Anion-exchange chromatographic separation of Bi and Sb from As, Sn and other elements in malonic acid solution

Abstract

Anion-exchange chromatographic studies of bismuth(III) and antimony(III) in malonate solution have been carried out. Bi(III) forms anionic malonate complexes at pH4.5–6, whereas Sb(III) forms them at pH5.5–6. Such complexes were sorbed on a Dowex-21K column and HCl, H2SO4, HNO3, HClO4 and chlorides, nitrates and sulphates of sodium and ammonium were tested as eluants, their efficiencies being evaluated in terms of elution constants (E) and volume distribution coefficients (Dv). Methods have been developed for the separation of Bi(III) and Sb(III) from a large number of elements by exploiting the differences in complexing power of these elements. The sequential separation of As(III), Sb(III), Bi(III) and Sn(IV) was the important feature of the work.