発光分光分析法による粗銅中の不純分の定量

抄録

A method of spectrographic determination of arsenic, antimony, tellurium, nickel, bismuth, aluminum, lead, tin and iron in crude copper was devised. The sample was dissolved in acid, heated on sand-bath and converted into cupric oxide. This was mixed with 1/5 part of graphite powder, charged into the cavity of a graphite electrode and was excited under the following conditions with Vari-Source. For the determination of arsenic, antimony and tellurium, D.C.-Arc, current: 5 A, arc gap: 2 mm, exposure: 50 sec. For the determination of arsenic, antimony, bismuth, nickel, aluminum, lead, iron and tin, Uni-Arc, L₂: 40 mH, C₂: 0.0025 μF, R₂: 1 Ω, current: 5 A, arc-gap: 2 mm, exposure: 60 sec. The reproducibility of the recommended methods is 6∼10%, as expressed by coefficient of variation, for the determination of 0.003∼0.03% antimony, nickel, bismuth and aluminum; 8∼16% for the determination of 0.002∼0.1% arsenic, lead and tellurium; and 18∼25% for the determination of about 0.03% iron and tin. The analytical results obtained by the recommended method agreed with those obtained by other methods except with iron and tin. Special precautions must be taken in the sample preparation for the determination of iron and tin.