Abstract: A method of analysis by high performance liquid chromatography is provided for obtaining an analysis of three components, namely acyclic paraffins, cycloparaffins and unsaturates, present in a liquid hydrocarbon mixture. The method comprises introducing a sample of the mixture to be analyzed into an unsaturates-selective column, passing the eluents from the unsaturates-selective column to a second column, eluting the separated components from the second column, detecting the presence of paraffins and naphthenes in the effluent from the second column, eluting the separated components from the unsaturates-selective column, and detecting the presence of unsaturates in the effluent from the unsaturates-selective column. The unsaturates-selective column is a silver-modified ion exchange column. The second column is a slurry packed column packed with a microparticulate material. The detector is a dielectric constant 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: A post-column photochemical reaction method to improve the detection limits of compounds which absorb radiation in the range of 240 nm to 800 nm has been developed for high performance liquid chromatography (HPLC). Specifically, the limit of detection of HPLC has been reduced to a range of from about 0.5 pg to about 10 pg for a large class of organic compounds which promotes the formation of "singlet oxygen". These compounds transfer excitation energy to ground state oxygen, forming the excited singlet species, O.sub.2 (.sup.1 .DELTA.g). Singlet oxygens in turn react with a substituted furan such as 2,5-dimethylfuran (DMF) or 2,5-diphenylfuran (DPF). UV absorption or fluorescence is used to detect either the loss of the substituted furan or the appearance of the oxidation product of the substituted furan. The reaction is photocatalytic in nature and results in a large chemical amplication of the signal.
Type:
Grant
Filed:
February 27, 1987
Date of Patent:
February 21, 1989
Assignee:
Cooperative Institute for Research in Environmental Sciences Univers. of Colorado
Abstract: The invention disclosed is a method of determining gum content and performing quality control in the production of a gasoline to minimize the gum content in the produced gasoline. A representative sample of the gasoline is subjected to UV spectrophotometric analysis and the peak heights representing absorption in the range of 310 to 600 nm are integrated to determine a total absorption quantity which relates to the actual and potential quantity of gum in the gasoline. Use of this quality control technique will result in a refiner having more control over gum content at a hydrocarbon processing unit, such as a catalytic reformer.
Abstract: A novel method of detecting and diagnosing lung cancers by monitoring and analyzing expired lung air for the presence of selected aromatic amines, particularly aniline and ortho-toluidine, is provided.
Type:
Grant
Filed:
March 31, 1987
Date of Patent:
September 20, 1988
Assignees:
Monell Chemical Senses Center, University of Pennsylvania
Inventors:
George Preti, John N. Labows, Ronald Daniele, James G. Kostelc
Abstract: Tagging compounds (which function as both dyes and markers) having the following structures: ##STR1## wherein x is an integer between 0 and 3 inclusive, y is an integer between 1 and 3 inclusive, z is 0 or 1, and R is a straight or branched chain hydrocarbon having from 1 to 5 carbon atoms are disclosed. These compounds can be dissolved in a diluent at a concentration of from about 10 percent to about 30 percent, forming a concentrate which can be further dispersed in an organic liquid to form a final concentration of from about 1 ppm to about 15 ppm of said tagging compound in said liquid. Methods for detecting the presence of a tagged compound in an organic liquid are also disclosed.
Abstract: A chemical test kit and method for detecting the presence of impurities in an oil sample is provided. The test kit is comprised of two flexible translucent or transparent containers, each with at least one breakable capsule mounted within it. One of the flexible containers has a means for separating an aqueous layer from an oil layer. The capsules contain reagents capable of extracting the impurity to be detected from the oil into an aqueous layer and indicating the presence of a threshold concentration of the impurity. The method involves the steps of introducing an oil sample into a first flexible container, breaking the capsule within it by squeezing the flexible container in the vicinity of the capsule, transferring the aqueous layer to the second container, and breaking the capsule within the second container in the same manner. A chemical reaction occurs in the second container indicating whether the impurity is present at a given threshold concentration.
Abstract: The quantity of an anionic material in a sample is determined by adjusting the pH of the sample to place the material in nonionic extractable form, extracting out the material, spectrophotometrically measuring the extracted material, and comparing the measured value to a standard in order to determine the quantity of the anionic material.
Type:
Grant
Filed:
October 22, 1984
Date of Patent:
May 19, 1987
Assignee:
International Business Machines Corporation
Abstract: A process for detecting the presence of trace amounts of non-fluorescent soluble compounds each having at least one labile hydrogen atom in a carrier solution by adding a non-fluorescent quinone which is reducible to a fluorescent hydroquinone, and irradiating the resulting solution in the absence of oxygen with light of sufficient energy to cause the quinone to be reduced to a hydroquinone. The invention further provides a novel photochemical reactor--recording fluorometer combination and carrier liquid--quinone solution for performing the analysis.
Abstract: The geochemical oil prospecting method is disclosed in which a crude oil sample is analyzed for the presence of distinctive patterns of aromatic sulfur compounds which are indicative of the petroleum source rock type. Using relative proportions of benzothiophenes, dibenzothiophene, isomeric methyl dibenzothiophenes, dimethyl- and trimethydibenzothiophenes a crude oil can be identified as having a carbonate or siliciclastic source. The information obtained can be used in combination with geological and seismic studies to determine potential oil locations.
Abstract: A system for analyzing constituents of coal-derived materials comprises three adsorption columns and a flow-control arrangement which permits separation of both aromatic and polar hydrocarbons by use of two eluent streams.
Type:
Grant
Filed:
October 29, 1982
Date of Patent:
May 1, 1984
Assignee:
The United States of America as represented by the United States Department of Energy
Abstract: A method for detecting fluorescent materials in liquid chromatography. Fluorescent materials are excited by chemical reaction with chemical reagents to yield light (chemiluminescence) and detected at high sensitivity. The detection apparatus is composed of a mixer for mixing a solution containing separated fluorescent materials and solutions of chemical reagents to afford chemiluminescence, a flow cell and a light receptive detection means for detecting the light thus produced.
Abstract: A sensing apparatus and method for qualitatively and quantitatively analyzing small amounts of selected oxidizable gases in a carrier gas including the associated electronic circuitry is described. The apparatus preferably includes two semi-conductor type sensing elements in electrical parallel so that the difference in resistance of the two sensors can be detected, which can be of the N or P type and which decrease or increase in electrical resistance as a function of the concentration of an oxidizable gas. Also, a method for determining fruit maturity and ripeness by the detection of ethylene in the internal atmosphere of a fruit is described which preferably uses the apparatus with the semi-conductor type sensing elements, but can use other variable resistance type gas sensing means.
Type:
Grant
Filed:
December 18, 1980
Date of Patent:
October 18, 1983
Assignee:
Board of Trustees operating Michigan State University
Inventors:
David R. Dilley, Julian J. L. Lee, Mikal E. Saltveit, Jr.
Abstract: The paraffin, olefin and aromatic compounds in a gasoline containing hydrocarbons up to about C.sub.13 can be analyzed and identified by gas liquid chromatography. The aromatics are reversibly absorbed from the gasoline sample by N,N-bis(2-cyanoethyl) formamide while the olefins are irreversibly absorbed by sulfuric acid. Following separation by compound type, each group is resolved and identified by gas liquid chromatography.