Estimation of Ruthenium

Estimation of Ruthenium may be performed by precipitation with magnesium from solutions of its salts. The precipitate is washed with dilute sulphuric acid to remove excess of magnesium, dried, ignited in a current of hydrogen, cooled in carbon dioxide, and weighed as metal.

Ruthenium may be precipitated from solutions of its salts with hydrogen sulphide in the form of ruthenium sesquioxide. This is washed, dried, and ignited in a platinum boat in a current of oxygen to expel the sulphur, reduced in hydrogen and weighed as metal.

Ruthenium may be separated from all metals except osmium by distilling in alkaline solution in a current of chlorine at 70° C. The ruthenium distils over as tetroxide, and is collected in dilute hydrochloric acid. The liquid in the distilling-flask must be kept alkaline to prevent iridium chloride from distilling over with the ruthenium. The distillate is evaporated to dryness, and the residue ignited in hydrogen, cooled in carbon dioxide and weighed as metal.