Stable Isotopes of Oxygen

Oxygen-18 has mainly been used in chemical and biochemical studies as a tracer, requiring relatively low enrichments, of the order of a few per cent, which is sufficient to be detectable in the products. 

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Calcium carbonate is also the main constituent of the shells of sea animals, which make their shells from elements acquired from the surrounding waters. Now, the degree of fractionation of the oxygen isotopes as well as the formation of mineral carbonates and of animal shells in sea waters are determined on the basis of the temperature-dependent fractionation of the isotopes of oxygen the oxygen isotope composition of these materials reflects, therefore, the temperature at the time of their formation. Thus determining the isotope ratio between the stable isotopes of oxygen... 

Guy RD, Fogel ML, Berry JA (1993) Photo synthetic fractionation of the stable isotopes of oxygen and carbon. Plant Phys 101 37 7... 

Hitchon B, Krouse HR (1972) Hydrogeochemistry of the surface waters of the Mackenzie River drainage basin, Canada. III. Stable isotopes of oxygen, carbon and sulfur. Geochim Cosmochim Acta 36 1337-1357... 

Suzuoki T, Epstein S (1976) Hydrogen isotope fractionation between OH-bearing minerals and water. Geochim Cosmochim Acta 40 1229-1240 Swart PK, Bums SJ, Leder 11 (1991) Eractionation of the stable isotopes of oxygen and carbon in carbon dioxide during the reaction of caldte with phosphoric acid as a function of temperature and technique. Chem Geol 86 89-96... 

Mass Spectral Techniques. Samples for isotope ratio analysis are typically converted to sulfates or sulfides, then to S02(g) for analysis on a mass spectrometer (MS). The precision of the S02 measurement is commonly reported as 0.1 to 0.2 0/00 (16.241. yet systematic errors of 1 0/00 or larger may result from 1) memory effects due to adsorption of S02 on the walls of the MS, and 2) secondary isotope effects due to the existence of two stable isotopes of oxygen, 160 and lsO (251. Both of these errors can be eliminated by using SF6 rather than S02 as the analyte in the MS (25.261. However, existing sulfur fluorination procedures are relatively dangerous and tedious, making the SF6 method less desirable as a routine environmental technique (261. 

Oxygen isotopes have been the most thoroughly studied isotopes in carbonate mineral systems. There are three stable isotopes of oxygen 160 = 99.763%, 170 = 0.0375% and 180 = 0.1995% (Garlick, 1969). The fractionation of 180 relative to 160 is commonly measured and reported as the value of 8180 relative to a standard. Two standards have been widely used in reporting 8180 values. The most common one in general usage now is "SMOW," which stands for standard mean ocean water. 

Garlick G.D. (1969) The stable isotopes of oxygen In Handbook of Geochemistry, V. II-1 (ed. K.H.Wedepohl), Springer-Verlag, Chapter 8B. 

Anderson, T.F., and Arthur, M.A. (1983) Stable isotopes of oxygen and carbon and their application to sedimentologic and paleoenvironmental problems. In Stable Isotopes in Sedimentary Geology (Arthur, M.A., Anderson, T.F., Kaplan, I.R., Veizer, J., and Land, L.S., eds.), pp. 1-151, Soc. Econ. Paleontol. Mineral. 

At the present time there are sufficiently reliable data on the distribution of the stable isotopes of oxygen, carbon, and sulfur in Precambrian sedimentary rocks. On the basis of analysis of these data, it is possible to obtain additional information on the geochemical history of the ocean and conditions of sedimentation. 

Elements in nature come in forms called isotopes that differ only in the number of their neutrons. Most isotopes are stable and can be distinguished from their counterparts simply by their masses. Remarkably, isotopes are associated with a few simple and mass-dependent traits that result in a wide range of useful isotopic signals in natural processes. Coupled with the invention of the isotope ratio mass spectrometer in 1940s (McKinney et al., 1950 Nier, 1947) stable isotope signals provide the basis for application of stable isotopes to environmental sciences. Stable isotopes are denoted by their atomic mass such as and for the two stable isotopes of carbon, and 0, and for the stable isotopes of oxygen. Because the heavy isotope is normally rare (e.g., -1.1% for i c, 0.2% for 0, and 0.04% for O), routine measurements of the absolute isotopic concentrations is difficult and not reliable. Alternatively, the ratio, R, of the rare to the abundant isotopes is measured, such as... 

Aravena R., Evans M. L., and Cherry J. A. (1993) Stable isotopes of oxygen and nitrogen in source identification of nitrate from septic systems. Ground Water ll, 180-186. 

Cooper L. W., Olsen C. R., Solomon D. K., Larsen 1. L., Cook R. B., and Grebmeier J. M. (1991) Stable isotopes of oxygen and natural and fallout radionuchdes used for tracing runoff during snowmelt in an arctic watershed. Water Resour. Res. 27, 2171-2179. 

The use of the stable isotopes of oxygen and hydrogen for tracing the origin of salinity is straightforward in the case of river salinization. 

Guy, R. D., M.L. Fogel and J.A. Berry (1993) Photos5nithetic fractionation of stable isotopes of oxygen and carbon. Plant Physiol. 101, 37-47. 

Because of rapid protonation and deprotonation, the monophosphate group is torsionally symmetrical. The symmetry can be broken by stereospecific substitution with sulfur, or by stereospecifically labelling with the three stable isotopes of oxygen, 0, and An ingenious NMR-based method of analysis, which relies on the isotope shift of the P resonance (the heavier the... 

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