摘要
试样以硝酸-氢氟酸溶解，高氯酸冒烟除尽硅和氟，用稀盐酸溶解盐类后制取母液。分取一定量母液两份，以三乙醇胺半胱氨酸联合掩蔽铁等干扰元素，以氢氧化钾调节pH≥13。第一份母液，钙黄绿素为指示剂，用EGTA标准溶液滴定钙钡合量，另一份母液在相同条件下以硫酸钾沉淀钡后，用EGTA标准溶液滴定钙量，用差减法计算钡的百分含量。测定结果令人满意，钙相对标准偏差小于0．31％，钡小于0．37％。
The sample was dissolved by nitrate acid and hydrofluoric acid, silicon and fluoride were removed by smoking perchloric acid, then the mother solution was prepared through dissolving salts with dilute hydrochloric acid. Two parts of mother solution was taken separately, and after masking the interferences such as Fe through combining triethanolamine and cysteine, the solution was regulated to pH ≥13 by KOH. For first part of mother solution, taking calcein as indicator, the content of Ca and Ba was titrated by EGTA standard solution; for another part of mother solution, under the same conditions, Ba was precipitated by potassium sulfate, the content of Ca was titrated by EGTA standard solution, and the content of Ba was calculated by subtraction method. Then the determination result was satisfactory, and according to the standard, the deviation of Ca less than 0. 31% and the deviation of Ba less than 0. 37%.
出处
《莱钢科技》
2012年第3期65-67,共3页
Laigang Science & Technology
