Flame Ionization Detector Patents (Class 422/54)
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Patent number: 4965048Abstract: A flame ionization detector is used for carrying out a quantitative analysis of chromatographically-separated substances in thin-layer chromatography. The detector comprises a gas burner for forming a hydrogen flame. A thin-layer chromatographic element or a rod-like element which carries the chromatographically-separated substances is passed through the hydrogen flame so that the separated substances are burned and ionized. The detector further comprises an electrode which is disposed above the hydrogen flame and exposed to the ionized gas generated by the burning of the separated substances. A voltage is applied between the gas burner and the electrode so that the former is given a positive polarity and the latter a negative polarity. An electric current which is caused by the exposure of the negative electrode to the ionized gas is detected and amplified.Type: GrantFiled: September 25, 1989Date of Patent: October 23, 1990Assignee: Iatron Laboratories, Inc.Inventor: Minoru Ogasawara
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Patent number: 4863691Abstract: A gas-passage change-over apparatus, in which two gas lines are connected to one detector so that either of the two gas lines may be opened into the detector under the condition that the pressures at the ends of the two gas lines having different volumes are regulated by a pressure regulator. Switching valves are provided in each of the gas lines, and the connection of the flow from the gas lines to the detector is changed over by means of the two switching valves, such that switching valves are both closed for a predetermined period of time between changeovers.Type: GrantFiled: December 18, 1987Date of Patent: September 5, 1989Inventors: Naoki Noguchi, Yo Fukui
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Patent number: 4839143Abstract: An ion mobility spectrometer, ionization detector and mass spectrometer is described having a reaction region, and means 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 and provides a means for ionization of a broad class of compounds.Type: GrantFiled: February 15, 1985Date of Patent: June 13, 1989Assignee: Allied-Signal Inc.Inventors: Kishore N. Vora, Donald N. Campbell, Robert C. Davis, Jr., Glenn E. Spangler, Julio A. Reategui
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Patent number: 4834945Abstract: A propellant sample combustion apparatus employing a multiply optical ported pressure vessel for sample illumination, sample viewing, and sample burn face elevation is described. High-speed motion picture filming using short-duration high-intensity laser provided optical illumination from a copper-vapor laser is employed. Details of the employed pressure vessel, a burn inhibiting coating for the propellant sample, a laser coherence spoiler, and a sample level maintaining closed-loop apparatus are also disclosed.Type: GrantFiled: November 20, 1987Date of Patent: May 30, 1989Assignee: The United States of America as represented by the Secretary of the Air ForceInventors: Roger J. Becker, James M. Aulds
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Patent number: 4828704Abstract: A thin-layer rod for thin-layer chromatography conducted by the use of a flame ionization detector, comprising a rodlike support and a stationary phase made of an adsorbent which is superposed on the rod-like support, with chemical modification made in at least part of the stationary phase.Type: GrantFiled: December 14, 1987Date of Patent: May 9, 1989Assignees: Cosmo Oil Company, Ltd., Iatron Laboratories, Inc.Inventor: Yojiro Yamamoto
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Patent number: 4820044Abstract: A transport detector system comprises(a) a liquid delivery tube,(b) a plurality of moveable spokes, the spokes being positioned to pass in sequence under the delivery tube, the spokes being constructed from a refractory inorganic material of low thermal conductivity,(c) one or more evaporators, positioned so that the spokes pass sequentially through it or them after liquid has been deposited on the spokes,(d) a detector positioned so that the spokes pass sequentially through it after passage through the evaporator(s),(e) one or more coolers, positioned so that the spokes pass through it or them after passage through the detector,(f) a stepper motor adapted to move the spokes in a series of discrete steps, and(g) a control system for the stepper motor, evaporators and coolers.The system is particularly suitable for use in HPLC analysis and may be interfaced with a plasma spectrometer.Type: GrantFiled: November 12, 1987Date of Patent: April 11, 1989Assignee: The British Petroleum Company p.l.c.Inventors: James S. Crighton, David J. Malcolme-Lawes
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Patent number: 4804519Abstract: An analysis system includes a sample inlet, a diluent inlet, and a mixing chamber that has an outlet through which a mixture of the sample and diluent is flowed and in which a mechanical mixing member is housed. Positive displacement pumps preferably concurrently flow diluent to the mixing chamber and draw diluted sample to be analyzed from the mixing chamber. Bubble separation apparatus has a first branch connected to a drain and a second branch connected to the analyzer input. In a particular embodiment, the analyzer apparatus includes a nebulizer that controls the flow rate of the bubble-free stream through the second branch, sample excitation apparatus in the form of an induction coupled plasma (ICP) torch for exciting the sample to spectroemissive levels, and means for spectroanalysis of the excited sample at the output of the torch.Type: GrantFiled: March 6, 1987Date of Patent: February 14, 1989Assignee: Thermo Jarrell Ash CorporationInventors: Mario A. Sainz, Richard C. Anderson, Jr., Richard J. Belmore, Stanley B. Smith, Jr.
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Patent number: 4801430Abstract: An interface generally useful for liquid chromotography systems and methods is provided for the separation of an analyte of interest from a liquid solvent. The interface provides for separation and collection of solvent and the analyte of interest in a gaseous molecular state. In this manner, the ability to detect, identify, and quantify the analyte of interest using a variety of specific and non-specific detectors is made possible.Type: GrantFiled: September 25, 1986Date of Patent: January 31, 1989Assignee: Trustees of Tufts CollegeInventors: Robbat, Jr. Albert, Nicholas P. Corso
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Patent number: 4798805Abstract: An apparatus for analysis of samples containing organic matter, especially of rock from oil drilling mud, including a loading arm hinged at its base to be movable from a tilted position when it receives a sample-bearing cartridge, which fits on the top of the arm, to a vertical position in which the arm can be raised to fit the upper end of the cartridge within a selectively electrically heated and air cooled chamber. A channel for carrier gas, e.g. hydrogen, passes up the arm so that gas passes through the cartridge when it is held in the heating and cooling chamber, and through the heating and cooling chamber and then through a conduit to a burner within an ignition an analysis chamber.In use, the container is heated to pyrolyze the sample and the resultant vapors are entrained in the gas, burnt and analyzed by flame ionization. After which the sample-bearing cartridge is cooled in the heating and cooling chamber.Type: GrantFiled: March 28, 1986Date of Patent: January 17, 1989Assignee: Geoservices, Societe AnonymeInventor: Olivier Issenmann
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Patent number: 4786475Abstract: The invention concerns a method and an equipment for the simulated distillation, by means of gas chromatography, of petroleum products, capable of characterizing also high boiling products, exceeding C55, over 600.degree. C. TBP. A chromatograph is used with a capillary column having a length less than or equal to 10 m, containing an immobilized non polar polydimethylsilicon gum stationary phase with a film thickness less than or equal to 0.2 .mu.m. The sample is introduced through a non vaporizing direct cold on-column injection and the eluted sample is detected by means of a FID detector. The column oven is operated in temperature programming conditions up to temperatures exceeding 400.degree. (up to 430.degree.-450.degree. C.).Type: GrantFiled: December 11, 1987Date of Patent: November 22, 1988Assignee: Carlo Erba Strumentazione S.p.A.Inventors: Sorin Trestianu, Fausto Munari, Carlo Saravalle
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Patent number: 4780284Abstract: Apparatus for detecting gas in a sample gas in a carrier gas stream and including a windowless ionization detector having a pulsed power supply which is switchable at a rate which provides a pulse period shorter that the transit time of ions to be detected to the collector electrode of an ionization chamber of the detector. Switching allows any signal due to ion detection to be separated from background noise due to other effects in the chamber.Type: GrantFiled: March 27, 1986Date of Patent: October 25, 1988Assignee: Hewlett-Packard CompanyInventor: James E. Lovelock
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Patent number: 4757023Abstract: The invention concerns a method and an equipment for the simulated distillation, by means of gas chromatography, of petroleum products, capable of characterizing also high boiling products, exceeding C55, over 600 C TBP. A chromatograph is used with a capillary column having a length less than or equal to 10 m, containing an immobilized non polar polydimethylsilicon gum stationary phase with a film thickness less than or equal to 0.2 .mu.m. The sample is introduced through a non vaporizing direct cold on-column injection and the eluted sample is detected by means of a FID detector. The column oven is operated in temperature programming conditions up to temperatures exceeding 400 (up to 430-450 C.).Type: GrantFiled: December 19, 1985Date of Patent: July 12, 1988Assignee: Carlo Erba Strumentazione S.p.A.Inventors: Sorin Trestianu, Fausto Munari, Carlo Saravalle
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Patent number: 4713327Abstract: A multilayer analytical element for the determination of creatine kinase comprises a support having thereon, in order and in fluid contact, a registration layer and an isotropically porous spreading layer. The registration layer contains a binder material at a coverage of at least about 8 g/m.sup.2, which coverage improves the stability and keeping properties of the element in high humidity environments. This element is useful in an analytical method for determining total creatine kinase or any one of its isoenzymes, e.g. creatine kinase-MB.Type: GrantFiled: May 1, 1985Date of Patent: December 15, 1987Assignee: Eastman Kodak CompanyInventors: John B. Findlay, Annie L. Wu, Gary E. Norton
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Patent number: 4684509Abstract: An apparatus for measuring a gas concentration in a hot gas sample withdrawn from a process chamber, comprising a metal block (10) adapted to be tempered and housing at least the detector (12) and those components of the flow path guiding the gas to be measured between a sampling probe and the detector. A suction pump (14) sucks the gas sample into the metal block (10) where the gas to be measured is divided into two conduits. The first conduit leads to the detector and the second conduit back to the process chamber.Type: GrantFiled: July 16, 1985Date of Patent: August 4, 1987Inventor: Tibor Bernath
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Patent number: 4657872Abstract: A pulsed or discontinuous laser-enhanced flame ionization detector for detection of traces of hydrocarbons in gaseous samples. The use of a laser in conjunction with flame ionization significantly increases the ratio of electronically excited CH radicals to ground electronic state CH radicals thereby increasing the signal to noise ratio during measurement, thus increasing the sensitivity of the flame ionization detection method.Type: GrantFiled: November 13, 1984Date of Patent: April 14, 1987Assignee: Cornell Research Foundation, Inc.Inventor: Terrill A. Cool
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Patent number: 4524047Abstract: Method and apparatus for analyzing specific chemical substances in a gaseous environment comprises 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.Type: GrantFiled: March 2, 1983Date of Patent: June 18, 1985Inventor: Paul L. Patterson
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Patent number: 4517461Abstract: Method and apparatus are provided for analysis of a sample of matter for at least one isotopic constituent of the sample. The method involves introduction of a sample containing an isotope of interest into an analytical detector operative to convert the sample into a product analyzable by a mass spectrometer and to detect a property of the sample representative of the quantity of at least one of its constituents, and passing the conversion product from the detector to a mass spectrometer operative to detect the isotopic ratio of interest. The method optionally includes passing the sample or a source material through a chromatograph column for separation into suitable fractions. The apparatus includes an appropriate analytical detector and a mass spectrometer with optional chromatography column. The method and instrument are particularly suited for analysis of oil-related samples such as crude oil fractions, natural gas, soil gas and oil shale as a tool in oil prospecting.Type: GrantFiled: November 29, 1982Date of Patent: May 14, 1985Inventor: John A. Crandall
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Patent number: 4508685Abstract: The invention relates to a modified-flame thermionic detector for gas chromatographs, of the type including a burner nozzle, an excitation electrode and a collecting electrode. The electrical connections of the nozzle and the excitation electrode can be changed at the operator's will, together with the spatial position of the excitation electrode with respect to the flame and the collector, to find out the presence of certain compounds, leaving all other conditions of analysis performance and detector supply unaltered. This allows obtaining chromatograms of unknown samples under different conditions of the detector configuration, to put into evidence the presence of certain compounds in the sample by comparing peaks of chromatograms obtained under said different operating conditions of the detector.Type: GrantFiled: May 26, 1982Date of Patent: April 2, 1985Assignee: Carlo Erba Strumentazione S.p.A.Inventors: Giorgio Sisti, Giuseppe Verga
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Patent number: 4466943Abstract: A flame detector analyzer of the type wherein a sample gas is introduced into a flame formed by burning a fuel gas in presence of a combustion supporting gas, comprises a background providing device for supplying a background component gas capable of emitting a characteristic spectrum having the same wave length as that of the characteristic spectrum of a measuring object component contained in the sample gas, the light spectrums emitted from the measuring object component and the background component gas being received and treated to be detected, thereby increasing the measuring accuracy for the measuring object component and improving the resolving power at a low concentration detection region.Type: GrantFiled: November 26, 1980Date of Patent: August 21, 1984Assignee: Nissan Motor Co., Ltd.Inventors: Isao Murase, Katsutoshi Hirose
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Patent number: 4420255Abstract: A research type burner is provided which permits ready optical access for study of precombustion and primary reaction zones of adiabatic flames of premixed gases. The burner includes a channel for relatively laminar gas flow having an outlet with a pair of essentially parallel closely spaced knife edges for providing an essentially stable and adiabatic flame. The knife edges project sufficiently above the burner housing to allow the passage of a laser beam between the knife edges through the zone to be studied.Type: GrantFiled: September 16, 1981Date of Patent: December 13, 1983Assignee: The United States of America as represented by the Secretary of the ArmyInventors: Mark A. DeWilde, Richard A. Beyer
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Patent number: 4388411Abstract: The invention relates to apparatus for detecting a constituent gas in a gas flow. Means is provided for removing the constituent gas from a sample flow and directing this sample flow together with a reference flow containing the constituent gas through an equilibrator means wherein contaminants can be removed before the sample gas and the reference gas are compared in detector means, for example, an electron capture detector. The apparatus and method are also applicable to the detection of a liquid in a flow thereof.Type: GrantFiled: April 29, 1981Date of Patent: June 14, 1983Assignee: Hewlett-Packard CompanyInventor: James E. Lovelock
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Patent number: 4379402Abstract: An apparatus for compensating for changes in the mass flow rate of a sample gas stream in gas analysis instruments having outputs that are calibrated in terms of the concentration of a component of the sample stream. In instruments in which a pressure regulated sample gas stream is applied to a detector assembly through a flow restrictor such as a sample capillary, a gas flow sensor is connected in series with the flow restrictor to develop a correction signal that varies in accordance with the mass flow rate of the sample stream. A correcting circuit combines the correction signal from the flow sensor with the output signal from the detector assembly to produce a corrected output signal that correctly indicates the concentration of the component of interest.Type: GrantFiled: January 22, 1981Date of Patent: April 12, 1983Assignee: Beckman Instruments, Inc.Inventor: John N. Harman, III
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Patent number: 4361810Abstract: An arrangement for monitoring the concentration of potentially explosive substances in gas streams includes a first flame-ionizer and a second flame-ionizer, both ionizers being accommodated in a common chamber which is maintained at a predetermined temperature, such as 180.degree. C. A common conduit for supplying both ionizers with a fuel gas is provided in the arrangement. A common conduit for feeding both ionizers with combustion air is mounted in the arrangement. Each ionizer is provided with an individual conduit connecting the assigned ionizer with a respective drying chamber of a coating installation. A sample gas stream discharged from the respective drying chamber is fed into the assigned ionizer through a capillary pipe and passed through a flame produced in each ionizer. The electric current flowing between the electrodes in each ionizer shows the concentration of potentially explosive substance in gas streams being tested.Type: GrantFiled: September 8, 1980Date of Patent: November 30, 1982Assignee: Ratfisch InstrumenteInventor: Wolfgang Schlosser
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Patent number: 4346055Abstract: Apparatus for igniting a flame ionization detector wherein means are provided for gradually reducing the flow of oxygen to the jet in response to a sudden increase in the temperature at a point downstream from the jet and wherein normal oxygen flow is restored after the temperature decreases to an operating value.Type: GrantFiled: June 13, 1980Date of Patent: August 24, 1982Assignee: Hewlett-Packard CompanyInventors: Andrew J. Murphy, Robert P. Rhodes, Terry A. Woodruff
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Patent number: 4341108Abstract: By means of a suction pump located at the outlet of the analyzer device and a combination of choke members connected in parallel in a row and respective low pressure controllers at the outlet of the gas analyzer and at the connection point of the series connection and parallel connection of the choke members, a constant sample flow through the analyzer is produced. Thus, even where there is a fluctuating measuring gas pressure and a variable flow resistance in the inlet part of the gas analyzer, the proportionality of the measuring signal to the concentration of the measuring component is ensured.Type: GrantFiled: August 8, 1980Date of Patent: July 27, 1982Assignee: Bayer AktiengesellschaftInventors: Heinz Warncke, Melchior Kahl, Hans H. Meyer, Paul Schurmeyer
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Patent number: 4325907Abstract: An improved method and system for analyzing pyrolysis product gases wherein a portion of the gases are collected while another portion is being analyzed during the pyrolysis reaction.Type: GrantFiled: September 22, 1980Date of Patent: April 20, 1982Assignee: Conoco Inc.Inventors: Harry Dembicki, Jr., Roger A. Woods
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Patent number: 4316381Abstract: The continuous flow of sample fluid, e.g., the elution from the column of a chromatograph, is modulated with the aid of a storage volume such that the flow of sample fluid into the fluid input of a detector varies between maximum and minimum values at a given frequency, the flow of reference fluid to the fluid input of the detector is modulated out of phase, and the differences in output of the detector resulting from these modulated flows is derived by a synchronous detector or demodulator.Type: GrantFiled: July 14, 1980Date of Patent: February 23, 1982Assignee: Hewlett-Packard CompanyInventor: Terry A. Woodruff
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Patent number: 4311664Abstract: A flame-photometric detector burner of a gas chromatograph employing a system of two nozzles arranged in relation to each other for securing mutual flame jump-over from one nozzle onto the other one, and vice versa. One nozzle is designed to supply carrier gas with the substance to be analyzed, and the other is designed to only supply an oxidizer. The outlets of both nozzles are arranged within a hydrogen stream in a cavity of a combustion chamber of a detector block. The nozzle where only the oxidizer is supplied can be electrically insulated from the detector block, and connected to a high-voltage source.Type: GrantFiled: April 11, 1978Date of Patent: January 19, 1982Assignee: Wojskowy Instytut Chemii I RadiometriiInventors: Marek Zaremba, Czeslaw Rozycki, Rafal Staszewski
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Patent number: 4278441Abstract: A mass spectrometer is employed to analyze the boron and phosphorus content in silicon or a silicon compound such as SiH.sub.4 or SiHCl.sub.3. According to the preferred embodiment a first non-seeded flame is surrounded by a second seeded flame. The velocities of both flames are approximately the same so that the boundary between them is relatively stable. Small quantities of BO.sub.2.sup.- and PO.sub.2.sup.- are formed in the second flame seeded with a silicon compound. The positively charged inlet orifice of a mass spectrometer is placed in the first flame sufficiently close to the boundary so as to attract negative ions into the instrument. In this manner the relatively small orifice of the sampling cone is not plugged by the SiO.sub.2 particles that are generated in the outer flame and the boron and phosphorus content of the silicon or silicon compound can be measured.Type: GrantFiled: February 14, 1980Date of Patent: July 14, 1981Assignee: Aerochem Research Laboratories, Inc.Inventors: Hartwell F. Calcote, Douglas B. Olson
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Patent number: 4273559Abstract: An alkali flame ionization detector having an independently biased activator intermediate the flame tip member and the ion collector has been found to yield ion current collector signals which will be selectively positive-going, negative-going or null in response to selected ionic species at an appropriately chosen value of bias potential. Elemental specificity has been found for those values of bias potential which produce a null signal in the presence of a sample.Type: GrantFiled: December 21, 1978Date of Patent: June 16, 1981Assignee: Varian Associates, Inc.Inventor: Norvell J. Nelson
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Patent number: 4248599Abstract: The API gravity of an oil is determined by vaporizing its volatile and pyrolyzable components, measuring the ratio of the amount vaporized within a range of relatively high temperatures to the total amount vaporized and determining that the gravity of the oil being tested equals that of an oil which has a similar composition and which, when a substantially equal amount is tested under substantially the same conditions, yields a similar ratio of amounts vaporized at the same temperatures.Type: GrantFiled: September 19, 1979Date of Patent: February 3, 1981Assignee: Shell Oil CompanyInventors: Pierre R. Mommessin, John R. Castano, John G. Rankin, Mary L. Weiss
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Patent number: 4221761Abstract: A reducer for the quantitative reduction of NO.sub.2 to NO in gas mixtures. The reducer comprises two compartments of which one is filled with a granular preparation consisting of ferrosulphate and an acid alkalisulphate and the second comprises a granular preparation consisting of ferrosulphate and a strong acid. The preparation is preferably provided on the surface of granular inert carrier material, for example pumice.Type: GrantFiled: June 28, 1978Date of Patent: September 9, 1980Assignee: U.S. Philips CorporationInventors: Valere G. J. Bullens, Hermanus Pauw, Rudy A. Falkenburg
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Patent number: 4215090Abstract: A flame ionization detector is disclosed that is particularly useful for liquid chromatography. The detector is preferably utilized with a disc transport assembly with flame jets being positioned at opposite sides of the solute-bearing periphery of the disc. Hydrogen and air are injected through the flame jets and coaxial cables are connected to make electrical contact with the flame jets so that a flame ionization response occurs when organic compounds on the disc of the disc transport assembly are combusted in a potential field. When so combusted, a current is caused to flow from the flame jets through the coaxial cable to an electrometer where the current is amplified for display on a strip chart recorder or other output device.Type: GrantFiled: December 18, 1978Date of Patent: July 29, 1980Assignee: Purdue Research FoundationInventor: Jack B. Dixon
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Patent number: 4213703Abstract: A sample holder and shutter assembly for photometers is disclosed in which a stationary sample chamber body is mounted in close proximity to a photosensitive device. A light path is provided from the sample chamber to the photosensitive device and shutter means is provided for selectively interrupting and opening the light path between the photosensitive device and the sample chamber without moving the sample chamber. Heat exchange means including a heat pump and a heat reservoir are provided for maintaining a desired temperature in the sample chamber. The sample chamber body is thermally connected to said heat pump and is preferably thermally isolated from the means mounting it. In one embodiment, the heat pump and heat reservoir are flexibly connected.Type: GrantFiled: May 30, 1978Date of Patent: July 22, 1980Assignee: Beckman Instruments, Inc.Inventors: Otto Haunold, Malbone W. Greene
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Patent number: 4211746Abstract: Flame ionization detector in which the burner consists of electrically conductive material, preferably a noble metal, and is one of the electrodes in the apparatus. The mixture of fuel gas and sample is ignited by passing a current through the burner to incandesce the same. The burner is preferably a hairpin-shaped capillary tube with an aperture in the hairpin bend, disposed in the upper part of the detector with the aperture facing the bottom part of the detector. There is also described a flame trap for preventing propagation of flame into discharge line and facilities connected to it. The detector is designed to meet extreme requirements for dependability and reliability, such as when used in apparatus for monitoring anesthesia in patients.Type: GrantFiled: March 28, 1978Date of Patent: July 8, 1980Assignee: WTI Wetenschappelijk Technische Instrumentatie B.V.Inventor: Rudolf A. Mees
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Patent number: 4203726Abstract: An instrument for the analysis of a sample material to detect the presence of specific substances that thermally decompose into electronegative species comprises a sensitized surface, means for heating the sensitized surface in a gaseous environment to generate a gaseous boundary layer adjacent the sensitized surface, means for causing the sample material to interact with the sensitized surface to form negative ions, a collector electrode maintainable at a different electrical potential from the sensitized surface to cause a current of these negative ions to the collector electrode, and means for measuring the ion current. The sensitized surface is formed on a ceramic body that is impregnated with an alkali metal. The composition and temperature of the sensitized surface, and the composition of the gaseous boundary layer are selected according to the specific substance to be detected.Type: GrantFiled: February 28, 1978Date of Patent: May 20, 1980Assignee: Varian Associates, Inc.Inventor: Paul L. Patterson
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Patent number: 4202666Abstract: A method and apparatus for preventing the destruction of an alkali source in a nitrogen-phosphorus detector by certain reactive and derivatizing reagents encountered in gas chromatography is disclosed. Protection is afforded by lowering the temperature of an electrically heated alkali source during the period in which offensive substances in a gas under analysis are eluted, with the temperature of the source being restored after passage of the offensive substances. The temperature of the alkali source is changed by altering the current through an electrical resistance heater with a temperature control circuit that utilizes a wheatstone bridge.Type: GrantFiled: February 24, 1978Date of Patent: May 13, 1980Assignee: Tracor, Inc.Inventors: Randall C. Hall, Burney J. Ehrlich
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Patent number: 4201550Abstract: Process and apparatus for the determination of the total organic substance content of gases by a flame ionization detector, respectively comprising the steps and means for allowing components of the gas to be analyzed to diffuse through a pore-free polymeric membrane having a permeability coefficient that exceeds 10.sup.-7 Ncm.sup.3.cm/sec.cm.sup.2.Hgcm. related to the total organic substance contained in the gas, leading the gas components into a flame of another gas that contains hydrogen, passing the burning hydrogen-containing gas along one side of the membrane at a flow rate of max. 25 cm.sup.3 /min.Type: GrantFiled: December 19, 1977Date of Patent: May 6, 1980Inventors: Zoltan Noszticzius, Gabor Patonay, Gyorgy Palmai, Karoly Olah, Gyula Gaspar, Gyorgy Szekely, Zsofia Vajta, Karoly Langer, Ferenc Szommer
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Patent number: 4182740Abstract: Dimensionally optimized flame ionization detector for use in chromatography in which positive ions are caused to be collected by applying positive potential to flame tip. It has been discovered that there exists optimum dimensions of the collector electrode and the spacing between collector electrode and flame tip to resist glassing and corrosion without diminishing other operating parameters. The collector electrode inside diameter is in the range of 0.114 inch to 0.3 inch and the flame tip to collector electrode is in range from 1 mm to 3 mm.Type: GrantFiled: July 28, 1977Date of Patent: January 8, 1980Assignee: Varian Associates, Inc.Inventors: Charles H. Hartmann, Michael R. Martin
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Patent number: 4118193Abstract: An improved catalytic reactor system and method for removing interferents such as reactive hydrocarbons from the gas being sampled by gas component determination apparatus is disclosed. The sample from which the interferents are to be removed is blended with ozonized air and saturated to at least 15% with water vapor. The mixture is then passed through the catalytic reactor which, preferably, contains a mixture of platinum oxide mixed with sand and maintained at an operating temperature of 200.degree. to 280.degree. C. Additional catalytic mixtures which may be employed in the reactor are also disclosed. Methods of preventing the poisoning of catalytic reactors and rejuvenating poisoned catalytic reactors are also disclosed.Type: GrantFiled: July 29, 1977Date of Patent: October 3, 1978Assignee: Beckman Instruments, Inc.Inventors: Radhakrishna Murty Neti, Kenneth Bruno Sawa
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Patent number: H406Abstract: 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.Type: GrantFiled: February 17, 1984Date of Patent: January 5, 1988Assignee: United States of AmericaInventor: Henry Wohltjen