Sorption and atomisation of metallic hydrides in a graphite furnace

Abstract

Introduction of volatile hydrides of As, Sb, Sn, Pb and Bi into a pre-heated graphite furnace results in their thermal decomposition and deposition on to the graphite tube surface. Characterisation of the subsequent atomic absorption signals with respect to appearance temperatures and Arrhenius energies has shown that the mechanisms of atomisation of As, Sb, Se and Sn are the same for both the hydride deposits and those resulting from the conventional introduction of these elements in aqueous solutions. For Pb and Bi, atomisation of the hydride-deposited samples appears to originate with the reduced metal, in contrast to the thermal decomposition of oxides which occurs for aqueous samples of these elements. Auger electron microprobe spectroscopy and electron microscopy with energy-dispersive X-ray fluorescence were also used to characterise the sample deposits.