Ir(Ⅳ)-KBrO_3-DBS-偶氮氯膦催化分光光度法测定微量铱的研究

Catalytic Spectrophotometric Determination of Iridium in the Iridium(Ⅳ) Potassium Bromate DBS Chlorophosphonazo System

ＫＢｒＯ３－ＤＢＳ－偶氮氯膦在０．８ｍｏｌ·Ｌ－１的Ｈ２ＳＯ４介质中长时间加热亦无明显退色现象，但在有微量铱存在时，褪色反应在３ｍｉｎ内完成，且与Ｉｒ（Ⅳ）的浓度有良好的线性关系．据此建立了微量铱的催化褪色分光光度分析法．其检出限为０．０１μｇ·１０ｍＬ－１，铱的含量在０．０１－０．２０μｇ·１０ｍＬ－１范围内符合比尔定律．

A new catalytic spectrophotometric method for the determination of Iridium was established based on the catalytic action of Ir(Ⅳ) on the oxidative fading between 2 (4 chloro 2 phosphonophenyl)azo 7 (2,6 dibromo 4 sulfophenyl)azo 1,8 dihydroxy 3,6 naphthalenedisulfonic acid and KBrO 3 in the acid medium. Beers law is obeyed in the range of 0.01-0.20μg Ir/10mL.