Open AccessBeam‐induced oxidation of monomeric U(IV) species
Author(s) -
Alessi Daniel S.,
Uster Benjamin,
Borca Camelia N.,
Grolimund Daniel,
BernierLatmani Rizlan
Publication year - 2013
Publication title -
journal of synchrotron radiation
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.172
H-Index - 99
ISSN - 1600-5775
DOI - 10.1107/s0909049512041763
Subject(s) - uranium , microbeam , oxidation state , monomer , chemistry , beam (structure) , spectroscopy , radiochemistry , redox , analytical chemistry (journal) , nuclear chemistry , materials science , inorganic chemistry , environmental chemistry , optics , metal , metallurgy , physics , polymer , organic chemistry , quantum mechanics
Uranium L III ‐edge X‐ray absorption spectroscopy is often used to probe the oxidation state and coordination of uranium in environmental samples, and micrometre‐sized beams can be used to spatially map the distribution of uranium relative to other elements. Here a variety of uranium‐containing environmental samples are analyzed at both microbeam and larger beam sizes to determine whether reoxidation of U(IV) occurred. Monomeric U(IV), a recently discovered product of U(VI) reduction by microbes and certain iron‐bearing minerals at uranium‐contaminated field sites, was found to be reoxidized during microbeam (3 µm × 2 µm) analysis of biomass and sediments containing the species but not at larger beam sizes. Thus, care must be taken when using X‐ray microprobes to analyze samples containing monomeric U(IV).