8-羟基喹啉重量法快速测定钨铁合金中钨

8-羟基喹啉与许多金属元素(除碱金属外),在弱酸性或弱碱性溶液中能形成螯合物沉淀,这种沉淀分子量大,组成恒定。试样以硝酸和氢氟酸溶解,EDTA为掩蔽剂,在乙酸铵-乙酸(pH=6.5)的缓冲溶液中,8-羟基喹啉与钨生成黄色沉淀,灼烧称重无水WO3。分别对沉淀时pH值、陈化时间、沉淀剂的用量进行选择,研究出了一种快速、准确、经济的分析方法。分析准确度好、精密度高,完全能够满足生产分析要求。

Rapid Analysis of Molybdenum Element in Molybdenum-iron Using 8-hydroxyquinoline Gravimetric Method

In weakly acidic or weakly alkaline solutions, 8-hydroxyquinoline and many metal elements (except for alkali metal elements) form chelate precipitates which have large molecular weights and constant compositions. The samples were dissolved in nitric and hydrofluoric acids. EDTA was used as a masking agent. In ammonium acetate-acetic acid (pH=6.5) buffer solution, 8-hydroxyquinoline and tungsten form a yellow precipitate which was later burned to form anhydrous WO3 compound and weighed. By separately studying optimal pH value and aging time as well as appropriate amount of precipitant, we developed a fast, accurate and economic analysis method. This method has high precision and good accuracy which fully meet the production analysis requirements.