泡沫塑料富集-石墨炉原子吸收光谱法测定地质样品中微量铊

Determination of Trace Thallium in Geological Samples by Plastic Foam Preconcentration Graphite Furnace Atomic Absorption Spectrometry

采用HF-HClO4-HNO3-HCl溶解样品，泡沫塑料富集-石墨炉原子吸收光谱法测定岩石、土壤、水系沉积物等地质样品中微量铊。以抗坏血酸为基体改进剂，Fe^3＋加入量选择100mg，灰化温度为600℃，原子化温度为1600℃。方法用于测定国家一级标准物质，结果与标准值基本一致。方法精密度（RSD，n=8）为2．88％～6．27％，回收率为95．24％～101．3％，检出限可达0．058μg/g。

A method for the determination of trace thallium in geological samples （rocks, soils and stream sediments） using plastic foam preconcentration graphite furnace atomic absorption spectrometry（GFAAS） was developed. HF-HClO4-HNO3-HCl mixed acid was used for sample digestion and plastic foam was used for the concentration of thallium. The trace thallium in the samples was determined by GFAAS with ascorbic acid as matrix modifier, ashing temperature at 600℃ and atomisation temperature at 1600℃. The method has been verified by analyzing the National Standard Reference Materials and the results are in good agreement with the recommended values. The detection limit of the method for Tl is 0.058 μg/g with recovery of 95.24%～101.3% and precision of 2.88%～6.27% RSD （n = 8）.