碘化钾-甲基异丁基甲酮萃取-火焰原子吸收分光光度法连续测定地球化学样品中痕量银镉铊  

Continuous Determination of Trace Silver,Cadmium and Thalliumin Geochemical Samples by Flame Atomic Absorption Spectrophotometry with KI-MIBK Extraction

作　　者：肖凡[1] 徐崇颖[1] 邢刚[1] 付爱瑞[1] 

机构地区：[1]河北省地矿中心实验室,河北保定071051

出　　处：《岩矿测试》2007年第1期67-70,共4页Rock and Mineral Analysis

基　　金：河北省地勘局科技计划项目(0401)

摘　　要：研究了碘化钾-甲基异丁基甲酮（KI—MIBK）萃取-火焰原子吸收分光光度法连续测定地球化学样品中痕量银、镉和铊的主要条件。通过对火焰原子吸收分光光度计气路控制系统及雾化器的改进，较大地改善了萃取-火焰原子吸收分光光度法测定银、镉和铊的稳定性和灵敏度。选择萃取酸度为1．2mol／L HCl、水相和有机相体积配比为3：1～4：1，方法精密度（RSD，n=12）为Ag4．5％～9．6％、Cd1．5％～7．9％、T14．5％～5．4％，检出限（3s）为Ag0．004μg/g、Cd0．007μg／g、T10．011μg/g，符合多目标地球化学调查样品测试及质量监控要求。用国家一级标准物质和密码组合标准物质进行验证，测试结果令人满意。A method for continuous determination of trace Ag, Cd and T1 in geochemical samples by flame atomic absorption spectrophotometry with KI-MIBK extraction was developed. The sensitivity and signal stability for these elements were remarkably improved by modification of gas control system and nebulizer of flame atomic absorption spectrophotometer. The extraction condition was also optimized with l. 2 mol/L HC1 extraction system and phase ratio （A/O） of 3 ： 1 - 4 ： 1. At the optimum conditions the detection limits （3s） were 0. 004 μg/g for Ag, 0. 007μg/g for Cd and 0.011 μg/g for T1. The precisions （RSD, n = 12） of the method for Ag, Cd and T1 were 4.5% - 9.6%, 1.5% - 7.9% and 4.5% - 5.4% respectively. The method has been applied to the determination of these elements in internal control samples and National Standard Reference Materials with sarisfactory results.

关 键 词：碘化钾-甲基异丁基甲酮萃取 气路控制系统及雾化器改进 火焰原子吸收分光光度法 银 镉 铊 地球化学样品 

分 类 号：O657.31[理学—分析化学] O614.122[理学—化学]