ICP-AES中基体干扰效应及其机理研究——Ⅱ.干扰现象的进一步探讨

MATRIX EFFECTS AND THEIR MECHANISMS IN ICP-AES

本文探讨了共存元素对碱金属以及Al对碱土金属的基体效应,测定了不同基体浓度、入射功率及载气压力时一般基体效应分布的变化,并观察了3种基体对Cd、Fe电离度的影响。在尾焰区,碱金属发射信号受到共存基体的明显增感,增感幅度随观察高度的增加而增大;Al基体对碱土金属产生抑制作用,抑制幅度随观察高度的升高而下降;基体干扰(增感或抑制)的幅度随基体浓度及载气压力的增加而增大,随入射功率的增加而减小。

The influences of the concentration of matrix elements, the forward power and the carrier gas flow on the matrix effects were examined. In the tail flame of ICP, the atomic line emission of analyte with low ionization potential is enhanced in the presence of metallic matrix elements(MME) with low ionization potential. Depression effects of aluminium on alkali-earth elements were observed. The degree of depression lessens with the increase of observation height. The magnitude of the matrix effects is proportional to the concentration of MME and to the carrier gas flow, but is inversely proportional to the forward power. The positions of the 'non-interference' points from enhancement to depression vary with the change of forward power or carrier gas flow.