中性红褪色阻抑动力学光度法测定痕量铁  

Kinetic spectrophotometric determination of trace iron based on inhibitory of neutral red descoloring

作　　者：赵登山[1] 高明[1] 高强[1] 孙永明[1] 

机构地区：[1]淮阴工学院生命科学与化学工程学院,江苏淮安223003

出　　处：《冶金分析》2012年第11期36-39,共4页Metallurgical Analysis

基　　金：淮安市科技支撑计划(HAG09002);2011年江苏省高等学校大学生实践创新训练计划

摘　　要：在H2SO4介质中,加热80℃条件下,Fe?对溴酸钾氧化中性红褪色反应具有较强的阻抑作用,基于在波长520nm处Fe?的量与阻抑反应体系(吸光度为A)和非阻抑反应体系(吸光度为A0)吸光度差值呈线性关系,建立了阻抑褪色动力学光度法测定痕量Fe?的分析方法。在优化实验条件下,方法的线性范围为0.000 4～0.064μg/mL,检出限为1.41×10-4μg/mL。测定了动力学参数,该阻抑反应为准一级反应,表观速率常数k=4.53×10-4s-1,表观活化能为69.25kJ/mol。方法用于天然水中痕量铁的测定,标准加入回收率为99.0%～99.5%;RSD为3.8%～6.2%。Under the conditions of 80℃ and in sulfuric acid medium,Fe had strong inhibitory action on the colour decolorization of neutral red oxidized by potassium bromate.There was a linear relationship between the amount of Fe and the absorbance difference of the inhibitory reaction system（absorbance A） and un-inhibitory reaction system（absorbance A0） at the wavelength of 520 nm.Based on the fact,a inhibition kinetic spectrophotometry for the determination of trace Fe was established.Under optimal experimental conditions,the linear range of the method was between 0.000 4 μg/mL and 0.064 μg/mL,and the detection limit was 1.41 × 10-4 μg/mL.The kinetic parameters were determined.It was shown that the inhibitory reaction was first-order reaction,the apparent rate constant k was 4.53 × 10-4 s-1 and the apparent activation energy was 69.25 kJ/mol.The method was used for the determination of the trace iron in natural water,with the recoveries of 99.0%-99.5% and the relative standard deviation（RSD） of 3.8%-6.2%.

关 键 词：阻抑动力学光度法 溴酸钾 中性红 Fe(Ⅲ) 

分 类 号：O657.32[理学—分析化学]