钌催化高碘酸钾氧化溴酚蓝褪色动力学光度法测定痕量钌  

Fading kinetic spectrophotometric determination of trace ruthenium(Ⅲ) based on catalytical action of ruthenium on reaction of bromophenol blue and potassium periodate

作　　者：王洪福[1] 苏智先 罗英[3] 马兰[1] 

机构地区：[1]绵阳师范学院化学与化学工程学院,四川绵阳621000 [2]生态与环境保护四川省重点实验室,四川绵阳621000 [3]绵阳师范学院生命科学与技术学院,四川绵阳621000

出　　处：《冶金分析》2012年第6期56-59,共4页Metallurgical Analysis

摘　　要：在稀硫酸和四硼酸钠介质中,于85℃热水浴中加热,发现痕量钌(Ⅲ)对高碘酸钾氧化溴酚蓝褪色反应有明显的催化作用,据此提出了用催化动力学光度法测定痕量钌?的方法。实验表明,于波长591nm处,吸光度差值ΔA与钌(Ⅲ)的质量浓度在9.60×10-4～4.4×10-2μg/mL范围内呈良好的线性关系,方法检出限为1.506×10-10g/mL。该催化反应对钌?为一级反应,在试验条件下总反应为准一级反应,表观速率常数为4.137×10-3/s,表观活化能为56.45kJ/mol。在25mL溶液中对1.0μg钌(Ⅲ)进行测定,其结果的相对标准偏差为1.3%(n=11)。将本方法用于测定分子筛和活性炭样品中痕量钌(Ⅲ),测得结果的相对标准偏差(n=6)分别为4.7%、1.1%,加标回收率为98%和102%。Ruthenium （Ⅲ） had significant catalytic effect on the fading reaction of bromophenol blue oxidized by potassium periodate in the medium of diluted sulfuric acid and sodium tetraborate at 85 ℃ water bath. On the basis of this fact, a novel method for determination of ruthenium（1） was proposed by catalytic kinetic spectrophotometry. The experiment results indicated that the absorbency differ ence AA remained a good linear relationship with the mass concentration of ruthenium（Ill） in the range of 9.6X10^-44.4X10μg/mL. Detection limit of this method was 1. 506 X 10^-10μg/mL. The cata lytic reaction was a first order reaction for ruthenium（μ）） while the whole reaction was pseudofirst or der reaction under the experiment condition with apparent rate constant of 4. 137- 103/s and appar ent activation energy of 56.45 kJ/mol. The determination was conducted on 1.0 μg of ruthenium（Ⅲ） in 25 mL of solution and the relative standard deviation was 1.3%（n=11）. This method was applied to determine ruthenium（Ⅲ） in molecular sieve and activated carbon samples with the relative standard de viations （n=6） of 4.7% and 1.1% respectively and the recoveries of 98% and 102%.

关 键 词：催化动力学光度法 溴酚蓝 钌(Ⅲ) 四硼酸钠 分子筛 

分 类 号：O657.32[理学—分析化学]