Cr(Ⅵ)-亚甲基蓝-KBrO_3体系催化光度法测定赤泥样品中痕量Cr(Ⅵ)  

Catalytic Spectrophotometric Determination of Trace Cr(Ⅵ) from Red Mud Using Cr(Ⅵ)-Methylene Blue-Potassium Bromate System

作　　者：罗道成[1,2] 罗铸 LUO Dao-cheng;LUO Zhu(School of Chemistry and Chemical Engineering, Hunan University of Science and Technology ,Xiangtan 411201;Hunan Provincal Key Laboratory of Clean Coal and Mine Environmental Protection ,Xiangtan 411201)

机构地区：[1]湖南科技大学化学化工学院,湖南湘潭411201 [2]煤炭清洁利用与矿山环境保护湖南省重点实验室,湖南湘潭411201

出　　处：《分析科学学报》2018年第2期245-248,共4页Journal of Analytical Science

摘　　要：在H_2SO_4-硼砂介质中,痕量Cr(Ⅵ)对KBrO_3氧化亚甲基蓝的褪色反应具有强烈的催化作用,据此建立了一种测定痕量Cr(Ⅵ)的催化光度分析新方法。结果表明,体系的最大吸收波长为665nm,Cr(Ⅵ)含量在10~500μg/L范围内符合比尔定律,方法的检出限为5μg/L。样品中Cr(Ⅵ)经磷酸三丁酯(TBP)萃淋树脂分离富集后,大多数常见离子不干扰测定。方法用于测定赤泥中痕量Cr(Ⅵ),测定结果与电感耦合等离子体发射光谱法相符,6次测定值的相对标准偏差(RSD)为3.7%,加标回收率在97.8%~103.5%之间。A new catalytic spectrophotometric method for the determination of trace Cr（VI） was established,which was based on the catalytic effect of trace Cr（Ⅵ） on the oxidative decoloration of methylene blue by potassium bromate. The results showed that the maximum absorption wavelength of the system was 665 nm and the detection limit was 5 μg/L. Beer＇s law was obeyed in range of 10-500 μg/L for Cr（Ⅵ ）. After Cr（Ⅵ ） in samples had been separated and enriched with tributyl phosphate（TBP） extraction resin, most of common ions would not interfere with the analytical results. This proposed method was applied to the determination of trace Cr（V[） in red mud. The determination results were consistent with those obtained by ICP-OES method with RSD of 3. 7% （n = 6）, and the recoveries of spiking experiment were 97.8%-103.5%.

关 键 词：催化光度法 亚甲基蓝 KBRO3 磷酸三丁酯萃淋树脂 Cr(Ⅵ) 

分 类 号：O657.31[理学—分析化学]