极谱法快速测定锌烟尘中的微量铟

Rapid Polarographic Determination of Micro Indium in Zinc Flue Dust

将锌烟尘样品用盐酸-硝酸-氢氟酸消解后,在盐酸-盐酸羟胺支持电解质溶液中用单扫描极谱法直接测定其铟含量。探讨了试剂用量的影响和一些共存离子的干扰情况,确定了适宜的试验条件。试验表明,铟络合物于-0.63V(相对于饱和甘汞电极)处产生一灵敏的极谱波,其峰电流与铟浓度(0.01～5g/mL)有良好的线性关系,检出限为0.003g/mL。本法简便快速、灵敏准确,用于测定锌冶炼烟尘中的微量铟,测定结果与ICP-AES法的测定结果相符,相对标准偏差为0.5%～2.7%,加标回收率为98%～104%。

The zinc flue dust sample was digested by HCl-HNO3 -HF and the indium content was directly measured by a single-sweep polarography in the supporting electrolyte solution of HCl-HONH3 Cl. The effect of reagent dosage and some interference ions were studied, and the suitable conditions were selected. The experimental results show that a sensitive polargraphic wave of indium complex is produced at - 0.63V （vs. SCE） , whose peak current has a good linear relationship with indium concentration in the rang of 0.01 -5 g/mL,with the detection limit being 0. 003 g/mL. This method is simple, rapid, sensitive and accurate. When it was used for direct determination of micro-amount indium in flue dust of zinc smel- ting samples, the RSD was 0.5 % - 2.7 % and the recovery was in the range of 98 % -104% , with the results agreeing with those obtained by ICP-AES.