Prospective and comparative Novel technique for evaluation the affinity of alginate for binding the alkaline-earth metal ions during formation the coordination biopolymer hydrogel complexes

A prospective novel technique has been developed for evaluation the capacity of alginate as a natural polymer absorbent for binding Ca (II), Sr (II) and Ba(II) as alkaline earth metal ions for formation of coordination biopolymer hydrogel complexes. This method was based on avoiding the non-chelated metal-ions which may present free into the interstitial spaces of the spongy network of the alginate matrix. Neglecting of non-chelated metal ions in the various techniques will lead to miscalculation in the definite concentration of the binding metal ions. Hence, some uncertainty and dissimilarity were observed in the reported data with respect to the alginate capacity for binding themetal ions. Therefore, a novel technique formore precise determinationwas achieved by synthesis of coordinationmetal alginate gels of granule naturewhich are free fromsuch non-chelatedmetal ions. Here, the true bindingmetal ionswere eluted by addition of dilute HClO4 and the concentration of the metal ions into the effluentwas determined, conductometrically. The experimental results indicated that the capacity of alginate was decreased in the order Ba2+> Sr2+> Ca2+ ions in good accordwith their thermal stability. The factors affected the affinity of alginate for binding the metal ions were interpreted and discussed. (C) 2020 Elsevier B.V. All rights reserved.