SPECTROPHOTOMETRIC STUDIES ON ASCORBINATE COMPLEXES OF MN(II), FE(II), CO(II), NI(II) AND ZN(II)

Equilibria in solutions containing bivalent metal ions (M=Mn, Fe, Co, Ni and Zn) and ascorbic acid (H(2)Asc) were examined by spectrophotome try. It has been found that complexes [M(HAsc)(n)] were formed at pH f rom 5.5 to 6.5 while in slightly alkaline and medium (pH 7.8-9.0) [M(A sc)(n)] respectively. Stability constants of these complexes were dete rmined by the Yatsymirskii-Budarin's method.