利用混合线性分析分光光度法同时测定微量铜、锌、镍

Simultaneous spectrophotometric determination of trace copper, zinc and nickel with hybrid linear analysis method

研究以5 Br PADAP为显色剂,用混合线性分析分光光度法同时测定铜、锌、镍。在pH8.2的硼砂 盐酸缓冲溶液中,Cu2+、Zn2+、Ni2+分别与5 Br PADAP形成稳定的配合物,其吸收光谱相互重叠。用一种新的数学模型,即混合线性分析进行光谱分辨,各组分的纯光谱则用最小二乘法求得。讨论了反应条件、测量波长的选择等因素的影响。铜、锌、镍的标准回收率分别为95.0%～102.5%、94.2%～101.3%和96.2%～104.2%。应用于铝合金中铜、锌、镍的同时测定。

Simultaneous spectrophotometric determination of copper, zinc and nickel using 5-Br-PADAP as the color developing reagent with hybrid linear analysis (HLA) method was studied. In borax-HCl buffer solution of pH 8.2, Cu^(2+), Zn^(2+) and Ni^(2+) formed stable complexes with 5-Br-PADAP, respectively. The absorption spectra of these three complexes had similar features with severe overlapping spectra in visible spectral range. The hybrid linear analysis was applied to resolve these spectra, and the pure spectrum of each component was obtained by the least squares method. The effects of coloring reaction condition , selection of wavelengths and additivity of absorbances. on the determination were discussed. The recoveries of copper, zinc and nickel for the analysis of the standard mixtures were in the rang of 95.0%～102.5%, 94.2%～101.3% and 96.2～104.2%, respectively. This method was applied to simultaneous determination of copper, zinc and nickel in aluminum alloy samples with satisfactory results.