阴离子交换树脂分离甲苯萃取ICP-AES测定铋系超导粉中的痕量镍

Determination of Trace Nickel in Bi-Based Superconductor Powder by Inductively Coupled Plasma Atomic Emission Spectroscopy after Separation with Anion Exchange Resin and Extraction with Methylbenzene

建立了ICP-AES测定超导粉中痕量镍的新方法。优化了仪器工作参数,对超导前驱粉中痕量镍测定时的基体干扰及干扰消除方法进行了系统研究,结果表明:大量存在的基体元素产生严重基体效应,导致测定重现性及准确度变差,实验采用分离富集方法以提高测定结果的准确度和精密度。实验中首先用阴离子交换树脂,除去Bi3+及部分Pb2+,Sr2+,Ca2+,Cu2+等基体元素;在碱性条件下再通过甲苯萃取镍与丁二酮肟的络合物、稀盐酸反萃取富集镍;对分离富集条件进行了优化。对模拟标准样品进行测定,分析结果与理论值一致,相对标准偏差为1.9%,方法检出限为0.19μg.g-1。该方法已用于超导前驱粉样品中痕量镍的分析,结果令人满意。

A new method for the determination of trace nickel in superconductor powder by ICP-AES was proposed.The instru-ment parameters were optimized,and the matrix effects as well as the method of eliminating interferences were also studied sys-temically.The results showed that matrix interference in the superconductor powder was serious when the amount of matrix in-creased,and the repeatability as well as the accuracy was poor,so it was necessary to used separation and preconcentration toimprove the accuracy and precision.In this experiment,Ni-diacetyl dioxime complexes were enriched by toluene extraction in al-kaline condition after eliminating the interference of major element Bi and partial Pb,Sr,Ca and Cu by eluting with anion ex-change resin,then the Ni-complexes were back extracted by diluted hydrochloric acid.The enrichment conditions were investiga-ted in detail and the recovery rate of Ni was higher than 95%.Under the optimal condition,an artificial sample was analysed,the result showed that the found values were identical with reference values,and the RSD and detection limit were 1.9%and0.19μg.g-1,respectively.The method has been applied to the determination of trace nickel in Bi-based superconductor powdersamples with satisfactory results.