EDTA滴定法测定镁-锌-钇三元合金成分

Determination of components in magnesium-zinc-yttrium ternary alloy by EDTA titrimetry

研究了采用EDTA络合滴定法连续快速测定镁-锌-钇三元合金中各主体成分的方法。控制溶液pH值为5.0~5.5,先以EDTA滴定镁-锌-钇三元合金中的锌钇合量,再在pH值为9.0~9.4时,通过氨水沉淀分离钇后滴定锌的含量,滴定时加入三乙醇铵掩蔽主要干扰元素铁。采用所确定的分析方法对多种组分的三元合金样品进行测定,Zn∶Y∶Mg=3∶1∶96时RSD小于3%,Zn∶Y∶Mg=6∶3∶91时RSD小于2%,标准加入回收率在98%~100%范围内。

The determination method of components in magnesium-zinc-yttrium ternary alloy was studied by EDTA titrimetry.The content of（Zn＋Y） was determined firstly at pH 5.0-5.5.Then,the content of Zn was measured after separating yttrium by ammonia at pH 9.0-9.4.During the titrimetry,triethanolamine was added to mask the interference from iron.The proposed method was applied to the determination of ternary alloy with several components.When the ratio was Zn∶Y∶Mg =3∶1∶96,the relative standard deviation（RSD） was smaller than 3 %.When the ratio was Zn∶Y∶Mg =6∶3∶91,the RSD was smaller than 2 %.The standard addition recoveries were 98 %-100 %.