摘要
研究了在NH3-NH4Cl（pH=9．0）缓冲介质中，铜（Ⅱ）对H202氧化偶氮胂Ⅰ的褪色反应具有催化作用、加入活化剂α，α’-联呲啶形成稳定的三元配合物，催化作用显著增强，据此建立了催化动力学光度法测定痕量铜（Ⅱ）的新方法。体系在500nm处，吸光度差值与铜（Ⅱ）质量浓度在0．012—0．150μg·mL^-1范围内具有良好的线性关系，检测限为2．318×10^-9g·mL^-1，样品回收率在98．8～103．6％之间。表观速率常数k为5．22×10^-3S^-1，表观活化能为81．10kJ·mol^-1。该方法可用于自来水或工厂排放废水中痕量铜（Ⅱ）的测定。
A new kinetic Spectrophotometry for the determination of Cu（ Ⅱ ）is established on the fact that Ⅱ ） can catalyze the oxidation reaction of arsennazo Ⅰ oxidized by H2O2 in the buffer solvent of NH3 - NH4Cl （pH =9.0）, and with the presence of α,α＇ -bipyridine, because the complex of copper（ Ⅱ ） and arsenazo Ⅰ - α,α＇ -bipyridine strongly enhance the catalyzing effect of the oxidation reaction under the selected conditions. When the measure wavelength is at 500nm and the concentration of Cu（ Ⅱ ） is 0.012 -0. 15μg·mL^- 1, the difference between the absorbency of the system with the complex and the system without the complex has good linearity. The detecting limit of this method is 2. 318μ 10^ -9 g· mL^ - 1 ,and the recovery of the sample is 98.8 - 103.6. The rate constant is 5.22 μ 10^-3s^- 1, and the activation energy of the reaction is 81.10kJ · mol^ - 1. This method is very sensitive and with good selectivity. It can be applied to determine the trace Cu（ Ⅱ ） in the tap water or waste water.
出处
《绵阳师范学院学报》
2007年第5期39-42,共4页
Journal of Mianyang Teachers＇ College
关键词
催化动力学
偶氮胂Ⅰ
铜(Ⅱ)
α
α’-联呲啶
catalytic kinetic spectrophotometers
arsennazo Ⅰ
copper （ Ⅱ ）
α, α＇ - bipyridine
