on the reagent composition. Preferably the test composition is incorporated in a porous matrix which results in a convenient solid state test device.
Abstract: A detection system for detecting the presence of predetermined compounds in a sample. The system comprises a sample injection means, a chromatographic column, a conversion means and one or more specific gas detectors. The conversion means transforms the column effluent to combustion products in the gas phase, after which those combustion products are transferred to the specific gas detectors. In one embodiment for detecting nitrogen compounds, the conversion means includes an oxygen-rich flame, a means to control the flame to have a temperature in the range 600.degree.-1700.degree. C., means to inject the column effluent into the flame, and an input port for transferring the flame effluent to a specific nitrogen detector.
Abstract: Articles comprise transition metal double-complex salts which contain arenyl isonitrile ligands derivatized with long aliphatic chains, the cation being a tetrakis isonitrile platinum ion and the anion being a tetracyanopalladate ion. These double-complex salts exhibit novel vapochromic effects and are useful as personal and badge monitors, threshold monitors, optical waveguide sensors, chemical field effect transistors, and in related monitoring applications.
Type:
Grant
Filed:
January 30, 1987
Date of Patent:
May 2, 1989
Assignee:
Minnesota Mining and Manufacturing Company
Abstract: The alkaline picrate reagent solution employed in the Jaffe procedure for determining the presence and concentration of creatinine is stabilized for at least one year to permit long shelf life and improve the efficiency of creatinine testing. Stability is achieved by the addition of 5 to 20% by volume of a low molecular weight alcohol such as methanol.
Abstract: New phosphoric ester having the following formula (I) and a method for the analysis of an alkaline phosphatase, using the phosphoric ester as a substrate: ##STR1## wherein M is a hydrogen atom or an alkali metal atom; A is phenyl, naphthyl, 2- or 4-pyridyl, 2- or 4-pyrimidyl, pyrazinyl, sym-triazinyl, 2-imidazolyl, 2-oxazolyl, 2-thiazolyl, or sym-thiadiazolyl group which may or may not be substituted with other substituent(s) or may form a condensed ring together with a benzene ring, if possible; B is paraphenylene group or may form naphthylene group by condensation together with a benzene ring, said groups may or may not be substituted with other substituent(s).
Abstract: A briefcase contains components capable of sampling air for analysis. For example, air can be introduced into the briefcase through inlet ports and that air can be monitored for components of environmental tobacco smoke. A chemical collection device such as a sorbent tube can collect nicotine, a filter can collect respirable suspended particulate matter, and a chemical detector can monitor carbon monoxide levels. The environmental temperature and barometric pressure of the environment can be monitored also. Data is stored on a microcomputer within the briefcase, and can be transferred to a computer at a later time for data analysis.
Type:
Grant
Filed:
August 21, 1986
Date of Patent:
November 22, 1988
Assignee:
R. J. Reynolds Tobacco Company
Inventors:
Bain C. McConnell, Guy B. Oldaker, III, Richard F. Walsh
Abstract: A dosimeter for collecting vapors and gases of hydrazine and of hazardous derivatives of hydrazine such as monomethylhydrazine and 1,1-dimethylhydrazine, employs a housing with a perforated cover. Situated inside the housing is a removable disk on which is coated a solution of citric acid in methanol. The solution initially contains 20% to 30% of citric acid monohydrate dissolved in methanol and the solution is permitted to age for seven or eight days before being coated on to the disk.
Type:
Grant
Filed:
September 9, 1986
Date of Patent:
October 25, 1988
Assignees:
Geo-Centers, Inc., United States of America
Inventors:
James R. Holtzclaw, Susan L. Rose, Jeffrey R. Wyatt, Chester M. Hawkins
Abstract: Disclosed is a method and apparatus for detecting hydrazine, monomethylhydrazine (MMH), and unsymmetrical dimethylhydrazine (UDMH) in a gaseous sample. The hydrazine compound detector includes a sample converter wherein vapors of an aldehyde such as acetaldehyde or a ketone such as acetone are mixed with a sample in gaseous form, and the mixture is allowed to react to form azine and hydrazone derivatives of the aldehyde or ketone. The derivatives may be transported long distances and then analyzed, as by heating in the presence of an oxidant in a pyrolyzer containing a nickel surface to produce nitric oxide (NO), followed by measurement of the NO in a NO detector such as a chemiluminescent analyzer.
Abstract: A method which involves the isolation, analysis and characterization of dispersants present in motor oils is disclosed. The method is particularly useful in connection with the characterization of high molecular weight polybutenyl succinimide dispersants present in finished motor oils so as to provide detailed information with respect to the starting material reactants needed to synthesize such dispersants. The method involves breaking down complexation present in the oil followed by the isolation of the dispersant from the oil via dialysis. The isolated dispersant in the form of a dialysis residue is then acidified and passed through an ion exchange chromatographic column to adsorb acid materials away from the dispersant. Dispersant content and total carbonyl content can then be determined. The dispersant is then subjected to saponification with sodium hydroxide to provide a hydrocarbyl sodium succinate and a polyamine.
Type:
Grant
Filed:
August 15, 1986
Date of Patent:
December 1, 1987
Assignee:
The Lubrizol Corporation
Inventors:
Gilbert R. Malone, Susan K. Skursha, Robert M. Jost
Abstract: A method for analyzing specific chemical substances in a gaseous environment which utilizes a thermionic source formed of multiple layers of ceramic material composition, an electrical current instrumentality for heating the thermionic source to operating temperatures in the range of 100.degree. C. to 1000.degree. C., an instrumentality for exposing the surface of the thermionic source to contact with the specific chemical substances for the purpose of forming gas phase ionization of the substances by a process of electrical charge emission from the surface, a collector electrode disposed adjacent to the thermionic source, an instrumentality for biasing the thermionic source at an electrical potential which causes the gas phase ions to move toward the collector, and an instrumentality for measuring the ion current arriving at the collector.
Abstract: Organic isocyanates are detected with an indicator comprising bis-4-(dimethylamino)-phenyl-methylenimine-hydrochloride provided on a carrier along with a catalyst for its reaction with the organic isocyanates contained in a tested gas. Through an acid developer brought subsequently into contact with the indicator, this reaction occurs and thus the concentration of the organic isocyanates is made evident by a red coloration of the indicator.
Abstract: A tape coated with an adsorbent and impregnated with a processing solution which includes silver nitrate, an acid, an alcohol and a glycol is a sensitive detecting means for hydride gases and is stable upon exposure to light.
Abstract: A novel reagent useful for preparing adducts of diene so that the diene may be assayed by gas liquid chromatography utilizing an electron capture detection system.
Abstract: An ion mobility spectrometer for analysis of a gaseous sample wherein only nitrogen and phosphorus containing molecules of the sample are ionized. The spectrometer is of the type having an ion source for ionizing the sample gas and a shutter for gating ions into a drift region, wherein an electric field gradient exists. The ion source includes a bead which comprises a thermally stable material, such as a ceramic or glass, having an alkali metal compound on its surface. The bead is immersed in a gaseous mixture of hydrogen and air, and is heated to a temperature of 200.degree.-1000.degree. C. The bead selectively ionizes phosphorus and nitrogen containing molecules of the sample upon contact with the bead.