稀土镁硅铁合金试样经氢氟酸和硝酸溶解后,用火焰原子吸收光谱法测定试样溶液中镁的含量。测定时,加入释放剂镧(Ⅲ)溶液,以消除共存物的干扰。镁的质量浓度在0.2~12.0 mg·L-1范围以内与其吸光度呈线性关系,方法的检出限(3s)为0.057 mg·L-1。方法用于两个稀土镁硅铁合金样品分析,加标回收率分别为99.4%,97.6%,相对标准偏差(n=11)分别为0.89%,0.43%。

Sample of RE-Mg-Si-Fe alloy was dissolved with con. HF and con. HNO3, and Mg2+ in the solution was determined by FAAS. La(Ⅲ) solution as releasing agent was added to eliminate the interferences of coexisting ions. Linear relationship between values of absorbance and mass concentration of Mg2+ was kept in the range of 0.2-12.0 mg·L-1, and detection limit (3s) of the method found was 0.057 mg L-1. The proposed method was applied to the analysis of two samples, giving values of recovery found by standard addition method of 99.4% and 97.6%, and RSD′s (n=11) of 0.89% and 0.43% respectively.