亮绿-十六烷基三甲基溴化铵催化动力学光度法测定痕量钛(Ⅳ)  

Determination of trace titanium(Ⅳ) by catalytic kinetic spectrophotometry in brilliant green-cetyl trimethyl ammonium bromide system

作　　者：王洪福[1] 魏成富[1] 罗娅君[1] 何黎明[1] 杨小利[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

出　　处：《冶金分析》2011年第8期52-55,共4页Metallurgical Analysis

基　　金：绵阳市科技局重大专项(08c022)

摘　　要：在H2SO4介质中及活化剂十六烷基三甲基溴化铵存在下,于90℃加热时,痕量Ti(Ⅳ)对H2O2氧化亮绿褪色反应具有显著的催化作用,据此提出了用催化动力学光度法测定痕量钛的方法,并研究了反应的最佳实验条件。在625 nm波长处,非催化反应(吸光度为A0)与催化反应(吸光度为A)吸光度的差值△A与Ti(Ⅳ)的质量浓度ρ在0.021～0.08μg/mL范围内呈良好的线性关系,检出限为7.87×10-10g/mL。该催化反应对Ti(Ⅳ)为一级反应,总反应为准一级反应,表观速率常数为5.70×10-4/s,表观活化能Ea=45.52 kJ/mol。用该方法测定了两个炼钢烧结矿样品中钛(Ⅳ),结果与参考值相符,测定结果的相对标准偏差分别为2.4%和2.0%,加标回收率在98%～102%范围。Trace titanium（Ⅳ） had significant catalytical action on the fading reaction of brilliant green oxidized by hydrogen peroxide in the presence of cetyl trimethyl ammonium bromide in H2SO4 medium at 90 ℃.On the basis of this fact,a catalytic kinetic spectrophotometric determination method of trace titanium was proposed.The optimized experimental conditions were studied.At 625 nm,the absorbance difference（△A） between non-catalytic system（A0） and catalytic system（A） showed good linear relationship with the mass concentration（ρ） of titanium（Ⅳ） in the range of 0.021-0.08 μg/ mL,with detection limit of 7.87×10-10 g/mL.This catalytic reaction was found as the first order reaction for titanium （Ⅳ）,and the total reaction was pseudo first order reaction.The apparent reaction rate constant was 5.70×10-4 /s,and the apparent activation energy Ea=45.52 kJ/mol.The proposed method had been applied to the determination of titanium （Ⅳ） in two steelmaking sinter ore samples,and the results were consistent with the reference values.The relative standard deviations（RSD） were 2.4 % and 2.0 %,respectively.The recoveries of standard addition were in the range of 98 %-102 %.

关 键 词：催化动力学光度法 过氧化氢 亮绿 钛(Ⅳ) 十六烷基三甲基溴化铵 烧结矿 

分 类 号：O657.32[理学—分析化学]