학술논문
Ice-vapor equilibrium fractionation factor of hydrogen and oxygen isotopes: Experimental investigations and implications for stable water isotope studies.
Document Type
Article
Source
Subject
*WATER
*DOSE fractionation
*CHEMICAL equilibrium
*HYDROGEN isotopes
*OXYGEN isotopes
*PHASE transitions
*EQUILIBRIUM isotope effects
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Language
ISSN
0951-4198
Abstract
RATIONALE The equilibrium fractionation factors govern the relative change in the isotopic composition during phase transitions of water. The commonly used results, which were published more than 40 years ago, are limited to a minimum temperature of -33°C. This limits the reliability in cold regions. With recent instrumental developments it is now possible to test the accuracy of the earlier results as well as extend the temperature range. METHODS Novel measurements were made of the ice-vapor equilibrium fractionation factor α between 0°C and -40°C, from a unique experimental setup using both a Picarro cavity ringdown spectrometer and a TC/EA IRMS system. Using both systems allows for continuous monitoring of the equilibrium state of the system as well as testing for reproducibility. RESULTS The results of the experiments show fractionation factors for δ2H and δ18O values, with a temperature dependency in accordance with theory for equilibrium fractionation. We obtain the following expressions for the temperature dependency of the fractionation coefficients: [ABSTRACT FROM AUTHOR]