| 摘要 |
PURPOSE:To determine copper contained in steel simply and accurately without removing iron, by a method wherein trivalent Fe contained in an aqueous solution containing copper is reduced to divalent Fe in order to allow only the copper to be extracted by electrolyzing the solution so that the quantity of the copper is determined. CONSTITUTION:A sample containing a large amount of Fe is heat melted by adding H2SO4 and H2O2, before being cooled. 20% solution of a sulphuric hydroxylamine is added to the sample, which is then heated to reduce Fe<+3> to Fe<+2> and cooled. A deposit, if any, is removed by passing it through a filter. After a small amount of undiluted nitric acid is added to the sample, it is electrolyzed using Pt for the cathod and anode to weigh the amount of copper extracted on the anode. In this manner, without the generation of poisonous gases such as H2S and the necessity of an special apparatus for colorimetric and other purposes and of the cumbersome adjustment of pH and coloration, copper contained in a sample containing iron can be determined even if iron ions about 1,000 times as many as Cu ions exist. The amount of Cu can be determined even when Pb in addition to iron is contained. |
