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

Catalytic Kinetic Spctrophotometric Determination of Trace Iron (Ⅲ) with 2-(5-Carboxy-1,3,4-triazolylazo)-5-diethylamino Aniline and Hydrogen Peroxide

在pH3.5的HAc-NaAc缓冲溶液介质和加热条件下,痕量铁(Ⅲ)对H2O2氧化2-(5-羧基-1,3,4-三氮唑偶氮)-5-二乙氨基苯胺(CTZAN)的褪色反应具有显著的催化作用,褪色反应程度与铁(Ⅲ)量在一定范围内呈线性关系,建立了测量痕量铁(Ⅲ)的催化动力学光度法。褪色体系的最大吸收波长为425nm,Fe(Ⅲ)质量浓度在(0.01—0.20)mg/L范围内符合线性关系,回归方程为ΔA=4.491ρ+0.0066(ρ:mg/L),相关系数为0.9982,检出限为2.02×10-9g/mL。方法用于面粉及头发中痕量铁的测定,结果与AAS测定结果相符。

A new catalytic kinetic method for the determination of trace iron catalytic action of Fe3 ＋ on the oxidative fading reaction between 2- （ 5-carboxy-1 aniline （CTZAN） and hydrogen peroxide in the medium of HAc-NaAc at pH （ Ⅲ ） is established based on the ,3,4-triazolylazo ） -5-diethylamino 3.5 and heating conditions. The maximum of the absorbance shows at 425 nm. The calibration curve was linear in the range of （0.01--0.20） mg/L for iron,and the linear regression equation is △A = 4. 491p ＋ 0. 006 6 （p： mg/L）with the correlation coefficient of 0.998 2. The detection limit is 2.02 × 10 -9 g/mL for iron. The method has been applied to determine trace iron in flour and hair samples. The results are good agreement with the values obtained by atomic absorption spectrometry.