Purification Methods
Dissolve it in H2O and evaporate until crystals are formed. The crystals are iridescent green prisms which appear red in thin films. A possible impurity is RuO4; in this case wash with CCl4 (which dissolves RuO4). The concentration of an aqueous solution of RuO42-(orange colour) can be estimated from the absorbance at 385nm ( 1030 M-1 cm -1), or at 460nm ( 1820 M-1 cm-1). [Lee et al. Can J Chem 50 3741 1972, Connic & Hurley J Am Chem Soc 74 5012 1952, Grube et al. Handbook of Preparative Inorganic Chemistry (Ed. Brauer) Academic Press Vol II p 1600 1965].
