Progress of Cryogenics and Isotopes Separation , ISSN: 1582-2575
2008, Volume 11, Issue 21+22

Stable Isotope Signature (D/H, 18O/16O) in a Hydrologies Study

Abstract

Environmental isotope hydrology is a relatively new field of investigation based on isotopic variations observed in natural waters. These isotopic characteristics have been established over a broad space and time scale. They cannot be controlled by man, but can be observed and interpreted to gain valuable regional information on the origin, turnover and transit time of water in the system which often cannot be obtained by other techniques. The cost of such investigations is usually relatively small in comparison with the cost of classical hydrological studies.

The main environmental isotopes of hydrological interest are the stable isotopes deuterium (hydrogen-2), carbon-13, oxygen-18, and the radioactive isotopes tritium (hydrogen-3) and carbon-14. Isotopes of hydrogen and oxygen are ideal geochemical tracers of water because their concentrations are usually not subject to change by interaction with the aquifer material. The stable water isotopes (∂¹⁸O and ∂D) in precipitation are the basis for the reconstruction of paleotemperatures due to the empirical linear relationship between mean annual air temperature and the mean isotopic composition of precipitation.

The present paper emphasize the isotopic analysis for D/H and ¹⁸O/¹⁶O from precipitation and river water samples using a new generation Isotope Ratio Mass Spectrometer in Continuous Flow (CF-IRMS) Delta V Plus, coupling with a GasBench II preparation device.