一阶导数吸光光度法同时测定铜和锌的研究

Study on simultaneous determination of copper and zinc by first derivative spectrophotometry

提出了用一阶导数吸光光度法同时测定铜和锌的方法,在pH10.5的Na2B4O7-Na0H缓冲溶液中,铜、锌与PAPC形成稳定的配合物,配合物一阶导数光谱等吸收点分别在504,492nm,铜配合物在492nm处有负吸收,而锌配合物在504 nm处有正吸收,记录混合体系在两波长处一阶导数值可以分别测定铜、锌含量,互不影响,铜、锌含量分别在1.0～18μg/25ml、0.5～20μg/25 ml范围内呈良好线性,用于测定人发和血清中铜、锌含量,结果满意.

A new method for Simultaneous determination of Cu and Zn by first derivative spectrophotometry is reported in this paper. In the pH=10. 5 buffer medium, the reagent PAPC react with Cu(Ⅱ) and Zn(Ⅱ) to form stable complexes, It can be seen from the first derivative absorption spectrum Cu(Ⅱ)-PAPC has a negative absorption at 492nm and the complex Zn(Ⅱ)-PAPC has a positive absorption at 504nm, It is proposed that copper and zinc can be determined at the above mentioned wavelength respectively where the co-existing component (eg, the presence of Zn(Ⅱ) in the determination of Cu(Ⅱ) and vise versa)show a zero absorption. Thus, the interference between Cu( Ⅱ ) and Zn( Ⅱ ) is avoided, Beer's Law is obeyed in the concentration range of 1.0 -18μg/25ml for copper and 0. 5-20μg/25ml for zinc. The proposed method has been applied to the analysis of hair and blood with satisfactory results.