Volatility of ruthenium during heating of a residue containing calcium phosphate

By heating a residue attained by the evaporation of a solution containing calcium phosphate, ruthenium and nitric acid, ruthenium volatilizes. The amount of ruthenium volatilized /both carrier-free¹⁰⁶Ru and milligram amounts of ruthenium/ depends on the composition of the solution before evaporation, on the temperature and time of residue heating. At 500 °C up to 90% of ruthenium can volatilize within six min.