title: Evidence for Hydroxamate Siderophores and Other N-Containing Organic Compounds Controlling (239,240)Pu Immobilization and Remobilization in a Wetland Sediment.
abstract: Pu concentrations in wetland surface sediments collected downstream of a former nuclear processing facility in F-Area of the Savannah River Site (SRS), USA, were ∼2.5 times greater than those measured in the associated upland aquifer sediments; similarly, the Pu concentration solid/water ratios were orders of magnitude greater in the wetland than in the low-organic matter content aquifer soils. Sediment Pu concentrations were correlated to total organic carbon and total nitrogen contents and even more strongly to hydroxamate siderophore (HS) concentrations. The HS were detected in the particulate or colloidal phases of the sediments but not in the low molecular weight fractions (<1000 Da). Macromolecules which scavenged the majority of the potentially mobile Pu were further separated from the bulk mobile organic matter fraction ("water extract") via an isoelectric focusing experiment (IEF). An electrospray ionization Fourier-transform ion cyclotron resonance ultrahigh resolution mass spectrometry (ESI FTICR-MS) spectral comparison of the IEF extract and a siderophore standard (desferrioxamine; DFO) suggested the presence of HS functionalities in the IEF extract. This study suggests that while HS are a very minor component in the sediment particulate/colloidal fractions, their concentrations greatly exceed those of ambient Pu, and HS may play an especially important role in Pu immobilization/remobilization in wetland sediments.
authors: Department of Marine Sciences, Texas A&M University , Building 3029, Galveston, Texas 77554, United States.
authors: Chen
authors: C
authors: Xu
authors: Department of Marine Sciences, Texas A&M University , Building 3029, Galveston, Texas 77554, United States.
authors: Saijin
authors: S
authors: Zhang
authors: Savannah River National Laboratory , Aiken, South Carolina 29808, United States.
authors: Daniel I
authors: DI
authors: Kaplan
authors: Department of Marine Sciences, Texas A&M University , Building 3029, Galveston, Texas 77554, United States.
authors: Yi-Fang
authors: YF
authors: Ho
authors: Department of Marine Sciences, Texas A&M University , Building 3029, Galveston, Texas 77554, United States.
authors: Kathleen A
authors: KA
authors: Schwehr
authors: Savannah River National Laboratory , Aiken, South Carolina 29808, United States.
authors: Kimberly A
authors: KA
authors: Roberts
authors: Department of Chemistry and Biochemistry, College of Sciences, Old Dominion University , Norfolk, Virginia 23529, United States.
authors: Hongmei
authors: H
authors: Chen
authors: Department of Chemistry and Biochemistry, College of Sciences, Old Dominion University , Norfolk, Virginia 23529, United States.
authors: Nicole
authors: N
authors: DiDonato
authors: Department of Marine Sciences, Texas A&M University , Building 3029, Galveston, Texas 77554, United States.
authors: Matthew
authors: M
authors: Athon
authors: Department of Chemistry and Biochemistry, College of Sciences, Old Dominion University , Norfolk, Virginia 23529, United States.
authors: Patrick G
authors: PG
authors: Hatcher
authors: Department of Marine Sciences, Texas A&M University , Building 3029, Galveston, Texas 77554, United States.
authors: Peter H
authors: PH
authors: Santschi
mesh_terms: D003676:Deferoxamine / Q000737:chemistry; D019015:Geologic Sediments / Q000737:chemistry*; D006877:Hydroxamic Acids / Q000737:chemistry*; D007525:Isoelectric Focusing; D009584:Nitrogen / Q000737:chemistry; D009930:Organic Chemicals / Q000737:chemistry; D011005:Plutonium / Q000032:analysis* / Q000737:chemistry*; D017262:Siderophores / Q000032:analysis / Q000737:chemistry*; D012990:Soil Pollutants, Radioactive / Q000032:analysis* / Q000737:chemistry; D013022:South Carolina; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods; D053833:Wetlands
chemical_list: D006877:Hydroxamic Acids; D009930:Organic Chemicals; D017262:Siderophores; D012990:Soil Pollutants, Radioactive; D011005:Plutonium; D003676:Deferoxamine; D009584:Nitrogen