An investigation of the nickel gluconate system

Abstract

Spectrophotometric, polarographic, conductometric, and potentiometric techniques were used to examine the nickel gluconate system. Three complex species were identified: a cationic species, NiG⁺, in solutions of pH < 7; an anionic complex, Ni₂(OH)₄G^-, in solutions of pH > 9; and an insoluble product, Ni₂(0H)₃G, in solutions of pH 7-9; the symbol G represents the gluconate ion CH₂0H(CHOH)COO^-. Values have been calculated for the dissociation constants of these three species at 25°.