一般纯锌中仅含有极微量的铟,因此铜、铅和镉可以不经任何分离而在盐酸介质中用极谱法直接测定。但是如果纯锌中含铟量较高而其他杂质较少时,镉的测定便发生困难,因为在盐酸介质中,铟、镉的半波电位很相近,往往使镉的分析结果发生不应有的正误差。为了正确分别测定镉和铟,我们曾参考了苏联分析化学杂志进行了初步的试验。试验证明能得满意的结果。 In general pure zinc contains only a trace amount of indium, so copper, lead and cadmium can be directly determined by polarography in hydrochloric acid medium without any separation. However, if pure zinc is high in indium and less in other impurities, determination of cadmium will be difficult because the half-wave potentials of indium and cadmium in hydrochloric acid medium are very similar and tend to make the analysis of cadmium undesirable The positive error. For the correct determination of cadmium and indium, we conducted a preliminary test with reference to the Soviet Union Journal of Analytical Chemistry. Test proved satisfactory results.