Proteins containing gelsolin in bovine plasma were bound to anion-exchange porous hollow-fiber membrane before gelsolin was specifically eluted with a calcium ion-containing solution. The epoxy group introduced into the polymer chain grafted onto the porous hollow-fiber membrane was converted into two kinds of anion-exchange groups, i.e., diethylamino (DEA) and 2-hydroxyethylamino (HEA) groups with various mole fractions. The porous membrane containing exclusively HEA group exhibited the highest liquid permeability and the largest amount of gelsolin recovered. Furthermore, the HEA-group-containing porous membrane was advantageous over a column charged with commercially available anion-exchange beads in that the amount of gelsolin recovered was constant irrespective of space velocity, i.e., residence time across the membrane thickness, of the protein solution.

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An epoxy group of the polymer chain grafted onto a bundle of fiber by radiation-induced graft polymerization was converted into a chelate-forming group by a reaction with iminodiethanol. The resultant chelating fiber was wound to a plastic core with an inner diameter of 3 cm and a length of 25 cm to yield a filter thickness of 2 cm. The filter had a chelating group density of 2.9 mmol/g of the fiber. Equilibrium adsorption capacity of the filter of 2.3 mmol per g of the fiber was evaluated in a batch mode by circulating a 0.46 g-GeO₂/L germanium oxide solution through the filter. Germanium oxide adsorbed onto the filter was eluted quantitatively by permeating 0.4 M hydrochloric acid through the filter.

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We carried out the structure and stability analysis of β-diketones derivatives-group 13 metals and calix [4] arene derivatives-alkaline metals by molecular mechanics, semi-empirical molecular orbital, and density functional theory (DFT) methods.
The selectivity of β-diketones for aluminium (III) and indium (III) was examined by the liquid-liquid extraction method, and molecular mechanics calculations were performed for each complex with the MOMEC force field. The force field parameters, not yet available, were developed so that the calculated structures were fitted to the relevant Xray crystal structures. The calculations indicate that the quantitative structure-property relationship (QSPR) can be obtained. This relates the complexation strain energy differences among the metal complexes to their relative extractability.
A calix [4] arene carboxylic acid derivative was utilized as an extractant for alkaline metal ion separation. The host compound exhibited a high extractability to sodium ion compared to lithium ion and potassium ion. We also discussed the experimental results with a computaional modeling by means of semi-empirical molecular orbital and DFT methods. From the molecular geometries and heat of formation of the calix [4] arene derivative before and after extraction, the important factors for alkaline metal ion separation were found to be its cyclic structure and its cavity size.

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