偶氮荧光桃红催化动力学光度法测定痕量钌(Ⅲ)

Determination of trace ruthenium(Ⅲ) by catalytic kinetic spectrophotometry with azophloxine

在磷酸介质中,痕量钌能灵敏地催化溴酸钾氧化偶氮荧光桃红褪色,据此建立了一种测定痕量钌的新方法。通过实验,确定了该催化褪色反应的最佳反应条件及动力学参数。于波长528nm处,钌的质量浓度在3～10μg/L范围与催化反应和非催化反应的吸光度差有良好的线性关系,线性相关系数等于0.995 4,方法的检出限为7.96×10-8 g/L。测得反应速率常数为3.30×10-3/s,表观活化能为193.72kJ/mol。干扰实验表明,其他离子的允许量均在钌量的10倍以上。将本测定方法与蒸馏分离法相结合成功地测定了矿石和冶金产品中钌,测定结果的相对标准偏差小于1.9%(n=6),加标回收率在98.6%～104.0%之间。

In phosphorie acid medium,trace ruthenium can sensitively catalyze potassium bromate to oxidize azo phloxine fading and based on this fact,a novel method for determining trace ruthenium is established.Through the experiment,the optimum reaction condition and kinetic parameter of the catalytic fading reaction was confirmed.At the wavelength of 528 nm,the mass concentration of ruthenium in 3-10 μg/L had excellent linearity with the absorption difference of catalytic and non-catalytic reaction.The linear correlation coefficient was 0.995 4,and the detection limit was 7.96 × 10-8 g / L.The reaction rate constant was 3.30×10^-3 /s and the apparent activation energy was 193.72 kJ/mol.The interference experiment indicated the allowable amounts of other ions were more than 10 times of amount of ruthenium.The method combined with distillation separation was successfully applied for determining ruthenium in ore and metallurgical products with the RSD less than 1.9%（n=6） and the recovery between 98.6%-104.0%.