Heterometric microdetermination of cobalt using nitron as titrant

Small amounts of cobalt (0.1–0.25 mg in 15 ml solution) were determined heterometrically in the presence of potassium thiocyanate by titration with nitron acetate solution. A strong electrolyte (Na₂SO₄) must be added to obtain a clear end point. The titration can be carried out in the presence of a number of diverse ions e.g., Cd²⁺, Ni²⁺, Pb²⁺, Mn²⁺, Cr³⁺, MoO₄^2?, WO₄², CrO₄^2?, NO₃^?, Au³⁺, Pt⁴⁺ without interference; Fe³⁺ can be masked with NaF. Copper and zinc interfere and must be absent. The titration takes about 2–3 min. and the maximum error was 1.5%.