ICP-MS法测钪的干扰研究及选冶尾矿中钪的直接测定  

Study on the Interferences and Direct Determination of Sc in Metallurgical Tails with Inductively Coupled Plasma Mass Spectrometry

作　　者：李建亭[1,2] 张翼明[2] 杜梅[2] 郝茜[2] 李建强[1] 

机构地区：[1]北京科技大学化学系,北京100083 [2]包头稀土研究院,内蒙古包头014030

出　　处：《光谱学与光谱分析》2017年第4期1259-1263,共5页Spectroscopy and Spectral Analysis

基　　金：国家自然科学基金项目(21176027)资助

摘　　要：白云鄂博矿经选铁后,尾矿中钪含量可达0.05%,具有很高的开发利用价值。建立了一种操作简便、灵敏度高并能够准确测定尾矿及富铌渣中微量钪的电感耦合等离子体质谱(ICP-MS)测定方法。对仪器参数、试样处理方法、共存元素的干扰和消除方法进行了系统研究,选用铯、铊和铑作为内标元素,对非谱干扰加以校正。对质谱干扰研究表明,尾矿中的硼、硅、钙、锆和铝均可能对钪的测定造成质谱干扰,其中硼浓度较低(<100μg·mL^(-1))时,对钪测定没有明显干扰,在测定条件下铝和钙的干扰较小,可以忽略。锆和硅的质谱干扰较严重,其中锆的干扰为双电荷(^(90)Zr^(++))干扰,由于双电荷离子电离产率一般不高,锆含量低时干扰可忽略,锆的含量较高时,采用公式c′=0.021c_((Zr))-0.55对结果加以校正。硅的干扰为氧化物干扰,而硅氧键解离能大,硅的氧化物(^(28)Si^(17)O^+,^(29)Si^(16)O^+)稳定性高,且相关同位素丰度较大,在测定条件下干扰较严重,可以采用式c″=0.013c(Si)+0.019扣除该影响。选择了四种不同的样品处理方式,结果表明采用HCl+HF+H_2SO_4混酸方法处理,标样测定结果与标准值一致,且能有效的克服硅和硼的质谱干扰,同时降低了测定液的含盐量,减小了非质谱干扰,标样回收率在97%~99%之间。标准样品及实际样品测定表明,采用ICP-MS法直接测定白云鄂博选冶尾矿中钪含量,结果准确,相对标准偏差小于5%,方法测定下限为0.000 1%。After the mineral dressing of iron ore from Bayan Obo ore, the content of scandium is up to 0. 05% in tailings, which make it very valuable for utilization. A method for determine the trace scandium in the railings and Niobium-rich slag with ICP- MS was established in this paper as a simple method with high sensitivity and accuracy. The working parameters of instrument, sample processing, the interference and eliminating method of coexisting elements were researched systemically. Cesium, thalli- um and rhodium were selected as the proper internal standard elements to overcome the non-mass spectrometry interference in the procedure of determination. The results of interference investigation showed that some elements in tailings, such as boron, sili- con, calcium, zirconium and aluminum, were likely to cause mass spectrometry interference for the determination of scandium, but the concentration of boron was low（~100 ~g ~ mL-1 ） in the sample that made it have not noticeable interference in the de- termination. In addition, smaller mass spectrometry interferences made by aluminum and calcium were negligible under the con- dition of determination. Most noticeably of all, zirconium and silicon mass interferences were more serious, zirconium would form a double charge （90 Zr＋＋ ） ion to interfere the 45 Sc＋ , actually double-charged ions ionization yield was generally not high enough, the interference would be ignored at low concentration, if higher content of zirconium existed, the equation c＇= 0. 021c（zr）-0. 55 was used to correct results. Moreover, high dissociation energy of silicon-oxygen bond and high related isotopic abundance made silicon oxides （28 Si17O＋, 29 Si16 O＋） have higher stability, therefore the interference in the Bayan Obo ore rail- ings at measurement condition was more serious, and the formula c＇=0. 013C（si） ＋0. 019 can be used to correct results when sili- con was not removed in the pretreatment. In summary, the mass spectrometry interferences to the scandium co

关 键 词：钪 测定 电感耦合等离子体质谱 质谱干扰 选冶尾矿 

分 类 号：O657.6[理学—分析化学]