Scandium Adsorption Research Articles

Adsorptive Stripping Determination of Scandium(III) with Mordant Blue 9 on Silver Amalgam Film Electrode

AbstractA new adsorptive stripping voltammetric method for the determination of trace scandium(III) based on the adsorption of scandium(III)‐mordant blue 9 complex on the cyclic renewable mercury film silver based electrode (Hg(Ag)FE) is presented. The effects of various factors such as: preconcentration potential and time, pulse height, step potential and supporting electrolyte composition are optimized. The calibration graph is linear from 2 nM (0.09 μg L−1) to 90 nM (4 μg L−1) for a preconcentration time of 45 s, with correlation coefficient of 0.9995. For a Hg(Ag)FE with a surface area of 7.9 mm2 the detection limit for a preconcentration time of 90 s is as low as 5 ng L−1. The repeatability of the method at a concentration level of the analyte as low as 0.2 μg L−1, expressed as RSD is 1.9 % (n=5). The proposed method was successfully applied and validated by studying the certified reference material (CRM 320 – river sediment) and natural samples with simultaneous recovery of Sc(III) from spiked water and sediment samples.

Adsorption of metal ions by carboxymethylchitin and carboxymethylchitosan hydrogels

Radiation cross-linking of CM-chitin and CM-chitosan has been investigated. Such parameters of radiation cross-linking as gelation doses, cross-linking and degradation radiation yields and ratios of scission to cross-linking has been determined for both polymers.The absorption ability of various metal ions into EB-radiation cross-linked carboxymethylchitin and carboxymethylchitosan has been investigated. The highest adsorption of scandium and gold has been obtained for carboxymethylchitin (CMCht) and carboxymethylchitosan (CMChts), respectively. Kinetic studies showed that adsorption of most of the metal ions occur in a relatively short period of time (2h). Detail investigation of adsorption of gold ions has been carried out for both hydrogels. The maximum uptake of Au cations, based on Langmuir equation was determined to be 37.59 for CM-chitosan and 11.86 for CM-chitin. Both hydrogels indicate favorable adsorption of gold cations.

Unoccupied electronic resonances of Sc adsorbed on W(001) by k-resolved inverse photoemission.

Scandium adsorbed on the (001) face of tungsten has been studied using Auger-electron spectroscopy, low-energy electron diffraction, k-resolved inverse photoelectron spectroscopy, work-function measurements, and relativistic-electronic-structure calculations. We find that the work function of W(001) does not decrease monotonically as a function of scandium adsorption but reaches a minimum value of \ensuremath{\varphi}=3.25 eV at 50% coverage. For a complete monolayer, an order 1\ifmmode\times\else\texttimes\fi{}1 Sc overlayer is formed. Inverse photoemission in the isochromat mode was used to map the unoccupied energy levels of this overlayer along the \ensuremath{\Gamma}\ifmmode\bar\else\textasciimacron\fi{} M\ifmmode\bar\else\textasciimacron\fi{} symmetry direction of the surface Brillouin zone. Local-density-functional calculations using the muffin-tin orbital method were performed for a 1\ifmmode\times\else\texttimes\fi{}1 Sc overlayer on W and are compared with the experimental two-dimensional band structure.

Adsorption and desorption of hydrolyzed metal ions. III. Scandium and chromium

Adsorption of scandium (III) and chromium (III) species on a PVC latex was measured using radioactive isotopes; the uptake increased with increasing pH. The data were interpreted by combining aspects of the models of James and Healy and also of Anderson and Bockris. The experimental and calculated results agree quite well for scandium, but not for chromium. The deviation in the latter case is believed to be due to polymerization of the hydrolyzed chromium cations and to the interaction of chromium with the anionic surface groups of the latex. Neither of these interactions occur with scandium. Hydrolyzed scandium species adsorbed on the latex were removed by acidifying the dispersion, while chromium complexes were not, substantiating the proposed difference in the chemical nature of chromium and scandium species at the solid/solution interface.

Anion-exchange behavior of scandium, rare earths, thorium and uranium in magnesium nitrate solution

Pronounced adsorption of scandium, rare earths, thorium and uranium in magnesium nitrate solution has been demonstrated with a strongly basic anion exchanger. The adsorbability of these metals increases sharply with increasing concentration of magnesium nitrate solution. Fractionation of the lighter rare earths was possible in a 3 M magnesium nitrate solution. The distribution coefficients were found to decrease within the cerium group, reaching a minimum near gadolinium, to increase slightly with further increase of atomic number. Sufficiently large differences in adsorbability to permit the separation of scandium and thorium/or uranium were found and selected pairs of the lighter rare earths were also found to be separable with relatively short columns.

La séparation du scandium, du lanthane et de l'yttrium

The behaviour of scandium on a resin column has been studied and an efficient separation of scandium, lanthanum and yttrium has been effected using citric acid at different pH's. The hysteresis phenomenon which accompanies the adsorption of scandium and its importance for calculations, based on the theory of levels, are discussed.