摘要
针对原来高氯酸氧化硫酸亚铁铵滴定法中存在的冒烟温度不易控制和硫磷混酸存在还原性物质影响测定的问题,对该法进行了改进。采用在氧化完全后加入适量的高锰酸钾再酸化,多余的高锰酸钾用氯化铵还原,以硫酸亚铁铵滴定铬,有效地消除了硫磷混酸中存在还原性物质影响,冒烟温度易于控制。测定了几个钢铁标样中铬,测定值与标样推荐值相符,RSD在0 18%～2 63%之间。方法简便快速,终点直观,准确度较高。
An improved method was proposed for solving that smoking temperature is not easy to control and reducing materials in mixed acid with sulfuric acid and phosphoric acid can influence the determination of chromium in the titration method based on ferrous ammonium sulfate oxidized by perchloric acid. After chromium was completely oxidized by perchloric acid, an opportune amount of potassium permanganate was added and the solution was acidified once more, surplus potassium permanganate was reduced by ammonium chloride and chromium was titrated with ferrous ammonium sulfate. The effect of reducing materials in mixed acid with sulfuric acid and phosphoric acid was effectively eliminated and smoking temperature was controlled easily. The method was applied to the determination of chromium in a little standard steel. The determined values were in good agreement with the certified values and RSD was 0.18% - 2.63%.The method has simple and convenient, rapid, audio-visual end point advantages and high accuracy.
出处
《冶金分析》
EI
CAS
CSCD
北大核心
2005年第2期78-80,共3页
Metallurgical Analysis
