Comparative Marine Chemistries of Rhenium, Platinum Group Metals and Their Periodic Table Neighbors

目前，海水中仅有的两种稳定元素尚未分析。这是可预见的极低浓度(PG/L)和分析困难的结果。与元素周期表中的其他铂族金属相比，它们的海洋化学性质可能会显著增加我们对海洋中络合反应和氧化还原反应的了解。在我们广泛了解它们在含氧和缺氧的海洋沉积物和海洋水域中的分布之前，我们不能追查这一问题。戈德伯格博士建议，不仅要开发这两种金属的分析技术，而且要开发它们在海水和半成品中的分析技术，这些技术以前曾用于其他铂族金属及其元素周期表邻居的分析。这两种元素的分析方法将使用石墨炉原子吸收光谱分析。放射性产额示踪剂Rh-102和Os-185将从Ru-102和Re-185的回旋加速器轰击中制备，并将用于所有分析。这两种金属将在加利福尼亚州海岸外4000米深的海水中、铁锰矿物、远洋沉积物、沿海沉积物中的磷矿和热液硫化物中进行分析。它们在海水中的氧化还原状态(可能还有形态)将从它们在氧化和还原条件下形成的矿物中的富集态或缺乏态中寻找。

Rhodium and osmium are the only stable elements not yet analyzed in seawater. This is a consequence of their predictably very low concentrations (pg/l) and of the diffi- culties of analysis. Their marine chemistries, compared to other platinum-group metals in the periodic table may remarkably increase our understanding of complexing and redox reactions in the oceans. Until we have a broad understanding of their disposition within oxic and anoxic marine sediments and marine waters, we cannot pursue this matter. Dr. Goldberg proposes to develop not only analytical techniques for these two metals but their analyses in seawaters and semiments previously assayed for other platinum group metals and their periodic table neighbors. Analytical methods for both elements will utilize graphite furnace atomic absorption spectrometry. Radioactive yield tracers, Rh-102 and Os-185, will be prepared from cyclotron bombardments of Ru-102 and Re-185 and will be used in all analyses. These two metals will be analyzed in seawaters to depths of 4000m off the coast of California, in ferromanganese minerals, pelagic sediments, coastal sediments phosphorites and hydrothermal sulfides. Their redox state (and perhaps speciation) in seawaters will be sought from their enrichments, or lack thereof, in minerals that form under oxidizing and reducing conditions.