Rapid simultaneous determination of ruthenium and osmium in aqueous solutions of their tetroxides by second-order derivative spectrophotometry

Direct and simple spectrophotometric methods for the simultaneous determination of ruthenium and osmium in aqueous solutions of their tetroxides are described. The methods are based on the calculation of derivative spectra of RuO4and OsO4 in water. The second-order derivative values of RuO4 at 310 nm (the ‘zero-crossing’ point of osmium) and of OsO4 at 250 nm (the ‘zero-crossing’ point of ruthenium) can be used for the determination of the concentration of ruthenium and osmium, respectively. Beerʹs law is obeyed up to 32 μg Ru ml−1 and 40 μg Os ml−1 in the examined solutions. Using the developed methods 97.3 μg Ru ml−1 and 95.8 μg Os ml−1 in a plasma standard solution of the noble metals were determined.