过氧化氢氧化亚甲基蓝褪色催化动力学光度法测定镍  

Catalytic kinetic spectrophotometric determination of trace nickel based on fading reaction of methylene blue oxidized by hydrogen peroxide

作　　者：赵艳[1,2] 柴红梅[1,2] 

机构地区：[1]延安大学医学院,陕西延安716000 [2]延安大学化学与化工学院,陕西延安716000

出　　处：《冶金分析》2015年第9期73-76,共4页Metallurgical Analysis

基　　金：陕西省教育厅重点实验室基金(13JS122);延安大学自然科学重点基金项目(YDZ2012-09)

摘　　要：在pH 8.00的NH3-NH4Cl缓冲溶液中,在100℃加热条件下,痕量镍（Ⅱ）能催化过氧化氢氧化亚甲基蓝的褪色反应,建立了测定痕量镍的催化动力学光度方法。研究发现,非催化反应吸光度（A0）和催化反应吸光度（A）在655nm处的差值ΔA与镍（Ⅱ）的质量浓度在0.01--0.30μg/mL范围内呈良好的线性关系,方法检出限为8.6×10-3μg/mL。该催化反应的表观速率常数为8.2×10-4s-1,表观活化能为66.08kJ/mol。方法用于延河水和自来水厂污水中痕量镍的测定,测定值与原子吸收光谱法一致,相对标准偏差（RSD,n=6）为1.2%--1.6%,加标回收率为99%--102%。The fading reaction of methylene blue oxidized by hydrogen peroxide could be catalyzed by trace nickel（H） in NH3-NH4C1 buffer solution at pH 8. 00 under heating condition at 100℃ Accordingly, a method was established for determination of trace nickel by catalytic kinetic spectrophotometry. It was found that the difference of absorbance （AA） between non-catalytic reaction （A0） and catalytic reaction （A） at 655 nm had good [inearity to the mass concentration of nickel（U） in range of 0.01 0.30μg/mL. The detection limit of method was 8.6 ×10μg/mL. The apparent rate constant of this catalytic reaction was 8.2×10 4 s-1 , and the apparent activation energy was 66.08 kJ/mol. The proposed method was applied to the determination of trace nickel in waste water samples from Yanhe River and tap water plant. The results were consistent with those obtained by atomic absorption spectrometry. The relative standard devia tion （RSD, n=6） was 1.2%-1.6%. The recoveries were between 99% and 102%.

关 键 词：催化动力学光度法 镍 亚甲基蓝 过氧化氢 

分 类 号：O657.3[理学—分析化学] X832[理学—化学]