矿石样品铂、钯、铑和铱经铅试金富集,所得金属合粒用硝酸-盐酸溶解,用石墨炉原子吸收光谱法测定矿石样品中铂、钯、铑和铱的含量。在优化的石墨炉工作条件下测得:铂的质量浓度在20~150 μg·L-1、钯在15~120 μg·L-1、铑和铱在6~100 μg·L-1范围内与其吸光度呈线性关系,检出限(3s/k)依次为4.6,4.0,1.5,1.5 μg·L-1。方法用于分析了2种矿石国家标准物质(GBW 07341、GBW 07342),测定结果与认定值相符。方法的回收率在87.6%~105.5%之间。测定值的日内和日间相对标准偏差(n=7)分别在2.8%~3.6%和3.5%~4.7%之间。

Platinum, palladium, rhodium and iridium in ore samples were enriched by the lead fire assaying method, and the alloy of precious metals obtained was dissolved in HNO3 and HCl. The contents of Pt, Pd, Rh and Ir in the sample solution were determined by GFAAS. It was found that under the optimum working conditions of the graphite furnace, linear relationships between values of absorbance and mass concentration were obtained in the ranges of 20-150 μg·L-1 for Pt, 15-120 μg·L-1 for Pd, 6-100 μg·L-1 for Rh and Ir. Detection limits (3s/k) found were 4.6 μg·L-1 (Pt), 4.0 μg·L-1 (Pd) and 1.5 μg·L-1 (Rh and Ir). The proposed method was used in the analysis of 2 ore CRM′s (GBW 07341, GBW 07342) and the results obtained were in conformity with the certified values. Values of recovery found by standard addition method were in the range of 87.6%-105.5%. Values of intra-day and inter-day RSD′s (n=7) found were in the ranges of 2.8%-3.6% and 3.5%-4.7% respectively.