石墨炉原子吸收法测定海水痕量元素中有机基体改进剂作用机理

The Mechanisms of Organic Matrix Modifiers Used for the Determination of Trace Elements in Seawater by GFAAS

在用石墨炉原子吸收法直接测定海水中的痕量元素Cd、Pb、Cu、Co、Ni、V、Se、As、Mn和Cr中发现,所选用的有机基体改进剂如柠檬酸、酒石酸和抗坏血酸等,可以有效地消除海水的基体干扰。本文详细地探讨了有机基体改进剂的作用机理。有机基体改进剂主要几种作用为:助熔,阻止分析元素与海水形成共挥发体,降低分析元素的挥发度以及形成强的还原气氛。

Organic matrix modifiers such as citric acid, tartaric acid and ascorbic acid have been usedfor the determination of Cd, Pb, Cu, Co, Ni, V, Se, As, Mn, and Cr in seawater by GFAAS.Matrix interferences of seawater are completely eliminated by using appropriate organic matrixmodifier for each element. The mechanisms of their eliminating effects are discussed in detail.Generally, the organic matrix modifiers act as flux; prevent the analyte forming covolatile com-pound with the matrix and create strong reduction atmosphere.