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

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(CH₂)₆N₄ -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 1.56×10⁵ L· mol^-1 cm^-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.