Direct Determination of Oxygen in Organic Substances

Oita, I. J.; Conway, H. S.

doi:10.1021/ac60087a064

Cited by 85 publications

(15 citation statements)

References 11 publications

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“…Different carbon catalysts (natural and synthetic diamond, charcoal, Ni/C, Pt/C) have been investigated to achieve better conversion yields at lower temperatures. 11,[22][23][24][25] A few of these studies were directed at the determination of the 18 O/ 16 O ratio. Taylor and Chen, 23 for instance, reported the capability of a Pt/C catalyst to reduce the temperature of carbon reduction from 1200 to 900°C.…”

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confidence: 99%

“…[26][27][28] As a result of this research there has been a considerable reduction in the time needed for sample preparation by the automation of the 18 O/ 16 O determination, using a commercial elemental analyser coupled to an IRMS system in the continuous flow mode. Several technical parameters must be considered when applying these on-line techniques for the routine analysis of organic compounds: (a) the type of catalyst used, such as platinized or nickelized carbon, 22,24 and the nature of the reaction tube of the elemental analyser; (b) the temperature adjusted for the pyrolysis: the yield of CO is highly temperature dependent, e.g. at temperatures lower than 1100°C residual CO 2 remains after the pyrolysis, whereas at temperatures higher than 1100°C there is quantitative conversion of organic oxygen into CO; 29 (c) handling of samples and sample preparation for continuous flow microanalysis.…”

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confidence: 99%

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Oxygen-18 measurement by continuous flow pyrolysis/isotope ratio mass spectrometry of vegetable oils

Bréas

Guillou

Reniero

et al. 1998

Rapid Commun. Mass Spectrom.

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confidence: 99%

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confidence: 99%

Oxygen-18 measurement by continuous flow pyrolysis/isotope ratio mass spectrometry of vegetable oils

Bréas

Guillou

Reniero

et al. 1998

Rapid Commun. Mass Spectrom.

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“…Ethyl acetate was selected as the test substance solely for its ready availability and convenience of handling. Furthermore flow systems similar to that given here can probably also be set up to determine oxygen-18/oxygen-16 [9] a nd nitrogen-lSI nitrogen-l4 [10] ratios. Due to the great difference in their thermal cond uctivities deuterium/hydrogen l ratios can probably be determined most accurately using thermal conductivity detectors.…”

Section: Resultsmentioning

confidence: 99%

Stable carbon isotope ratio measurements with a gas density meter

Wasik¹,

Tsang²

1968

J. RES. NATL. BUR. STAN. SECT. A.

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A method is presented for measuring CI3/CI2 isotope ratio of organic compounds by burning the material in a stream of normal CO2, separating the ccmbustion products by gas chromatography and sequentially measuring the density of the enri ched CO2 peak with a gas density meter. Data are pre· sented for the ana lysis of enri c hed et hyl acetate from 15 to I percent enrichment. The method is applicable for other stab le isotope a na lysis.

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“…over a carbon catalyst to yield CO, and this is oxidized to CO2 with 1,06, Bender and Dewey (10) have reported a considerable blank using this method, i.e., CO2 in excess of that expected from the oxygen in the original sample. Jensen and coworkers (11) have been able greatly to reduce the blank by substituting a platinized carbon catalyst (12) thus permitting them to lower the temperature of pyrolysis to 930 ± soc. Anbar et al (13) have shown that it is possible to equilibrate oxygen of a variety of organic substances directly with CO2 at 150-200° by using a trace of H2S04 as catalyst.…”

Section: Techniquesmentioning

confidence: 99%

Applications of Oxygen Isotopes in Chemical Studies

Taube¹

1956

Annu. Rev. Nucl. Sci.

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The choice of the general subject of this article requires no apology, but the choice of the specific material to fit to the space allotted does. The limita tions and research interests of the reviewer were a governing factor in mak ing the selection, but also the consideration entered that the effects of the major omissions are tempered by other recent reviews in which much of the material omitted is discussed. Thus the important work in geochemistry involving oxygen isotopes is discussed in excellent reviews by Dole (I), and more recently by Craig & Boata (2). The work on heterogenous systems is discussed more completely in the article by Dole. It is hoped in this connec tion that a general article on the application of isotopes in the study of heterogeneous catalysis, induding work with oxygen isotopes, will be forth coming. In the subjects chosen for review, an effort has been made to be com plete ; and earlier literature as well as the more recent has been referred to. When work which is within the scope of the subject matter is not cited, it is because of oversight or because the work is dealt with in a more general article by the same author.The present article stresses the application of oxygen isotopes to the study of chemical phenomena in homogeneous solution. Much of the work exploiting oxygen isotope effects has been done for such systems. For reac tions of oxygen-containing substances in an oxide-labile solvent such as water, isotope studies can answer important questions which no other method can answer as directly; and they have been of great help in defining the nature of the solvent and of the substances dissolved in it, and in exposing the mechanisms of reactions in solution. TECHNIQUESIn the work reviewed, mainly the oxygen isotopes of mass 18 and 16 come into question. The mass spectrometric method of measuring isotope ratios has almost completely supplanted that depending on the determination of density differences in water. With care, commercial instruments can measure differences to a precision of 1 part in 1000 in O2 or CO2 of normal oxygen isotopic composition. With specially designed instruments (3), a precision of one part in approximately 10,000 on CO2 can be attained.When the oxygen is available as water, an accurate method (4) of isotopic assay is equilibration of CO2 with the H20, followed by measurement of the isotopic ratio in the CO2• Dostrovsky & Klein (5) have described the high temperature equilibration of CO2 and H20, and have derived an equation 1 The survey of literature pertaining to this review was completed in January, 1956.

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Direct Determination of Oxygen in Organic Substances

Cited by 85 publications

References 11 publications

Oxygen-18 measurement by continuous flow pyrolysis/isotope ratio mass spectrometry of vegetable oils

Oxygen-18 measurement by continuous flow pyrolysis/isotope ratio mass spectrometry of vegetable oils

Stable carbon isotope ratio measurements with a gas density meter

Applications of Oxygen Isotopes in Chemical Studies

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