X-RAY PHOTOELECTRON SPECTROSCOPIC AND ATOMIC-FORCE MICROSCOPIC STUDIES OF PYROLYTICALLY COATED GRAPHITE AND HIGHLY ORIENTED PYROLYTIC-GRAPHITE USED FOR ELECTROTHERMAL VAPORIZATION

The interaction between solid or liquid samples on the one hand and py rolytically coated graphite or highly oriented pyrolytic graphite (HOP G) sample holders on the other hand during electrothermal vaporization was studied, For the characterisation of the micrometer scale topogra phical changes occurring on these graphite surfaces as a result of sol id sample evaporation, atomic force microscopy (AFM) was used. The mig ration of Cd(NO3)(2) and Na2HAsO4 deposited as solutions on the surfac e of the HOPG was studied by depth resolved X-ray photoelectron spectr oscopy(XPS) using argon ion sputter etching, It was found that the inv estigated compounds migrate into the graphite to a depth of at least 1 -1.5 mu m. XPS data suggest that the migration involves either the hyd rated metal ions or the molecules.