锍镍试金富集-等离子体质谱法测定煌斑岩中铂族元素

Determination of Platinum Group Elements in Lamprophyre Sample by Nickel Sulfide Fire Assay-Inductively Coupled Plasma Mass Spectrometry

试金配料中适量加入铁粉，控制硫化铁在锍扣中的含量在20％-40％，获得的锍扣直接用水浸泡粉化后加盐酸分解，分解结束后趁热过滤，沉淀用1mL王水溶解，定容后上机测定，Cs作内标。改进后的方法空白水平进一步降低，检出限得到显著改善，分析流程简化。采用改进后的锍镍试金富集-等离子体质谱法测定了云南哀牢山金矿带煌斑岩和国家一级标准物质GBW07288（GPt-1）、GBW07290（GPt-3）中的铂族元素（PGEs）含量，方法检出限为0．001-0．01ng／g，精密度（RSD，n=5）为7．49％-16．6％。

Iron powder was mixed with assaying ingredient and the quantity of FeS was adjusted to 20% -40% in nickel sulfide button. The button was pulverized by water dipping and then dissolved by hydrochloric acid. The solution was filtered and the precipitate was dissolved with aqua regia. Platinum group elements （PGEs） in the solution were determined by inductively coup]led plasma mass spectrometry （ICP-MS） with Cs as internal standard. The modified method reduced the total procedure blank value and improved the detection limits of PGEs remarkably. The method has been verified by determination of PGEs in National Standard Reference Materials（ GBW 07288, GBW 07290） and has been applied to the determination of PGEs in lamprophyres of Ailaoshan gold delt, Yunnan province with satisfactory results. The detection limits of the method for PGEs are 0.001-0.01 ng/g with the precision of 7.49%-16.6% RSD （ n = 5）.