氯化物中锂离子存在时EDTA质量滴定锶离子含量  

EDTA Complex Mass Titration for the Content of the Strontium Ion Coexisting with Lithium Ion in Chlorite

作　　者：孙柏[1] 李海军[1] 赵静[1,2] 丁秀萍[1] 宋彭生[1] 

机构地区：[1]中国科学院青海盐湖研究所,青海西宁810008 [2]中国科学院大学,北京100049

出　　处：《盐湖研究》2014年第3期29-37,67,共10页Journal of Salt Lake Research

基　　金：国家自然科学基金项目(20773152);青海省科技创新能力促进计划项目(2009-Z-725)资助

摘　　要：锂共存时对EDTA络合滴定Sr2＋离子产生较强的干扰，使分析结果偏高。根据被测液中氯化锂的大约含量，通过加入适量混合醇，可消除Li＋离子的干扰，质量滴定法相对误差〈0．3％。在锂锶质量比为0．100—14．5范围内。被测样中LiCl质量与加入混合醇体积呈线性关系。混合醇掩蔽体积范围为3～5mL。根据锂离子与水分子、短链醇形成蔟合物的键能，对消除Li＋离子干扰络合滴定的机理进行探讨。It is well known that the presence of lithium would lead to significant errors in strontium measurements by EDTA titration methods. Depend on the content of lithium chloride in measured solution, the interference of Li＋ was eliminated and the analytical deviation of the mass titration was within 0. 3% by adding different amounts of the alcohol mixture to samples. When the mass ratio of lithium with strontium was 0. 100 between 14. 5 ,the mass of lithium chloride in the sample was presented linear relation to the volume of adding mixed alcohol. The dosage of the mixed alcohol volume was about 3 -5 mL. According to the binding energies of lithium ions to water molecule and short chain alcohol in cluster, the influence mechanism was discussed for removing the influence of Li ＋ on EDTA complexometric titration.

关 键 词：氯化锂 氯化锶 正丁醇 质量滴定 掩蔽滴定 

分 类 号：O642[理学—物理化学]