石墨炉原子化器中原子化过程的研究(Ⅲ)——石墨炉中锗的原子化机理

Studies on Atomization Process in Graphite Furnace Atomizer (Ⅲ)--Atomization Mechanism of Germanium in Graphite Furnace

有关锗的石墨炉原子吸收光谱分析,文献报道较少,对锗的原子化机理,亦有不同的看法.本文基于右墨炉中锗原孚化行为的观察,对锗原子形成的过程进行了讨论,认为原子化过程中,并存着二种还原反应:GeO_(2)(s)+C→GeO(g)+CO(g),GeO_(2)(s)+CO→GeO(g)+CO_(2),而锗原子的形成是GeO(g)热分解的结果。

The atomization mechanism of germanium is discussed on the basis of observation of atomization behavior of germanium and enhancement effects of HNO3, HC1O4 and organic compounds on absorption signal of Ge in graphite furnace. It is affirmed that two types of reduction reaction in atomization process are existed.GeO_(2)(s)+C→GeO(g)+CO and GeO_(2)(s)+CO→GeO(g) +CO_(2) .The appearancetemperature of Ge experimentally was measured to be 2150K.The △H° value of Ge is 138.5 kcal/mol calculated by using △H° =γTapp.It is corresponding to the dissociation energy of the Ge-O bond(l58.8 kcal/mol). The germanium atoms in vapor phase are formed which is due to the thermal decomposition of GeO(g).