催化动力学极谱法测定痕量铟的研究

Catalytic Kinetic Polarographic Determination of Trace Amount of Indium

在盐酸与硫酸混合酸介质中，铟 (Ⅲ )对溴酸钾氧化甲基橙褪色的反应具有强烈的催化作用，而甲基橙在电极上还原产生灵敏的极谱吸附波，据此作为监测催化反应过程中甲基橙浓度的变化，建立了催化动力学极谱法测定痕量铟的新方法。该方法的线性范围为 20－ 400ng／ ml，检出限为 3.75ng／ ml。方法用于金属锌中铟的测定，结果令人满意。

This method is based on the catalytic effect of In(Ⅲ ) on the discoloring oxidizing reaction of methyl orange by poassium bromate in H2SO4－ HCl medium at 90℃， methyl orange exhibits a sensitive polarographic wave at－ 0.45(vs.SCE). The change in methyl orange concentration is traced by polarography. The detection limit and the linear range of In(Ⅲ ) are 3.75ng/ml and 20－ 400ng/ml respectively.The new catalytic method has been applied to determining indium in pure metallic zine with satisfactory results.