锂盐-锍镍试金-等离子质谱法测定黑色页岩中铂族元素

Determination of platinum group elements in black shale by inductively coupled plasma-mass spectrometry with lithium salt-nickel sulphide fire-assay

建立锍镍试金-等离子质谱法测定黑色页岩中铂族元素(PGEs)的方法。在不减少称样量的前提下,结合黑色页岩成分特点,调整试金配料,利用硝酸钾的氧化性,解决形成锍扣难的问题;利用四硼酸锂的助融性,使盐酸溶解锍扣后黑色沉淀量大幅度降低,用等离子质谱法测定黑色页岩中铂族元素。PGEs的线性相关系数均不小于0.9995。Pt,Pd,Rh,Ir,Ru的检出限分别为0.30,0.36,0.032,0.028,0.041 ng/g。用该方法测定实际样品,测定值与参考值一致,测定结果的相对标准偏差为1.2%~10.6%(n=10)。该方法满足地质矿产实验室测试质量管理规范(DZ/T 0130-2006)的要求,可用于黑色页岩中铂族元素的测定。

The method for determining platinum group elements in black shale was established by inductively coupled plasma-mass spectrometry with nickel sulphide fire-assay.On the condition of without reducing the sample weight,the reagent formula was adjusted in consideration of the characteristics of black shale.The advantage of the oxidation of KNO3 and the melt-assistance of Li2B4O7 was taken,respectively,to solve the problem of failure to get the button and get rather less black precipitate when the button was dissolved with HCl,then,the platinum group elements in black shale was determined by ICP-MS.The linear correction coefficients of platinum group elements were all not less than 0.9995.The determination limits of Pt,Pd,Rh,Ir,Ru were 0.30,0.36,0.032,0.028,0.041 ng/g,respectively.The method was applied to practical samples,the analytical results were in good agreement with the reference value.The relative standard deviation of determination results was 1.2%-10.6%(n=10).The method can meet the requirements of testing quality management for geological laboratories(DZ/T0130-2006),which can be applied to the determination of platinum group elements in black shale.