Pressurized polytetrafluoroethylene (PTFE) vessel acid digestion was applied in decomposition of sediments, soil and rock samples. Sensitive and accurate detection of selenium was achieved by hydride generation atomic fluorescence spectrometry (HG-AFS) with a low detection limit of 0.008 mu g g(-1). Aliquots (25 mg) of dried samples were decomposed with 0.5 mL HCl, and 0.5 mL HBF4 in closed pressurized PTFE vessels in an electronic oven at 125 degrees C for 5 h. Obtained and certified selenium concentrations for Chinese certified reference materials showed no statistically differences. Low detection limits and good repeatability made this method an accurate and useful tool for selenium analysis in sediments, soil and rock samples. (c) 2007 Elsevier Ltd. All rights reserved.