甲基异丁酮-N,N-二甲基甲酰胺萃取石墨炉原子吸收法测定植物样品中微量锗

Determination of Trace Germanium in Plants by Graphite Furnace Atomic Absorption Spectrometry With Methyl Iso-butyl Ketone and N,N-Dimethylformamide Extraction

本文研究了用钼酸铵浸渍处理石墨管,石墨炉原子吸收法测定锗时的最佳条件。实验证明,锗与苯基萤光酮形成螯合物溶胶萃取在甲基异丁酮(MIBK)中,溶解在N,N-二甲基甲酰胺(DMF)中,用氨水作为基体改进剂,涂钼热解石墨管可使测定锗的灵敏度提高约20倍,可以直接测定人参及其它植物样品中的微量锗,灵敏度(1％吸收)为1.07×10^(-11)g,检测下限为2.20×10^(-10)g,相对标准偏差3.4％～7.6％,回收率为97％～103％。

The optimal conditions for the determination of germanium were studied by gra phite furnace atomic absorption spectrometry using graphite tube impregnated and treated with ammonium molybdate. The experimental results show that chelates of germanium and phenylfluorone could be extracted by methyl iso-buthyl ketone and dissolved by N,N-dimethylformamide. Using ammonium hydroxide as a matrix modifier, the sensitivity of germanium was 20 times as high as that in graphite furnace one. The method was used to determine trace germanium in Ginseng and other plants directly.The sensitivity (1％A), detection limit, relaive standard deviation and recovery were 1.07×10^(-11), 2.20× 10^(-10)g, 3.4％～7.6％ and 97％～103％, respectively.