Elastic and inelastic scattering of 14C + 18O versus 12, 13C + 18O and 14C + 16O

The relationship between 18O/16O and 13C/12C ratios of ambient CO2 in two Amazonian tropical forests

Oxygen and carbon isotopic compositions of ambient carbon dioxide in two tropical forests in the Amazonian basin were determined at the beginning and the end of the dry season. One site, Fazenda Vitoria, is typical of a seasonal forest with a pronounced dry season from May to November whereas the other site, Reserva Ducke, has a milder dry season. Samples collected at night revealed that in the...

Continuous flow 2H/1H and 18O/16O analysis of water samples with dual inlet precision.

A method for isotope ratio analysis of water samples is described comprising an on-line high-temperature reduction technique in a helium carrier gas. Using a gas-tight syringe, injection of 0.5 to 1 microL sample is made through a heated septum into a glassy carbon reactor at temperatures in excess of 1300 degrees C. More than 150 injections can be made per day and both isotope ratios of intere...

Simultaneous analysis of 17O/16O, 18O/16O and 2H/1H of gypsum hydration water by cavity ring‐down laser spectroscopy

RATIONALE The recent development of cavity ring-down laser spectroscopy (CRDS) instruments capable of measuring (17) O-excess in water has created new opportunities for studying the hydrologic cycle. Here we apply this new method to studying the triple oxygen ((17) O/(16) O, (18) O/(16) O) and hydrogen ((2) H/(1) H) isotope ratios of gypsum hydration water (GHW), which can provide information a...

18O/16O and D/H Isotopic Preference in Hydration Spheres of Alkali Metal Ions

With the final goal set at theoretical elucidation of experimentally observed isotope salt effects, molecular orbital calculations were performed to estimate the 18 O/16 O and D/H isotopic reduced partition function ratios (RPFRs) of water molecules around lithium, sodium, and potassium ions. As model water molecules in the ith hydration sphere of the cation in aqueous solutions containing that...

18O/16O Isotope Abundance Ratios in Water by Means of Laser Spectrometry