火焰原子吸收光谱法中铁对微量锌测定的光谱干扰研究

在利用火焰原子吸收光谱法测定微量Zn时，Fe在Zn吸收波长215．856nm处有显著的谱线重叠干扰。本文研究了火焰原子吸收光谱法中，Fe共存时对微量Zn测定的干扰以及校正情况。实验考察不同校正方法（塞曼效应校正法、氘灯校正法、Smith-Hieftje校正法）对Fe、Zn干扰的校正情况，这些方法都不能有效消除Fe对Zn的干扰。通过利用高分辨连续光源原子吸收光谱法对Fe、Zn的干扰情况研究表明，在一定的Fe浓度范围内（0-700mg·L^-1）利用高分辨连续光源原子吸收光谱法可以进行多元素顺序测定的特点，及线阵CCD检测器对吸收谱线轮廓具有的可视化的性能，通过联立方程组进行数据处理可以有效的校正Fe对微量Zn元素测定的吸收谱线重叠干扰。这为准确测定不同含Fe（浓度小于700mg·L^-1时）样品中微量Zn的浓度提供一个切实可行的方法．

Correction of Iron Spectral Overlap Interference for Zinc Measurement Using Flame Atomic Absorption Spectrometry

In measurements of trace zinc in iron matrices using atomic absorption spectrometry （AAS）, there is spectral interference of the zinc absorption at 213.856 nm by the iron absorption at 213.859nm. We found that this spectral interference by the iron absorption cannot be effectively eliminated using three current methods for background correction （Zeeman effecting, Lamp D2, and Smith-Hieftie）. In this paper we described a background correction method developed to eliminate the iron absorption interference of trace zinc measurement in iron matrices. This method is based on sequential determination of iron and zinc using high-resolution continuum source AAS （HR-CS AAS）, taking advantage of the properties of the continuum source and the CCD array detector for making the spectral environment visible at higher resolutions on both sides of the analytical line. With this method, employing simultaneous equation data processing, we were able to effectively eliminate the iron absorption interference of zinc measurements at trace levels when the iron concentration was less than 700 mg/L. This background correction method should be generally applicable for measurements of trace-level zinc in iron matrices using AAS （when Fe is at 〈 700 mg/L）.