电感耦合等离子体质谱法测定铜矿区20种植物中的金银

采用灰化-王水处理试样,选取103 Rh和203 Tl作为测定107 Ag、109 Ag和197 Au的内标元素,建立了电感耦合等离子体质谱法测定铜矿区栓皮栎等20种植物中金和银的方法。所建立方法用于不同矿区植物样品的分析,相对标准偏差(n=5)为9.05%～0.85%,加标回收率在93.6%～101.6%之间,Au和Ag检出限分别为0.048和1.06ng.g-1。该方法简便、准确,适用于铜矿区植物中金和银的测定。测定结果表明,矿区中金和银含量因不同植物而存在较大差异,变动范围为Au:0.18～0.99ng.g-1,Ag:282～2 150ng.g-1,其中凤尾蕨、芒萁和长叶实蕨中Ag具备地球化学异常特征,可作为找矿有效指示的植物。

Determination of gold and silver in twenty plants from the copper mining area by inductively coupled plasma-mass spectrometry

The preconcentration and determination of gold and silver in twenty plants from the copper mining area by ICP-MS was described. The plant samples were decomposed by dry-ashing and aqua regia. 107Ag, 109Ag and 197Au were chosen as determining isotopes and 103Rh and 203Tl were chosen as internal standards. The conditions of sample digestion were elected and the interferences on instrument measurement were eliminated through the experiments. The detection limits of method were 0.048 and 1.06 ng x g(-1) for Au and Ag. The precisions (n=5) were between 0.85% and 9.05% RSD, and the recoveries were between 93.6%-101.6% (Au, Ag). The method is sensitive quick,simple and has been applied to the analysis of gold and silver in plants from the copper mining area. Under the given analytical conditions, the results showed that the contents of the Au and Ag varied in these diferent plants, the ranging between 0.181-0.99 ng x g(-1) for Au and 280-2150 ng x g(-1) for Ag respectively. The geochemical anomalies on Ag were discovered in Pteris, Dicranopteris pedata and Bolbitis heteroclita, which can be regarded as prospecting effective indicator plants.