Hydrogen isotope ratio mass spectrometry

For example, little is known about the isotopic composition of formaldehyde in the atmosphere. Formaldehyde is a chemical intermediate in hydrocarbon oxidation. The carbon (8 C) and hydrogen (8D) isotopic composition of atmospheric formaldehyde is analyzed using continuous flow gas chromatography isotope ratio mass spectrometry." Isotope ratios were measured using GC-IRMS (Finnigan MAT 253 stable isotope ratio mass spectrometer, single-sector field with electron impact ion source and multiple ion collection) with a precision of 1.1 and 50%(lo ) for 8 C and 8D, respectively. The accuracy of the online continuous flow isotope technique was verified by calibrating three aliquots of the gas phase standard via the offline dual inlet IRMS technique. The concentration of formaldehyde in ambient air was determined on IRMS major ion peak areas (i.e., mass 44 for 8 C and mass 2 for 8D)." ... 

H.J. Tobias, K.J. Goodman, C.E. Blacken, J.T. Brenna (1995) High-precision D/H measurement from hydrogen gas and water by continous-flow isotope ratio mass spectrometry. Anal. Chem. 67. 2486-2492... 

CF-IRMS Continuous flow-isotope ratio mass spectrometry. A procedure that uses an instrument that is capable of repeatedly and rapidly measuring the masses of selected gases (e.g., carbon dioxide, hydrogen, nitrogen) delivered in a continuous gas stream from another instrument, such as an elemental analyzer or a gas chromatograph, to determine their isotopic compositions. 

Gas Chromatography Sano et al. first published a systematic approach to measuring the carbon isotope ratios of GC peaks in 1976 [34]. Further developments occurred over the years however, it was not until 1988 that gas chromatography-isotope ratio mass spectrometry (GC-IRMS) systems were commercially available. Since this time, the systems have been enhanced and extended to include the analysis of nitrogen, oxygen, and hydrogen isotope values [10 2]. Jasper et al. [35] describe the specificity of the GC-IRMS technique... 

The use of isotope ratio mass spectrometry (IRMS) to compare the ratios of light atom isotopes in samples of forensic interest is finding increased importance. A recent report by Benson et al. details the use of IRMS to differentiate between samples of TATP that were prepared under differing conditions and from different precursors [61]. A three-dimensional plot of the carbon, hydrogen, and oxygen data clearly showed four clusters corresponding to the different sample sets. 

In another approach using stable isotopes to measure retinoids in human serum, Parker and coworkers (296,297) studied the absorption and metabolism of C-labeled P-carotene using GC-isotope ratio mass spectrometry. Retinol and retinyl esters were separated using HPLC, the retinyl esters were hydrolyzed to retinol, and each retinol sample was analyzed using GC-isotope ratio mass spectrometry. As the retinol peak eluted from the GC, it was combusted to carbon dioxide, and the C02/ C02 ratio was measured using an isotope ratio mass spectrometer. In a similar way, lutein isolated from C3 and C4 plant sources was hydrogenated to perhydrocarotene which was subjected to GC-combustion-inter-faced isotope ratio-mass spectrometry (GC-C-IR-MS) to determine natural abundance C in lutein (298). 

Sessions, A. L., Burgoyne, W. W. and Hayes, J. M (2001a) Correction of H3+ contributions in hydrogen isotope ratio monitoring mass spectrometry. Analytical Chemistry 73, 192 199. 

A.L. Sessions, T.W. Burgoyne, J.M. Hayes (2001) Correction of Hj contributions in hydrogen isotope ratio monitoring mass spectrometry. Anal. Chem. 22, 192-199... 

Riciputi, L.R., Chacho, T., Cole, D.R., Horita, J. (1998) Analysis of hydrogen isotope ratios by SIMS and appU-cations to determining mineral-fluid isotope fractionation factors. In Secondary Ion Mass Spectrometry SIMS XI, edited by Gillen, G., Lareau, R., Bennett, J., Stevie, F. New York John Wiley Sons, pp. 79-82. 

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