藏红T催化光度法测定痕量钌

Catalytic spectrophotometric determination of ruthenium using safranine T

在H2 SO4 和热水浴中 ,Ru(Ⅲ )催化KIO4 氧化藏红T褪色 ,由此建立了测定钌的新催化光度法。钌质量浓度在 0～ 0 0 0 32 μg mL范围内符合比尔定律 ,检出限为 3.3× 1 0 -8g L。对 0 .0 0 2 0 μg mLRu(Ⅲ )测定的相对标准偏差为 1 .7% (n=1 1 )。催化反应的表现活化能为 38.2kJ mol。催化反应对Ru(Ⅲ )和藏红T分别为一级反应。试验了 40多种共存离子的影响 ,允许 2 0 0倍量的Ag+、Pt(Ⅳ ) ,2 0倍量的Pd(Ⅱ )、Ir(Ⅳ )及Cu2 +存在。该方法可用于岩矿和冶金产品中钌的测定 ,相对标准偏差为 1 .1 %～ 2 .4 % ,标准加入回收率为 1 0 0 .3%～ 1 0 1 .5 %。

A new catalytic kinetic method for determination of ruthenium was established based on the catalytic effect of Ru(Ⅲ) on the oxidation fading reaction of safranine T by KIO 4 in sulfuric acid in the hot-water bath. Beer′s law was obeyed in the range of 0～0.0032 μg/mL for Ru(Ⅲ) with a detection limit of 3.3×10 -8 g/L. The relative standard deviation for 11 replicate measurements of 0.0020 μg/mL of Ru(Ⅲ) was 1.4%. The apparent activation energy of catalytic reaction was found to be 38.2 kJ/mol. The reaction was the first-order for Ru(Ⅲ) and safranine T, respectively. The interference from 200-fold amounts of Ag+ and Pt(Ⅳ), and 20-fold amounts of Pd(Ⅱ), Ir(Ⅳ) and Cu 2+ was allowable. The method was applied to the determination of trace ruthenium in some ore and metallurgical product samples with the RSD of 1.1%～2.4% (n=7) and the recovery of 100.3%～101.5%.