5-(5-硝基-2-吡啶偶氮)-2,4-二氨基甲苯分光光度法测定微量铱(Ⅲ)的研究  

Spectrophotometric Determination of Micro Amount Iridium Using 5-(5-Nitro-2-pyridylazo)-2, 4-diamino-toluene

作　　者：周艳梅[1,2,3] 王贵方[1,2,3] 张光 

机构地区：[1]陕西师范大学化学系 [2]河南开封师专化学系 [3]河南安阳师专化学系

出　　处：《冶金分析》1998年第3期14-16,共3页Metallurgical Analysis

摘　　要：研究了用新试剂５－（５－硝基－２－吡啶偶氮）－２，４－二氨基甲苯（５－ＮＯ２－ＰＡＤＡＴ）分光光度法测定微量铱（Ⅲ）的适宜条件。结果表明，在ｐＨ５．０－６．４的ＮａＡｃ－ＨＡｃ缓冲溶液中，５－Ｎ０２－ＰＡＤＡＴ与Ｉｒ（Ⅲ）反应生成稳定的络合物。在０．１２ｍｏｌ／ＬＨ２ＳＯ４溶液中其最大吸收波长，表现摩尔吸光系数铱浓度在０－０．７ｕｇ／ｍｌ范围内遵守比尔定律。以ＤＣＴＡ为掩蔽剂。大量的常见金属离子对测定无干扰，方法灵敏度高，选择性好，用于催化剂中微量铱的测定，结果满意。A sensitive and selective method for the spectrophotometric determination of micro amount iridium is reported. The results show that Ir(Ⅲ) reacts with 5-(5-nitro-2-pyridylazo)-2,4-diamino-toluene to form stable red* complex(1:2)in the HAc-NaAc medium at pH5.0-6.4. The complex can clanged into another species in 0.12mol/L* H2SO4 mediuom. The apparent molar absorptivity is 5.1 x104L·mol-1 · cm-1 at 564nm. Beer's law is obeyed in* the range of 0-0.7ug/ml for Ir. In the presence of DCTA,most common ions do not interfere. The method has applied to the determination of trace iridium in a catalyst with satisfactory results.

关 键 词：铱 分光光度法 显色剂 

分 类 号：O614.825[理学—无机化学]