Separation of nickel and cobalt by controlled potential coulometer:

Reagents: Standard nickel and cobalt ion solution was prepared through dissolving pure ammonium nickel sulphate and ammonium cobalt sulphate (10 mg cm^-3) correspondingly within water.

Pyridine A.R grade pyridine sample is used.

Supporting electrolytes: 1.00 M pyridine and 0.5 M chloride ion and adjust to pH 7.0 ± 0.2, while silver anode is used. 1.00 M pyridine, 0.30 M. Chloride ion and 0.2 M hydrazinium sulphate and adjust to the pH to 7.0 ± 0.2 while Pt is used as the cathode. A small background current is acquire is the last case.