Environmental isotopes in New Zealand hydrology ; 2. Standards, measurement techniques, and reporting of measurements for oxygen-18, deuterium, and tritium in water

The present internationally adopted measurement scales and standards for 18O/16O, D/H, and T/H in environmental waters are defined and explained. Present measurement techniques at Institute of Nuclear Sciences, DSIR, Lower Hutt, are summarised with appropriate reference to earlier procedures. For 18O/16O determination, water samples are equilibrated with CO2 gas which is then analysed by mass spectrometry. For D/H measurement, the water is reduced to hydrogen which is also analysed by mass spectrometry. Levels of T/H in waters of the South Pacific region are so low that beta-particle counting must be preceded by electrolytic enrichment to attain good accuracy. Sampling procedures are described. (author). 26 refs., 3 figs