Speciation of iodine (127I and 129I) in lake sediments

Speciation of <sup>127</sup>I and <sup>129</sup>I in atmospheric aerosols at Risø, Denmark: insight into sources of iodine isotopes and their species transformations

“…This indicates that NSI is relatively stable and less affected by the source and pathways of air masses than WSI. NaOH leaching is often used to extract organic substance in fractionation analysis of soil and sediment (Englund et al, 2010a;Hou et al, 2003) based on the high solubility of organic matter, such as humic substances, as well as on nucleophilic substitution and decomposition of organic matter. Organic compounds are important contributors to aerosols, such as lipidic, saccharides, and proteinaceous materials (O'Dowd et al, 2004;Quinn et al, 2014).…”

Progress on 129I analysis and its application in environmental and geological researches

“…Migration of 129 I is highly retarded by organic matters in the geological medium. The chemical speciation analysis of soil and sediment samples has also confirmed that a dominated fraction of 129 I is in organic form [56,68]. In minerals such as ferric hydroxides and kaolinite, iodide is less adsorbed, whereas iodate sorbed strongly to ferric hydroxide.…”

“…Typically, fractions in the sample and corresponding separation methods are: the water soluble fraction (leached with water); exchangeable fraction (ion adsorption; leached with NH 4 Ac or MgCl 2 at the soil/sediment pH); carbonates associated fraction (leached with NH 4 Ac at pH5); reducible or metal oxides fraction (leached with NH 2 OH•HCl at pH2); organic matter association fraction (leached with NaOH or H 2 O 2 at pH2); and mineral associated fraction (released by combustion). Iodine in the extracted fractions is then further separated from the solution for 129 I measurement [56,57]. In some cases, modified procedures are used to combine some fractions together, or use different leaching agents.…”

Fluoride and iodine enrichment in groundwater of North China Plain: Evidences from speciation analysis and geochemical modeling

“…Due to the high sorption capacities of iodine on iron (oxy)hydroxides and natural organic matter (NOM), they are usually considered as the primary reservoirs of sediment iodine (Englund et al, 2010;Li et al, 2013;Shetaya et al, 2012;Shimamoto et al, 2011). Under reducing condition, the weathering and/or reductive dissolution of iodine-loaded Fe (oxy)hydroxides should be responsible for iodine release from sediment into surrounding groundwater.…”