Isotopic fractionation during diffusion of transition metal ions in solution.
Isotope ratios and elemental concentrations were measured in aqueous solutions sampled at varying distances from sources of Fe or Zn ions. The measurements reveal fractionation of isotopes resulting from pure diffusion in solution. Our data demonstrate that diffusion alone can cause changes in (56)Fe/(54)Fe and (66)Zn/(64)Zn isotope ratios in excess of -0.3 per thousand. These findings thus confirm previous suspicions that transport processes contribute to observed variations in isotopic compositions. Diffusion must therefore be considered when attempting to make inferences from isotope measurements on samples originating from aqueous systems where concentration gradients may develop.
Rodushkin
Ilia
I
Analytica AB, Aurorum 10, SE-977 75 Luleå, Sweden. ilia.rodushkin@analytica.se
Stenberg
Anna
A
Andrén
Henrik
H
Malinovsky
Dmitry
D
Baxter
Douglas C
DC