多波长分光光度法同时测定Fe、Cu、Cr、Ni

研究多波长分光光度法对Fe、Cu、Cr、Ni 4 种金属同时定量分析.考察了通常存在的Ca、Mg、Zn对测定的干扰，确定了4 种金属的最佳吸收波长，并在特定波长下测定摩尔吸光系数，建立了完整的线性方程.采用本方法对配制的Fe、Cu、Cr、Ni 混合溶液进行测定，验证其线性方程的准确性，结果表明其相对误差在±5 %以内.考虑不同样品金属离子的含量不同，对多波长分光光度法进行了测定下限的研究.结果表明:采用本方法Fe、Cu、Cr、Ni 的测定下限分别为5×10-4 mg/mL、1×10-3 mg/mL、5×10-3 mg/mL、5×10-3 mg/mL， 在此浓度以上的样品均可获得可靠的定量分析结果. 最后对实际电镀污泥中Fe、Cu、Cr、Ni 的含量进行测定，分析测定结果与原子吸收分光光度法是一致的. 

Simultaneous determination of iron,copper, chrome,nickel by multi-wavelength spectrophotometry

Through multi-wavelength spectrophotometry, the contents of four kinds of metal ions （Fe, Cu, Cr, Ni） can be determined simultaneously in this paper. The interferences of usually existing ions of Ca, Mg, Zn on measurement are discussed, and the best absorption wavelengths of the four metal ions are found out. The molar absorption coefficient under the specific wavelength is determined, and the complete linear equation is established. To verify the accuracy of the linear equations, the prepared mixed solution of Fe,Cu,Cr,Ni is measured by this method, and the result shows that the relative error can be controlled within ±5 %. Considering the content of metal ions can be varied in different realistic samples, the lower limit of this method was studied. The experimental result shows that the lower limit of Fe, Cu, Cr, Ni are 5×10-4 mg/mL, 1×10-3 mg/mL, 5×10-3 mg/mL, 5×10-3 mg/mL, respectively, and the reliable result of quantitative analysis can be obtained when the concentration of samples can exceed that. Finally, the content of Fe, Cu, Cr, Ni in electroplating sludge are measured, and the result is consistent with atomic absorption spectrophotometry.