主成分回归光度法选择性测定稀土物料中的铁

Determination of Iron(Ⅲ) in the Rare Earth Samples by Principal Component Regression Spectrophotometry

混合物中未知干扰背景下已知组分的选择性测定 ,是分析化学中有意义的课题。本文基于铬天青S -CTMAB与Fe3 +显色体系中吸收光谱灵敏度高但选择性差的特点 ,应用主成分回归法处理校正样吸光度数据 ,并根据校正样中的Fe3 +浓度向量求算浓度转换向量 ,转换向量求出后就可对任意待测样吸光度向量进行转换从而求出Fe3 +浓度。本方法对含有干扰背景的人工合成样及几种实际稀土样品中Fe3 +的分析均取得了满意结果。

Because of the high sensitivity and bad selectivity for CAS- iron(Ⅲ) color system,the principal component regression method for selectively determination of iron(Ⅲ) in the rare earth mixtures is developed and described. In the method, the transformation vector from abstract concentration matrix to true concentration was calculated with a set of standard samples and the principal component matrix. When having determined the transformation vector, it is used to predict the content of iron(Ⅲ) in unknown samples. The method here has been successfully applied to determine iron(Ⅲ) in the synthetic samples and some rare earth samples.