Fractionation of Sulfur Isotopes during Oxidation

Fractionation of Sulfur and Oxygen isotopes during SO2 photolysis

The discovery of sulfur mass-independent fractionation (S-MIF) in ancient sedimentary rocks [1] has created the opportunity for quantitative constraints on the composition of the early atmosphere. Laboratory experiments have shown that S-MIF occurs during SO2 photodissociation at a variety of UV wavelengths [2, 3]. The source of the S-MIF in experiments at wavelengths ~ 200 nm is self-shielding...

Theoretical investigation of the anomalous equilibrium fractionation of multiple sulfur isotopes during adsorption

Mass-independent sulfur isotope fractionation during photochemistry of sulfur dioxide

Mass-independent sulfur isotope signatures are observed in Archean and early Paleoproterozoic sedimentary sulfate and sulfide minerals, and provide the most robust constraints on early atmospheric oxygen levels. Smaller mass-independent sulfur isotope anomalies are observed in ice cores and interpreted as a tracer of stratospheric volcanic loading. Photochemistry of sulfur dioxide (SO 2) has be...

Sulfur isotope fractionation during oxidation of sulfur dioxide: gas-phase oxidation by OH radicals and aqueous oxidation by H2O2, O3 and iron catalysis

The oxidation of SO2 to sulfate is a key reaction in determining the role of sulfate in the environment through its effect on aerosol size distribution and composition. Sulfur isotope analysis has been used to investigate sources and chemical processes of sulfur dioxide and sulfate in the atmosphere, however interpretation of measured sulfur isotope ratios is challenging due to a lack of reliab...

Fractionation of Carbon Isotopes during Biogenesis of Atmospheric Isoprene.

The stable carbon isotope composition of isoprene emitted from leaves of red oak (Quercus rubra L.) was measured. Isoprene was depleted in (13)C relative to carbon recently fixed by photosynthesis. The difference in isotope composition between recently fixed carbon and emitted isoprene was independent of the isotopic composition of the source CO(2). beta-Carotene, an isoprenoid plant constituen...