甲基异丁基甲酮萃取－石墨炉平台原子吸收法测定地质样品中痕量硒和碲

Determination of Trace Selenium and Tellurium in Geological Samples by MIBK Extraction- Graphite Furnace Atomic Absorption Spectrometry

样品经ＨＮＯ＿３－ＨＦ－ＨＣｌＯ＿４分解，在５．４ｍｏｌ／Ｌ的ＨＣｌ介质中，以抗坏血酸为还原剂用甲基异丁基甲酮同时萃取样品中的Ｓｅ、Ｔｅ。以Ｐｄ和Ｎｉ作混合基体改进剂，使用自制的涂锆石墨平台直接测定有机相中的Ｓｅ、Ｔｅ。方法的检出限分别为０．２１×１０￣（－９）ｇＳｅ，０．１３×１０￣（－９）ｇＴｅ；测定０．０６ｇＳｅ、０．０３ｇＴｅ的ＲＳＤ（ｎ＝１１）分别为７．０％和８．９％。

he sample is decornposed by HNO_3-HF-HClO_4,and methyl isobutyl ketone(MIBK)isused to extract Second from a 5.4mol/L HCl-ascorbic acid medium. Se and Te are determined in the organic extract by zirconium coated platform-graphite furnace AAS,using Pd and Ni asmixed matrix modifier. The detection limit is 0.21×10￣(-9)g Se,0.13×10￣(-9)g Te and RSD(n=11)is 7.O%(0.06g Se),8.9%(0.03g Te)respectively.The method is suitable for determinating g/g levels of Se and Te.