Temperature programmed static secondary ion mass spectrometric study of phosphate chemical modifiers in electrothermal atomizers

Abstract

Temperature programmed static secondary ion mass spectrometry is used to investigate surface chemical reactions of phosphate chemical modifiers used for the determination of Cd and Ag in electrothermal atomic absorption spectrometry. Cadmium–oxyphosphorus reactions are initiated on the surface at dry cycle temperatures, with further stabilizing reactions occurring on the surface in the char cycle temperature range. This leads to a delay in the atomization of Cd to a higher appearance temperature. However, for the determination of Ag, addition of phosphate results in an attenuation in the atomic absorption spectrometric signal intensity with no change in appearance temperature. Similar Ag–oxyphosphorus surface reactions are not observed.