Abstract: An optical absorbance method for the quantitative determination of Lewis acid decomposition products in nonaqueous electrolytes.

Abstract: A method of measuring the amount of organic material adhered to the surface of a semiconductor substrate. In the method, a metal is precipitated by bringing the reaction solution into contact with organic material on the surface of semiconductor substrate. The amount of the organic material adhered to the semiconductor substrate can be determined by detecting the amount of the metal precipitated.

Abstract: A method of determining acid value with high accuracy, using an infrared spectrometer is provided, in which the absorbance is determined attributable to carboxylic group based on an infrared absorption spectrum at wave numbers around 3300 cm.sup.-1.

Abstract: Methods for determining the corrosivity of a substance to human skin or membrane are disclosed. In one approach, corrosivity is evaluated by measuring the time required for the test substance to transit a biobarrier that mimics human skin or membranes or the time required to cause a component of such biobarrier to break down and transit the membrane. The invention also envisions alternative approaches which involve series of layers of dyes and corrosive-resistant materials coated onto microspheres or test strips. Use of these methods provides a rapid determination of the corrosivity of test materials.

Abstract: This invention provides a measuring method and a device suitable for the quantitative analysis of metal elements contained in body fluids comprising:using the flow injection method for reacting a sample with a reagent in a tubule and analyzing the reacted solution. In essence, the present invention provides;a method for introducing a body fluid sample and a protein release reagent into a carrier solution, reacting the two solutions with one another in the tubule in order to liberate the protein contained in the body fluid sample, followed by introducing the reacted solution into a quantitative analysis means for determining and measuring the concentration of target metal(s) contained in the body fluid; anda quantitative analysis device for performing the foregoing method.

Abstract: A method and system for controlling an HF alkylation system comprising a reactor, a settler, an HF acid regenerator and a source of fresh HF acid wherein a stream of olefins and a stream of isobutanes are contacted in the reactor in the presence an HF acid catalyst. At least the reactor feed is sampled, and the sample is passed to an analyzer using an attenuated total reflectance cell. Signals are generated which are representative of infrared spectra of the samples in a range providing information on the amount of at least one of HF, water, ASO and sulfolane. These signals are simultaneously determined and generated because all absorb in the same spectral region. This aspect provides for viewing these distortions of the main HF absorption band to quantify these three components. The infrared spectra signals are compared with stored signals to generate control signals; and at least one of HF, water and sulfolane fed to the reactor feed is adjusted in response to the control signal.

Abstract: Disclosed is a source of visible and ultraviolet radiation that provides a focused beam for performing chemical analysis of a test element having a biological fluid deposited thereon.

Abstract: A process for rapidly and conveniently measuring the magnesium concentration of a biological fluid, such as blood or urine, is carried out by fixing amounts of a chelatometric dye, metal cation masking agents, a chelating agent, an alkaline buffer, and a stabilizer on a bibulous material covered with a semipermeable membrane, adding the test specimen, and measuring the amount of color change of the dye at a selected wavelength. The amount of color change is proportional to the quantity of magnesium in the original specimen and can be measured by visual comparison to a standard color chart or with a dedicated reflectance photometer. Furthermore, a method is given for expanding the range of linearity. The method for making the dry indicator includes coating bibulous material with a reaction solution which is dried thereon, followed by coating this material with an organic solution which is dried thereon.

Abstract: A method detecting the presence or concentration of an analyte in a sample is described in which the sample is mixed with a particulate reagent to form a stable flowable suspension prior to introduction of the sample into an analytical device or detector in order to eliminate memory effects. Preconcentration of the sample bound to the particulate reagent improves sensitivity of the analytical method.

Abstract: An organic substance analyzing method is disclosed. A sample container 21 charged with a granulated rock sample is installed in a thermal cracking furnace 1. The thermal cracking furnace 1 is connected to a vacuum suction line 27 to be evacuated until a substantial vacuum is created therein, whereupon the furnace is closed. The closed thermal cracking furnace is rapidly heated to a first temperature at which hydrocarbons are more or less cracked but inorganic carbonates are not decomposed. The thermal cracking furnace is maintained at this temperature for a fixed time and then is cooled to a temperature at which the hydrocarbons in the thermal cracking furnace do not react with air. Then the furnace is connected to an air supply line 29 and an exhaust line 35 to pass the produced gases in the furnace to a hydrocarbon detector 34 and a CO.sub.2 detector 33. From the output signals therefrom, HC peak P1 and CO.sub.2 peak P3 are found and recorded.

Abstract: A method of testing oil for unstable reactive compounds include reacting unstable compound from an oil sample with an acid catalyst to form a reaction product, the color of which is then related to the presence and/or amount of reactive compound in the oil. Kits combining the necessary materials and reagents for performing the test method are also provided.

Abstract: One or more properties of a refrigerant are analyzed by evacuating a refrigerant sample vessel, drawing a refrigerant vapor sample into the vessel, and condensing the refrigerant sample within the vessel for measurement and indication of one or more desired properties of the liquid refrigerant sample. By drawing the sample refrigerant in vapor phase rather than liquid phase, the sample will be relatively free of lubricant, particulate or water contamination. The sample vessel can be readily cleaned by simple evacuation in preparation for the next measurement cycle.

Abstract: In the elemental analysis of an analyte present in a sample by optical or mass spectrometry, a nebulizer sprays the liquid sample into a chamber which has a wall transparent to infra-red radiation. Infra-red radiation from a heater external to the chamber is focused on to the droplets of sample as they emerge from the nebulizer, disrupting the droplets into smaller ones and evaporating solvent from them as they pass through the chamber. The thus desolvated sample stream is delivered into a plasma and the reaction accuracy within the plasma is qualified by the spectrometer.

Abstract: A method for the detection of at least one polyamine associated with bacterial infection, which comprises contacting a sample suspected of containing polyamine-associated bacteria in aqueous medium at alkaline pH with indigo carmine and dimethyl sulfoxia and observing whether a blue color develops in five minutes indicating the presence of polyamine.

Abstract: The flow-injection system includes a microwave oven having a flow-through reactor having a flow-through conduit located in windings around a conduit carrier for absorbing microwaves. The windings extend through the radiation cavity of the microwave oven only with a part of their length and transversely to the radiation direction. The microwave oven includes programmable adjusting means for the heating power and the heating period. Thus, in connection with a reduction flow-through reactor and an atomic absorption spectrometer, a determination of hydride formers and mercury in a material sample is possible, independently of the valence state.

Abstract: A DNA sequencing system and method are described to detect the presence of radiant energy emitted from different excited reporter dye-labeled species (DNA fragments) following separation in time and/or space, and the identity of the species which emit radiant energy closely spaced in wavelength. Functions of the emitted energy are obtained which vary over the wavelengths of the closely spaced spectra in different senses and the functions ratioed, whereby the ratio is indicative of the identity of the DNA fragments.The emitting portion of the reporter-labeled DNA fragment is preferably one of a family of fluorescent dyes based on 9-carboxyethyl-6-hydroxy-3-oxo-3H-xanthene. These xanthene dyes are covalently attached to the DNA fragments through the carboxylic acid functionality, preferably via an amide linkage. The dyes may be protected by including an alkoxy group at the 9-position. A spacer may be inserted between the dye and the amine.

Abstract: A test device and method of determining the presence or concentration of a predetermined ion, such as a cation of medical interest, like sodium, potassium, calcium, magnesium or lithium, in an aqueous test sample are disclosed. The test device includes a test pad comprising a hydrophilic indicator reagent composition capable of interacting with a predetermined ion, or electrolyte, to produce a detectable or measurable response. The hydrophilic indicator reagent composition consists essentially of a hydrophobic ion specific ionophore, a hydrophobic reporter substance, and a stabilizer polymer such as gelatin. The hydrophilic indicator reagent composition, either as a film or layer, or after incorporation into a suitable carrier matrix, provides a test pad of sufficient sensitivity to the predetermined ion to achieve an accurate and trustworthy electrolyte assay of an aqueous test sample, such as plasma or serum, by a dry phase test strip assay.

Abstract: A method for measuring the concentration of a chemical substance by spectrophotometry comprising the steps of placing a sample of a photoreactive substance between the light source and a spectrophotometer, obtaining an absorption spectrum of the substance using a fixed amount of light from the light source, obtaining a second absorption spectrum after a short interval, comparing the two to determine the concentration of the chemical substance from the difference in the spectra. If the chemical substance is not photoreactive, a photoreactive mixture can be made with a photoreactive dye that has photoreactive properties unique to the mixture. Alternatively, an optically transparent substrate can absorb the substance or the dye/substance mixture.

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 high angle light scattering detector using classical Rayleigh scattering. A high intensity arc light source, filtered to leave only one wavelength illuminates a flow cell. Through the flow cell, very small particles such as biological proteins flow in solution after separation by HPLC or some other means. A UV detector generates data regarding the weight concentration of the eluting particles and a scattered light detector collecting scattered light at angles of approximately 90.degree. generates a scattered light signal. The incident light intensity is also measured. The average molecular weight is then computed using the scattered and incident light data the weight concentration data and a simplified mathematical relationship from which the size factor P and the viral coefficients have been eliminated.

Abstract: A process for measurement of low levels of phosphonates in brine waters wherein the phosphonate samples are acidified with hydrochloric acid promptly upon removal from an oil or gas well to prevent phosphonate precipitation or adsorption. The hydrochloric acid acidified phosphonate is digested in the presence of an oxidizing agent at elevated temperature and pressure for sufficient time to oxidize substantially all of the phosphonate to orthophosphate. The phosphorous containing compound is extracted with an organic extractant, preferably selected from the group consisting of methyl iso-butyl ketone/cyclohexane mixture and ethyl acetate, followed by color development for absorption spectrophotometry.

Abstract: A spectrophotometric assay for quantitative determination of 5-hydroxyindoleacetic acid in fluid samples. 3-methyl-2-benzthiazolone hydrazone is oxidized with sodium periodate to the corresponding diazonium salt. The resulting diazonium salt adds electrophilically to activated positions on indole ring of 5-hydroxyindoleacetic acid to yield azo dyes which absorb light at 510 nm.

Abstract: A method and apparatus for calibrating or checking the calibration of vertical photometers. The invention may also provide easy and convenient assay results for diagnostic profiles. The invention comprises pre-dispensed amounts of a suitable reagent, chosen for the particular use, disposed in a vessel with an amount of a wetting agent or other means to yield a reproducible meniscus in the resulting control solution. The control solution is dried to leave a precise amount of dried reagent and other constituents in the vessel which can then be stored and distributed until subsequent use. The dried control solution can then be reconstituted to provide a standard having known absorbance and physical characteristics.

Abstract: A high angle light scattering detector using classical Rayleigh scattering. A high intensity arc light source, filtered to leave only one wavelength illuminates a flow cell. Through the flow cell, very small particles such as biological proteins flow in solution after separation by HPLC or some other means. A UV detector generates data regarding the weight concentration of the eluting particles and a scattered light detector collecting scattered light at angles of approximately 90.degree. generates a scattered light signal. The incident light intensity is also measured. The average molecular weight is then computed using the scattered and incident light data, the weight concentration data and a simplified mathematical relationship from which the size factor P and the viral coefficients have been eliminated.

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: The present invention is directed to a novel method for analyzing aqueous systems to simultaneously quantify the concentrations of multiple active or inactive treating components which may be contained therein. The method comprises determining the absorbance or emission spectrum of the components in the aqueous system over the wavelength range of from 200 to 2500 nm, and then applying chemometrics algorithms to extract and analyze features in the spectrum that are specific to the qualitative and quantitative concentrations from the specific components to simultaneously determine the concentrations of the components.

Abstract: An improved ion mobility spectrometer (IMS) and method for operating the same which enables analysis of ammonia in a mixture of gases when air is used as the carrier gas and the drift gas in the IMS. A controlled concentration of an ester such as Dimethyl methyl phosphonate (DMMP) is added to the air carrier gas stream prior to application of the carrier gas stream. The DMMP clusters with the ammonia, and the drift times of the ionized clusters differ from the drift times of the ions generated from the other constituents of the sample, thereby enabling identification and quantification of the ammonia.

Abstract: A chemical analysis method for the determination of a first organic acid in the presence of a second organic acid both of which are in a solution to be analyzed, the pK.sub.a of the first acid being at least 2 pK.sub.a units larger than the pK.sub.a of the second acid. The method includes three steps. The first step if to form a pH adjusted solution to be analyzed by adjusting the pH of the solution to be analyzed to be between the pK.sub.a of the first acid and the pK.sub.a of the second acid so that the first acid is predominately in its unionized form and so that the second acid is predominately in its ionized form.

Abstract: A method for detecting ischemic states in a patient by contacting a sample of serum, plasma, fluid or tissue with a metal ion capable of binding to metal ion binding sites in the sample to form a mixture, and then detecting the presence of unbound metal ions to determine the occurrence of ischemia.

Abstract: A quantitative method including separating a mixture of olefins, aromatics, and saturates by supercritical fluid chromatography to obtain an eluent stream that over a first time period contains a mixture of olefins and saturates, and over a second time period contains aromatics, and passing the eluent first to an ultraviolet absorption detector (UV). Importantly, the eluent is irradiated in the UV detector at a wavelength capable of producing an ultraviolet absorbance response of olefins that is independent of specific olefins present, and preferably is substantially similar to a mass detector response for olefins. From a combination of UV and mass response, the mass of the olefins in the mixture of olefins and saturates can be determined. Thereafter, the eluent is passed to a mass detector whereby the mass of the mixture of saturates and olefins is determined and then the mass of the aromatics is determined.

Abstract: A chromogenic cryptand found to be especially selective in the determination of lithium in blood of the general formula (I): ##STR1## where: n=1 or 2,R.sub.1 and R.sub.2, same or different, are hydrogen, lower alkyl, lower alkenyl, or lower alkylidene; andQ is a chromogenic moiety capable of providing a detectable response upon complexation of said compound with lithium ion and has the structure: ##STR2## wherein: X is CH, C--OH or N; and Z is p-nitrophenylazo, 2,4-dinitrophenylazo, 2,4,6-trinitrophenylazo, p-nitrostyryl, p-benzoquinonemonoimino, bis-(4-dimethylaminophenyl) hydroxymethyl, 3-phenylisothiazolyl-5-azo, thiazolyl-5-azo; or isothiazolyl-5-azo.A reagent composition and synthesis of a preferred chromogenic cryptand are also disclosed.

Abstract: A method for determining the carbonate content of washing suspensions of flue gas desulfurization plants using limestone is carried out by first admixing the samples, being at a temperature of from 40.degree. C. to 70.degree. C., with an excess amount relative to the maximum possible sulfite content, of an iron(III) chloride solution for the oxidation of the sulfite to sulfate, and then by addition of an excess amount of sulfuric acid or another acid, measuring the amount of escaping gas corresponding to the carbonate content.

Abstract: A method for determining the fibrinogen level of a patient blood plasma in an optical density based prothrombin time test. The method and apparatus utilize a novel parameter DELTA which factors out statistical inaccuracies associated with prior art test methods. The patient fibrinogen level is determined using DELTA points calculated from blood samples having known fibrinogen levels in the low, normal and high ranges. A piece wise function is then constructed around the DELTA points and the fibrinogen level of a patient blood sample is calculated using four equations pre-stored in a non-volatile memory.

Abstract: A method and an apparatus for measuring and controlling the efficiency of a combustion whereby, ash samples are drawn at predetermined time intervals from a region of a combustion plant, each drawn sample is set in an exhausted reaction cell, combustion reaction gas is introduced under controlled pressure, a superficial layer of the sample is heated to the carbon combustion temperature by a CO.sub.2 laser beam, the reaction gas is drawn from the cell and the amount of carbon dioxide produced by the carbon combustion is measured in a calibrated detector. The amount of unburnt carbon contained in the ashes is determined based on a preceding calibration carried out on ashes of known carbon content.

Abstract: A method utilizing a novel reagent for the assay (determination)of serum iron.The serum iron assay reagent is a single, stable reagent, which includes the chromogen chromazurol B (CAB), chromazurol S (CAS), or an alkali metal, alkaline earth metal, rubidium or ammonium base addition salt of CAB or CAS, a surfactant that forms a ternary complex with iron and the chromogen, a buffer, and dimethylsulfoxide.

Abstract: There is provided a method for determination of hydroxyacetophenone derivatives such as 3,5-dichloro-4-hydroxyacetophenone in the presence of protein such as albumins or globulins with high sensitivity. The hydroxyacetophenone derivative can be measured in the neutral to acidic region, whereby the method is not affected by interferrants such as bilirubin or hemoglobin. The hydroxyacetophenone derivatives are useful as the chromogen of synthetic substrates for determining acid phosphatase activity.

Abstract: Mid-distillate hydrocarbon fuels, preferably having initial boiling points above 350.degree. F., are separated e.g. by prep-HPLC into non-aromatic and aromatic fractions which are used to set 0% aromatics (the non-aromatics) and 100% aromatics (the aromatics) on an NIR spectrophotometer. From NIR aromatic band absorbances of unknown samples, their percent aromatics is determined using this two-point calibration and the Beer-Lambert equation. Preferred NIR bands of 1650-1700 and 2120-2256 exhibit excellent correlation with aromatics content.

Abstract: A carbon monoxide detecting sensor of a derivative of Ni(TBC) which reacts with carbon monoxide to form a carbon monoxide adduct with a concomitant change in color.

Abstract: A method for testing for the removal of tritiated water using deuterated water in which the infrared absorption spectra of deuterated water in an effluent stream passing through a tritiated water filtering media is measured.

Abstract: An assay technique for qualitative and quantitative detection of a chemical, biochemical or biological detection of a chemical, biochemical or biological species in sample. The technique comprises: (a) coating at least a predetermined part of a pre-formed surface on a substrate with a thin film of a material capable of binding the species to be assayed, the pre-formed surface being optically active with respect to radiation at least over a predetermined band of wavelengths; (b) contacting the coated surface with sample; and (c) observing the optical properties of said pre-formed surface in order to determine a qualitative and quantitative change in optical properties as a result of the binding of the species onto said thin film of material. The optical properties as a result of the pre-formed surface may be observed before and after step (b) in order to determine any change in optical properties, or they may be monitored during step (b). The pre-formed surface is preferably a grating.

Abstract: A reagent format having an inverse funnel shaped body which includes a central capillary tube that opens into a flow passageway. The flow passageway is formed, in part, by providing a recessed flow surface at one end of the inverse funnel shaped body which is surrounded by a stepped shoulder. A test substrate, such as reagent film, is secured to the shoulder so as to form one surface of the flow passageway. The device is suitable for both drawing and spreading a fluid test sample onto a test substrate in one step. Additionally, one or more small diameter vent passageways open into the flow passage to allow for air to escape when fluid is drawn into the flow passage through capillary action. The pen-shaped body is also formed of a clear or translucent material such that the flow of the test fluid can be observed by the user.

Abstract: A method is provided for detecting the endpoint of an interfacial aromatic polycarbonate polymerization reaction. The method involves illuminating a sample of the polymerization reaction mixture with a light source and monitoring the extent of apparent light scattering of the sample throughout the course of the polycondensation reaction until at the endpoint, a predetermined threshold extent of apparent light scattering is achieved.

Abstract: For the simultaneous measurement of two parameters of a liquid or gaseous sample, in a fluorescence measuring device in which the influence of the aging processes of the indicator substance and the fluctuations in the light intensity of the excitation light source are to be avoided, it is proposed that the change in the first parameter to be measured is obtained from the change in the ratio of two intensity values, determined for different wavelengths of the excitation and emission spectrum of the indicator substance, and the change of a second parameter is obtained from the change in the decay time t of the fluorescence radiation of the same indicator substance from the group of aromatic hydrocarbons, the aromatic heterocycles and the metal organic complexes.

Abstract: A matrix modifier of finely-divided metallic palladium dispersed to contact a metal constituent to improve analysis of the constituent during graphite furnace atomic absorption spectroscopy. The palladium interacts with a variety of metals in a sample to increase the vaporization temperatures of the metals. One way of contacting palladium with the metal analyte is to introduce it as a salt in solution with the sample into the graphite furnace along with a surfactant. A finely-divided metallic palladium having high surface area is produced in the furnace by introduction of hydrogen gas, which acts as a reducing agent, to reduce and maintain palladium in its metallic form at an early point in the temperature program, prior to evaporation of the surfactant.

Abstract: An automated, high volume process for detecting, identifying and quantifying physical incompatibility between two or more chemicals in solution includes mixing the chemical solutions in all possible orders and reading the light absorption of each at two wavelengths to differentiate between color reactions and other physical reactions.

Abstract: An apparatus for chemically analyzing a sample on a test piece that includes a reagent layer, comprises a test piece table for positioning a test piece thereon, and an applying station wherein a sample may be applied to the reagent layer. The test table moves to a position below a row of holes with the reagents aligned to the holes and a sample is applied to each reagent layer from a nozzle, the samples passing through the respective holes. Covers are moved over the holes after the samples are applied and the test pieces are moved to a measuring station for measuring the reaction between the sample and reagent layer. Photometric techniques are used in evaluating the reaction. Opening and closing of the covers is controlled by motion of the sample dispensing nozzle as it moves from one opening to the next.

Abstract: To inject samples into a mass spectrometer, one end of a capillary tube is affixed directly to the vacuum chamber of the mass spectrometer or to a mass spectrometer interface to bring gaseous samples into close proximity to the mass spectrometer ionizing means, and the other end is in close proximity to the surface of a tape. The tape is in a cassette and a probe is inserted through the cassette frame between the cassette reels and draws the tape to the end of a capillary tube. Regions of tape with samples adsorbed to tape surface are transported rapidly from a low temperature region for a high temperature region which includes the entrance end of the capillary tube. Sample vaporizes from the tape surface and is carried into the capillary tube by a carrier gas. The tape position is indicated by bar codes on the tape that control tape movement.

Abstract: A system for in-line alloying of a molten metal stream comprises: means for controlling mass flow rate of the stream; means for adding alloying material to the stream at an adjustable rate; means for determining chemical composition of the stream downstream from the material adding means, preferably at timed intervals; and means for adjusting the rate at which alloying material is added to the stream based on mass flow rate and the extent to which the determined stream composition differs from a desired composition. A method for conducting in-line alloying and analysis of a continuous metal stream is also disclosed.

Abstract: An apparatus and method for analyzing mercury by the atomic absorption spectrometry technique consisting of a quartz collecting tube containing a metallic net for collecting an amalgam of mercury sample, a heater for heating the collecting tube sufficiently to convert the mercury sample to an atomic state for appropriate analysis at another location, and a fluid cooling device for quickly cooling the collecting tube and metallic net to thereby prepare for the next sample analysis. The collecting tube is positioned and arranged such that in a first position it is inside of the heater and quickly after conversion of the mercury sample the tube is moved to a second position outside of the heater and adjacent to the cooling device.

Abstract: Techniques are described for extracting lead from a sample of potable water and analyzing for the amount of lead so extracted. A complexing agent is added to the water to form a complex with the lead. The water is then contacted with unmodified cellulosic or siliceous material on which the lead complex is retained. The complexed lead can be removed from the cellulosic or siliceous material with a weak acid. The amount of lead in the sample can be readily determined colorimetrically.