CAJ | 학술논문

先用稀乙酸溶解试样中的钙粒，再用盐酸使还原铁粉溶解，在热的盐酸介质中，用SnCl2还原大部分的Fe3+为Fe2+，然后用TiCl3定量还原剩余的Fe3+，用钨酸钠做指示剂指示还原终点。在硫磷混酸存在下，以二苯胺磺酸钠为指示剂，用重铬酸钾标准溶液滴定铁量。测定结果满意，相对标准偏差≤0.2071%（n=6）。
선용희을산용해시양중적개립，재용염산사환원철분용해，재열적염산개질중，용SnCl2환원대부분적Fe3+위Fe2+，연후용TiCl3정량환원잉여적Fe3+，용오산납주지시제지시환원종점。재류린혼산존재하，이이분알광산납위지시제，용중락산갑표준용액적정철량。측정결과만의，상대표준편차≤0.2071%（n=6）。
The calcium particles in iron-calcium cored wire sample were dissolved by dilute acetic acid and the reduced iron powder in the sample was dissolved further by hydrochloric acid. In the hot hydrochloric acid medium, the most Fe3+was reduced to Fe2+by SnCl2, and then the residual Fe3+was reduced quantitatively by TiCl3, with sodium tungstate as indicator for reducing end. In the presence of sulfuric acid and phosphoric acid, making sodium diphenylamine sulfonate as indicator, the iron content was titrated by potassium dichromate standard solution. The satisfactory results were obtained and the relative standard deviation is less than 0.207 1%(n=6).