Establishment of appropriate protocols for analysis of tree bark for use in biomonitoring atmospheric pollution

The aim of this study was to establish appropriate protocols for collection and processing of tree barks and multielement analysis by the method of Neutron Activation Analysis (NAA). For analysis, barks of Tipuana and Sibipiruna species were cleaned and crushed. For the procedures of the Neutron activated analysis, aliquots of samples and synthetic elementary standards were irradiated in the nuclear reactor IEA-R1 then analyzed by gamma spectrometry. The quality of the results was evaluated by analysis of certified reference materials that indicated good accuracy and precision. In the analyzes of different layers of barks was verified higher concentration or the same order of magnitude for most elements in the outer layer of the barks than in the inner. For both species studied, the concentrations of Ca and K did not show significant differences with the trunk diameter differences, but for the other elements showed variability. The Tipuana species showed higher concentration for most elements in relation to Sibipiruna. From the results obtained, a procedure for sample preparation and analysis of NAA to barks for monitoring air pollution was established