摘要
利用分光光度法研究了试剂5-(5-碘-2-吡啶偶氮)-2,4-二氨基甲苯(5-I-PADAT)与铱(Ⅲ)的显色反应。结果表明,在HAc-NaAc缓冲介质(pH 5.5～6.8)中,铱(Ⅲ)与5-I-PA-DAT形成1∶2的稳定络合物,以强酸酸化,可转化为另一种具有较高吸收特性的质子化型体,灵敏度显著提高。在1.2mol/L H2SO4溶液中,络合物呈现分别位于542nm和584nm的两个吸收峰,表观摩尔吸光系数为ε584=5.9×104 L.mol-1.cm-1。铱含量在0.03～1.0μg/mL范围内符合比尔定律。方法应用于催化剂中铱的测定,测定值与参考值相符,相对标准偏差为0.52%。
The color reaction of 5-（5-iodine-2-pyridylazo）-2,4-diaminotoluene（5-I-PADAT） and iridium（Ⅲ） was investigated by spectrophotometry.The results showed that iridium（Ⅲ） and 5-I-PADAT could form stable complex（1∶2） in HAc-NaAc buffer solution（pH 5.5-6.8）.After acidification with strong acid,the complex could be converted to another protonized form with high absorption characteristic,significantly enhancing the sensitivity.In 1.2 mol/L of H2SO4 solution,the complex exhibited two absorption peaks at 542 nm and 584 nm,respectively.The apparent molar absorptivity was ε584=5.9×104 L·mol-1·cm-1.Beer＇s law was obeyed for iridium（Ⅲ） in the range of 0.03-1.0 μg/mL.The proposed method has been applied to the determination of iridium in catalyst.The result was consistent with the reference value and the relative standard deviation（RSD） was 0.52%.
出处
《冶金分析》
CAS
CSCD
北大核心
2011年第9期59-62,共4页
Metallurgical Analysis
基金
陕西省自然科学基础研究计划项目(编号:2010JM2018)
