石墨炉原子吸收测定岩石样品中超痕量铂

Determination of Ultra-trace Platinum in Rock Samples by GF-AAS Method

样品分解后,用超低灰分活性炭吸附φ为5%～15%HCl溶液中的Pt,活性炭灰化,灰分用王水溶解后,在10%HCl溶液中用GF-AAS方法测定岩石样品中超痕量铂。作者研究了测定酸度、介质及石墨炉灰化温度、原子化温度等因素对吸光度的影响。在选定条件下测定方法的检出限达到0.1×10-9,精密度(SD,n=12)5%～9%,经国家一级标准物质分析验证,结果吻合。

After the rock sample was dissolved, the solution was adjusted to the volume fraction of 5%～10% HCl and the Pt in the solution was adsorbed by active carbon. The active carbon was ashed and the ash was re-dissolved by pure aqua regia, and Pt was determinated by GF-AAS using pyrolytically coated electrographite cuvettes produced by Thermo Elemental Corporation. The determination conditions, such as acidity, media and the GF-AAS ashing temperature and graphite furnace atomizing temperature and their effects on the determination were investigated in detail. The detection limit of the method is 0.11×10^-9 for Pt with RSD of 5%～9% for 12 times determination. And the method was used to determine national standard substances with coincidence results.