摘要
本文采用离子色谱法对碳酸锂中Cl^(-)和SO_(4)^(2-)离子的测定进行研究,建立了消除大量碳酸盐和锂离子基体干扰的快速测定方法。称取0.25 g样品于300 mL玻璃烧杯中,加入少许超纯水使样品浸润,滴加1 mL(1+1)HNO_(3)使样品完全溶解,大部分碳酸根随着酸的加入被酸化,CO_(3)^(2-)被转化为H_(2)CO_(3)和气体CO_(2)逸出,样品再通过On Guard H柱进一步有效地除去剩余CO_(3)^(2-)离子和基体锂离子,处理后锂离子经ICP检测由原来的333.6μg/mL降为0.021μg/mL不再产生干扰,待测液达到理想的分析状态。试验采用IonPac AS15阴离子分析柱分离,38 mmol/L KOH溶液为流动相,流速1.2 mL/min,柱温30℃,等度淋洗,电导检测器检测。结果表明:Cl^(-)和SO_(4)^(2-)离子的质量浓度与峰面积呈良好线性关系,r均大于0.9999,相对标准偏差小于3.10%(n=11),回收率均大于95%,检出限均小于0.0005%。该方法与光度法比较操作简便、快速、灵敏度、准确度高,可用于碳酸锂中Cl^(-)和SO_(4)^(2-)离子的实际测试。
In this paper,the determination of Cl^(-) and SO_(4)^(2-) in lithium carbonate by ion chromatography was studied,and a rapid determination method was established to eliminate the matrix interference of carbonate and lithium ion.Weigh 0.25 g of sample into a 300 mL glass beaker,add a little ultrapure water to soak the sample,drop 1 mL(1+1)HNO_(3)to dissolve the sample completely,most of the carbonate is acidified with the addition of acid,CO_(3)^(2-) is converted into H_(2)CO_(3)and gas CO_(2)is escaped,and the sample is passed through On Guard H column to effectively remove the remaining CO_(3)^(2-) ions and matrix lithium ions,the ICP test indicates that the lithium ion after treatment is reduced from 333.6μg/mL to 0.021μg/mL,while the liquid to be tested achieves the ideal analytical state without matrix interference.The separation is carried out on a IonPac AS15 anion analysis column with a flow rate of 1.2 mL/min,38 mmol/L KOH liquid is of mobile phase,with an isocratic elution at 30℃and a conductivity detector.The results show that there is a good linear relationship between the mass concentration of Cl^(-) and SO_(4)^(2-) as well as the peak area,r is greater than 0.9999,the relative standard deviation is less than 3.10%(n=11),and the recovery rate is more than 95%.The detection limits are all less than 0.0005%.The method is simple,rapid,sensitive and accurate compared with photometry,which can be used to determine Cl^(-) and SO_(4)^(2-) in lithium carbonate.
作者
吴豫强
张莹莹
Wu Yuqiang;Zhang Yingying(Zhengzhou Non-ferrous Metals Research Institute Co.,Ltd.of CHALCO,Zhengzhou 450041,China)
出处
《轻金属》
北大核心
2021年第8期50-53,共4页
Light Metals
