摘要
研究了试剂2_(5_溴_2_吡啶偶氮 )_5_二甲氨基苯胺 (5_Br_PADMA)与铱 (Ⅲ )的显色反应 ;在 pH4.75～6.00的HAc -NaAc缓冲溶液中 ,铱 (Ⅲ )与5_Br_PADMA形成摩尔比为1∶2型稳定的红色络合物 ,在0.6mol/LH2SO4溶液中 ,其最大吸收波长为558nm ,表观摩尔吸光系数为5.1×104L/(mol·cm) ,铱 (Ⅲ )含量在0～0.8mg/L范围内符合比尔定律 ,采用加入适量EDTA的方法消除了Fe3 + 、Co2 + 、Ni2 + 等干扰离子 ,建立了在二元络合物体系中测定微量铱 (Ⅲ )的灵敏度高、选择性好、简便。
The colour reaction of iridium(Ⅲ) with reagent 2 _ (5 _ bromo _ 2 _ pyridylazo) _ 5 _ dimethylamino _ amino_ benzene(5 _ Br _ PADMA) was investigated. In the HAc-NaAc medium at pH 4.75～6.00 iridium(Ⅲ) reacts with 5 _ Br _ PADMA to form a stable red complex, in which the stoichiometric ratio of iridium(Ⅲ) to 5 _ Br _ PADMA is 2∶1. In the medium of 0.6 mol/L H2SO4 the complex has a maximum absorption at 558 nm and an apparent molar absorptivity of 5.1×104 L/(mol·cm). Beer's law is obeyed in the range of 0～0.8 mg/L for iridium(Ⅲ). No significant interference of common anions and cations was observed except Fe3+, Co2+ and Ni2+, which interference can be eliminated using EDTA as a masking agent. On these grounds a method for the determination of trace iridium(Ⅲ) was established in a binary complex system by spectrophotometry. The method is simple, selective and sensitive.
出处
《分析测试学报》
CAS
CSCD
北大核心
2003年第3期51-53,共3页
Journal of Instrumental Analysis
基金
陕西省教育厅专项科研计划项目 (00JK132)
