【摘要】 研究了显色剂偶氮氯膦 -mA在酸性介质中与Nb(Ⅴ )的显色反应。在HNO3 介质中 ,阿拉伯树胶存在下 ,偶氮氯膦 -mA与铌形成 2∶1的络合物 ,其最大吸收波长为 63 0nm ,摩尔吸光系数为 9.0 9× 1 0 4L·mol-1·cm-1,铌的质量浓度在 0～ 0 .40mg/L符合比尔定律。试验了3 0多种共存离子的影响 ,结果表明大多数离子对测定铌无影响 ,且体系可允许 1 0余倍量的Ta(Ⅴ )存在。方法经标准样品分析验证 ,铌的测定结果与标准值相符 ,标样及样品分析的RSD≤7.3 % (n =8)。更多还原

【Abstract】 The chromatogenic reaction of CPA mA with niobium in strong acid medium was studied. In the optimized conditions niobium reacts with CPA mA to form a complex with n Nb(Ⅴ) ∶ n R = 1∶2. The maximum absorption is at 630 nm with apparent molar absorptivity of 9.09×10 4 L·mol -1 ·cm -1 . Beer’s law was obeyed in the concentration range of 0～0.40?mg/L for Nb. More than 30 coexistent elements were examined and no serious interference was observed. The method has been applied to the determination of Nb(Ⅴ) in standard samples and the results are in agreement with certified values with precision of 3.5%～7.3% RSD ( n =8).更多还原