The measurement background of accelerator mass spectrometry was evaluated using a B-removed Be carrier solution. Therefore, we anticipate that the direct packing method can also potentially be used to measure 10Be in Be-bearing minerals for geological applications.

Fragments of Be-bearing minerals from target samples were directly packed, and showed effective beam currents.

In addition to the necessity of finding raw materials that contain low 10Be, our results indicate that it is preferable to select a starting material with a low B concentration. Analyses of the 10Be/ 9Be ratios of phenakite (Be 2SiO 4) and beryl (Be 3Al 2Si 6O 18) obtained from a mineral collection at the Geological Survey of Japan indicate that phenakite generally contains more 10B, interfering isobar of 10Be, than beryl. That is, measuring the 10Be/ 9Be ratios of Be-bearing minerals by direct Cs sputtering. Here, we present a simple method for selecting appropriate raw minerals for in-house Be carriers. The first step in preparing in-house Be carriers is selecting suitable Be-bearing minerals that contain less 10Be. Recently, in-house Be carriers have been successfully applied to samples that contain small amounts of in-situ-produced 10Be. This is because commercially available Be carriers are non-negligibly contaminated by 10Be. Preparing Be carrier solutions with low 10Be/ 9Be ratios is essential for the applications of in-situ-produced cosmogenic 10Be in geochronology. Thus, our developed model is useful not only for estimating the solid-liquid partitioning of selenate by soil oxide minerals, but also for assessing its response to changing aqueous conditions and ageing processes. Calculations with the theoretically derived selenate adsorption constants indicate that, in addition to aqueous condition, crystalline states of Fe and Al oxides significantly influence the surface adsorption affinity for selenate. With the three reactions formulated in the extended triple layer model, we demonstrate adequate reproduction of a large number of adsorption, surface titration, and proton co-adsorption data for various selenate-oxide systems reported in literature. Respectively, for all oxides except for ferrihydrite, which requires an additional surface species,Дў>MOH + SeO 4 2- + 2H+ в†’ (>MOH 2 +)(>MOSeO 3 -) + H 2O. The principle selenate surface species are a monodentate-mononuclear inner-sphere and a bidentate-binuclear outer-sphere complexes represented byДў>MOH + SeO 4 2- + 2H+ в†’ (>MOH 2 +)2_SeO 4 2-,

This article describes a comprehensive predictive model for selenate adsorption on oxide minerals applicable for a wide range of pH, ionic strength, selenate concentration, solid/water ratio, and amorphous and crystalline adsorbents. Because selenate (SeO 4 2-) is the most prevalent form of bioavailable Se in agricultural soils, the prediction of selenate adsorption/desorption behaviors on soil constituting minerals is an important step to minimize potential health problems. Selenium (Se) is a micronutrient for human with a very narrow range between deficit and toxic levels.

Comprehensive meta analysis v2 download