岩石、土壤、沉积物中氧化亚铁与氧化高铁的分离及测定

Separation and Determination of Ferrous Oxide and Ferric Oxide in Rocks,Soils and Sediments

本文根据亚铁与邻菲啰啉在pH2—9范围内,形成稳定的络合物[1-4]的事实,研究了亚铁与高铁的分离及分别直接测定。即以氟化氢铵—邻菲啰啉分解硅酸盐,然后加入盐酸溶解磁铁矿等。以硼酸消除氟的影响,用氢氧化铵沉淀高铁。亚铁在样品分解时即与邻菲啰啉生成橙红色络合物,不被空气氧化,也不被氢氧化铵沉淀。

The sample is decomposed with ammonium bifluoride, 1, 10-phenanthroline and hydrochloric acid. Boric acid and ammonium hydroxide are used to complex fluoride and to precipitate iron (Ⅲ) while the colored iron (Ⅱ) chetate remains in solution.The mixture is filtered and ferrous oxide is determined in the filtrate photometrically.The precipitate collected on the filter is dissolved in hydrochloric acid and titrated for the ferric oxide.