2-(1,3,4-三氮唑偶氮)-5-二乙氨基苯甲酸-过氧化氢催化动力学光度法测定痕量铁(Ⅲ)  

Catalytic Kinetic Spectrophotometric Determination of Trace Iron(Ⅲ) with 2-(1,3,4-Triazolylazo)-5Diethylaminobenzoic Acid and Hydrogen Peroxide

作　　者：陈素清[1] 葛昌华[1] 梁华定[1] 潘富友[1] 黄莉莉[1] 

机构地区：[1]台州学院医药化工学院,浙江台州317000

出　　处：《分析科学学报》2011年第4期491-494,共4页Journal of Analytical Science

基　　金：浙江省教育厅计划(No.20050051)

摘　　要：本文研究了铁(Ⅲ)催化H2O2氧化2-(1,3,4-三氮唑偶氮)-5-二乙氨基苯甲酸(TZDBA)的褪色反应及其动力学条件,建立了测定痕量铁(Ⅲ)的催化动力学光度法。在pH=4.0的HAc-NaAc缓冲溶液中,褪色体系的最大吸收波长488nm,催化反应的表观活化能Ea=42.10kJ/mol,速率常数k=8.57×10-4 s-1,Fe(Ⅲ)的质量浓度在0.01～0.20mg/L范围内符合比耳定律,检出限为6.62×10-10 g/mL。方法用于头发和面粉中痕量铁的测定,结果与原子吸收法测定结果相符,相对标准偏差为1.88%～2.84%(n=6),加标回收率为96.4%～104.4%。A new catalytic kinetic method for the determination of trace Fe（Ⅲ） was established based on the catalytic action of Fe（Ⅲ） on the oxidative fading reaction between 2-（1,3,4-triazolylazo）-5-diethylaminobenzoic acid（TZDBA） and hydrogen peroxide.In HAc-NaAc buffer solution with pH=4.0,the maximum absorption wavelength of the fading system was 488 nm.The apparent activation energy Ea of the catalytic reaction was 42.10 kJ/mol and the rate constant k was 8.57×10-4 s-1.The calibration curve was linear in the range of 0.01～0.20 mg/L for Fe（Ⅲ）,and the linear regression equation was △A=4.3611c＋0.006（c：mg/L） with the correlation coefficient of 0.9992.The detection limit was 6.62×10-10 g/mL.The method was applied to the determination of trace iron in flour and hair samples.The results were in good agreement with the values obtained by atomic absorption spectrometry.The relative standard deviations of this method was between 1.88%～ 2.84%（n=6） and recoveries were in the range of 96.4%～104.4%.

关 键 词：铁(Ⅲ) 2-(1 3 4-三氮唑偶氮)-5-二乙氨基苯甲酸 过氧化氢 催化动力学光度法 

分 类 号：O657.3[理学—分析化学]