STUDIES ON THE SEPARATION OF OSMIUM BY FLOTATION AND SPECTROPHOTOMETRIC DETERMINATION WITH CRYSTAL VIOLET AND MALACHITE GREEN

A solvent flotation technique was used for the separation of osmium from aqueous solutions in the form of the ion associates of the anionic complexes OsCl6(2-) and OsCl2(SnCl3)2(2-) with two basic dyes, Crystal Violet and Malachite Green. A sensitive spectrophotometric method for the determination of osmium based on the system osmium-tin(II) chloride-Crystal Violet-cyclohexane (epsilon = 2 x 10(5) l mol-1 cm-1) was developed. Aqueous acetone solutions of the ion associate examined obey Beer's law in the range 0.04-1.0 mu-g Os ml-1. The relative standard deviation is 1-6%. Ruthenium interferes with the determination of osmium.