Complexation of silver by macromolecular organic sulfur complexes in estuarine waters of Galveston Bay


1997 2001 Sep 28


Santschi PH
Tang D
Wen LS
Gill G
Cantois J
Wisconsin Univ. MUSGI Andren AW
Bober TW

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Studies are currently being conducted which have the objectives of gaining a better understanding of the degree of organic complexation of Ag in fresh and estuarine waters by relating the ambient concentration of stable Ag in colloidal organic matter (COM) to the concentration of reduced S groups in macromolecular organic matter. Here, we report preliminary results from experimental studies using Trinity River and Galveston Bay colloids isolated using cross flow ultrafiltration. Natural organic sulfur compounds, to which small amounts of Ag and a fluorescent tag had been added, were separated by HPLC and eluent fractions were collected. S was determined by fluorescence detection, while Ag in the same fractions was determined by GF-AAS. Ag was found in a single well defined peak in the more hydrophobic region of the HPLC spectrum coinciding with a relatively minor thiol peak. No Ag was found in the more hydrophilic fractions, indicating that all Ag was complexed by ligands of a small fraction of hydrophobic natural organic matter. Since thiols in COM from Galveston Bay are not oxidized for at least one day, and since they are considerably more stable towards oxidation by air-O sub(2), H sub(2)O sub(2) or UV than low molecular weight thiols, further laboratory tests to study the binding of Ag to natural thiols should be promising




ASW,USA,Texas,Galveston Bay, Colloids, complexation, estuaries, Filtration, Fluorescence, Galveston Bay, Laboratories, Ligands, Liquid Chromatography, Metal Complexes, Molecular weight, organic compounds, organic matter, Oxidation, P 1000 MARINE POLLUTION, Q5 01503 Characteristics,behavior and fate, silver, Sulfur, Sulfur Compounds, Sulphur compounds, SW 0890 Estuaries, SW 3020 Sources and fate of pollution, Texas, thiols, Ultrafiltration, USA, USA,Texas,Galveston Bay, water, Water Pollution