萃取-原子吸收法测定高纯氧化钐中的镍

Determination of Trace Nickel in High Purity Samarium Oxide by Solvent Extraction Atomic Absorption Spectrometry

在ｐＨ３的弱酸性介质中，用二乙基二硫代氨基甲酸钠＿甲基异丁基酮萃取分离氧化钐以消除基体干扰，用４ｍｏｌ／ＬＨＮＯ３溶液反萃取后火焰原子吸收测定被富集的杂质镍。萃取时水相与有机相体积比为５∶１，反萃时体积比为１∶１，萃取时间５ｍｉｎ，测定高纯氧化钐中杂质镍的回收率达９８％。分离后的共存非稀土元素对测定镍无干扰。方法检出限为４０μｇ／ＬＮｉ，对ｗ（Ｎｉ）＝０３×１０－６的氧化钐测定６次，ＲＳＤ＝７１％，试样加标回收率在９３％～１０４％。

A method for the determination of trace nickel in high purity samarium oxide by solvent extraction atomic absorption spectrometry was developed. The inferences from samarium matrix on determination of Ni was removed by solvent extraction with sodium diethyldithiocarbamate (DDTC)_methyl isobutyl ketone (MIBK). Ni was extracted in pH 3 solution and back_extracted by 4 mol/L HNO 3 with liquid and organic phase ratios of 5∶1 and 1∶1 respectively. Trace Ni in back_extraction solution was determined by flame_AAS. No interferences from non_rare earth elements were observed after solvent extraction separation. The detection limit for Ni was 40 μg/L. The recovery of standard addition was 93%～104% with precision of 7.1% RSD ( n =6).