Kinetic Fractionation of Antimony Isotopes during Reduction by Sulfide

Antimony Isotope Fractionation during Kinetic Sb(III) Oxidation by Antimony-Oxidizing Bacteria Pseudomonas sp. J1

“…The constant Sb concentration and undetectable Sb­(V) in the abiotic control experiment demonstrated that no abiotic oxidation occurred during the reaction process. Other research also showed that the abiotic isotopic equilibrium fractionation of 3 mM Sb was negligible for 6 weeks and that exchange was much slower at lower concentrations . Hence, the abiotic isotope exchange for the Sb concentration of 50–200 μM was insignificant in 68 days.…”

“…Scheme of Sb isotope fractionation (expressed as ε) caused by biogeochemical transformations (* results of theoretical calculations). ,− ,,,,, Length of the arrows is proportional to the magnitude of fractionation.…”

“…Sb­(V) reduction by KI and ascorbic acid mixture causes Sb isotope fractionation with an isotope enrichment factor (ε, ε = ( 123 Sb/ 121 Sb) product /( 123 Sb/ 121 Sb) reactant –1) × 1000) of −0.55 to −0.9‰ . Sb­(V) reduction by sulfide to form amorphous Sb 2 S 3 can produce large isotope fractionation with an ε value of −1.42‰ . Significant Sb isotope fractionation also occurred during bacterial reduction of Sb­(V) .…”