电感耦合等离子体原子发射光谱法测定氟化钪中铁

氟化钪是钪生产的主要原料之一,测定氟化钪中铁元素对节约生产资源、保证钪产品品质十分重要。钪作为稀土元素之一,若采用溶解氟化稀土常用的硝酸、高氯酸,则难以溶解完全。实验以硝酸-高氯酸-硫酸(1+1)溶解氟化钪,待测液中硝酸体积分数为10%,采用Fe 238.204 nm为分析谱线,利用两点法进行背景校正,建立了电感耦合等离子体原子发射光谱法(ICP-AES)测定氟化钪中铁的方法。钪基体对铁测定的基体效应影响可以忽略,因此不需要钪基体匹配,只需在标准溶液系列中加入与待测液相同浓度的酸进行酸基体匹配绘制校准曲线。校准曲线线性相关系数为0.999;方法检出限为0.001 0%,定量限为0.003 3%。方法用于测定氟化钪样品中铁,测定结果的相对标准偏差(RSD,n=11)为2.2%;同时采用碱熔-分光光度法测定,结果相一致。

Determination of iron in scandium fluride by inductively coupled plasma atomic emission spectrometry

Scandium fluoride is one of the major feedstocks for scandium production. The determination of iron in scandium fluoride is very important to save resources and guarantee the quality of scandium product. Scandium is one of rare earth elements, but it is hardly and completely digested by nitric acid and perchloric acid which are usually used to decompose rare earth fluorides. The scandium fluoride sample was dissolved with nitric acid-perchloric acid-sulfuric acid (1+1). The volume fraction of nitric acid in testing solution was 10%. Fe 238.204 nm was chosen as the analytical line. Two-point method was used for background correction. The method for the determination of iron in scandium fluoride by inductively coupled plasma atomic emission spectrometry (ICP-AES) was established. The influence of matrix effect of scandium on the determination of iron could be ignored. Therefore, the matching of scandium matrix was not required, and only the acid with same concentration was added into testing solution in standard series solution for acid matrix matching to prepare the calibration curve. The correlation coefficient of calibration curve for iron was higher than 0.999. The limit of detection was 0.001 0%, and the limit of quantification was 0.003 3%. The proposed method was applied for the determination of iron in scandium fluoride sample. The relative standard deviations (RSD, n=11) of determination results was 2.2%. Meanwhile, the found results were consistent with those obtained by alkali fusion-spectrophotometry.