Co-crystallization of ultramicro quantities of cobalt with α-nitroso-β-naphthol

The co-crystallization of ultramicro quantities of cobalt with α-nitroso-β-naphthol, was investigated by radio-tracer techniques. More than 99% cobalt, even when carrier-free, could be recovered. The distribution was studied and appeared to follow the logarithmic distribution law. The interference of a large excess of zinc was almost negligible. The method was applied to tlie carrier-free separation of cobalt isotopes (⁵⁵Co, ⁵⁶Co, ⁵⁷Co, ⁵⁸Co) produced by deuteron bombardment of an iron target. Contamination by manganese (⁵⁴Mn, ⁵²Mn) and iron (⁵⁹Fe) was, even in the absence of manganese carrier, almost negligible.