石墨炉原子吸收法中镉的灰化损失及原子化反应机理  

Mechanisms of Cadmium Ashing Loss and Atomization in Graphite Furnace Atomic Absorption Spectrometry

作　　者：戴青山[1] 谢文兵[1] 姚金玉[1] 董文 陆永正 王国平[3] 

机构地区：[1]中国科学院长春应用化学研究所国家电化学和光谱研究分析中心,长春130022 [2]松辽水利委员会水资源保护局 [3]中国科学院长春地理研究所

出　　处：《分析化学》1996年第7期773-776,共4页Chinese Journal of Analytical Chemistry

摘　　要：用动力学方法得到灰化损失反应活化能和原子化反应活化能，并采用X-射线光电能谱技术鉴定灰化处理后的产物，推出，镉的灰化损失是由于镉的氧化物被碳还原，以气态单质镉的形式蒸发而导致的，而原子化过程则分为两个阶段，在原子化升温初期与扶化损失情况相同，即氧化镉被碳还原产生气态镉原子。但随着原子化温度的升高，氧化镉分解生成气态镉原子的反应很快成为原子化过程的主要反应。Kinetic approaches were used for studying mechanisms of ashing loss and atomiza tion for cadmium in GFAAS. The pyrolysis products were determined by X-ray photoelec tron spectroscopy. According to our results, CdO(s) is reduced to Cd (s) by carbon during ashing process. Then, Cd(s) sublimes to Cd (g), leading to the loss of substance. Two steps are involved in the atomization of cadmium. At starting of atomization, it is regarded that CdO(s) is reduced to Cd (g), just as the reaction of ashing loss; but with the rise of atomiza tion temperature, the gas phase dissociation of the cadmium oxide become the main reaction of atomization.

关 键 词：原子吸收法 灰化损失 原子化反应 镉 

分 类 号：O614.242[理学—无机化学] O657.31[理学—化学]