偶氮胂Ⅲ催化光度法测定锇  

Catalytic spectrophotometric determination of osmium using arsenazo Ⅲ

作　　者：李祖碧[1] 曹秋娥[1] 侯能邦 徐其亨[1] 

机构地区：[1]云南大学 [2]曲靖师范专科学校

出　　处：《黄金》1999年第12期43-45,共3页Gold

摘　　要：在硫酸和热水浴中，Ｏｓ（ Ⅳ） 催化高碘酸钾氧化偶氮胂Ⅲ褪色，建立了测定锇的新催化光度法。锇质量浓度在０ ～０－１０μｇ／２５ｍｌ 范围内符合比尔定律，检出限为９－７ ×１０ － ５μｇ／ｍｌ。对０－０５０μｇ／２５ｍｌ Ｏｓ（ Ⅳ） 测定的相对标准偏差为１－２８ ％ （ｎ ＝ １１） 。催化反应的表观活化能为１０２－２ｋＪ／ｍｏｌ。催化反应对Ｏｓ（ Ⅳ） 和偶氮胂Ⅲ分别为一级反应。试验了４０ 多种共存离子的影响，允许５００ 倍量Ａｇ＋ ，４００ 倍量Ａｕ（ Ⅲ） 和Ｐｔ（ Ⅳ） ，２５ 倍量Ｐｄ（ Ⅱ） 、Ｉｒ（ Ⅳ） 及Ｃｕ２ ＋ 存在。该方法已用于岩矿和冶金产品中锇的测定，相对标准偏差为０－６８ ％ ～３－９２ ％ ，标准加入回收率为９９－８ ％ ～１０３－０ ％ 。A new catalytic kinetic method for the determination of osmium was established based on the catalytic action of Os(Ⅳ) on the oxidative fading between arsenazo Ⅲ and KIO 4 in sulfuric acid medium on the hot water bath.Beer's law is obeyed in the range of 0 0.10μg/25ml;for Os(Ⅳ) ,and the detection limit was 9.7×10 -5 μg/ml.The relative standard deviation for 11 replicate measurements of 0 050μg/25ml for Os(Ⅳ) was 1.28% .The apparent activation energy of catalytic reaction is found to be 102.2kJ/mol.The reaction is first order with respectively to Os(Ⅳ) and arsenazo Ⅲ. The interference from 500 fold amounts of Ag + ,400 fold amounts of Au(Ⅲ) and Pt(Ⅳ),and 25 fold amounts of Pd(Ⅱ),Ir(Ⅳ) and Cu 2+ are adimissible.The method has been applied to the determination of trace osmium in some ores and metallurgical products. The RSD(n=8) were 0.68% 3.92% and recovery rate 99.8% 103.0%.

关 键 词：锇 高碘酸钾 偶氮胂Ⅲ 催化光度法 测定 

分 类 号：O614.824[理学—无机化学]