Stable isotopes abundance

Bocherens, H., Pacaud, G., Lazarev, P. and Mariotti, A. 1996 Stable isotope abundances ( C, N) in collagen and soft tissues from Pleistocene mammals from Yakutia. Implications for the paleobiology of the mammoth steppe. Palaeogeography, Palaeoclimatolology, Palaeoecology 126 31. ... 

Mass spectrometry is one of the oldest instrumental analytical methods. Positive rays were discovered by Goldstein in 1886 (after Barrie Prosser, 2000). The first mass spectrometer for routine measurements of stable isotope abundances was reported in 1940 and improved upon over the following ten years Nier, 1940, Nier, 1947, Murphey, 1947, McKinney et al, 1950, after Prosser, 1993. It is remarkable that the vast majority of active gas spectrometers in use today are little changed from those described around 50 years ago. For most people, mass spectrometry now means organic molecular structure determination. However, within the last 15... 

Because the natural variations in stable isotope abundances are usually very small (see above), and since routine measurements are usually made in an isotope ratio mass spectrometer which compares the relative intensities of the mass resolved beams of the sample with those of some standard material (Section 7.2.2), it is standard practice to report abundance ratios using the dimensionless 8-value notation. 

Baur ME, Hayes JM, Studley SA, Walter MR (1985) Millimeter-scale variations of stable isotope abundances in carbonates from banded iron-formations in the Hamersley Group of Western Australia. Econ Geol 80 270-282... 

Oxygen is present as three stable isotopes, abundance of which varies slightly with its natural source, so that the precision of its atomic weight is hmited to 15.9994 0.0003. is the most abundant (99.760% 15.994915), the two... 

Talma AS, Netterberg F (1983) Stable isotope abundances in calcretes. In Residual Deposits Surface Related Weathering Processes and Materials. Wilson, RCL (ed) Oxford Blackwell Scientific Publ., p 221-233 Tian L, Masson-Delmotte V, Stievenard M, Tao T, Jouzel J (2001) Tibetan Plateau summer monsoon northward extent revealed by measurements of water stable isotopes. J Geophys Res 106 28,081-28,088 Tian L, Yao T, White JWC, Yu W, Wang N (2005) Westerly moisture transport to the middle of Himalayas revealed from the high deuterium excess. Chinese Sci Bull 50 1026-130 Uba CE, Heubeck C, Hulka C (2006) Evolution of the late Cenozoic Chaco foreland basin, southern Bolivia. Basin Res 18 145-170... 

Element Atomic number Atomic weight Stable isotopes (% abundance) Natural radionuclide Atom % of the Earth... 

Talma, A.S. Netterberg, F. (1983) Stable isotope abundances in calcretes. In Residual Deposits (Ed. Wilson, R.C.I.), Spec. Publ. Geol. Soc. London, 11, 221-233. 

Table 1.1 Stable isotope abundances of biogeochemically important elements and their associated standards (after...

In Earth sciences, the relative differences in isotopic ratios between a sample and a standard are mostly used for reporting stable isotope abundances and variations. The reason is that the absolute value of an isotopic ratio is difficult to determine with sufficient accuracy for geochemical applications. The reporting notation employed is the 5-value, defined as... 

Relative measurements are most commonly used to express small variations in the natural abundance of light stable isotopes and find applications in areas such as the geosciences and ecological research. No consensus exists on the appropriate units in which isotope ratios are reported, especially in the biomedical field. Most isotope ratio mass spectrometers (IRMS) report isotopic abundance in terms of delta notation ( parts per thousand or per mil ), which is a convention determined by geochemistry, because most of the original IRMS instruments were developed in isotope geochemistry laboratories. Delta units are not SI units. The SI base unit for quantity is the mole, from which atom fraction and mole fraction are derived. The units of stable isotope abundance, at.% and mol.%, are the atom and mole... 

The small abundance differences of stable isotopes are best represented by the delta notation (Eq. 2.29) in which the stable isotope abundance is expressed relative to an isotope standard, measured in the same run for reference ... 

A fundamental requirement in the application of stable isotopes and MS techniques is the knowledge of the measurement and interpretation of stable isotope abundances in molecules. For further details, the reader is directed to several excellent reviews on MS techniques (Hellerstein and Neese, 1999), mathematical formahsms for resolving mass spectral data (Lee ei o/., 1991 Fernandez etal., 996), and application of stable isotopes and mass isotopomer distribution (MID) to metabolic and nutrition research (Hellerstein and Neese, 1992 Berthold et al, 1994 Brunengraber et al., 1997 Reeds et al, 1997 Young and Ajami, 1999 Hellerstein, 2003). 

Fernandez, C.A., C. Des Rosiers, S.F. Previs, F. David and H. Bmnengraber, 1996. Correction of C mass isotopomer distributions for natural stable isotope abundance. J. Mass Spectrom. 31, 255-262. 

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