原子吸收光谱法测定高纯稀土中的微量铜

A determination on trace copper of highly purity RE by atomic absorption spectrometry

应用钨丝灯和原子吸收分光光度计(AAS)对胡椒基荧光酮(PIF)与铜的显色反应进行了研究。结果表明 :在pH5.8～6.6的六次甲基四胺 -HCl缓冲介质中和十六烷基三甲基溴化铵存在下 ,Cu2 +与PIF形成稳定的1∶2的蓝紫色配合物。其最大吸收峰为585nm,负峰为525nm。正负峰吸光度绝对值之和与Cu2 +浓度线性相关 ,铜的质量浓度在0～0.2μg·mL-1 范围内符合比耳定律 ,表观摩尔吸光系数 ε585,525 为1.56×105L·mol-1·cm-1。方法用于高纯稀土氧化物中微量铜的测定 ,结果满意。

The colour reaction between Cu2+ and piperonal fluorone(PIF)has been studied by using tungsten wire light and atomic absorption spectrophotometer.The study results show the blueviolet complex formed between Cu2+and piperonal fluorone(PIF) with(CH 2)6N 4-HCl buffer medium and CTMAB , the pH value is 5 .8～6 .6 and the proportion is 1∶2.The measuring and reference wavelengths are 585nm and 525nm respectively, the absorptivity is 1.56×10 5 L·mol-1cm-1. Beer′s law is obeyed in the range of 0～0.2 μg·m L-1 for Cu2+. The above method has been applied in the determination of trace Cu2+ in highly pure RE oxides.