天青Ⅰ催化光度法测定钌

CATALYTIC PHOTOMETRIC DETERMINATION OF RUTHENIUM WITH AZURE Ⅰ

基于在稀磷酸介质中,钌(Ⅲ)对高碘酸钾与天青Ⅰ的氧化褪色反应的催化作用,建立了微量钌的催化光度测定法.对此催化反应条件的优化试验及反应的动力学参数的测定,确定了反应介质的磷酸浓度0.48 mol·L-1,测定波长620 nm,反应的温度条件65～100 ℃,为操作方便,方法采用在沸水浴中加热7 min,测得表观活化能(Ea)为17.70 kJ·mol-1,反应速率常数(K)为3.7×10-4s-1,钌(Ⅲ)浓度在0～0.48 mg·L-1范围内,与lg(A0/A)值呈线性关系(相关系数为0.999 3),其检出限为0.040 mg·L-1,对0.24 mg·L-1钌(Ⅲ)进行11次测定,算得RSD为2.0%.此方法应用于三个含不同量钌的模拟试样分析,所得结果与已知值相符.

A new catalytic photometric method for determination of ruthenium（Ⅲ） based on the catalytic action of Ru （Ⅲ） on the oxidation-decoloration reaction of azure Ⅰ by KIO4 in a ditute H3PO4 medium is established. Through a study of the optimum condition of the catalytic reaction together with its reaction kinetics, following results were obtained： concentration of H3PO4 of the reaction solution： 0. 48 mol · L^-1 ; wavelength of determination： 620 nm; optimum reaction temperature： 65-100℃;, Heating in a boiling water bath for 7 min was adopted in the method; apparent activity energy （Ea） of the catalytic reaction was found to be 17. 70 kJ · mol^-1 ; reaction rate constant （K） of the catalytic reaction was found to be 3. 7 × 10^-4 s^-1 ; linear relationship between lg （A0/A） and concentration of Ru（Ⅲ） was obtained in the range of 0-0. 48mg · L^-1 （r=0. 999 3） with a detection limit of 0. 040 mg · L^-1 ; test for precision was performed at Ru（ Ⅲ ） concentration level of 0. 24 mg · L^-1 and the RSD （n= 11） found was 2. 0%. The proposed method has been applied to the determination of Ru（ Ⅲ） in 3 simulated samples, the results obtained were in consistency with the known values.