Isotope techniques

The Advanced Seminars have been crucial for evaluating the utility and validity of existing methods and results, discussing potential improvements in methods, and setting priorities for future research. A brief summary of the advances made in previous seminars and future directions of research on chemical and isotopic techniques of diet reconstruction follows. 

Boutton, T.W. 1991 Tracer studies with C-enriched substrates humans and large animals. In Coleman, D.W. and Fry, B., eds.. Carbon Isotope Techniques. Academic Press, San Diego 219-242. 

Coleman, D.C. and Fry, B. 1991 Carbon Isotope Techniques. Academic Press, San Diego. 

Byrne AR, and Kucera J (1997) Role of the self-validation principle of NAA in the quality assurance of bioenvironmental studies and in the certification of reference materials. Proc. Int. Symp. Harmonization of Health Related Environmental Measurements Using Nuclear and Isotopic Techniques, Hyderabad, India, pp 223-238. IAEA Vienna. 

Fritz P, Drimmie RJ, Frape SK, O Shea K (1987) The isotopic composition of precipitation and groundwater. In Canada International Symposium on the Use of Isotope Techniques in Water Resources Development. IAEA Symposium, Vienna 299 539-550 Frumkin A, Ford DC, Schwarcz HP (1999) Continental oxygen isotopic record of the last 170,000 years in Jerasalem. (JuatRes 51 317-327... 

Ambrose, S. H. (1987), Chemical and isotopic techniques of diet reconstruction in eastern North America, in Keegan, W. F. (ed.), Emergent Horticultural Economies of the Eastern Woodlands, Southern Illinois Univ., Carbondale, Center for Archaeological Investigations, Occasional Papers, Vol. 7, pp. 78-107. 

DelDuca M, Yeager E, Davies MO, Havorka F (1958) Isotopic technique in the study of the sonochemical formation of hydrogen peroxide. J Acoust Soc Am 30(4) 301-307... 

Rabinowitz M.B., Wetherill G.W. Identified sources of lead contamination by stable isotope techniques. Environ Sci Technol 1972 1 6 705-709. 

Kokes and Dent by combining IR spectroscopy with hydrogen isotope techniques, and by applying kinetic and stereochemical considerations were able to determine the intermediate surface species in the hydrogenation and isomerization of simple olefins over zinc oxide. 

Allmaras et al. (2004) developed a C-budgeting approach based on combining experimental and isotopic techniques. The data needed to use calculations derived by Allmaras et al. (2004) required that the experiment contain com stover harvested and removed treatments. These calculations assume that the removal of above-ground biomass will not influence the sequestering of below-ground biomass. The SOC derived from com stover (sSOC) is calculated with the equation ... 

Carbon turnover in production fields can be determined, using non-isotopic techniques, by combining historical soil samples, current soil samples, and whole field yield monitor data. Sensitivity analysis of such data shows that the amount of above-ground biomass that could be harvested decreases with root to shoot ratio (Table 8.1). For example, if root biomass is ignored, analysis suggests that only 20-30% of the above-ground biomass can be harvested, whereas if the root to shoot ratio is 1.0, then between 40% and 70% of the residue could be harvested. 

Ehleringer JR (1991) 13C/12C fractionation and its utility in terrestrial plant studies. In Coleman DC, Fry B (eds) Carbon isotopic techniques. Academic, New York, pp 187-200 Ehleringer JR, Buchmann RN, Flanagan LB (2000) Carbon isotope ratios in belowground carbon cycle processes. Ecol Appl 10 412-422... 

Goy KM (1991) Carbon dating. In Coleman DC, Fry B (eds) Carbon isotope techniques. Academic, New York, pp 125-145... 

Isotope techniques provide some very powerful tools for scientists. However, IRMS instruments are relatively expensive and overcomplicated for laboratories with limited applications. 

The development of the area of biochemical individuality is made urgent by the foregoing considerations. It is made possible because of the introduction of new techniques and tools. Many of the facts related to biochemical individuality which are presented in later chapters of this book could not have been brought to light if it were not for some of the newer tools chromatography, isotopic techniques, and physical methods of analysis and separation. The collection of data in the area of individuality is in its infancy, and newer techniques will make possible the collection of vastly more pertinent and satisfactory information than is available at present. Many of the data which are now available have been collected by investigators who appear to have no particular interest in variation as such or concern with its possible significance. 

Ann McNichol is a Research Specialist at the National Ocean Sciences Accelerator Mass Spectrometry Facility at the Woods Hole Oceanographic Institution, which produces high-precision 14C measurements from small-volume samples. Dr. McNichol s research interests include the study and use of carbon, nitrogen, and oxygen isotope techniques to quantify bio-geochemical processes, the study of the fate of organic matter (both natu-... 

Abstract In this chapter we discuss practical techniques and instrumentation used in experimental measurements of kinetic and equilibrium isotope effects. After describing methods to determine IE s on rate constants, brief treatments of mass spectrometry and isotope ratio mass spectrometry, NMR measurements of isotope effects, the use of radio-isotopes, techniques to determine vapor pressure and other equilibrium IE s, and IE s in small angle neutron scattering are presented. 

Cook. A.M. and Hiitter, R. Ametryne and prometryneas sulfur sources for bacteria. Appl Environ. Microbiol, 43(4) 781 -786,1982. Cooley. R.A. and Banks, H.O. The aqneous solubility of hafnium oxide by the radioactive isotope technique. J. Am. Chem. Soc, 73(8) 4022, 1951. 

Dual isotope technique The technique uses two heavy isotopes, oxygen ( 0) and deuterium ( H). Water that contains these isotopes is prepared. The subject drinks a glass of this water, as part of a normal meal. Once equilibrated with body water, which occurs quickly, the content of in the water falls due to the production of unlabelled water from the oxidation of fuels. Similarly, the 02 content in the water also falls but the rate is greater than that of since the 02 equilibrates not only with the oxygen atoms in water but also with those in carbon dioxide. An equihbrium between water and carbon dioxide is rapidly estabhshed due to the activity of the enzyme carbonate dehydratase. 

Quantitative studies of energy metabolism and fuel utilisation in very prolonged physical activity were performed by Mike Stroud during his Antarctic expedition with Ranulph Fiennes in 1992. One part of the study was measurement of energy expenditure by the dual isotope techniques (Chapter 2). Calculated over the whole expedition, the average daily energy expenditure of Stroud and Fiennes was 29 MJ but on particularly arduous days it increased to... 

Taylor, B.E. 2004. Fluorination Methods in Stable Isotope Analysis. In DeGroot, P.A.jed.), Handbook of Stable Isotope Techniques, 1, Elsevier, Amsterdam, 400-472. 

Recent work by Wilson Orr ( ) and others using stable isotope techniques has provided strong evidence that incorporation from an inorganic source is the most probable explanation. Inorganic sulphur (sulphate) tends to be richer in the heavy sulphur isotope, compared with reference meteoritic sulphur... 

---