锇Ⅳ催化抗坏血酸还原三溴偶氮胂的褪色反应特性及痕量锇的测定

The Catalysis of Osmium Ⅳin Tribromineo-arsenazo-Ascorbic Acid Decolorizing Reaction and Determination of Trace OsmiumⅣ

研究了在盐酸介质中 ,在活化剂磷酸存在下 ,Os 催化抗坏血酸还原三溴偶氮胂的褪色反应特性 ;测定了反应级数和表观活化能 ;拟定了反应的最佳条件 ,建立了测定痕量锇的新方法。在 85± 0 .0 5℃水浴中加热 8min ,测定的检出限为 3.6 5× 10 - 8g L ,线性范围为 0～ 4 .0 μg L ,相对标准偏差为 2 .8%～ 2 .9%。用于合金和催化剂样品中锇的测定 。

The decolorizing reaction character of tribromineo arsenazo ascorbic acid with osmium? as a catalyst and of H 3PO 4 as an activator has been investigated. The order of the reaction and apparent activation energy has been determined. A new catalytic kinetic spectrophotometric method for the determination of trace osmium? was proposed. The detection limit is 3.65×10 -8 g/L and linear range is 0～4.0 μg/L for osmium?. The method has been applied to the determination of trace osmium in samples of alloy and catalyst with satisfactory results and the relative standard deviation is 2.8%～2.9% ( n =6).