微色谱柱分离-原子荧光光谱法测定矿石矿物中硒

Determination of trace selenium in ores and minerals by hydric generation-atomic fluorescence after separation with decompressed chromatographic micro column

建立了适用于多金属矿石及矿物中痕量Se的分离和测定方法。样品经HNO3-HFHClO_4分解,HCl提取,最后定容为<3%HCl介质溶液。在负压条件下,分取部分试液通过内径3mm的微型阳离子色谱柱,Cu,Pb,Zn,Co,Ni等阳离子被吸附,以阴离子形式存在的Se流经柱床,从而实现Se与大量共存阳离子的有效分离。整个分离过程仅需几分钟,柱体对Cu,Pb,Zn,Co,Ni等离子的吸附容量可达15~90mg,使用后的柱子用1~2mLHCl(1+1)淋洗后即可再生。将过柱溶液用原子荧光光谱法测定即可得到Se的含量。对多种金属矿石矿物标准物质进行了分析,结果相符。适用于富含Cu,Pb,Zn,Co,Ni等多金属矿石及矿物中微量Se的准确测定,方法检出限为0.02μg/g。

Geological samples such as ores and minerals contain a large amount of interfering elements which seriously affect the determination of Selenium （Se）. A new method to determine Se in geological samples was developed based on hydric generation-atomic fluorescence （HG-AFS） after separation with decompressed chromatographic micro column. Samples were digested by HNOa-HF-HC104 and dissolved by HC1 to a final solution of 〈 3% HC1 medium. Part of the test solution was passed through the 3 mm diameter micro-cationic column. Cations such as Cu, Pb,Zn, Co, Niwere extracted onto the column, whereasSe was left in filtrate. The whole separation process takes only a few minutes. The adsorption capacity of Cu, Pb, Zn, Co and Ni ions can reach 15 -90 mg. The column can be regenerated with 1 - 2 mL HC1 （1 ＋ 1 ） after washing. The content of Se was finally obtained afteranalyzing the filtrate by HG-AFS. The method has the advantages of high adsorption capacity, less leakage, small volume of leaching and sharp peak of elution curve, and is characterized by high efficiency, rapidity, low consumption, environmental data of Se in ore and mineral standard materials protection and simple operation. The analytical agreed well with their literature values, which confirmed that the method can be used to accurately determine the content of Se in complex samples. The method detection limit was achieved of 0. 02 μg/g. geological