US3844716A - Combustion method apparatus for preparing samples for liquid scintillation counting - Google Patents

Combustion method apparatus for preparing samples for liquid scintillation counting Download PDF

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Publication number
US3844716A
US3844716A US00203796A US20379671A US3844716A US 3844716 A US3844716 A US 3844716A US 00203796 A US00203796 A US 00203796A US 20379671 A US20379671 A US 20379671A US 3844716 A US3844716 A US 3844716A
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United States
Prior art keywords
sample
combustion
oxygen
gaseous
products
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US00203796A
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English (en)
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J Noakes
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TM ANALYTIC Inc AN IL CORP
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Nuclear Chicago Corp
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Priority to US00203796A priority Critical patent/US3844716A/en
Priority to DE2255774A priority patent/DE2255774A1/de
Priority to JP47120285A priority patent/JPS4868297A/ja
Priority to FR7242681A priority patent/FR2164214A5/fr
Priority to CA157,880A priority patent/CA966197A/en
Priority to NL7216262A priority patent/NL7216262A/xx
Priority to GB5548172A priority patent/GB1403075A/en
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Publication of US3844716A publication Critical patent/US3844716A/en
Assigned to NOAKES, JOHN E. reassignment NOAKES, JOHN E. ASSIGNMENT OF ASSIGNORS INTEREST. Assignors: NUCLEAR-CHICAGO CORPORATION, A CORP. OF DE
Assigned to TM ANALYTIC, INC. AN IL CORP reassignment TM ANALYTIC, INC. AN IL CORP ASSIGNMENT OF ASSIGNORS INTEREST. Assignors: TRACOR ANALYTIC, INC., A TX CORP
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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J37/00—Discharge tubes with provision for introducing objects or material to be exposed to the discharge, e.g. for the purpose of examination or processing thereof
    • H01J37/32—Gas-filled discharge tubes
    • H01J37/32009—Arrangements for generation of plasma specially adapted for examination or treatment of objects, e.g. plasma sources
    • H01J37/32055—Arc discharge
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01T—MEASUREMENT OF NUCLEAR OR X-RADIATION
    • G01T1/00—Measuring X-radiation, gamma radiation, corpuscular radiation, or cosmic radiation
    • G01T1/16—Measuring radiation intensity
    • G01T1/20—Measuring radiation intensity with scintillation detectors
    • G01T1/204—Measuring radiation intensity with scintillation detectors the detector being a liquid
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05H—PLASMA TECHNIQUE; PRODUCTION OF ACCELERATED ELECTRICALLY-CHARGED PARTICLES OR OF NEUTRONS; PRODUCTION OR ACCELERATION OF NEUTRAL MOLECULAR OR ATOMIC BEAMS
    • H05H1/00—Generating plasma; Handling plasma
    • H05H1/24—Generating plasma
    • H05H1/26—Plasma torches
    • H05H1/32—Plasma torches using an arc
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T436/00—Chemistry: analytical and immunological testing
    • Y10T436/21—Hydrocarbon

Definitions

  • combustion techniques have been employed in the preparation of radioactive-labeled samples containing carbon 14, tritium 3 and sulfur 35 for liquid scintillation counting. Such techniques produce samples which are uniform and which readily dissolve in scintillation solvents. Combustion solves most problems of quenching due to the color or chemical nature of the original sample material. The process also leads to greater uniformity of results.
  • the invention herein is applicable when chemical and biochemical analytical procedures require rapid quantitative conversion of samples to carbon dioxide, sulfur dioxide and water. It is uniquely suited to labeled samples wherein the combustion products are to be counted for their radioactivity by liquid scintillation counting, such as tissue, bone, wood, paper, urine, blood and the like.
  • liquid scintillation counting such as tissue, bone, wood, paper, urine, blood and the like.
  • the chief distinction over known combustion techniques is that a continuous spark is directed to the sample surface herein, continuous insofar as a visual observer is concerned.
  • This spark emanates from a current source, such as a capacitive discharge ignition system, capable of generating a DC current which oscillates in the frequency range of 20 cps to 25,000 cps with sufficient intensity to jump across two electrodes with the sample between.
  • a spark has been used in oxygen flask combustion. Its use, however, has been limited to an initial impulse to ignite paper in which the sample is wrapped.
  • a conventional oxygensustained combustion then follows. Herein the spark is moved from site to site across the sample until it is completely oxidized without the aid of combustible materials as fuel to maintain a combustion temperature.
  • the technique employed herein is basically that of Schoniger, the oxygen flask being modified by the addition of electrodes and the electrical circuit. Nevertheless some modification, such as the inclusion means for introducing oxygen, are desirable.
  • FIG. I is a sectional view of the apparatus generally used.
  • FIG. 2 is a sectional view illustrating a modification of the basic apparatus.
  • the reaction chamber 2 is a flat-bottomed pyrex glass vessel containing a combustion chamber within its lower portion.
  • a side arm 4 is used to admit oxygen although a hollow electrode is preferred, as shown in FIG. 2.
  • a positive charged electrode 6 is connected to an electrical oscillating circuit 8 and extends through the chamber as a side arm, terminating directly above the sample 10.
  • the sample to be combusted is contained in the chamber inside a conductive metal boat 12 which rests on a base plate 14 which is connected to electrical oscillating circuit 8 by a common negative ground. The boat, therefore, is the other electrode. This arrangement places the sample between the two electrodes.
  • An exhaust vent 16 is located at the top of the vessel to allow exhaust gases to leave the combustion chamber where they are collected in absorption solvents or in a condensation chamber as is known in the art.
  • the gaseous combustion products escape as indicated by the arrows through the tubing to be collected in flasks surrounded by freezing mixtures or solvents in which the emitted gases are highly soluble.
  • the composition of the counting solvent will, of course, depend upon whether the samples contain H, C or and whether the sample is single or double labeled.
  • tritium as tritiated water a mixture of methyl alcohol and toluene with a PPO phosphor and a POPOP spectrum shifter is used.
  • an amine such as ethylamine or phenylamine is employed as the scintillation solvent, any of the well known phosphors being included in the amine.
  • Sodium hydroxide or similar basic chemical solutions can also be used to trap carbon dioxide formed by the combustion.
  • the combustion products are swept out of the combustion chamber during sample ignition by the addition of excess oxygen.
  • the gaseous combustion products are passed to collection traps 18 containing collection solvents for subsequent use in liquid scintillation counting.
  • the combustion chamber and collection traps 18 are purged with nitrogen gas after the combustion step to remove any residual combustion products from their walls, whereby the samples are concentrated in the collection traps l8 and the collection solvents are purged of excess oxygen gas in a manner well known in the art.
  • Nitrogen gas can also be used to purge the last of the combustion products from the chamber which eliminates excess oxygen being contained in the collecting solvents.
  • FIG. 2 illustrates a more desirable embodiment of the basic apparatus.
  • the addition of sample heating means, and of a different method of admitting oxygen will be apparent from a description of the method of combustion using the apparatus shown in FIG. 2.
  • the sample to be combusted in chamber 2 is placed in a boat 12 which rests on a negative charged plate 14 constituting one electrode in an electrical circuit.
  • a negative charged plate 14 constituting one electrode in an electrical circuit.
  • the electrode is positioned about one-fourth to one-half inch above the sample and a capacitive discharge electrical circuit creating an approximately 40,000 volt output across the electrodes is energized.
  • the resulting electrical spark jumps from electrode to the sample, and combustion occurs at the point of contact of the sample. Ozone and singlet oxygen are formed by the high intensity spark.
  • reaction or combustion occurs only at the site of spark contact with the sample, eroding the sample away as it is moved across. In most reactions there is only a sign of any visible flame.
  • the electrode can be physically moved to new combustion sites during the process or the spark may jump directly by itself to the nearest point of contact. Combustion of milligram samples is normally complete in a few seconds and seldom in over three or four minutes. The characteristic ozone odor is quite noticeable following combustion.
  • combustion is enhanced by drying the sample with heated oxygen during ignition. This is accomplished by heater 20 preheating the oxygen to greater than 100 C. prior to admitting it to the combustion chamber. Even more important, this preheater can be employed prior to injecting oxygen to heat nitrogen gas to be used to drive off sample ingredients which volatilize at such temperatures and which in the presence of oxygen could form an explosive mixture within the combustion chamber.
  • Advantage is found in admitting the oxygen into the combustion chamber through a hollow electrode. This process intensities the formation of singlet and triplet oxygen since the oxygen stream is in close proximity to the high intensity spark. It also eliminates the need for construction of an additional oxygen orifice.
  • the oxygen flow rate is regulated depending on the desired rate of combustion and the resistance of the sample to combustion. Generally oxygen will be admitted at a rate of l cc to 1 liter per minute or higher.
  • the exhaust vent 16 may be constructed to contain catalytic converters 17 for converting CO to CO and H to H O.
  • catalytic converters 17 for converting CO to CO and H to H O.
  • a heated copper oxide converter can be provided in the combustion products outlet line.
  • Means can be included for converting hydrogen to water using appropriate platinum catalyst.
  • Sample placement into the flask can be accomplished either by lowering the base of the combustion chamber, such as in U.S. Pat. No. 3,485,565 or raising the upper combustion chamber flask or inserting the sample through a slide tray at the base of the chamber. It will also be appreciated that any type electrical conduction of sample boat or tub can be used. Indeed, the sample can be placed directly on the base plate if desired.
  • a tub is easier to insert into the combustion chamber, easier to clean and when necessary, ideally suited for rapid sequential multisample handling.
  • Additional heating can be incorporated into the apparatus when wet samples are being combusted. This serves to hasten the dehydration of the sample and avoids condensation of oxygen products on the chamber walls. Heating is accomplished by several means: (a) an electric heater beneath the sample can be employed, (b) a hot air stream can be directed onto the outer flask walls or (c) the oxygen or nitrogen directed into the combustion chamber can be preheated.
  • the output of the electrical circuit employed will generally be 40,000 to 80,000 volts derived from a 6 or 82 volt input DC circuit.
  • the circuit can be designed for a 110 or 220 volt AC input and/or a constant discharge rather than an intermittent spark of high frequency.
  • the current can range from a few milliamps to multiamperage, but is preferably in a low (less than 1 amp) range.
  • a DC circuit is preferred since the direction of spark travel is constant from the overhead electrode towards the sample, thereby forming a more even combustion reaction.
  • a method for the combustion of organic materials containing a radioactive isotope in an oxygen atmosphere to produce gaseous by-products for subsequent radioactivity measurement comprising the steps of providing a combustion chamber including an electrically conductive plate adapted to receive a sample of material to be burned and an electrode positioned near the sample, introducing oxygen into said combustion chamber from an oxygen source, energizing said electrode to produce a continuous high intensity spark therefrom to said electrically conductive plate to form singlet and triplet oxygen to react locally at the surface of the sample and to burn the sample at said surface, continuing the localized oxidation until combustion of the total sample is complete, and collecting gaseous products of combustion produced thereby.
  • a process for the combustion of organic material containing a radioactive isotope in an oxygen atmosphere to produce gaseous by-products for subsequent radio-activity determinations comprising placing a sample of organic material between two ignition electrodes, blanketing the sample with oxygen, generating an electric spark between the electrodes from an oscillating electric current having a frequency of from 20 cps to 25,000 cps and of sufficient energy to excite oxygen to convert a portion of the oxygen to reactive singlet and triplet oxygen, directing said spark to the surface of the sample to generate additional quantities of singlet and triplet oxygen and to provide locally sufficient heat to effect oxidation and combustion at the surface of the sample, continuing localized combustion, and burning away portions of the sample thereby, until the sample is completely converted to its gaseous combustion products, and collecting said gaseous combustion products.
  • a method of oxidizing organic samples containing radioactive isotopes using oxygen supplied to an air-tight combustion chamber to produce gaseous oxides for subsequent radioactivity determinations comprising positioning an organic sample between two spaced electrodes in said combustion chamber, and energizing said electrodes with an oscillating electrical potential to produce and sustain an electrical spark passing between the electrodes and through the aforesaid sample to ionize oxygen in said chamber and to produce localized heating in said sample, thereby effecting total oxidation of said sample into gaseous oxides, and collecting said gaseous oxides.

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  • Physics & Mathematics (AREA)
  • Engineering & Computer Science (AREA)
  • Plasma & Fusion (AREA)
  • Spectroscopy & Molecular Physics (AREA)
  • Health & Medical Sciences (AREA)
  • Analytical Chemistry (AREA)
  • Chemical & Material Sciences (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • General Physics & Mathematics (AREA)
  • High Energy & Nuclear Physics (AREA)
  • Molecular Biology (AREA)
  • Measurement Of Radiation (AREA)
  • Investigating Or Analyzing Non-Biological Materials By The Use Of Chemical Means (AREA)
  • Sampling And Sample Adjustment (AREA)
US00203796A 1971-12-01 1971-12-01 Combustion method apparatus for preparing samples for liquid scintillation counting Expired - Lifetime US3844716A (en)

Priority Applications (7)

Application Number Priority Date Filing Date Title
US00203796A US3844716A (en) 1971-12-01 1971-12-01 Combustion method apparatus for preparing samples for liquid scintillation counting
DE2255774A DE2255774A1 (de) 1971-12-01 1972-11-14 Verbrennungsvorrichtung zur herstellung von proben fuer das fluessigkeit-scintillierungszaehlen
FR7242681A FR2164214A5 (ja) 1971-12-01 1972-11-30
CA157,880A CA966197A (en) 1971-12-01 1972-11-30 Combustion apparatus for preparing samples for liquid scintillation counting
JP47120285A JPS4868297A (ja) 1971-12-01 1972-11-30
NL7216262A NL7216262A (ja) 1971-12-01 1972-11-30
GB5548172A GB1403075A (en) 1971-12-01 1972-12-01 Combustion method for preparing samples for liquid scintillation counting

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US00203796A US3844716A (en) 1971-12-01 1971-12-01 Combustion method apparatus for preparing samples for liquid scintillation counting

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US (1) US3844716A (ja)
JP (1) JPS4868297A (ja)
CA (1) CA966197A (ja)
DE (1) DE2255774A1 (ja)
FR (1) FR2164214A5 (ja)
GB (1) GB1403075A (ja)
NL (1) NL7216262A (ja)

Cited By (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3946228A (en) * 1973-05-24 1976-03-23 Siemens Aktiengesellschaft Method and apparatus for determining gas content in inorganic substances
US4094640A (en) * 1976-02-12 1978-06-13 Siemens Aktiengesellschaft Method for processing biomaterials
US4116632A (en) * 1977-05-31 1978-09-26 Packard Instrument Company, Inc. Countercurrent combustion system for preparing radioactive samples and the like
US4582004A (en) * 1983-07-05 1986-04-15 Westinghouse Electric Corp. Electric arc heater process and apparatus for the decomposition of hazardous materials
US5744104A (en) * 1994-02-25 1998-04-28 Toyota Jidosha Kabushiki Kaisha Electrically heated catalytic converter for an engine
US5789256A (en) * 1994-04-14 1998-08-04 Mw Technologies, Inc. Detonation/deflagration precursor detection of gases, vapors, aerosols, and mixtures thereof
US6001308A (en) * 1994-04-14 1999-12-14 Mw Technologies, Incorporated Detonation/deflagration precursor detection of gases, vapors, aerosols, and mixtures thereof
US6004128A (en) * 1998-07-29 1999-12-21 Kurata; Tadao Combustion system
US6007323A (en) * 1998-07-16 1999-12-28 Kurata; Tadao Combustion method
DE19846039A1 (de) * 1998-10-06 2000-04-27 Friese Klaus Christian Verfahren zur Probenvorbehandlung für elementspurenanalytische Messungen und Apparatur hierzu
CN102928551A (zh) * 2012-10-26 2013-02-13 上海化工研究院 一种回旋式化学物质燃烧性筛选装置
CN112834565A (zh) * 2020-12-31 2021-05-25 西南科技大学 一种用于小型量热仪的微型氧弹

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DD268843A3 (de) * 1982-12-30 1989-06-14 Akad Wissenschaften Ddr Vorrichtung zur plasmachemischen Niedertemperaturveraschung oxidierbarer kohlenstoffhaltiger Materialien
DE102007011021B8 (de) * 2006-08-01 2013-03-28 Analytik Jena Ag Verfahren zur Analyse von gasförmigen Proben
JP2011033576A (ja) * 2009-08-05 2011-02-17 Kagoshima Univ ヒ素の定量方法

Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1931989A (en) * 1931-05-25 1933-10-24 Davis Emergency Equipment Comp Air-purifying device
US2313028A (en) * 1939-05-04 1943-03-02 Siegmann Friedrich Process for the production of sodium and potassium hydride
US2396190A (en) * 1943-09-28 1946-03-05 Cities Service Oil Co Purification of submarine atmospheres
US2468174A (en) * 1943-05-06 1949-04-26 Koppers Co Inc Apparatus for electriclaly transforming materials
US3346341A (en) * 1965-06-28 1967-10-10 Beckman Instruments Inc Fragmentation inlet for gas chromatography and method of loading a sample thereinto
US3650929A (en) * 1963-08-16 1972-03-21 Licentia Gmbh Oxidizing method and apparatus
US3671195A (en) * 1968-08-19 1972-06-20 Int Plasma Corp Method and apparatus for ashing organic substance
US3682598A (en) * 1969-04-29 1972-08-08 Packard Instrument Co Inc Apparatus for the preparation of liquid form samples for radioactive isotope tracer studies

Patent Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1931989A (en) * 1931-05-25 1933-10-24 Davis Emergency Equipment Comp Air-purifying device
US2313028A (en) * 1939-05-04 1943-03-02 Siegmann Friedrich Process for the production of sodium and potassium hydride
US2468174A (en) * 1943-05-06 1949-04-26 Koppers Co Inc Apparatus for electriclaly transforming materials
US2396190A (en) * 1943-09-28 1946-03-05 Cities Service Oil Co Purification of submarine atmospheres
US3650929A (en) * 1963-08-16 1972-03-21 Licentia Gmbh Oxidizing method and apparatus
US3346341A (en) * 1965-06-28 1967-10-10 Beckman Instruments Inc Fragmentation inlet for gas chromatography and method of loading a sample thereinto
US3671195A (en) * 1968-08-19 1972-06-20 Int Plasma Corp Method and apparatus for ashing organic substance
US3682598A (en) * 1969-04-29 1972-08-08 Packard Instrument Co Inc Apparatus for the preparation of liquid form samples for radioactive isotope tracer studies

Cited By (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3946228A (en) * 1973-05-24 1976-03-23 Siemens Aktiengesellschaft Method and apparatus for determining gas content in inorganic substances
US4094640A (en) * 1976-02-12 1978-06-13 Siemens Aktiengesellschaft Method for processing biomaterials
US4116632A (en) * 1977-05-31 1978-09-26 Packard Instrument Company, Inc. Countercurrent combustion system for preparing radioactive samples and the like
US4582004A (en) * 1983-07-05 1986-04-15 Westinghouse Electric Corp. Electric arc heater process and apparatus for the decomposition of hazardous materials
US5744104A (en) * 1994-02-25 1998-04-28 Toyota Jidosha Kabushiki Kaisha Electrically heated catalytic converter for an engine
US6001308A (en) * 1994-04-14 1999-12-14 Mw Technologies, Incorporated Detonation/deflagration precursor detection of gases, vapors, aerosols, and mixtures thereof
US5789256A (en) * 1994-04-14 1998-08-04 Mw Technologies, Inc. Detonation/deflagration precursor detection of gases, vapors, aerosols, and mixtures thereof
US6007323A (en) * 1998-07-16 1999-12-28 Kurata; Tadao Combustion method
US6004128A (en) * 1998-07-29 1999-12-21 Kurata; Tadao Combustion system
DE19846039A1 (de) * 1998-10-06 2000-04-27 Friese Klaus Christian Verfahren zur Probenvorbehandlung für elementspurenanalytische Messungen und Apparatur hierzu
CN102928551A (zh) * 2012-10-26 2013-02-13 上海化工研究院 一种回旋式化学物质燃烧性筛选装置
CN102928551B (zh) * 2012-10-26 2015-02-18 上海化工研究院 一种回旋式化学物质燃烧性筛选装置
CN112834565A (zh) * 2020-12-31 2021-05-25 西南科技大学 一种用于小型量热仪的微型氧弹

Also Published As

Publication number Publication date
GB1403075A (en) 1975-08-13
FR2164214A5 (ja) 1973-07-27
CA966197A (en) 1975-04-15
DE2255774A1 (de) 1973-06-20
NL7216262A (ja) 1973-06-05
JPS4868297A (ja) 1973-09-18

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Owner name: NOAKES, JOHN E., 2495 BARNETT SHOALS, ATHENS, GA.

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