FN Archimer Export Format PT J TI Does ultrafiltration kinetics bias iron isotope compositions? BT AF Lotfi-Kalahroodi, Elaheh Pierson-Wickmann, Anne-Catherine Rouxel, Olivier Coz, Martine Bouhnik-Le Davranche, Mélanie AS 1:1;2:1;3:2;4:1;5:1; FF 1:;2:;3:PDG-REM-GM;4:;5:; C1 Univ. Rennes, CNRS, Géosciences Rennes - UMR 6118, 35000 Rennes, France IFREMER, Unité de Géosciences Marines, 29280 Plouzané, France C2 UNIV RENNES, FRANCE IFREMER, FRANCE SI BREST SE PDG-REM-GM IN WOS Ifremer UPR copubli-france copubli-univ-france IF 4.685 TC 1 UR https://archimer.ifremer.fr/doc/00677/78880/81171.pdf LA English DT Article DE ;Ultrafiltration kinetics;Speciation;Iron;Isotopic fractionation AB Iron (Fe) isotopes are now recognized as useful tracers of Fe sources and biogeochemical processes in natural environments but many uncertainties remain regarding the mechanisms that control their isotopic fractionation. Ultrafiltration techniques applied to separate Fe species could potentially bias Fe isotopic compositions. Here, we investigated frontal centrifugal ultrafiltration. We have set up time-ultrafiltration experiments at low and high Fe concentrations both with and without organic matter (OM) at pH values of 1 and 6.5. The ultrafiltration impact was studied by monitoring the Fe isotope composition in the <30 kDa ultrafiltrates relative to the ultrafiltration time. No Fe isotopes bias resulted from the ultrafiltration technique regardless the Fe and OM concentrations and speciation. This work, therefore, validates the use of the frontal centrifugal ultrafiltration technique to study the signature of Fe isotopes in environmental samples composed of various Fe species sizes such as colloids, nanoparticles, clusters or soluble complexes. PY 2021 PD APR SO Chemical Geology SN 0009-2541 PU Elsevier BV VL 566 UT 000628895300003 DI 10.1016/j.chemgeo.2021.120082 ID 78880 ER EF