封闭溶样-电感耦合等离子体质谱法测定硫化铅矿石中40种微量元素

Determination of 40 Elements in Lead Sulfide Ores by Inductively Coupled Plasma Mass Spectrometry with Pressurized Acid Digestion of Samples

铅矿石在电感耦合等离子体质谱测定中,元素Pb的双电荷离子206Pb^(2+)干扰内标元素103Rh而影响其他元素的测定结果。本文建立了用^(105)Pd和^(187)Re的混合溶液为内标溶液,封闭酸溶-电感耦合等离子体质谱测定硫化铅矿石中的铍、钪、钛、铬、钴、镍、铜、锌、镓、锗、砷、锑和稀土等40种微量元素分析方法,提高了电感耦合等离子体质谱分析铅矿石中低质量的元素(质量为133Cs以下的元素)测定数据的准确度。通过大量的实验确定了该方法的检出限为0.04~5.00μg/g,对国家一级标准物质GBW07235(铅矿石)、GBW07236(铅矿石)、GBW07286(铜铅锌矿石)、GBW07287(铅锌矿石)、GBW07165(富铅锌矿石)、GBW07172(铅矿石)进行分析测定,其准确度(RE)均小于10%,加标回收率为90%~120%。

In the process of measuring trace elements of lead ores by using ICP-MS,206Pb^2＋ion would affect analytical results of other elements due to its interference to the internal standard element103 Rh. In this paper,a modified method with a mixed solution containing^105Pd and^187Re as internal standard and the pressurized bomb acid digestion for dissolving samples has been applied to determine 40 elements,including Li,Sc,Ti,V,Cr,Co,Ni,Cu,Zn,Ga,Ge,V,As,Sb,Te,Rb,Y,Mo,Cd,In,Sn,Cs,La,Ce,Pr,Nd,Sm,Eu,Gd,Tb,Dy,Ho,Er,Tm,Yb,Lu,Ag,W,Th and U,of lead ores by using ICP-MS. This method has improved the accuracy of the measurement of light mass elements（ with mass number lower than133Cs） in lead ores by using ICP-MS.,Through a large number of measurements,the detection limits of the modified method vary from 0. 04 μg / g to 5μg / g for various elements. The accuracy and precision of the method were examined by analyzing various standard materials including GBW07235（ Pb ore）,GBW07236（ Pb ore）,GBW07286（ Cu-Pb-Zn ore）,GBW07287（ Pb-Zn ore）,GBW07165（ Zn-rich ore）,GBW07172（ Pb ore）,with analytical results in good agreement with the certified values of those standard materials. The precision（ RSD） and accuracy of the method for most elements are less than 5% and 10% respectively. Its standard addition recovery is about 90% ～ 120%.