原子吸收法测定矿石中铬

Atomic Absorption Spectrophotometric Determination of Chromium in Ores

采用乙炔空气火焰原子吸收法测定铬,要获得较高的灵敏度必须使用富燃气火焰。在此火焰中,有许多元素干扰铬的测定。使用干扰抑制剂是一种比较简便的方法,其中以硫酸钠作为干扰抑制剂是比较理想的,可以克服几乎所有元素对铬的干扰作用。文献中提到铁镁对铬的影响无法克服,而采用分离的办法进行铬的测定。作者经过试验认为,只要不引入氯化物,适当增加干扰抑制剂量,完全可以消除铁镁对铬测定的影响,并且对干扰现象进行了解释。此一问题的解决,免去了分离铁镁的手续,大大加快了分析速度。

A simple method of atomic absorption spectrophotometric determination of chromium in ores was tested. The interference from iron and magnesium ions in solution was eliminated by adding suitable amount of the restrainer solution(Na2SO4). This method must be free from chloride substance. The samples were sintered with sodium peroxide, and the leaching liquor was neutralized by adding 18 N sulfuric acid. The detection limit is 0.05μg/ml.