萃取/反相萃取分离富集-氢化物无色散原子荧光法测定复杂地质样品中的痕量碲

采用MIBK萃取/反相萃取分离富集的方法,建立了氢化物无色散原子荧光法测定复杂地质样品中的痕量碲的新方法.实验了HCI-NaBr-MIBK体系萃取Te(Ⅳ)的能力,研究了Te(Ⅳ)在KMnO4-HCI-MIBK体系中的反相萃取行为.当萃取条件为3.6 mol·L-1 HCI-100 g·L-1NaBr时,Te(Ⅳ)可被MIBK完全萃取;用HCI-KMnO4氧化MIBK相中的Te(Ⅳ),水相反相萃取Te(Ⅵ),成功分离了氢化物原子荧光法测定Te的Au,Ag,Pt,Pd,Cu,Pb,Co,Ni,Cd,As,Sb,Bi,Hg,Tl和Se等干扰元素,方法检出限为1.14×10-4μg·g-1,相对标准偏差为6.84%,对国家标准物质样品分析的结果与所给参考值吻合,可用于复杂地质样品中痕量Te的测定.

Separation and Preconcentration by Extraction and Anti-Extraction-Determination of Trace Te in Complex Geological Samples by Hydride Generation Atomic Fluorescence Spectrometry

A method for the determination of trace Te in the complex geological samples by hydride generation atomic fluorescence spectrometry using MIBK as extraction reagent was developed. The extraction ability of Te(Ⅳ) in the HCl-NaBr-MIBK system and the anti-extraction behavior of Te(Ⅳ) in the HCl-KMnO4-MIBK system were studied. Under the optimum extraction condition of 3.6 mol·L-1 HCl-100 g·L-1 NaBr, Te(Ⅳ) was extracted completely by MIBK, Te(Ⅳ) in the MIBK phase was oxidized to Te(Ⅵ) with HCl-KMnO4, Te(Ⅵ) in the MIBK phase was anti-extracted using water, then the interference elements such as Au, Ag, Pt, Pd, Cu, Pb, Co, Ni, Cd, As, Sb, Bi, Hg, Tl and Se for the determination of Te by hydride generation atomic fluorescence spectrometry were eliminated successfully. The detection limit of Te was 1.14 10-4 μg·g-1, and the relative standard deviations of Te was 6.84%. The method was applied to complicated geological samples.