Electrothermal at. absorption spectrometry is applied to study the release of the selenium and tin atoms from pyrocoated graphite support. The Coats and Redfern and Sturgeon approaches were used for estn. of the apparent activation energies of atom release. The addn. of tungsten and palladium modifiers leads to enhancement of the activation energies and changes the kind of the vaporizing species for analytes. [on SciFinder (R)]