硫氰酸钾和1,10-二氮杂菲分光光度法测定高纯氧氯化锆中痕量铁  

Determination of trace iron in high purity zirconium oxychloride by potassium thiocyanate and 1,10-phenanthroline spectrophotometry

作　　者：张红 于亚辉[1,2,3] 张秀艳 张慧珍[1,2,3] ZHANG Hong;YU Yahui;ZHANG Xiuyan;ZHANG Huizhen(State Key Laboratory for Research and Comprehensive Utilization of Rare Earth Resources in Bayan Obo,Baotou 014030,China;Baotou Research Institute of Rare Earths,Baotou 014030,China;National Engineering Research Centre of Rare Earth Metallurgy and Function Materials,Baotou 014030,China)

机构地区：[1]白云鄂博稀土资源研究与综合利用全国重点实验室,内蒙古包头014030 [2]包头稀土研究院,内蒙古包头014030 [3]瑞科稀土冶金及功能材料国家工程研究中心,内蒙古包头014030

出　　处：《冶金分析》2023年第12期73-77,共5页Metallurgical Analysis

摘　　要：高纯氧氯化锆是制取高纯锆化学制品的重要原材料,铁作为高纯氧氯化锆中一种常见的杂质元素,含量为0.000 1%~0.005 0%(质量分数,下同),其含量的准确测定对于高纯氧氯化锆生产工艺的研究以及下游应用都具有重要意义。用盐酸(1+1)溶解样品,利用硫氰酸钾、1,10-二氮杂菲可以与样品中铁在稀盐酸介质中反应生成紫红色三元络合物的特性,建立了硫氰酸钾和1,10-二氮杂菲显色-甲基异丁基酮萃取分光光度法测定高纯氧氯化锆中痕量铁的方法。优化后的测定条件如下:显色体系中盐酸含量为1.0~2.5 mL,分别加入2.0 mL 500 g/L硫氰酸钾溶液和2.0 mL 2.5 g/L 1,10-二氮杂菲乙醇溶液,振荡10 s,显色1 min,以5.0 mL甲基异丁基酮萃取,振荡30 s,于分光光度计520 nm处测量吸光度。实验表明,显色体系中铁含量在0.50~16μg范围内时与吸光度呈良好的线性关系,校准曲线线性相关系数r=0.999 7;摩尔吸光系数为2.081 8×10^(4)L·mol^(-1)·cm^(-1);方法的检出限为0.000 048%。按照实验方法测定3个高纯氧氯化锆样品中铁,结果的相对标准偏差(RSD,n=11)为2.6%~9.0%,加标回收率为96%~107%。High purity zirconium oxychloride is an important raw material for the production of high purity zirconium chemicals.As a common impurity element in high purity zirconium oxychloride,the content of iron is in range of 0.0001%-0.0050%(mass fraction,the same below).The accurate determination of iron content is of great significance for the research of high purity zirconium oxychloride production technology and its downstream application.The sample was dissolved with hydrochloric acid(1+1).Based on the characteristic that potassium thiocyanate and 1,10-phenanthroline could react with iron in sample in the dilute hydrochloric acid medium to form a purplish red ternary complex,a method for determination of trace iron in high purity zirconium oxychloride was established by potassium thiocyanate and 1,10-phenanthroline coloring spectrophotometry with methyl isobutyl ketone extraction.The determination conditions were optimized as follows:the volume of hydrochloric acid in the coloring system was 1.0-2.5 mL.2.0 mL of 500 g/L potassium thiocyanate solution and 2.0 mL of 2.5 g/L 1,10-phenanthroline ethanol solution were added.After vibration for 10 s and coloring for 1 min,5.0 mL methyl isobutyl ketone was added for extraction with 30 s oscillation.The absorbance of solution was measured at 520 nm by spectrophotometer.The results showed that the iron content in coloring system in range of 0.50-16μg had a good linear relationship with its corresponding absorbance,and the linear correlation coefficient of the calibration curve was r=0.9997.The molar absorption absorptivity was 2.0818×10^(4) L·mol^(-1)·cm^(-1).The detection limit of the method was 0.000048%.The contents of iron in three high purity zirconium oxychloride samples were determined according to the proposed method.The relative standard deviations(RSD,n=11)were between 2.6%and 9.0%,and the recoveries were between 96%and 107%.

关 键 词：高纯氧氯化锆 铁 硫氰酸钾 1 10-二氮杂菲 分光光度法 甲基异丁基酮 萃取 

分 类 号：O657.32[理学—分析化学] TF841.4[理学—化学]