电感耦合等离子体原子发射光谱法测定铝土矿中氧化锂的方法研究

Determination of lithium oxide in bauxite by inductively coupled plasma atomic emission spectrometry

用氢氟酸-硝酸-高氯酸-盐酸混合酸酸溶法和氢氧化钠碱融法两种前处理方法处理铝土矿样品,选择Li 670.7 nm作为分析线,研究了基体和共存元素对氧化锂测定的干扰,并通过两种前处理方法处理样品分析结果的比对,建立了电感耦合等离子体原子发射光谱法测定铝土矿中氧化锂的方法。研究表明,铝土矿中的主次元素对待测物质氧化锂的测定无影响;采用碱融法处理样品,基体元素钠对氧化锂的测定产生严重的电离干扰,使测定结果偏低,用基体匹配法无法消除;采用酸溶法处理样品,可取得满意结果:相对标准偏差(RSD,n=10)为1.01%~6.44%,回收率为93.57%~104.54%,ICP-AES法测定值与AAS法测定值基本一致;方法中氧化锂的检出限为0.0002%。

The bauxite samples were treated by HF-HNO 3-HClO 4-HCl mixed acid and sodium alkali fusion.Li 670.7 nm was selected as analytical lines.The interference from the matrix and coexisting elements were investigated.By comparing the sample analysis results of the two pre-treatment methods,the determination method of lithium oxide in bauxite by inductively coupled plasma atomic emission spectrometry(ICP-AES)was established.The results showed that the major and trace elements had no effect on the measuring results;the alkali-fused bauxite had lower results,because sodium introduced by flux had a significant effect on results and the interference can't be eliminated by matrix matching;the acid-solved bauxite had satisfactory results.The relative standard deviations(RSD,n=10)were 1.01%~6.44%,the recovery were 93.57%~104.54%,and the results by ICP-AES were basically agree with the results by AAS.The detection limit of lithium oxide is 0.0002%.