循环伏安法测定溶液中Fe³⁺和Fe²⁺浓度比

来源期刊：冶金分析2011年第3期

论文作者：李云 王晨雪 尚游 尚世智 郭建伟

文章页码：72 - 75

关键词：循环伏安法； Fe³⁺和Fe²⁺浓度比； 重铬酸钾滴定法

Key words：cyclic voltammetry； the concentration of Fe³⁺ to Fe²⁺； potassium dichromate titrimetry

摘    要：采用循环伏安法(CV)测定铁泥制备Fe₃O₄过程中Fe³⁺与Fe²⁺浓度比值的变化,为该工艺过程提供方便、快捷的监测方法。在实验条件下,溶液中的Fe³⁺与Fe²⁺组成可逆的氧化还原体系,产生一对峰形良好的氧化还原峰。对影响峰电流的扫描速度、pH值及干扰离子等因素进行考察,结果表明,扫描速度在0.002~0.01 V/s、pH在1.5~2.5时对氧化峰电流及还原峰电流没有影响;溶液中存在的SO₄^2-离子在实验范围内对体系基本无干扰。Fe3+的浓度在0.000 8~0.008 4 mol/L呈线性关系,相关系数为0.999 9,相对标准偏差(n=7)在0.70%~2.0%之间。该法与标准重铬酸钾滴定法对比,相对误差为1.7%。

Abstract: The concentration change of Fe³⁺ to Fe²⁺ in the preparation process of Fe₃O₄ from iron mud was determined by cyclic voltammetry(CV),which provided a simple and rapid monitoring method for this technological process.Under the experimental conditions,the Fe³⁺ and Fe²⁺ in solution formed reversible redox system,generating a pair of redox peak in good shape.The factors influencing the peak current were investigated,including the scanning rate,pH and interference ions.The results showed that the scanning rate in the range of 0.002-0.01 V/s and pH in the range of 1.5-2.5 had no influence on the oxidation peak current and reduction peak current.SO₄^2- in the solution basically had no interference with the system under experimental conditions.The relationship was linear for Fe³⁺ in the range of 0.000 8-0.008 4 mol/L with correlation coefficient of 0.999 9.The relative standard deviation (RSD,n=7) was 0.70%-2.0%.The proposed method was compared with standard potassium dichromate titrimetry with a relative error of 1.7%.