通常,高纯碳酸锂、氯化铯中微量铁的测定采用邻二氮杂菲吸光光度法或原子吸收光度法。因其中含铁量较低,且含有铜、镍、钴等杂质,一般需从基体中分离出铁,再进行测定。我们在文献的基础上,采用甲基橙光动力学法测定铁,加入EDTA消除少量铜(Ⅱ)的干扰。其测定结果与萃取原子吸收光度法测定结果相比,方法的准确度及精密度能满足要求。一试剂及仪器甲基橙溶液:4×10%。铁标准溶液:lmg ml~(-1),称取纯铁粉1.0000克,用硫酸(1+1)溶解,加过氧化氢(3%)3毫升,将铁(Ⅱ)氧化,加热分解多余的过氧化氢。冷却,移入1 In general, trace amounts of iron in high-purity lithium carbonate and cesium chloride are measured by using phenanthroline spectrophotometry or atomic absorption spectrometry. Because of its low iron content, and contains copper, nickel, cobalt and other impurities, the general need to separate the iron from the matrix, and then measured. Based on the literature, we determined the iron by methyl orange photodynamic method and added EDTA to eliminate the interference of a small amount of copper (Ⅱ). Compared with the results of extraction atomic absorption spectrometry, the accuracy and precision of the method can meet the requirements. A reagent and instrument methyl orange solution: 4 × 10%. Iron standard solution: lmg ml -1, weighed 1.0000 g of pure iron powder, dissolved in sulfuric acid (1 + 1), add 3 ml of hydrogen peroxide (3%) to oxidize the iron Of hydrogen peroxide. Cool, move in 1