硅钙合金中钙、铝的联合测定

JOINT DETERMINATION OF CALCIUM AND ALUMINIUM IN THE SILICO-CALCIUM ALLOY

硅钙合金用硝酸、氢氟酸溶解后,加入高氯酸并加热至冒烟以驱除氟,然后定容。移取两份样品溶液,一份中加入三乙醇胺溶液掩蔽铁、铝等干扰离子,再加入氢氧化钾溶液,使pH=12,用EDTA容量法测定钙。另一份中加入铁标准溶液、混合显色液(Zn-EDTA与络天青S的混合溶液)及六次甲基四胺缓冲溶液,用光度法测定铝。方法简便,结果准确、可靠。

The silieo-calcium alloy was solved with nitric acid and hydrofluoric acid, fluoride was elimilated with perchloric acid. Take two parts of the matrix solution, in one part, triethylamine was added to shelter the interfering ions as iron, aluminium, etc. , potassium hydroxide was then added to make pH = 12, calcium was determined by EDTA volumetry. In the other part, iron standard solution, mixing color-developing solution and buffer solution were added and aluminium was determined by photometry. This method is simple, the result is accurate and reliable.