Electron microscope observation of thermal pre-treatment and vaporization processes of Ag–Sb and Pd–Sb systems in graphite furnace atomic absorption spectrometry

Abstract

As the reproducibility of Sb in river water analysis based on graphite furnace atomic absorption spectrometry is not good, and the reliability is poor when Pd is used as a matrix modifier, Ag was used instead of Pd. The reason Ag has the function of a matrix modifier and Pd does not, was studied by observation of the atomic columns or lattice structures at the atomic level in binary alloys, by using a high-resolution transmission electron microscope. Since the Ag–Sb system has the characteristic of forming an intermetallic compound and a lower value of the activity coefficient of Sb in its intermetallic compound, Ag is able to function as a matrix modifier as a result. In the case of the Pd–Sb system, the phenomenon of radical vaporization that is observed in the Ag–Sb system does not occur through changes of the phases of Pd–Sb intermetallic compounds. This fact means Pd does not have the function of a matrix modifier.