Sulfur isotope effects associated with oxidation of sulfide by O2 in aqueous solution.
Normal sulfur isotope effects averaging epsilon = -5.2 +/- 1.4% (s.d.) were consistently observed for the oxidation of sulfide in aqueous solution.  Reaction products were sulfate, thiosulfate and sulfite at pH 10.8-11 in distilled water; S0 was formed in two experiments with synthetic seawater at pH 8-9.5.  Because the -5.2% normal isotope effect differs significantly from the previously measured +2% inverse effect associated with anaerobic oxidation of sulfide by photosynthetic bacteria, stable sulfur isotopic measurements are potentially useful for distinguishing aerobic vs. anaerobic sulfide oxidation in marine and freshwater sulfureta.
Fry
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Department of Chemistry, Indiana University, Bloomington 47405, USA.
Ruf
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Gest
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Hayes
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JM
D001421:Bacteria, Anaerobic / Q000378:metabolism; D010084:Oxidation-Reduction; D010100:Oxygen / Q000378:metabolism*; D012623:Seawater / Q000737:chemistry; D013431:Sulfates / Q000032:analysis / Q000378:metabolism; D013440:Sulfides / Q000737:chemistry* / Q000378:metabolism*; D013447:Sulfites / Q000032:analysis / Q000378:metabolism; D013455:Sulfur / Q000378:metabolism*; D013460:Sulfur Isotopes; D013885:Thiosulfates / Q000032:analysis / Q000378:metabolism
D013431:Sulfates; D013440:Sulfides; D013447:Sulfites; D013460:Sulfur Isotopes; D013885:Thiosulfates; D013455:Sulfur; D010100:Oxygen