Oxygen isotopes in water

Andersson P., Torssander P., and Ingri J. (1992) Sulphur isotope ratios in sulphate and oxygen isotopes in water from a small watershed in central Sweden. Hydrobiologia 235/ 236, 205-217. 

Most common is the process of mass-dependent fractionation, in which the stable isotope ratio is altered as the consequence of physical processes differentially affecting atoms or molecules of different mass. Isotopes are fractionated relative to one another according to thermodynamic, kinetic, and diffusion processes. A simple example is the way in which oxygen isotopes in water molecules are fractionated during the process of evaporation. Water molecules containing the lower mass isotope leO are more likely to become water vapor than those containing the higher mass isotope lsO. Hence the water vapor is enriched in isotope leO and the liquid water is enriched in isotope lsO. 

Heavy isotopes endow the compounds in which they appear with slightly greater masses than their unlabeled counterparts. These compounds can be separated and quantitated by mass spectrometry (or density gradient centrifugation, if they are macromolecules). For example, O was used in separate experiments as a tracer of the fate of the oxygen atoms in water and carbon dioxide to determine whether the atmospheric oxygen produced in photosynthesis arose from HgO, COg, or both ... 

It follows that, depending on the temperature, whenever limestone precipitates, it includes the oxygen isotope in which the water is rich in sea waters, for example, the limestone is enriched in oxygen-18 ... 

Yapp CJ (1990) Oxygen Isotopes in iron (III) oxides 1. Mineral-water factors. Chem Geol 85 329-335 Young ED, Galy A (2004) The isotope geochemistry and cosmochemistry of magnesium. Rev Mineral Geochem 55 197-230... 

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. 

Any isotope fractionation occurring in such a way that the products are isolated from the reactants immediately after formation will show a characteristic trend in isotopic composition. As condensation or distiUation proceeds, the residual vapour or liquid will become progressively depleted or enriched with respect to the heavy isotope. A natural example is the fractionation between oxygen isotopes in the water vapour of a cloud and the raindrops released from the cloud. The resulting decrease of the iso/i o ratio in the residual vapour and the instantaneous isotopic composition of the raindrops released from the cloud are shown in Fig. 1.4 as a function of the fraction of vapour remaining in the cloud. 

Longinelli A (1984) Oxygen isotopes in mammal bone phosphate a new tool for paleohydrological and paleoclimatological research . Geochim Cosmochim Acta 48 385-390 Longinelli A, Bartelloni M (1978) Atmospheric pollution in Venice, Italy, as indicated by isotopic analyses. Water Air Soil Poll 10 335-341... 

The oxygen isotopes in the water molecules locked up in polar ice sheets tell another version of the planet s climate story. The ice that covers Antarctica is a mile and a half deep at its thickest points, and the snow that became transformed into the deepest ice fell at least 250,000 years ago. So the Antarctic ice sheets, like deep-sea sediments, encode thousands of years of climate history in their isotope compositions. 

Distribution of Amino Acids and Oxygen Isotopes in Petroleum Brine Waters of Various Geologic Ages, Sedimentology (1964) 3, 199-225. 

One of the most important uses of oxygen isotopes in carbonates is as geothermometers. Isotope fractionation is pressure independent (Clayton et al., 1975), giving it an advantage over other geothermometers which are generally both temperature and pressure dependent. The equation for calculating the temperature at which calcite precipitates from water is ... 

Lipfert, G., Sidle, W. C., Reeve, A. S., Ayuso, R. A., and Boyce, A. (2007). High arsenic concentrations and enriched sulfur and oxygen isotopes in a fractured-bedrock ground-water system. Chem. Geol. 242, 385-399. 

Roden J. S. and Ehleringer J. R. (1999) Observations of hydrogen and oxygen isotopes in leaf water confirm the Craig-Gordon model under wide ranging environmental conditions. Plant Physiol. 120(4), 1165-1173. 

Deak J. and Coplen T. B. (1996) Identification of Pleistocene and Holocene groundwaters in Hungary using oxygen and hydrogen isotopic ratios. In Isotopes in Water Resources Management, IAEA, Vienna, vol. 1, 438p. 

Degens E. T., Hunt I. M., Reuter J. H., and Reed W. E. (1964) Data on the distribution of amino acids and oxygen isotopes in petroleum brine waters of various geologic ages. Sedimentology 3, 199-225. 

Geochemists have, since the 1950s, already come up with a remarkable array of paleo-temperature proxies in marine carbonates. These proxies work in diverse oceanic settings, in different organisms, in different parts of the water column, and on varied timescales. Each proxy has different strengths and weaknesses, and some of the proxies, such as Mg/Ca and oxygen isotopes in... 

Several procedures and systems for the on-line determination of the 8 H- and 8 0-values of water and organic compounds have been investigated in the last few years [183-194] and problems arising from isotope effects on the GC-separations of analytes and their pyrolysis (P) products have been discussed [195-202]. Today most of the complications have been overcome and the technical prerequisites for the on-line GC-C-IRMS analysis of carbon and the GC-P-IRMS analysis of hydrogen and oxygen isotopes in volatile organic compounds have been optimised and become available for routine application [203-205]. 

In addition to information about diet and seasonality, shells at archaeological sites provide information about the local habitat and climate change. Different species of shellfish live in different depths of water, and prefer different temperatures, salinity, and amounts of current. Shells are composed of calcium carbonate (CaCO ) which is a molecule composed of calcium, carbon, and oxygen. The exact ratio of oxygen isotopes in shell depends on the temperature of the water in which the shell formed. Determination of that ratio in the shell can provide information on changes in water temperature (correlated with air temperature) over time. That information can be used to estimate where along a coast the shell is coming from. 

There are strong spatial differences in the seasonal stratification of the NW European shelf sea areas reflecting the temperature difference between the surface waters and the bottom waters (Elliot et al. 1991). Austin et al. (2006) provided the first systematic view of the long-term averaged (modem) spatial and temporal pattern of oxygen isotopes in seawater, expressed according to... 

Muller J (1995) Oxygen isotopes in iron (111) oxides A new preparation line mineral-water fractionation factors and paleo-environmental considerations. Isotopes Environ Health Stud 31 301-302 Nahr T, Botz R, Bohrmarm G, Schmidt M (1998) Oxygen isotopic composition of low-temperature authigenic clinoptilolite. Earth Planet Sci Lett 160 369-381... 

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