在阳离子表面活性剂存在下锇与对硝基苯基荧光酮显色反应的研究

Spectrophotometric Determination of Osmium With 2,3,7-Trihydroxy-9-(p-Nitrophenyl)fluorone and Cetyltrimethylammonium Bromide

本文研究了在CTMAB存在下锇的分光光度测定新方法。络合物最大吸收峰位于570nm,摩尔吸光系数ε_(570)=1.0×10~5L·mol^(-1)·cm^(-1)。反应的pH为7.2～7.8。锇含量在0～7.0μg/10mL范围内服从比尔定律。锇在络合物中与p-NPF的摩尔比有1:1、1:2两种。采用蒸馏法锇能与所有金属离子分离,使该测定锇的方法具有专一性。用于人工合成样及矿样的分析结果满意。对显色反应机理进行了初步探讨。

In the presence of cetyltrimethylammonium bromide and sodium phosphate buffer solution at pH 7.2～7.8, osmium reacts with 2,3,7-trihydroxy-9-(p-nitrophenyl) fluorone (NPF) to form a purplish blue complex by heating in boiling water bath for 2 min. The apparent molar absorptivity is 1.0×10~5L·mol^(-1)·cm^(-1) at 570nm. Beer's law is obeyed in the osmium concentration range of 0～7.0μg/10ml. The composition of the complex is 1:1 and 1:2 (Os:NPF). The interference of all metaI ions is eliminated by distilling. The reaction proceeds with high sensitivity and selectivity after separating metal ions, and is a new method for the direct determination of Os(Ⅳ). It has been successfully applied to the determination of Os(Ⅳ) in synthetic samples and ores with satisfactory results.