Geology isotope analysis

Applications The application of the isotope dilution technique is especially useful in carrying out precise and accurate micro and trace analyses. The most accurate results in mass spectrometry are obtained if the isotope dilution technique is applied (RSDs better than 1 % in trace analysis). Therefore, application of IDMS is especially recommended for calibration of other analytical data, and for certification of standard reference materials. The technique also finds application in the field of isotope geology, and is used in the nuclear industry for quantitative isotope analysis. 

Macko, S. A., Ryan, M. and Engel, M. H. (1998) Stable isotopic analysis of individual carbohydrates by gas chromatographic combustion/isotope ratio mass spectrometry. Chemical Geology 152,205 210. 

Allegre, C. J. Rousseau, D. (1984). The growth of the continents through geological time studied by Nd isotope analysis of shales. Earth Planet. Sci. Letters, 67, 19-34. 

Volatile metal chelates are also useful in determining isotope ratios of geological interest, e.g., the Zr/Hf ratio (197). This method proved invaluable as a microtechnique for chromium isotope analysis of lunar samples from the Apollo program (198). 

Newer instrumental methods of potential utility in organic analysis of environmental and geological biomarkers are compound specific isotope analysis (CSIA) and carbon-14 dating with accelerator mass spectrometry (AMS). CSIA provides the carbon isotope composition of individual... 

For measurements of isotope ratios or isotope abundances, any of the mass spectrometers discussed in the previous chapters, such as SSMS, LIMS, GDMS56 and LA-ICP-MS,6 are of benefit for the direct isotope analysis of solid samples. SSMS and LIMS are rarely applied in isotope analysis due to their relatively low precision. Several applications of the isotope dilution technique as a calibration strategy in SSMS, mostly on geological samples, are known.57-59 GDMS has been mostly applied in multi-element trace analysis and depth profiling and plays only a minor role... 

Selected applications of isotope analysis in geology and geochronology by LA-ICP-MS are summarized in Table 8.8. 

In the twenty years since it was first proposed (24, 2S), strontium isotope analysis of archaeological human remains to examine residential mobility has become increasingly common. Briefly, 87Sr/86Sr in a given geologic zone is... 

Leipziger, F. D., and W. J. Croft Geologic age determination by direct lead isotope analysis. Geochim. cosmochim. Acta 28, 268 (1964). 

Halliday, A.N., Christensen, J.N., Lee, D-C., Hall, C.M., Ballentine, C.J., Rehkamper, M., Yi, W., Luo, X., and Barfod, D. (1998a) ICP multiple collector mass spectrometry and in situ high precision isotopic analysis. In Applications of Microanalytical Techniques to Understanding Mineralizing Processes, M.A. McKibben, W.C.P. Shanks, and W.I. Ridley, eds. Reviews in Economic Geology 7, Society of Economic Geologists, 37-51. 

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