石墨炉原子吸收法中磷酸二氢铵对镉灰化及原子化行为的影响

摘要/Abstract

摘要： 镉是易挥发性元素,在石墨炉原子吸收法中,灰化温度为300℃左右.文献已经对纯镐的灰化及原子化机理进行了讨论.在实际测定中,常常加入NH₄H₂PO₄作为基体改进剂,可使灰化温度提高到650℃,750℃,800℃.

Abstract: A kinetic approach and other informations were employed to study the mechanism of Cd ashing and atomization when NH₄H₂PO₄ was used as a modifier. During the pyrolysis stage Cd_x(PO₃)_n produced and a large amount of NH₄H₂PO₄ dehydrated to form metaphosphate with chain or ring shape. This may result in the physical embedment of Cd. So both chemical and physical factors lead to the rise of the pyrolysis temperature. During the atomization stage, the analyte atomization was considered to be governed by the decomposition of this meta phosphate.

Key words: graphite furnace atomic absorption spectrometry, kinetic model, Arrhenius plot

戴青山, 姚金玉, 谢文兵, 王国平. 石墨炉原子吸收法中磷酸二氢铵对镉灰化及原子化行为的影响[J]. 应用化学, 1996, 0(5): 85-87.

Dai Qingshan, Yao Jinyu, Xie Wenbing, Wang Guoping. Effect of NH₄H₂PO₄ on The Ashing and Atomization of Cd in GFAAS[J]. Chinese Journal of Applied Chemistry, 1996, 0(5): 85-87.