Determination of ultratrace amounts of osmium using catalytic wave of OsO4-bromate system by voltammetric method

Highly sensitive catalytic waves of OsO4-bromate linear sweep voltammetric and square wave voltammetric techniques were proposed for the determination of ultratrace amounts of osmium. Under optimized conditions, the catalytic linear sweep voltammetric procedure gives excellent reproducibility and li mits of detection and a linear dynamic range and gives a low signal for bac kground, whereas the square wave voltammetric technique gives higher sensit ivity, but the background signal was high and the linear dynamic range was narrower. The methods are suitable for the determination of osmium as osmiu m tetroxide as low as 1.5x10(-10) mol/l. The currents are linear for the co ncentration ranges of 0.10 - 210.0 ng/ml and 0.20 - 2.0 ng/ml for linear sw eep voltammetry and square wave voltammetry, respectively.