硝酸银吸光光度法测定高纯二氧化锗中痕量砷

Determination of trace arsenic in high-purity germanium dioxide with silver nitrate absorption photometry

研究硝酸银吸光光度法测定高纯二氧化锗中痕量砷的新方法.高纯二氧化锗中主体锗分离后,痕量砷被还原成砷化氢气体逸出,在酸性吸收液中还原硝酸银为单质银,单质银在聚乙烯醇作用下显均匀的黄色,其最大吸收波长在400nm处,砷量在0.2～5μg/10ml吸收范围内符合比耳定律.方法检出限为0.06μg/ml,加标回收率为96%～103%,结果令人满意.

A new method in which trace arsenic in high-purity germanium dioxide is determined using silver nitrate absorption photometry is described in this discussion. Trace arsenic which left over in the high-purity germanium dioxide obtained by separating the elemental germanium from it is in turn oxidized by hydrogen, with arsenic hydride formed and evolved; and the silver nitrate is reduced into elemental silver by the acidic absorption solution. The silver so formed appears yellow when distributed in polythene-alcohol, and possesses a maximum absorption wavelength of 400nm. Beer's law is well obeyed when the arsenic content is in the range of 0.2～5μg/10ml, thus yielding a detection limit of 0.06μg/ml and a recovery rate of 96% -103%.